Method and apparatus for controlling UE transmission power in wireless communication system

文档序号：75134 发布日期：2021-10-01 浏览：88次中文

阅读说明：本技术 用于在无线通信系统中控制ue发射功率的方法和装置 (Method and apparatus for controlling UE transmission power in wireless communication system ) 是由柳贤锡吕贞镐吴振荣朴成珍方钟弦申哲圭于 2020-02-13 设计创作，主要内容包括：本公开涉及一种用于融合支持超过第四代(4G)系统的更高数据速率的第五代(5G)通信系统与物联网(IoT)技术的通信方法和系统。本公开可以应用于基于5G通信技术和IoT相关技术的智能服务,例如智能家居、智能建筑、智能城市、智能汽车、联网汽车、医疗保健、数字教育、智能零售、安全和安保服务。(The present disclosure relates to a communication method and system for fusing a fifth generation (5G) communication system supporting a higher data rate than a fourth generation (4G) system with internet of things (IoT) technology. The present disclosure may be applied to smart services based on 5G communication technologies and IoT related technologies, such as smart homes, smart buildings, smart cities, smart cars, networked cars, healthcare, digital education, smart retail, security and security services.)

1. A method performed by a first user equipment, UE, in a wireless communication system, the method comprising:

receiving a radio resource control, RRC, message including information related to sidelink transmit power from a base station;

determining a sidelink transmit power based on the information; and

transmitting a sidelink control channel and a sidelink data channel based on the determined sidelink transmit power,

wherein the information comprises at least one of downlink path loss related information or sidelink path loss related information.

2. The method of claim 1, wherein the first and second light sources are selected from the group consisting of,

wherein determining the side link transmit power comprises: determining the sidelink transmit power according to a minimum between a first sidelink transmit power calculated based on the downlink path loss related information and a second sidelink transmit power calculated based on the sidelink path loss related information, in a case where the information includes the downlink path loss related information and the sidelink path loss related information.

3. The method of claim 1, further comprising:

transmitting a sidelink reference signal to a second UE; and

receiving, from the second UE, RSRP reference signal received power information based on the sidelink reference signal measurements.

4. The method of claim 1, wherein the side link transmit power is based on P_PSSCH(i)＝min(P_CMAX,P_MAX,CBR,min(P_PSSCH,D(i),P_PSSCH,SL(i)))[dBm]Is determined, and

wherein there is no AND P from the base station_MAX,CBRIn case of a relevant setting, the P_MAX,CBRIs set to 0.

5. A method performed by a base station in a wireless communication system, the method comprising:

transmitting a radio resource control, RRC, message including information related to sidelink transmit power to a first user equipment, UE; and

receive a sidelink control channel and a sidelink data channel based on sidelink transmit power from the first UE,

wherein the side link transmit power is determined based on the information, and

wherein the information comprises at least one of downlink path loss related information or sidelink path loss related information.

6. The method of claim 5, wherein, in a case where the information includes downlink path-loss related information and sidelink path-loss related information, the sidelink transmit power is determined according to a minimum value between a first sidelink transmit power calculated based on the downlink path-loss related information and a second sidelink transmit power calculated based on the sidelink path-loss related information.

7. The method of claim 5, wherein the first UE transmits a sidelink reference signal to a second UE and receives RSRP reference signal received power information measured based on the sidelink reference signal.

8. The method of claim 5, wherein the side link transmit power is based on P_PSSCH(i)＝min(P_CMAX,P_MAX,CBR,min(P_PSSCH,D(i),P_PSSCH,SL(i)))[dBm]Is determined, and

wherein there is no AND P from the base station_MAX,CBRIn case of a relevant setting, the P_MAX,CBRIs set to 0.

9. A first user equipment, UE, comprising:

a transceiver configured to transmit or receive at least one signal; and

at least one processor coupled to the transceiver,

wherein the at least one processor is configured to:

receiving a Radio Resource Control (RRC) message including information related to sidelink transmit power from a base station,

determining a sidelink transmit power based on the information, an

Transmitting a sidelink control channel and a sidelink data channel based on the determined sidelink transmit power, and

wherein the information comprises at least one of downlink path loss related information or sidelink path loss related information.

10. The first UE of claim 9, wherein the at least one processor is further configured to determine the sidelink transmit power as a minimum between a first sidelink transmit power calculated based on the downlink path loss related information and a second sidelink transmit power calculated based on the sidelink path loss related information where the information includes the downlink path loss related information and the sidelink path loss related information.

11. The first UE of claim 9, wherein the at least one processor is further configured to:

transmitting a sidelink reference signal to a second UE, an

Receiving, from the second UE, RSRP reference signal received power information based on the sidelink reference signal measurements.

12. The first UE of claim 9, wherein the side link transmit power is based on P_PSSCH(i)＝min(P_CMAX,P_MAX,CBR,min(P_PSSCH,D(i),P_PSSCH,SL(i)))[dBm]Is determined, and

wherein there is no AND P from the base station_MAX,CBRIn case of a relevant setting, the P_MAX,CBRIs set to 0.

13. A base station, comprising:

a transceiver configured to transmit or receive at least one signal; and

at least one processor coupled to the transceiver,

wherein the at least one processor is configured to:

sending a radio resource control, RRC, message to the first user Equipment, UE, including information relating to sidelink transmit power, an

Receive a sidelink control channel and a sidelink data channel based on sidelink transmit power from the first UE,

wherein the side link transmit power is determined based on the information, and

wherein the information comprises at least one of downlink path loss related information or sidelink path loss related information.

14. The base station as set forth in claim 13,

wherein, in a case where the information includes the downlink path-loss related information and the sidelink path-loss related information, the sidelink transmission power is determined according to a minimum value between a first sidelink transmission power calculated based on the downlink path-loss related information and a second sidelink transmission power calculated based on the sidelink path-loss related information, and

wherein the first UE transmits a sidelink reference signal to a second UE and receives RSRP reference signal received power information measured based on the sidelink reference signal.

15. The base station of claim 13, wherein the side link transmit power is based on P_PSSCH(i)＝min(P_CMAX,P_MAX,CBR,min(P_PSSCH,D(i),P_PSSCH,SL(i)))[dBm]Is determined, and

wherein there is no AND P from the base station_MAX,CBRIn case of a relevant setting, the P_MAX,CBRIs set to 0.

Technical Field

The present disclosure relates to a method for controlling User Equipment (UE) transmission power in a wireless communication system. More particularly, the present disclosure relates to a method and apparatus for setting transmission power when a UE (terminal) transmits a sidelink control channel and a sidelink data channel.

Background

In order to meet the increasing demand for wireless data traffic since the deployment of fourth generation (4G) communication systems, efforts have been made to develop improved fifth generation (5G) or first 5G communication systems. Accordingly, the 5G or first 5G communication system is also referred to as a "super 4G network" or a "Long Term Evolution (LTE) system". The 5G communication system is considered to be implemented in a higher frequency (millimeter (mm) wave) band (e.g., 60 gigahertz (GHz) band) to achieve a higher data rate. In order to reduce propagation loss of radio waves and increase transmission distance, beamforming, massive Multiple Input Multiple Output (MIMO), full-dimensional multiple input multiple output (FD-MIMO), array antenna, analog beamforming, massive antenna techniques are discussed in the 5G communication system. Further, in 5G communication systems, system network improvements are being developed based on advanced small cells, cloud Radio Access Networks (RANs), ultra dense networks, device-to-device (D2D) communications, wireless backhaul, mobile networks, cooperative communications, coordinated multipoint (CoMP), receiving end interference cancellation, and the like. In 5G systems, hybrid Frequency Shift Keying (FSK) and Quadrature Amplitude Modulation (QAM) (FQAM) and Sliding Window Superposition Coding (SWSC) have been developed as Advanced Coding Modulation (ACM), and filter bank multi-carrier (FBMC), non-orthogonal multiple access (NOMA) and Sparse Code Multiple Access (SCMA) as advanced access techniques.

The internet is a human-centric connected network in which humans generate and consume information, now evolving into the internet of things (IoT), where distributed entities (such as things) exchange and process information without human intervention. Internet of things (IoE) has emerged, which is a combination of internet of things technology and big data processing technology through connection with a cloud server. Since IoT implementations require technical elements such as "sensing technology", "wired/wireless communication and network infrastructure", "service interface technology", and "security technology", sensor networks, machine-to-machine (M2M) communication, Machine Type Communication (MTC), etc. have recently been studied. The IoT environment can provide intelligent Internet technology services, and creates new value for human life by collecting and analyzing data generated among the interconnected things. IoT can be applied to a variety of fields including smart homes, smart buildings, smart cities, smart cars or networked cars, smart grids, healthcare, smart appliances, and advanced medical services through the fusion and integration of existing Information Technology (IT) with various industrial applications.

In line with this, various attempts have been made to apply the 5G communication system to the IoT network. For example, technologies such as sensor networks, Machine Type Communication (MTC), and machine-to-machine (M2M) communication may be implemented through beamforming, MIMO, and array antennas. The application of cloud Radio Access Network (RAN) as the big data processing technology described above can also be considered as an example of the convergence of 5G technology and IoT technology.

According to the above and the development of mobile communication systems, various services can be provided, and thus a plan for efficiently providing these services is required.

The above information is provided merely as background information to aid in understanding the present disclosure. No determination has been made, nor has an assertion been made, as to whether any of the above can be applied as prior art to the present disclosure.

Disclosure of Invention

Technical problem

The present disclosure relates to a method for controlling transmit power of a sidelink control channel and a sidelink data channel.

Solution to the problem

In an aspect of the disclosure, a method performed by a first User Equipment (UE) in a wireless communication system is provided. The method includes receiving a Radio Resource Control (RRC) message including information related to sidelink transmit power from a base station, determining sidelink transmit power based on the information, and transmitting a sidelink control channel and a sidelink data channel based on the determined sidelink transmit power, wherein the information includes at least one of downlink path loss related information or sidelink path loss related information.

In another aspect of the present disclosure, a method performed by a base station in a wireless communication system is provided. The method includes transmitting an RRC message including information related to sidelink transmit power to a first UE, and receiving a sidelink control channel and a sidelink data channel based on the sidelink transmit power from the first UE, wherein the sidelink transmit power is determined based on the information, and wherein the information includes at least one of downlink path loss related information or sidelink path loss related information.

In another aspect of the disclosure, a first UE is provided. The first UE includes a transceiver configured to transmit or receive at least one signal, and at least one processor coupled to the transceiver. The at least one processor is configured to receive an RRC message from a base station including information related to sidelink transmit power, determine sidelink transmit power based on the information, and transmit a sidelink control channel and a sidelink data channel based on the determined sidelink transmit power, and wherein the information includes at least one of downlink path loss related information or sidelink path loss related information.

In another aspect of the present disclosure, a base station is provided. The base station includes a transceiver configured to transmit or receive at least one signal, and at least one processor coupled to the transceiver. The at least one processor is configured to transmit an RRC message to the first UE including information related to sidelink transmit power, and to receive a sidelink control channel and a sidelink data channel from the first UE based on the sidelink transmit power, wherein the sidelink transmit power is determined based on the information, and wherein the information includes at least one of downlink pathloss related information or sidelink pathloss related information.

Additional aspects will be set forth in part in the description which follows and, in part, will be obvious from the description, or may be learned by practice of the presented embodiments.

According to the technique, the transmission power of the sidelink control channel and the sidelink data channel can be effectively controlled.

Other aspects, advantages, and salient features of the disclosure will become apparent to those skilled in the art from the following detailed description, which, taken in conjunction with the annexed drawings, discloses various embodiments of the disclosure.

Advantageous effects of the invention

Aspects of the present disclosure are directed to solving at least the above problems and/or disadvantages and to providing at least the advantages described below. Accordingly, an aspect of the present disclosure is to provide a method for controlling transmission power of a sidelink control channel and a sidelink data channel.

Drawings

The above and other aspects, features and advantages of certain embodiments of the present disclosure will become more apparent from the following description taken in conjunction with the accompanying drawings, in which:

FIG. 1A illustrates a system according to an embodiment of the present disclosure;

FIG. 1B illustrates a system according to an embodiment of the present disclosure;

FIG. 1C illustrates a system according to an embodiment of the present disclosure; and

FIG. 1D illustrates a system according to an embodiment of the present disclosure;

FIG. 2A illustrates a vehicle-to-anything (V2X) communication method performed via a sidelink in accordance with an embodiment of the present disclosure; and

fig. 2B illustrates a V2X communication method performed via a sidelink in accordance with an embodiment of the disclosure;

fig. 3 illustrates V2X transmit power control in accordance with an embodiment of the disclosure;

fig. 4 illustrates interference caused in neighboring frequency blocks by a frequency block transmitted by a V2X UE according to an embodiment of the present disclosure;

fig. 5 illustrates interference caused in neighboring frequency blocks by a frequency block transmitted by a V2X UE according to an embodiment of the present disclosure;

fig. 6 illustrates V2X transmit power control in accordance with an embodiment of the disclosure;

fig. 7 is a diagram illustrating a sidelink resource for performing V2X communications in accordance with an embodiment of the present disclosure;

fig. 8 illustrates a multiplexing method of a sidelink resource inner link control channel and a sidelink data channel according to an embodiment of the present disclosure;

fig. 9 illustrates a multiplexing method of a sidelink resource inner link control channel and a sidelink data channel according to an embodiment of the present disclosure;

fig. 10 illustrates a multiplexing method of a sidelink resource inner link control channel and a sidelink data channel according to an embodiment of the present disclosure;

fig. 11 illustrates a multiplexing method of a sidelink resource inner link control channel and a sidelink data channel according to an embodiment of the present disclosure;

fig. 12 illustrates a multiplexing method of a sidelink resource inner link control channel and a sidelink data channel according to an embodiment of the present disclosure;

fig. 13 illustrates a multiplexing method of sidelink channels within sidelink resources according to an embodiment of the present disclosure;

fig. 14 illustrates a flow diagram of the operation of a V2X UE for sidelink transmit power control in accordance with an embodiment of the present disclosure;

fig. 15 is a diagram illustrating a UE configuration according to an embodiment of the present disclosure; and

fig. 16 is a diagram showing a base station configuration according to an embodiment of the present disclosure.

Throughout the drawings, it should be noted that the same reference numerals are used to describe the same or similar elements, features and structures.

Detailed Description

The following description with reference to the accompanying drawings is provided to assist in a comprehensive understanding of various embodiments of the disclosure as defined by the claims and their equivalents. It includes various specific details that are helpful for understanding, but these are to be considered merely illustrative. Accordingly, those of ordinary skill in the art will recognize that various changes and modifications of the various embodiments described herein can be made without departing from the scope and spirit of the present disclosure. Moreover, descriptions of well-known functions and constructions may be omitted for clarity and conciseness.

The terms and words used in the following description and claims are not limited to bibliographic meanings, but are used only by the inventors to enable a clear and consistent understanding of the disclosure. Therefore, it will be apparent to those skilled in the art that the following descriptions of the various embodiments of the present disclosure are provided for illustration only and not for the purpose of limiting the disclosure as defined by the appended claims and their equivalents.

It is to be understood that the singular forms "a," "an," and "the" include plural referents unless the context clearly dictates otherwise. Thus, for example, reference to "a component surface" includes reference to one or more of such surfaces.

In describing the embodiments, descriptions of technologies known in the technical fields to which the present disclosure pertains and which are not directly related to the present disclosure are omitted. Such unnecessary description is omitted to prevent the main ideas of the present disclosure from being obscured and to more clearly convey the main ideas.

For the same reason, in the drawings, some elements are enlarged, omitted, or schematically shown. Further, the size of each element does not completely reflect the actual size. In the drawings, the same or corresponding elements are denoted by the same reference numerals.

Advantages and features of the present disclosure and methods of accomplishing the same will become apparent by reference to the following detailed description of embodiments taken in conjunction with the accompanying drawings. However, the present disclosure is not limited to the following embodiments, and may be implemented in various different forms, and the embodiments of the present disclosure are provided to complete the present disclosure and fully inform the scope of the present disclosure to those skilled in the art, and the present disclosure is limited only by the scope of the claims. Throughout the specification, the same or similar reference numerals denote the same or similar elements.

Here, it will be understood that each block of the flowchart illustrations, and combinations of blocks in the flowchart illustrations, can be implemented by computer program instructions. These computer program instructions may be provided to a processor of a general purpose computer, special purpose computer, or other programmable data processing apparatus, such that the instructions, which execute via the processor of the computer or other programmable data processing apparatus, create means for implementing the functions specified in the flowchart block or blocks. These computer program instructions may also be stored in a computer usable or computer-readable memory that can direct a computer or other programmable data processing apparatus to function in a particular manner, such that the instructions stored in the computer usable or computer-readable memory produce an article of manufacture including instruction means that implement the function specified in the flowchart block or blocks. The computer program instructions may also be loaded onto a computer or other programmable data processing apparatus to cause a series of operations to be performed on the computer or other programmable apparatus to produce a computer implemented process such that the instructions which execute on the computer or other programmable apparatus provide operations for implementing the functions specified in the flowchart block or blocks.

Furthermore, each block of the flowchart illustrations may represent a module, segment, or portion of code, which comprises one or more executable instructions for implementing the specified logical function(s). It should also be noted that, in some alternative implementations, the functions noted in the blocks may occur out of the order. For example, two blocks shown in succession may, in fact, be executed substantially concurrently, or the blocks may sometimes be executed in the reverse order, depending upon the functionality involved.

As used herein, "unit" refers to a software element or a hardware element, such as a Field Programmable Gate Array (FPGA) or an Application Specific Integrated Circuit (ASIC), that performs a predetermined function. However, the "unit" does not always have a meaning limited to only software or hardware. A "unit" may be configured to be stored in an addressable storage medium or to execute one or more processors. Thus, a "unit" includes, for example, software elements, object-oriented software elements, class elements or task elements, procedures, functions, attributes, procedures, subroutines, segments of program code, drivers, firmware, microcode, circuitry, data, databases, data structures, tables, arrays, and parameters. The elements and functions provided by the "units" may be combined into a smaller number of elements: "Unit" is alternatively divided into a larger number of elements: a "cell". Further, the elements and "units" may be implemented as one or more Central Processing Units (CPUs) within a rendering device or secure multimedia card. Further, in an embodiment, a "unit" may include one or more processors.

In the detailed embodiment, the main objects are the radio access network (new RAN, NR) and the core network, i.e. the packet core (5G system, 5G core network or next generation core (NG core)) in the 5G mobile communication standard specified by the mobile communication standard standardization organization (3 GPP). However, the main idea of the present disclosure is that the present disclosure can be applied to other communication systems having similar technical backgrounds with minor modifications without departing from the scope of the present disclosure, and the application can be performed by determination of those skilled in the art to which the present disclosure pertains.

In the 5G system, in order to support network automation, a network data collection and analysis function (NWDAF), which is a network function that analyzes data collected in the 5G network and provides the analyzed data, may be defined. The NWDAF may collect/store information from/in the 5G network/analyze its information and provide results for unspecified Network Functions (NFs), which may be used independently for each NF.

Hereinafter, for convenience of description, a part of terms and names defined in a third generation partnership project long term evolution (3GPP LTE) standard such as standards of 5G, NR, LTE, or a system similar to these systems may be used. However, the present disclosure is not limited by terms and names, and may be equally applied to a system based on another standard.

Also, terms used below, for example, terms for identifying an access node, terms indicating a network entity, terms indicating a message, terms indicating an interface between network entities, terms indicating various identification information, and the like are shown for convenience of description. Accordingly, the present disclosure is not limited to the following terms, and other terms having the same technical meaning may be used.

In order to meet the increased wireless data traffic demand after commercialization of 4G communication systems, efforts have been made to develop improved 5G communication systems (new radios, NRs). To achieve high data transmission rates, 5G communication systems are designed to support the millimeter wave band (e.g., 28GHz band). In the 5G communication system, techniques such as beam forming, massive MIMO, full-dimensional multiple-input multiple-output (FD-MIMO), array antenna, analog beam forming, and massive antenna are under discussion as means for mitigating propagation path loss and increasing propagation transmission distance in the millimeter wave band. Unlike LTE, the 5G communication system includes 15kHz to support various subcarrier spacings, such as 30kHz, 60kHz, and 120kHz, the physical control channel uses polar coordinate coding, and the physical data channel uses Low Density Parity Check (LDPC). In addition to discrete fourier transform spread orthogonal frequency division multiplexing (DFT-S-OFDM), Cyclic Prefix (CP) -OFDM is used as a waveform for uplink transmission. LTE supports hybrid automatic repeat request (ARQ) (HARQ) retransmissions based on Transport Blocks (TBs), while 5G can also support HARQ retransmissions based on Code Block Groups (CBGs) consisting of code blocks.

In addition, 5G communication systems have developed techniques such as evolved small cells, advanced small cells, cloud radio access networks (cloud RANs), ultra-dense networks, device-to-device (D2D) communications, wireless backhaul, vehicle-to-everything (V2X) networks, cooperative communications, coordinated multipoint (CoMP), and receive interference cancellation to improve system networks.

Meanwhile, the internet has evolved from a human-oriented connection network in which humans generate and consume information to an internet of things (IoT) network in which distributed elements, such as objects, exchange and process information. Internet of everything (IoE) technology has emerged, in which big data processing technology is combined with IoT technology through a connection with a cloud server or the like. In order to implement IoT, technical factors such as sensing technology, wired/wireless communication, network infrastructure, service interface technology, and security technology are required, and research on technologies for connection between objects such as sensor network, machine-to-machine (M2M) communication, Machine Type Communication (MTC), etc. has recently been conducted. In the IoT environment, by collecting and analyzing data generated in interconnected objects, intelligent Internet Technology (IT) services can be provided, creating new value for people's lives. IoT can be applied to fields such as smart homes, smart buildings, smart cities, smart cars, networked cars, smart grids, healthcare, smart homes, and high-tech medical services through related art Information Technology (IT) and various industry convergence.

Accordingly, various attempts have been made to apply the 5G communication system to the IoT network. For example, technologies such as sensor networks, machine-to-machine (M2M) communication, and Machine Type Communication (MTC) have been implemented by 5G communication technologies such as beamforming, MIMO, and array antennas. The application of cloud RAN as the big data processing technology described above may be an example of the convergence of 3eG technology and IoT technology. Accordingly, a plurality of services can be provided to a user in a communication system, and in order to provide a plurality of services to a user, a method of providing each service according to characteristics in the same period of time and an apparatus using the same are required. Various services provided in a 5G communication system have been studied, and one of the services is a service that satisfies requirements such as low delay and high reliability.

In the case of vehicle communication, standardized operation of LTE-based V2X has been completed in 3GPP Rel-14 and Rel-15 based on a device-to-device (D2D) communication structure, and efforts have been made to develop 5G NR-based V2X at present. The NR V2X will support unicast, multicast (or multicast) and broadcast communications between UEs. Further, the purpose of LTE V2X is to transmit or receive basic safety information required for road travel of a vehicle, whereas the purpose of NR V2X is to provide more advanced services such as vehicle formation, advanced driving, extended sensors, and remote driving, unlike LTE V2X.

When NR V2X UEs are present within the coverage of a base station, NR V2X UEs may receive parameter values for controlling sidelink transmit power from the base station and control sidelink transmit power based on the parameter values. Further, when the NR V2X UE exists outside the coverage of the base station, the NR V2X UE may control the sidelink transmission power using a preset sidelink transmission power control parameter value. The sidelink transmit power control parameter may include P₀And alpha. Further, in addition to the above-mentioned P₀And α, the NR V2X UE can also set the transmission power value according to the frequency block size of the sidelink control channel and the data channel to be transmitted. That is, when the frequency block size of the sidelink control channel and the data channel to be transmitted increases, the transmission power value may increase, and when the frequency block size decreases, the transmission power value may decrease. Before transmission, the control channel and the data channel may be time division multiplexed (TDMed) on the time axis or frequency division multiplexed (FDMed) on the frequency axis. Therefore, there is a need for a method and apparatus for controlling UE transmit power to support sidelink transmit power among these different multiplexing methods.

Embodiments of the present specification are proposed to support the above-described various multiplexing methods, and an object is to provide a method and apparatus for controlling transmission power of a sidelink control channel and a data channel.

The V2X UE mentioned in the present disclosure may indicate an NR V2X UE or an LTE V2X UE. Further, the V2X UE of the present disclosure may indicate a vehicle supporting vehicle-to-vehicle (V2V) communications, a cell phone (i.e., a smartphone) of a vehicle or pedestrian supporting vehicle-to-pedestrian (V2P) communications, a vehicle supporting vehicle-to-network (V2N) communications, or a vehicle supporting vehicle-to-infrastructure (V2I) communications. Further, the UE of the present disclosure may indicate a roadside unit (RSU) having a UE function, an RSU having a base station function, or an RSU having a part of a base station function and a part of a UE function.

Fig. 1A illustrates a system according to an embodiment of the disclosure, fig. 1B illustrates a system according to an embodiment of the disclosure, fig. 1C illustrates a system according to an embodiment of the disclosure, and fig. 1D illustrates a system according to an embodiment of the disclosure.

FIG. 1A shows a case where all V2X UEs (UE-1101 and UE-2102) are located within the coverage of the base station 103.

Referring to fig. 1A, all V2X UEs 101 and 102 may receive data and control information from the base station 103 via a Downlink (DL) or transmit data and control information to the base station 103 via an Uplink (UL). The data and control information may be data and control information for V2X communication, or the data and control information may be data and control information for general cellular communication. Further, the V2X UEs 101 and 102 may send or receive data and control information for V2X communications over Sidelink (SL).

FIG. 1B shows the case where, in a V2X UE, UE-1111 is located within the coverage of base station 113 and UE-2112 is located outside the coverage of base station 113. FIG. 1B may illustrate partial coverage. A UE-1111 located within the coverage of base station 113 may receive data and control information from base station 113 through a downlink or transmit data and control information to the base station through an uplink.

Referring to fig. 1B, a UE-2112 located outside the coverage of a base station may not receive data and control information from the base station through a downlink or may not transmit data and control information to the base station through an uplink.

UE-2112 may send/receive data and control information for V2X communication to/from UE-1111 through a sidelink.

Fig. 1C shows the case where all V2X UEs are located outside the coverage of the base station.

Thus, referring to fig. 1C, UE-1121 and UE-2122 may not receive data and control information from a base station through a downlink and may not transmit data and control information to the base station through an uplink.

UE-1121 and UE-2122 may send or receive data and control information for V2X communication over the side link.

Fig. 1D shows a scenario where V2X communication is performed between UEs located in different cells. Specifically, fig. 1D shows a case where the V2X transmitting UE and the V2X receiving UE access a different base station (radio resource control (RRC) connected state) or camp on a different base station (RRC disconnected state, i.e., RRC idle state). UE-1131 may be a V2X transmitting UE, UE-2132 may be a V2X receiving UE, or UE-1131 may be a V2X receiving UE, and UE-2132 may be a V2X transmitting UE. UE-1131 may receive a V2X-specific System Information Block (SIB) from a base station 133 accessed by UE-1 (or where UE-1 resides), and UE-2132 may receive a V2X-specific SIB from another base station 134 accessed by UE-2 (or where UE-2 resides). The information of the V2X dedicated SIB received by UE-1131 and the information of the V2X dedicated SIB received by UE-2132 may be different from each other. Therefore, in order to perform V2X communication between UEs located in different cells, a plurality of pieces of information need to be unified.

For convenience of description, fig. 1A to 1D illustrate a V2X system composed of two UEs (UE-1 and UE-2), but the present disclosure is not limited thereto. In addition, the uplink and downlink between the base station and the V2X UE may be referred to as the Uu interface, and the sidelink between the V2X UE may be referred to as the PC5 interface. Therefore, they may be used in combination in the present disclosure.

Meanwhile, the UE of the present disclosure may indicate a vehicle supporting vehicle-to-vehicle (V2V) communication, a cell phone (i.e., a smartphone) of a vehicle or pedestrian supporting vehicle-to-pedestrian (V2P) communication, a vehicle supporting vehicle-to-network (V2N) communication, or a vehicle supporting vehicle-to-infrastructure (V2I) communication. Further, the UE of the present disclosure may indicate a roadside unit (RSU) having a UE function, an RSU having a base station function, or an RSU having a part of a base station function and a part of a UE function.

Further, the base station of the present disclosure may be defined in advance as a base station supporting V2X communication and general cellular communication, or a base station supporting only V2X communication. The base station may indicate a 5G base station (gNB), a 4G base station (eNB), or a roadside unit (RSU). Therefore, unless otherwise stated in this disclosure, the base station and the RSU may be mixedly used as the same concept.

Fig. 2A illustrates a V2X communication method performed through a sidelink according to an embodiment of the present disclosure, and fig. 2B illustrates a V2X communication method performed through a sidelink according to an embodiment of the present disclosure.

Referring to FIG. 2A, a TX UE (UE-1201) and an RX UE (UE-2202) may perform one-to-one communication, and the communication may be referred to as unicast communication.

Referring to fig. 2B, the TX UE and the RX UE may perform one-to-many communication, and the communication may be referred to as multicast or multicast communication.

FIG. 2B is a diagram showing UE-1211, UE-2212 and UE-3213 forming group A to perform multicast communication, and UE-4214, UE-5215, UE-6216 and UE-7217 forming group B to perform multicast communication. Each UE performs multicast communication within a group to which each UE belongs, and does not perform communication between different groups. Fig. 2B illustrates that two groups are formed, but the present disclosure is not limited thereto.

Although not shown in fig. 2A and 2B, the V2X UE may perform broadcast communication. The broadcast communication indicates that all V2X UEs receive the case where V2X transmits data and control information that the UE transmits via the sidelink. For example, assuming that UE-1 is a transmitting UE for broadcast communication in FIG. 2B, all UEs (UE-2212, UE-3213, UE-4214, UE-5215, UE-6216 and UE-7217) can receive data and control information transmitted by UE-1211.

Fig. 3 illustrates V2X transmit power control in accordance with an embodiment of the disclosure.

Referring to fig. 3, assume that UE 1301 is located near base station (gNB)303, and UE 2302 is located far away from gNB 303 (i.e., UE1 is located at the center of the cell and UE2 is located at the edge of the cell). When V2X communication is performed between UE 1301 and UE 2302, it is assumed that UE 1301 is a V2X transmitting UE and UE 2302 is a V2X receiving UE. The UE 1301 may perform sidelink transmit power control for V2X transmissions. The parameters for the sidelink transmit power of the UE 1301 may include at least P₀α, an estimated path loss value, and a size of an allocated frequency block, and may be equal to that shown in equation 1.

Side link transmit power min { Pcmax, P ═ c₀+ α PL +10log10 (number of RBs 2^μ)+Δ}[dBm].... equation 1

In equation 1, each parameter may indicate the following.

-Pcmax: pcmax is a P-max value (which is a preset value when there is no base station), indicates a maximum UE transmission output, is set by the base station through system information or RRC, and may be determined by the UE through a UE power class included in the UE.

-P₀：P₀The base station may be instructed to set a value for guaranteeing link quality of the receiving UE through system information or RRC (this is a preset value when there is no base station).

- α: α is a parameter for compensating a path loss value, has a value between 0 and 1, and may indicate a value set by a base station through system information or RRC (when there is no base station, this is a preset value). For example, when α is 1, 100% of the path loss can be compensated, and when α is 0.8, only 80% of the path loss can be compensated.

-number of Resource Blocks (RBs): the number of resource blocks may indicate the size of the frequency block allocated for sidelink transmission. 2^μMay be a parameter for compensating for a Power Spectral Density (PSD) that varies according to a subcarrier spacing. For example, the case of using a subcarrier spacing of 15kHz may indicate that μ ═ 0. Even if the same number of frequency blocks are used, when the subcarrier spacing is doubled to 30kHz, the PSD can be reduced by half compared to the case where the subcarrier spacing of 15kHz is used. Therefore, to compensate for the PSD, power doubling is required. More specifically, for example, when two frequency blocks are used, 10log10(2x 2) is required for a subcarrier spacing of 15kHz⁰) To maintain the same PSD as the 15kHz subcarrier spacing at 3dB, the transmit power needs to be increased to 10log10(2x 2) for a 30kHz subcarrier spacing¹)＝6dB。

-PL: PL may indicate an estimated path loss value. The path loss value can be estimated by equation 2.

(transmit power of signal for path loss estimation) - (measurement Reference Signal Received Power (RSRP) value of signal for path loss estimation.) equation 2

Equation 2 may be applied differently according to the following scenario.

When the signal used for path loss estimation is a side link signal: the UE 1301 transmitting a UE as V2X may transmit a sidelink synchronization signal or a sidelink reference signal to the UE 2302 receiving a UE as V2X. The UE 2302 may receive a sidelink synchronization signal or a sidelink reference signal to measure an RSRP value and report the measured RSRP value to the UE 1301. The RSRP value may be transmitted through a Physical Sidelink Feedback Channel (PSFCH) or a Physical Sidelink Shared Channel (PSSCH). Further, a Medium Access Control (MAC) Control Element (CE) may be used when the RSRP value is transmitted through the psch. The UE 1301 may estimate the sidelink path loss value using equation 2 by the transmit power of the reference signal sent by the UE1 to the UE 2302 and the RSRP value reported from the UE 2302. In another example, the UE 1301 may send information to the UE 2302 regarding the transmit power of a reference signal sent by the UE 1. Upon receiving this information, the UE 2302 may measure an RSRP value by using a reference signal sent by the UE1 and estimate a path loss value by equation 2. UE-2302 may send the estimated sidelink path loss value to UE 1301 via either the PSFCH or the PSSCH. The MAC CE may be used when the estimated sidelink path loss value is transmitted over the psch. However, as shown in fig. 3, when the distance between the UE 1301 and the UE 2302 is longer than the distance between the UE 1301 and the gNB 303, the sidelink signal transmitted by the UE 1301 may cause interference to the gNB received signal.

Fig. 4 illustrates interference caused in an adjacent frequency block by a frequency block transmitted by a V2X UE according to an embodiment of the present disclosure.

Fig. 5 illustrates interference caused in an adjacent frequency block by a frequency block transmitted by a V2X UE according to an embodiment of the present disclosure.

Fig. 4 and 5 show the degree of interference caused by the sidelink signal in the gbb received signal. Referring to fig. 4, it is assumed that side link control information or data information is transmitted in a resource block index 12 (using one resource block), and referring to fig. 5, it is assumed that side link control information or data information is transmitted by using five resource blocks from 12 to 17 of the resource block index. Referring to fig. 4, since the sidelink transmission is performed only in the resource block index 12, the transmission power should be generated only in the corresponding resource index, but it is found that the transmission power is generated even in the adjacent resource indexes (e.g., indexes 9, 10, 11, 13, 14, and 15) due to interference (in-band transmission). As shown in fig. 5, it is found that such an amount of interference becomes larger as the number of resource blocks allocated to sidelink transmission increases. Therefore, V2X UEs located near the gbb need to use low transmit power to not interfere with the received signal of the gbb.

When the signal used for path loss estimation is a downlink signal of the gNB: to reduce interference caused to the received signal of the gNB, UE1, which is a V2X transmitting UE, may apply the downlink path loss value of the gNB to equation 1. More specifically, the UE1 may estimate the downlink path loss value through a Channel State Information (CSI) Reference Signal (RS) transmitted by the gNB. In another example, the UE1 may estimate the downlink path loss value using a Secondary Synchronization Signal (SSS) transmitted by the gNB, or both the SSS and a demodulation reference signal (DMRS) transmitted over the Physical Broadcast Channel (PBCH). More specifically, the gNB may transmit information on the transmission power of the reference signal to the UE1 through system information or RRC configuration, and the UE1 may measure an RSRP value by using the reference signal transmitted by the gNB. The UE1 may estimate the downlink path loss value using equation 2 by the transmit power value of the reference signal sent from the base station and the RSRP value measured thereby. Due to the use of the downlink path loss value, the problem of interference to the received signal of the gNB as shown in fig. 4 and 5 can be solved.

Fig. 6 illustrates V2X transmit power control in accordance with an embodiment of the disclosure.

Referring to fig. 6, in the case where V2X UEs 601 and 602 are close to each other but far from the gNB 603, unnecessary power consumption and interference in neighboring V2X UEs may be caused when using downlink path loss values. Thus, both of the above methods may be required.

That is, the gNB may configure which reference signal the UE uses in equation 1 to estimate the Pathloss (PL) (i.e., whether to estimate the downlink pathloss using SSS or CSI-RS, or whether to estimate the sidelink pathloss using sidelink reference signals).

- Δ: Δ may indicate a Transmit Power Control (TPC) command or other RRC parameter used for closed loop power control. For example, Δ may indicate an offset value of transmission power according to a format of a sidelink control channel or a sidelink data channel. In another example, Δ may indicate a compensation value for transmit power based on spectral efficiency of a sidelink control channel or a sidelink data channel. That is, since it is necessary to use higher transmission power as spectral efficiency becomes higher (i.e., a case where the same bits are transmitted using less resources or a case where more bits are transmitted by using the same number of resources), Δ may be a parameter that compensates for the transmission power value according to spectral efficiency. In equation 1, Δ is shown as being made up of a single parameter, but may also be made up of a combination of two or more parameters as previously shown.

Fig. 7 is a diagram illustrating sidelink resources for performing V2X communications by a V2X UE, according to an embodiment of the present disclosure.

Referring to fig. 7, the side link resource may be composed of K symbols on a time axis and M Resource Blocks (RBs) on a frequency axis. One resource block may be composed of twelve subcarriers. The K symbols may be physically continuous or logically continuous on the time axis (in the case of logical continuity, the symbols may be physically discontinuous). Similarly, the M resource blocks may be physically continuous or logically continuous on the frequency axis (in the case of logical continuity, the blocks may be physically discontinuous). Although not shown in fig. 7, the V2X sending UE can use the sidelink resources of fig. 7 to send sidelink control information or data information. Further, the V2X receiving UE may receive the sidelink control information or data information using the sidelink resources of fig. 7. In another example, the V2X receiving UE may send UE transmit sidelink feedback information to V2X using the sidelink resources of fig. 7. Referring to fig. 7, the values of K and M may be the same or different according to the transmission time of the sidelink control information or the data information. For example, when V2X transmits the side link control information (or side link data information) by the UE at time T1, the values of K and M may be equal to or different from the values of K and M when V2X transmits the side link control information (or side link data information) by the UE at time T2. Similarly, referring to fig. 7, the values of K and M may be the same or different depending on the time when V2X receives the UE reception side link control information or data information. For example, the values of K and M when V2X receives the side link control information (or side link data information) received by the UE at time T1 may be equal to or different from the values of K and M when V2X receives the side link control information (or side link data information) received by the UE at time T2. In addition, referring to fig. 7, the values of K and M may be the same or different depending on when V2X receives the UE transmits the sidelink feedback information to V2X. For example, the values of K and M when V2X receives the UE transmission side link feedback information sent by the UE to V2X at time T1 may be equal to or different from the values of K and M when V2X receives the UE transmission side link feedback information sent by the UE to V2X at time T2.

Fig. 8 illustrates a multiplexing method of a sidelink resource inner link control channel and a sidelink data channel according to an embodiment of the present disclosure.

Referring to fig. 8, there is shown multiplexing of a physical side link control channel (PSCCH) and a physical side link shared channel (PSCCH), i.e., Time Division Multiplexing (TDM), on a time axis. The PSCCH and PSCCH may be composed of the same number of resource blocks (M RBs) on the frequency axis, and may be composed of K1 symbols and K2 symbols on the time axis, respectively. The values of K1 and K2 may be equal to or different from each other. Further, when the values of K1 and K2 are different from each other, these values may be K1> K2 or K1< K2. V2X sends side link control (SCI) information that the UE can send over the PSCCH including time/frequency allocation information for the PSCCH. The V2X receiving UE can receive and decode the PSCCH and then can acquire the time/frequency allocation information of the PSCCH and decode the PSCCH. Fig. 8 shows pschs made up of K2 symbols that are located physically contiguously after a PSCCH made up of K1 symbols, although they may not be located physically contiguously (i.e., the pschs may be located logically contiguously, rather than physically contiguously after the PSCCH). Further, although not shown in fig. 8, a Physical Sidelink Feedback Channel (PSFCH) may exist in the sidelink resource composed of K symbols. The PSCCH may be composed of K1 symbols, the PSCCH may be composed of K2 symbols and guard symbols, the PSFCH may be composed of K3 symbols, and the number of K1+ K2+ guard symbols + K3 may be less than K. The guard symbol may be one or at least two OFDM symbols. The V2X receiving the PSSCH the UE may decode and then may send the UE transmitting the PSFCH including the result (i.e., ACK/NACK information) to the V2X.

At the ith transmission time, the V2X UE using the sidelink resource structure of fig. 8 can determine the transmit power (P) of the PSCCH by equation 3_PSCCH) And PSSCH transmit power (P)_PSSCH) Each of which.

P_PSCCH(i)＝min{Pcmax(i),P_{0_PSCCH}+α_PSCCH*PL(q)+10log10(M*2^μ)+Δ_PSCCH(i)}[dBm]

P_PSSCH(i)＝min{Pcmax(i),P_{0_PSSCH}+α_PSSCH*PL(q)+10log10(M*2^μ)+Δ_PSSCH(i)}[dBm].. equation 3

In equation 3, each parameter may indicate the following.

-pcmax (i): pcmax (i) is a P-max value (a preset value when there is no base station), indicates the maximum UE transmission output of the ith transmission time, is set by the base station through system information or RRC, and may also be determined by the UE through a communication range and a UE power class included in the UE. Since Pcmax (i) is a function of the index "i", different transmission times can result in different values of Pcmax.

-P_{0_PSCCH}、P_{0_PSSCH}：P_{0_PSCCH}And P_{0_PSSCH}A parameter (a preset value when there is no base station) set by the base station through system information or RRC for guaranteeing link quality of each of PSCCH and PSCCH may be indicated. P_{0_PSCCH}And P_{0_PSSCH}The values of (c) may be different from each other according to the side link scheduling method. For example, the base station may transmit the UE scheduled sidelink transmission resource to V2X through Downlink Control Information (DCI). It may be referred to as a mode 1 resource allocation method. In another scheduling method, the gNB may configure resource pool information for sidelink transmission, and V2X transmits resources that the UE itself may determine to transmit sidelink control information and data information. It may be referred to as a mode 2 resource allocation method. Because the gNB can manage resources in a centralized manner in the case of mode 1, the gNB can control the inter-V2X UEInterference and resource collision problems. On the other hand, in case of mode 2, since the UEs manage resources in a distributed manner, interference and resource collision problems may occur between different V2X UEs, compared to mode 1. Thus, mode 1 and mode 2 side-link transmitted P₀The values may be different. That is, P of mode 1_{0_PSCCH}And P of mode 2_{0_PSCCH}With different values. Further, P of mode 1_{0_PSSCH}And P of mode 2_{0_PSSCH}With different values. In another example, as shown in fig. 2A and 2B, a V2X UE may perform V2X communications by using one of unicast, multicast, and broadcast communication methods. Depending on the communication method, different link qualities may be required. For example, in the case of unicast communication, since hybrid automatic repeat request (HARQ) ACK/NACK transmission can be performed through a sidelink feedback channel, degradation of link quality can be reduced. However, in the case of broadcast communication, since side link feedback transmission is not possible, higher link quality may be required compared to unicast communication. Thus, P_{0_PSCCH}And P_{0_PSSCH}The values of (a) may be different from each other according to communication methods including unicast, multicast, and broadcast communication methods. As mentioned above, P_{0_PSCCH}And P_{0_PSSCH}The value of (d) may be sent by the base station to the UE through system information or RRC configuration, or may be a preset value when there is no base station. Therefore, the base station may not recognize the V2X communication method (unicast/multicast/broadcast) to be transmitted by the side link UE. The base station may not know when the UE should use P_{0_PSCCH}And P_{0_PSSCH}And P should be used_{0_PSCCH}And P_{0_PSSCH}Which values of (a). To solve these problems, the following operations may be assumed. For each communication method, there may be one or more different pools of related resources. For example, a base station may configure a UE with one or more resource pools (e.g., resource pool 1, resource pool 2) for unicast communications, one or more resource pools (e.g., resource pool 3, resource pool 4) for multicast communications, and one or more resource pools (e.g., resource pool 5, resource pool 6) for broadcast communications. P_{0_PSCCH}And P_{0_PSSCH}The value of (c) may differ depending on the resource pool.In another example, P_{0_PSCCH}Can be composed of P_{0_PSCCH1}And P_{0_PSCCH2}Constitution P_{0_PSSCH}Can be composed of P_{0_PSSCH1}And P_{0_PSSCH2}And (4) forming. All UEs within a cell can receive information about P_{0_PSCCH1}And P_{0_PSSCH1}The same set value of (c). Different V2X UEs within one cell may receive information about P_{0_PSCCH2}And P_{0_PSSCH2}Different settings of (2). In the above example, P_{0_PSCCH1}And P_{0_PSSCH1}May be independent of the communication type (i.e., the same value is applied to unicast, multicast, broadcast communications), and P_{0_PSCCH2}And P_{0_PSSCH2}May differ depending on the type of communication.

-α_PSCCH、α_PSSCH：α_PSCCHAnd alpha_PSSCHAre parameters for compensating for the pathloss values of PSCCH and PSCCH, respectively, have values between 0 and 1, and may indicate values set by the base station through system information or RRC (preset values when there is no base station). For example, when α is 1, 100% of the path loss can be compensated, and when α is 0.8, only 80% of the path loss can be compensated. And the above P_{0_PSCCH}And P_{0_PSSCH}Likewise, α of mode 1_PSCCHAnd α of mode 2_PSCCHMay have different values. Further, α of mode 1_PSSCHAnd α of mode 2_PSSCHMay have different values. Further, α_PSCCHAnd alpha_PSSCHThe value of (b) may be set to be different according to communication methods including unicast, multicast, and broadcast communication methods. To this end, α_PSCCHAnd alpha_PSSCHMay have different values for each resource pool.

-M: m may indicate the size of the frequency block allocated for sidelink transmission. Referring to fig. 8, since both PSCCH and PSCCH use M frequency blocks, 10log10 (M2) may be used in equation 3^μ) The value of (c). 2^μMay be a parameter for compensating a Power Spectral Density (PSD) that differs according to a subcarrier spacing. For example, the case of using a subcarrier spacing of 15kHz may indicate that μ ═ 0. Even if the same number of frequency blocks is used, when the subcarrier spacing is doubled to 30kHz, the 15kHz sub-carrier is usedThe PSD can be reduced by half compared to the case of carrier spacing. Therefore, to compensate for the PSD, a power doubling is required. More specifically, for example, when two frequency blocks are used, 10log10(2x 2) is required for a subcarrier spacing of 15kHz⁰) To maintain the same PSD as the 15kHz subcarrier spacing at 3dB, the transmit power needs to be increased to 10log10(2x 2) for a 30kHz subcarrier spacing¹)＝6dB。

-pl (q): pl (q) may indicate an estimated path loss value. The path loss value can be estimated by equation 2. The index "q" may indicate an index of a reference signal used for path loss estimation. For example, when q is 0, V2X transmits SSS that the UE may transmit using gNB, or SSS and DMRS transmitted through PBCH, in order to estimate the pathloss value in equation 3. When q is 1, the V2X transmitting UE may use the CSI-RS transmitted by the gNB in order to estimate the pathloss value in equation 3. When q is 2, V2X sends a path loss value that the UE can use in estimating equation 3 using the sidelink reference signal. When the path loss of equation 3 is estimated by a side link reference signal, one of two methods mentioned in fig. 3 may be used. That is, there is a method in which the V2X receives the UE to estimate the sidelink path loss and sends the result to the V2X transmitting UE, and there is a method in which the V2X transmitting UE estimates the sidelink path loss using RSRP that has been received the UE measurement and report by the V2X. A reference signal index "q" may be associated with each resource pool. That is, different resource pools may set different reference signal indexes, and a UE receiving the set index may determine to apply a downlink path loss with a base station or to apply a sidelink path loss.

As described above, when receiving resource pool information from a base station through system information and RRC configuration, the V2X UE can use P included in the resource pool information_{0_PSCCH}、P_{0_PSSCH}、α_PSCCH、α_PSSCHAnd index information of a reference signal used for path loss estimation, and thereby sets transmission power values of PSCCH and pscsch through equation 3.

-Δ_PSCCH、Δ_PSSCH：Δ_PSCCHAnd Δ_PSSCHTPC commands or other RRC parameters may be indicated for closed loop power control. E.g. Δ_PSCCHAnd Δ_PSSCHThe offset value of the transmission power may be indicated according to the format of the sidelink control channel or the sidelink data channel. In another example, Δ_PSCCHAnd Δ_PSSCHThe offset value of the transmit power may be indicated according to the spectral efficiency of the sidelink control channel or the sidelink data channel. That is, since higher transmit power needs to be used as spectral efficiency becomes higher (i.e., the case where the same bits are transmitted using less resources or the case where more bits are transmitted by using the same amount of resources), Δ_PSCCHAnd Δ_PSSCHMay be a parameter for compensating the transmission power value according to the spectral efficiency. In equation 3, Δ_PSCCHAnd Δ_PSSCHIs shown as being comprised of a single parameter, but may be comprised of a combination of two or more of the parameters previously shown. In another example, when the closed loop power control is not operating on the side link, Δ may be omitted from equation 3_PSCCHAnd Δ_PSSCH。

In the above example, a UE existing outside the coverage of the base station may not receive information about P from the base station_{0_PSCCH}、α_PSCCH、Δ_PSCCHAnd P_{0_PSSCH}、α_PSSCH、Δ_PSSCHAnd setting parameters. Thus, these UEs may use preset values for the parameters. The preset values may include 0, 0dB, or 0 dBm. The preset value may indicate a value input in the UE in the factory, or may indicate a value set by the base station when the UE once exists within the coverage of the base station (the UE is now located outside the coverage of the base station).

Further, in the above example, even if the UE exists within the coverage of the base station, parameter exchange between UEs may not be performed (assuming that parameter exchange between UEs is performed in the PC5RRC layer) when a UE pair for performing unicast communication is not formed (for example, before PC5RRC configuration is completed in the PC5RRC layers of the UE a and the UE B), or before a UE packet for performing multicast communication is formed. Transmitting UEs for unicast and multicast communications may not set up transmission based on sidelink path loss measurementsAnd (4) a radio frequency power value. Therefore, as with the above method, a preset value may be used, or P transmitted from the base station through RRC configuration and system information of the base station may be used_{0_PSCCH}、α_PSCCH、Δ_PSCCHAnd P_{0_PSSCH}、α_PSSCH、Δ_PSSCHThe value of (c). P used at this time_{0_PSCCH}、α_PSCCH、Δ_PSCCHAnd P_{0_PSSCH}、α_PSSCH、Δ_PSSCHCan be compared with P used after PCT RRC configuration_{0_PSCCH}、α_PSCCH、Δ_PSCCHAnd P_{0_PSSCH}、α_PSSCH、Δ_PSSCHThe value of (c) is different. Prior to PC5RRC configuration, the pl (q) used by the transmitting UE in equation 3 may indicate a path loss value for the Uu link between the base station and the transmitting UE, instead of a side link path loss value.

In another example, when PSCCH, pscsch, and PSFCH should be transmitted before PC5RRC configuration between UEs that are to perform unicast or multicast communication is completed in the above example, the V2X UEs may use a preset transmission power value (e.g., [ X ] dBm) or a transmission power value set by the base station. The transmission power values (or transmission power values set by the base station) preset for transmitting the PSCCH, pscsch, and PSFCH may be different from each other.

In another example, the preset transmit power values of PSCCH, pscsch, and PSFCH or the transmit power values set by the base station may be expressed as a transmit power value and an offset value with respect to one channel. For example, when the transmission power values of PSCCH, and PSFCH are preset, the transmission power value of PSCCH may be set to [ X ] dBm, and the offset value of the transmission power of PSCCH and PSFCH may be set to +/- [ Y ] dB (or dBm) based on the transmission power value of PSCCH. This is also true even if the transmit power values for PSCCH, pscsch, and PSFCH are set by the base station.

Fig. 9 illustrates a multiplexing method of a sidelink resource inner link control channel and a sidelink data channel according to an embodiment of the present disclosure.

Referring to fig. 9, fig. 9 shows that PSCCH and PSCCH are time division multiplexed, but unlike fig. 8, fig. 9 shows that PSCCH and PSCCH are composed of different numbers of resource blocks on the frequency axis. That is, on the frequency axis, PSCCH may be composed of N1 frequency blocks, and PSCCH may be composed of M frequency blocks. N1 may be less than M (N1< M). Meanwhile, similar to fig. 8, the PSCCH may be composed of K1 symbols and the PSCCH may be composed of K2 symbols on the time axis. The values of K1 and K2 are equal to or different from each other. Further, when the values of K1 and K2 are different from each other, these values may be K1> K2 or K1< K2. V2X sends side link control information (SCI) including time/frequency allocation information of the PSCCH that the UE can send through the PSCCH. The V2X receiving UE can receive and decode the PSCCH and then can acquire the time/frequency allocation information of the PSCCH and decode the PSCCH. Fig. 9 shows pschs made up of K2 symbols that are located physically contiguously after a PSCCH made up of K1 symbols, although they may not be located physically contiguously (i.e., the pschs may be located logically contiguously, rather than physically contiguously after the PSCCH). Further, although not shown in fig. 9, the PSFCH may exist in a sidelink resource composed of K symbols. The PSCCH may be composed of K1 symbols, the PSCCH may be composed of K2 symbols and guard symbols, the PSFCH may be composed of K3 symbols, and the number of K1+ K2+ guard symbols + K3 may be equal to or less than K. The guard symbol may be one or at least two OFDM symbols. In addition, the size of the resource blocks may be equal to or different from the size of the resource blocks of the PSCCH and PSCCH on the frequency axis of the PSFCH. The V2X receives the PSSCH that the UE can decode and then transmits the PSFCH including the result (i.e., ACK/NACK information) to the V2X.

At the ith transmission time, the V2X UE using the sidelink resource structure of fig. 9 can determine the transmit power (P) of the PSCCH by equation 4_PSCCH) And PSSCH transmit power (P)_PSSCH) Each of which.

P_PSCCH(i)＝min{Pcmax(i),P_{0_PSCCH}+α_PSCCH*PL(q)+10log10(N1*2^μ)+Δ_PSCCH(i)}[dBm]

P_PSSCH(i)＝min{Pcmax(i),P_{0_PSSCH}+α_PSSCH*PL(q)+10log10(M*2^μ)+Δ_PSSCH(i)}[dBm].. equation 4

In equation 4, each parameter may be interpreted to be the same as equation 3 illustrated in fig. 8. Equation 4 differs from equation 3 in that the size of the frequency block allocated for the PSCCH is different. That is, in equation 4, N1 frequency blocks are used, and in equation 3, M frequency blocks are used.

Inclusion P used in equation 4_{0_PSCCH}、α_PSCCH、Δ_PSCCHAnd P_{0_PSSCH}、α_PSSCH、Δ_PSSCHMay be equal to the definition and embodiment described in equation 3 of fig. 8. For example, the transmit power parameter used in equation 4 may use a set value received by the transmitting UE from the base station, or use a value preset for the UE through the methods mentioned in fig. 8 and 9. For example, a UE that is away from the coverage of a base station may not receive settings from the base station regarding transmit power parameters. Thus, these UEs may use preset values for the parameters. The set point may comprise 0, 0dB or 0 dBm. The preset value may indicate a value input to the UE in a factory, or may indicate a value set by the base station when the UE once exists within the coverage of the base station (the UE is now located outside the coverage of the base station).

In another example, even if UEs exist within the coverage of the base station, parameter exchange between UEs may not be performed (assuming that parameter exchange between UEs is performed in the PC5RRC layer) when a UE pair for performing unicast communication is not formed (for example, before PC5RRC configuration is completed in the PC5RRC layers of UE a and UE B), or before a UE packet for performing multicast communication is formed. The transmitting UE for unicast and multicast communication may not set the transmit power value based on the sidelink path loss signal. For this, a preset value regarding the parameter may be used, or a value transmitted from the base station through RRC configuration and system information of the base station may be used. The parameter values used at this time may be different from those used after the PC5RRC configuration. The pl (q) used by the transmitting UE in equations 7, 8, 9, 10, and 11 before PC5RRC configuration may indicate a path loss value for the Uu link between the base station and the transmitting UE, instead of a side link path loss value. Further, when the UE uses preset parameters, each parameter may include a value of 0, 0dB, or 0 dBm.

In another example, when the PSCCH, pscsch, and PSFCH should be transmitted before the PC5RRC configuration between UEs that are to perform unicast or multicast communication is completed in the above example, the V2X UEs may use a preset transmission power value (e.g., [ X ] dBm) or a transmission power value set by the base station. The transmission power values (or transmission power values set by the base station) preset for transmitting the PSCCH, pscsch, and PSFCH may be different from each other.

In another example, the preset transmission power values of PSCCH, pscsch, and PSFCH or the transmission power values set by the base station may be expressed as a transmission power value and an offset value with respect to one channel. For example, when the transmission power values of PSCCH, and PSFCH are preset, the transmission power value of PSCCH may be set to [ X ] dBm, and the offset value of the transmission power of PSCCH and PSFCH may be set to +/- [ Y ] dB (or dBm) based on the transmission power value of PSCCH. This is also true even if the transmit power values for PSCCH, pscsch, and PSFCH are set by the base station.

Fig. 10 shows a V2X frame structure according to an embodiment of the present disclosure.

Referring to fig. 10, fig. 10 shows that PSCCH and PSCCH are frequency division multiplexed on a frequency axis unlike fig. 8 and 9, and shows that PSCCH and PSCCH are composed of different numbers of resource blocks similarly to fig. 9. That is, in the frequency axis, the PSCCH may be composed of N1 frequency blocks, the PSCCH may be composed of M frequency blocks, and in the time axis, the PSCCH and the PSCCH may be composed of the same number of symbols. N1 may be equal to or different from M. V2X sends side link control information (SCI) including time/frequency allocation information of the PSCCH that the UE can send through the PSCCH. The V2X receiving UE can receive and decode the PSCCH and then can acquire the time/frequency allocation information of the PSCCH and decode the PSCCH. Fig. 10 shows pschs made up of (M-N2) frequency blocks that are located physically contiguously after a PSCCH made up of N1 frequency blocks, although they may not be located physically contiguously (i.e., the pschs may be located logically contiguously, rather than physically contiguously after the PSCCH). Further, although not shown in fig. 10, a PSFCH may exist in the rear part of the K symbols. More specifically, the PSCCH and PSCCH may be composed of K1 symbols and guard symbols, the PSFCH may be composed of K2 symbols, and the number of K1+ guard symbols + K2 may be equal to or less than K. The guard symbol may be one or at least two OFDM symbols. The V2X receives the PSSCH that the UE can decode and then transmits the PSFCH including the result (i.e., ACK/NACK information) to the V2X.

At the ith transmission time, the V2X UE using the sidelink resource structure of fig. 10 can determine the transmit power (P) of the PSCCH by equation 5_PSCCH) And PSSCH transmit power (P)_PSSCH) Each of which.

P_PSCCH(i)＝γ1+min{Pcmax(i),P_{0_PSCCH}+α_PSCCH*PL(q)+β+Δ_PSCCH(i)}[dBm]

P_PSSCH(i)＝γ2+min{Pcmax(i),P_{0_PSSCH}+α_PSSCH*PL(q)+β+Δ_PSSCH(i)}[dBm].. equation 5

In equation 5, each parameter is indicated as follows.

- γ 1, γ 2: referring to fig. 10, the PSCCH and PSCCH may be simultaneously transmitted at the ith time because they are frequency division multiplexed. Therefore, the transmit power of the V2X UE needs to be properly allocated to PSCCH and PSCCH at the ith sidelink transmission time. γ 1 and γ 2 indicate values of power used for allocating PSCCH and PSCCH, and may be expressed by equation 6 as shown.

γ1＝10log10{(10^(ε/10)x N1)/[(M-N1)+10^(ε/10)x N1]}[dB]

10log10{ [10^ (ε/10) x (M-N1) ]/[ (M-N1) +10^ (ε/10) x N1] } [ dB ]. equation 6

ε indicates the value representing the difference between PSDs of PSCCH and PSSCH and may have units of [ dB ]. For example, when PSCCH and PSCCH use the same PSD, epsilon may be 0. In general, the control channel is required to guarantee higher reliability than the data channel. In this case, the PSD of the PSCCH is higher than that of the PSSCH. For example, when ∈ 3, it may indicate that the PSD of the PSCCH is 3dB higher than the PSCCH. A fixed value is always used as the value of epsilon (e.g., epsilon-3), or the base station may transmit the value of epsilon to the UE through system information or RRC configuration. In this case, as described in fig. 8 and 9, a different value of epsilon may be set for each resource pool.

In equation 5, β may indicate 10log10[ (M-N1) +10^ (ε/10) x N1] [ dB ].

In equation 5, the definition and usage method of parameters other than γ 1, γ 2, and β may be the same as those described in fig. 8 and 9. For example, with respect to the transmission power parameter used in equation 5, the transmitting UE may utilize a value set by the base station or utilize a value preset for the UE through the methods mentioned in fig. 8 to 10. For example, a UE existing outside the coverage of the base station may not receive the sidelink transmit power parameter set by the base station. Accordingly, these UEs may use values preset with respect to the parameters. The set point may comprise 0, 0dB or 0 dBm. The preset value may indicate a value input to the UE in a factory, or may indicate a value set by the base station when the UE once exists within the coverage of the base station (the UE is now located outside the coverage of the base station).

In another example, even if the UE exists within the coverage of the base station, parameter exchange between UEs that are to perform unicast/multicast communication may not be performed when a unicast UE pair for performing unicast communication is not formed (e.g., the case where the PC5RRC configuration is not completed), or before a UE packet for performing multicast communication is formed. Therefore, the transmitting UE for unicast and multicast communication may not set the sidelink transmit power value based on the sidelink path loss value. For this, as for the mentioned parameters, a preset value may be used, or a value transmitted from the base station through RRC configuration and system information of the base station may be used. The parameter values used at this time may be different from those used after the PC5RRC configuration. The pl (q) used by the transmitting UE before PC5RRC configuration in equation 7, equation 8, equation 9, equation 10, and equation 11 may indicate a path loss value with respect to the Uu link between the base station and the transmitting UE, instead of a side link path loss value. Further, when the UE uses preset parameters, each parameter may include a value of 0, 0dB, or 0 dBm.

Fig. 11 shows a V2X frame structure according to an embodiment of the present disclosure.

Referring to fig. 11, which is considered a combination of fig. 9 and fig. 10, it shows that PSCCH and PSCCH are frequency division multiplexed in K1 symbols, and in the remaining K2 symbols, only PSCCH is transmitted and no PSCCH is transmitted. The PSCCH may be composed of N1 frequency blocks on the frequency axis and may be composed of K1 symbols on the time axis. The PSCCH may be made up of N2 frequency blocks during K1 symbol lengths and may be divided in frequency with the PSCCH. The PSCCH does not divide by the PSCCH during the length of K2 symbols and may consist of M frequency blocks. The sum of N1 and N2 may be equal to or different from M. Fig. 11 shows that the PSCCH consisting of N1 frequency blocks and the PSCCH consisting of (M-N2) frequency blocks are located physically continuously, but they may not be located physically continuously (i.e., they may be located logically continuously and not physically continuously). Meanwhile, values of K1 and K2 may be equal to or different from each other, and when values of K1 and K2 are different from each other, it may be K1> K2 or K1< K2. V2X sends side link control information that the UE can send over the PSCCH including time/frequency allocation information for the PSCCH. The V2X receiving UE can receive and decode the PSCCH and then can acquire the time/frequency allocation information of the PSCCH and decode the PSCCH. Fig. 11 shows pschs made up of K2 symbols that are located physically contiguously after a PSCCH made up of K1 symbols, although they may not be located physically contiguously (i.e., the pschs may be located logically contiguously, rather than physically contiguously after the PSCCH).

Although not shown in fig. 11, the PSFCH may exist in a sidelink resource composed of K symbols. The PSCCH may be composed of K1 symbols, the PSCCH may be composed of K1+ K2 symbols and guard symbols, the PSFCH may be composed of K3 symbols, and the number of K1+ K2+ guard symbols + K3 may be equal to or less than K. The guard symbol may be one or at least two OFDM symbols. In addition, the size of the resource blocks may be equal to or different from the size of the resource blocks of the PSCCH and PSCCH on the frequency axis of the PSFCH. The V2X receives the PSSCH that the UE can decode and then transmits the PSFCH including the result (i.e., ACK/NACK information) to the V2X.

At the ith transmission time, the V2X UE using the sidelink resource structure of fig. 11 can determine the transmit power (P) of the PSCCH by using one of the methods mentioned below_PSCCH) And PSSCH transmit power (P)_PSSCH)。

Method 1) independent setup for determining P_PSCCHAnd P_PSSCHThe parameter (c) of (c).

Method 1-1) reducing or increasing the transmission power

The UE can temporarily calculate P by equation 7_PSCCHAnd P_PSSCHThe value of (c).

P_PSCCH(i)＝P_{0_PSCCH}+α_PSCCH*PL(q)+10log10(N1*2^μ)+Δ_PSCCH(i)[dBm]

P_PSSCH-1(i)＝P_{0_PSSCH}+α_PSSCH*PL(q)+10log10(N2*2^μ)+Δ_PSSCH(i)[dBm]

P_PSSCH-2(i)＝P_{0_PSSCH}+α_PSSCH*PL(q)+10log10(M*2^μ)+Δ_PSSCH(i)[dBm]

.. equation 7

In equation 7, referring to FIG. 11, P_PSSCH-1The transmit power of the PSCCH when the PSCCH and PSCCH are divided and transmitted during portions of K1 symbols may be indicated. Referring to fig. 11, the PPSSCH-2 may indicate a transmission power of the PSCCH when only the PSCCH is transmitted during a portion of K2 symbols. A problem may occur when the transmission power of symbols of the same channel is changed during one sidelink transmission time (e.g., sidelink transmission time i). Specifically, in fig. 11, the PSCCH and the PSCCH are simultaneously transmitted during a K1 symbol portion, and only the PSCCH is transmitted during a K2 symbol portion. As shown in equation 7, the PSCCH and PSCCH may use different transmit power control parameters. Thus, at the sidelink transmission time i, the transmit power used to transmit the K1 symbols may be different from that used to transmitK2 symbols of transmit power. In this case, the transmission signal may be transmitted while being distorted due to phase shift and discontinuity. To solve this problem, it is necessary to set the transmission power for transmitting K1 symbols and the transmission power for transmitting K2 symbols to have the same value, and this can be achieved by equation 8 or equation 9.

P_Sidelink(i)＝min{Pcmax(i),P_PSCCH(i)+P_PSSCH-1(i),P_PSSCH-2(i) }.. equation 8

P_Sidelink(i)＝min{Pcmax(i),max[P_PSCCH(i)+P_PSSCH-1(i),P_PSSCH-2(i)]}... equation 9

In equations 8 and 9, each parameter may indicate the following.

*P_Sidelink(i) The method comprises the following steps Side link transmitting power of ith side link transmitting time

Pcmax (i): pcmax (i) is equal to the values described in equation 1, equation 3, equation 4, equation 5, and equation 6.

*P_PSCCH(i) The method comprises the following steps PSCCH transmitting power of ith side link transmitting time

*P_PSSCH-1(i) The method comprises the following steps PSSCH transmit power in symbols transmitted at ith sidelink transmission time where PSCCH and PSSCH are divided

At the ith sidelink transmission time, P may occur_PSCCH(i)+P_PSSCH-1(i)<P_PSSCH-2(i)<Pcmax (i).

By equation 8, the transmit power for the ith sidelink transmission may be P_Sidelink(i)＝P_PSCCH(i)+P_PSSCH-1(i) And P obtained by equation 7 can be expressed_PSSCH-2(i) Scaling down w1 so that P is satisfied_PSCCH(i)+P_PSSCH-1(i)＝w1*P_PSSCH-2(i) In that respect w1 may have a value greater than 0 and equal to 1 or less than 1.

Using equation 9, the transmit power for the ith sidelink transmission may be P_Sidelink(i)＝P_PSSCH-2(i) And P obtained by equation 7 can be expressed_PSCCH(i)+P_PSSCH-1(i) Scaling up w1 so that P is satisfied_PSSCH-2(i)＝w1[P_PSCCH(i)+P_PSSCH-1(i)]. w1 may have a value greater than 1.

In another example, at the ith sidelink transmission time, P may occur_PSSCH-2(i)<P_PSCCH(i)+P_PSSCH-1(i)<Pcmax (i).

By equation 8, the transmit power for the ith sidelink transmission may be P_Sidelink(i)＝P_PSSCH-2(i) And P obtained by equation 7 can be expressed_PSCCH(i)+P_PSSCH-1(i) Scaling down w1 so that P is satisfied_PSSCH-2(i)＝w1[P_PSCCH(i)+P_PSSCH-1(i)]. w1 may have a value greater than 0 and equal to 1 or less than 1.

By equation 9, the transmit power for the ith sidelink transmission may be P_Sidelink(i)＝P_PSCCH(i)+P_PSSCH-1(i) And P obtained by equation 7 can be expressed_PSSCH-2(i) Scaling up w1 so that P is satisfied_PSCCH(i)+P_PSSCH-1(i)＝w1*P_PSSCH-2(i) In that respect w1 may have a value greater than 1.

Method 1-2) the side link transmit power depends on the transmit power of K1 symbols.

Method 1-2 is the same as method 1-1 in that the UE temporarily calculates P by equation 7_PSCCHAnd P_PSSCH-1The value of (c). However, unlike method 1-1, in method 1-2, P mentioned in equation 7 may not be calculated_PSSCH-2. Accordingly, the transmission power at the ith sidelink transmission time can be determined as shown in equation 10.

P_Sidelink(i)＝min{Pcmax(i),P_PSCCH(i)+P_PSSCH-1(i) }... equation 10

When the sizes of the frequency blocks in the K1 symbols and the K2 symbols are different, or due to the difference in the values of the transmission power control parameters, the transmission power values of the K1 symbols and the K2 symbols are also different, as described above, P_PSSCH-2(i) And may be scaled up or down.

Method 1-3) the side link transmit power depends on the transmit power of K2 symbols.

In methods 1-3, the transmit power for the ith sidelink transmit time may be determined from equation 11.

P_Sidelink(i)＝min{Pcmax(i),P_PSSCH-2(i) }... equation 11

In equation 11, P_PSSCH-2(i) May be equal to P shown in equation 7_PSSCH-2(i) In that respect The UE may use P obtained by equation 11_PSSCH-2(i) To calculate the transmit power of the PSCCH and PSCCH transmitted in portions of K1 symbols. More specifically, by P obtained by equation 11_PSSCH-2(i) And P shown in equation 7_PSCCH(i) And P_PSSCH-1(i) Temporary transmit powers for PSCCH and PSCCH in K1 symbol portions may be calculated, and values of X1, X2, and Y may be calculated as shown in equation 12.

X1＝10^[P_PSCCH(i)/10],X2＝10^[P_PSSCH-1(i)/10],Y＝10^[P_Sidelink(i)/10]

.. equation 12

By using the values of X1, X2, and Y obtained by equation 12, the UE can determine the transmit power of the PSCCH and PSCCH transmitted in a portion of K1 symbols through equation 13.

P_PSCCH(i)＝10log10[X1*Y/(X1+X2)]

P_PSSCH-1(i)＝10log10[X2*Y/(X1+X2)].. equation 13

Method 2) for determining P_PSCCHAnd P_PSSCHAre set to be the same.

In case of the method 2, since the parameters for determining the transmission power of the PSCCH and PSCCH are set to be the same, the parameters of the PSCCH and PSCCH shown in equation 3, equation 4, equation 5, and equation 7 may be the same. More specifically, at the ith sidelink transmission time, P may be indicated_{0_PSCCH}＝P_{0_PSSCH}＝P₀，α_PSCCH＝α_PSSCHα, and Δ_PSCCH＝Δ_PSSCHΔ. Another prerequisite for method 2 is P_PSCCHAnd P_PSSCHMay have a fixed power density offset or a set power density offset. Under these assumptions, method 2 may have two methods described below.

Method 2-1) the side link transmit power depends on the transmit power of K1 symbols.

P may be determined by equation 14 in the portion of K1 symbols where PSCCH and PSCCH are divided and transmitted at the ith sidelink transmission time_PSCCHAnd P_PSSCH-1。

P_PSCCH(i)＝γ1+P₀+αPL(q)+β+Δ(i)[dBm]

P_PSSCH-1(i)＝γ2+P₀+αPL(q)+β+Δ(i)[dBm]…Equation 14

In equation 14, γ 1 and γ 2 may be equal to the definition in equation 6. In equation 14, β may indicate 10log10[ (M-N1) +10^ (ε/10) x N1][dB]. By using equation 14, the transmission power of the ith side link transmission time can be calculated as shown in equation 10. In method 2-1, when the sizes of frequency blocks in K1 symbols and K2 symbols are different, P_PSCCH(i)+P_PSSCH-1(i) May be different from P_PSSCH-2(i) In that respect In this case, P is as described above_PSSCH-2(i) And may be scaled up or down.

Method 2-2) the side link transmit power depends on the transmit power of K2 symbols.

Unlike method 2-1, the side link transmit power can be determined by equation 11 for the portion of PSCCH and PSCCH at the ith side link transmit time that has no divided K2 symbols. P, which has been determined by equation 11, can be distributed by equations 12 and 13_Sidelink(i) In that respect Meanwhile, with respect to the transmission power parameter used in equation 7, equation 8, equation 9, equation 10, and equation 11, the transmitting UE may use a value set by the base station or use a value preset for the UE through the methods mentioned in fig. 8 to 11. For example, a UE existing outside the coverage of a base station may not receive a setting regarding a transmit power parameter from the base station. Accordingly, these UEs may use values preset with respect to the parameters. The set point may comprise 0, 0dB or 0 dBm. The preset value may be indicated inThe value of the UE is input in the factory or may indicate the value set by the base station when the UE was once present within the coverage of the base station (the UE is now outside the coverage of the base station). In another example, even if the UE exists within the coverage of the base station, parameter exchange between UEs that are to perform unicast/multicast communication may not be performed when a unicast UE pair for performing unicast communication is not formed (e.g., the case where the PC5RRC configuration is not completed), or before a UE packet for performing multicast communication is formed. Therefore, the transmitting UE for unicast and multicast communication may not set the transmission power value. For this, as for the mentioned parameters, a preset value may be used, or a value transmitted from the base station through RRC configuration and system information of the base station may be used. The parameter values used at this time may be different from those used after the PC5RRC configuration. The pl (q) used by the transmitting UE before PC5RRC configuration in equation 7, equation 8, equation 9, equation 10, and equation 11 may indicate a path loss value with respect to the Uu link between the base station and the transmitting UE, instead of a side link path loss value. Further, when the UE uses preset parameters, each parameter may include a value of 0, 0dB, or 0 dBm. In another example, the preset transmission power values of PSCCH, pscsch, and PSFCH or the transmission power values set by the base station may be expressed as a transmission power value and an offset value with respect to one channel. For example, when the transmission power values of PSCCH, and PSFCH are preset, the transmission power value of PSCCH may be set to X]dBm, and the offset values for the transmit power of PSSCH and PSFCH may be set to +/- [ Y ] based on the transmit power value of PSCCH]DB (or dBm). This may be the same even when the base station sets the transmit power values for PSCCH, PSCCH and PSFCH.

Fig. 12 shows a V2X frame structure according to an embodiment of the present disclosure.

Referring to fig. 12, it is shown that PSCCH and PSCCH are time division multiplexed similarly to fig. 8 and 9, but are composed of different numbers of resource blocks on the frequency axis unlike fig. 8. That is, on the frequency axis, PSCCH may be composed of M frequency blocks, and PSCCH may be composed of N1 frequency blocks (M > N1). Meanwhile, similar to fig. 8 and 9, the PSCCH may be composed of K1 symbols and the PSCCH may be composed of K2 symbols on the time axis. The values of K1 and K2 are equal to or different from each other. Further, when the values of K1 and K2 are different from each other, these values may be K1> K2 or K1< K2. V2X sends side link control information (SCI) including time/frequency allocation information of the PSCCH that the UE can send through the PSCCH. The V2X receiving UE can receive and decode the PSCCH and then can acquire the time/frequency allocation information of the PSCCH and decode the PSCCH. Fig. 12 shows pschs made up of K2 symbols that are located physically contiguously after a PSCCH made up of K1 symbols, although they may not be located physically contiguously (i.e., the pschs may be located logically contiguously, rather than physically contiguously after the PSCCH). Further, although not shown in fig. 12, the PSFCH may exist in a sidelink resource composed of K symbols. The PSCCH may be composed of K1 symbols, the PSCCH may be composed of K2 symbols and guard symbols, the PSFCH may be composed of K3 symbols, and the number of K1+ K2+ guard symbols + K3 may be equal to or less than K. The guard symbol may be one or at least two OFDM symbols. In addition, the size of the resource blocks may be equal to or different from the size of the resource blocks of the PSCCH and PSCCH on the frequency axis of the PSFCH. The V2X receives the PSSCH that the UE can decode and then transmits the PSFCH including the result (i.e., ACK/NACK information) to the V2X.

At the ith transmission time, the V2X UE using the sidelink resource structure of fig. 10 can determine the transmit power (P) of the PSCCH by equation 15_PSCCH) And PSSCH transmit power (P)_PSSCH) Each of which.

P_PSCCH(i)＝min{Pcmax(i),P_{0_PSCCH}+α_PSCCH*PL(q)+10log10(M*2^μ)+Δ_PSCCH(i)}[dBm]

P_PSSCH(i)＝min{Pcmax(i),P_{0_PSSCH}+α_PSSCH*PL(q)+10log10(N1*2^μ)+Δ_PSSCH(i)}[dBm].. equation 15

In equation 15, each parameter may be interpreted to be the same as equation 4 described in fig. 9.

Also, regarding the transmission power parameter used in equation 15, the transmitting UE may use a value set by the base station or use a value preset for the UE through the methods mentioned in fig. 8 to 12. For example, a UE existing outside the coverage of the base station may not receive the transmit power parameter set by the base station. Accordingly, these UEs may use values preset with respect to the parameters. The set point may comprise 0, 0dB or 0 dBm. The preset value may indicate a value input to the UE in the factory, or may indicate a value set by the base station when the UE once exists within the coverage of the base station (the UE is now located outside the coverage of the base station).

In another example, even if the UE exists within the coverage of the base station, parameter exchange between UEs that are to perform unicast/multicast communication may not be performed when no UE pairing is formed for performing unicast communication (e.g., before the PC5RRC configuration is completed), or before a UE packet for performing multicast communication is formed. The transmitting UE for unicast and multicast communications may not set the sidelink transmit power value based on the sidelink path loss estimate. For this, for the above parameters, the UE may use a preset value or a value transmitted from the base station through RRC configuration and system information of the base station. The parameter values used at this time may be different from those used after the PC5RRC configuration. The pl (q) used by the transmitting UE before PC5RRC configuration in equation 7, equation 8, equation 9, equation 10, and equation 11 may indicate a path loss value with respect to the Uu link between the base station and the transmitting UE, instead of a side link path loss value. Further, when the UE uses preset parameters, each parameter may include a value of 0, 0dB, or 0 dBm.

In another example, the preset transmission power values of PSCCH, pscsch, and PSFCH or the transmission power values set by the base station may be expressed as a transmission power value and an offset value with respect to one channel. For example, when the transmission power values of PSCCH, and PSFCH are preset, the transmission power value of PSCCH may be set to [ X ] dBm, and the offset value of the transmission power of PSCCH and PSFCH may be set to +/- [ Y ] dB (or dBm) based on the transmission power value of PSCCH. This also applies even if the transmit power values of PSCCH, pscsch and PSFCH are set by the base station.

Fig. 13 illustrates a method of multiplexing sidelink channels within sidelink resources according to an embodiment of the present disclosure.

Referring to fig. 13, it is shown that PSCCH and PSCCH are frequency division multiplexed in K1 symbols and only PSCCH is transmitted in K2 symbols as shown in fig. 11, but it is shown that there is a PSFCH consisting of K3 symbols unlike fig. 11. The value of K3 may be 1 or an integer greater than 1 (e.g., 2 or 3). That is, the K symbols may be composed of frequency division multiplexed K1 PSCCH/PSCCH symbols, K2 PSCCH symbols, K3 PSFCH symbols, and guard symbols (gap symbols). The values of K1 and K2 may be equal to or different from each other. Further, when the values of K1 and K2 are different from each other, these values may be K1> K2 or K1< K2. K1+ K2+ the number of guard symbols 1+ K3+ the number of guard symbols 2 may be equal to or less than K, and the guard symbols 1 and 2 may be one or at least two OFDM symbols. The guard symbol 1 and the guard symbol 2 may be OFDM symbols having different lengths. For example, the guard symbol 1 may be composed of two OFDM symbols, and the guard symbol 2 may be composed of one OFDM symbol. In addition, in fig. 13, M is shown as the size of the resource block on the frequency axis of the PSFCH, but the size of the resource block of the PSFCH may be equal to or different from the size of the resource blocks of the PSCCH and PSCCH. The V2X receives the PSSCH that the UE can decode and then transmits the PSFCH including the result (i.e., ACK/NACK information) to the V2X.

Referring to fig. 13, the V2X transmitting UE can transmit side chain control information (SCI) through PSCCH consisting of K1 symbols on a time axis and N2 frequency blocks on a frequency axis. The side link control information may include time/frequency allocation information of a pscch consisting of K1+ K2 symbols on a time axis and M frequency blocks on a frequency axis and then transmitted. The V2X receiving UE can receive and decode the PSCCH from the transmitting UE and can then acquire the time/frequency allocation information of the PSCCH and decode the PSCCH. Fig. 13 shows pschs made up of K2 symbols that are located physically contiguously after a PSCCH made up of K1 symbols, although they may not be located physically contiguously (i.e., the pschs may be located logically contiguously, rather than physically contiguously after the PSCCH).

Meanwhile, as shown in fig. 11, in fig. 13, the PSCCH may be composed of N1 frequency blocks on the frequency axis. The psch may be composed of N2 frequency blocks during K1 symbol lengths, and may be composed of K2 symbolsM frequency blocks in the symbol length period (N1+ N2 ═ M). At the ith transmission time, the V2X transmitting UE using the sidelink resource structure of fig. 13 can determine the transmit power (P) of the PSCCH by equation 16, equation 17, or equation 18_PSCCH) And PSSCH transmit power (P)_PSSCH)。

P_PSCCH(i)＝X1+min{Pcmax(i),10log10(X2*2^μ)+P_{0_PSCCH}+α_PSCCH*PL(q)}[dBm].. equation 16

P_PSCCH(i)＝X1+min{Pcmax(i),10log10(X2*2^μ)+P_{0_PSCCH}+α_PSCCH*PL(q),P_Congestion}[dBm].. equation 17

P_PSCCH(i)＝X1+min{Pcmax(i),10log10(X2*2^μ)+P_{0_PSCCH}+α_PSCCH*PL(q),P_Congestion,P_Range}[dBm].. equation 18

Each parameter of equation 16, equation 17, and equation 18 may indicate the following.

-pcmax (i): pcmax (i) indicates a maximum UE transmission output at an ith sidelink transmission time and a P-max value (a preset value when there is no base station) set by the base station through system information or RRC, and may be determined by the UE through a UE power class included in the UE.

-P_{0_PSCCH}：P_{0_PSCCH}A value (a preset value when there is no base station) set by the base station through system information or RRC for guaranteeing link quality of the receiving UE may be indicated.

-α_PSCCH：α_PSCCHIs a parameter for compensating a path loss value, has a value between 0 and 1, and may indicate a value (a preset value when there is no base station) set by the base station through system information or RRC. For example, when α_PSCCHWhen 1, 100% of the path loss can be compensated, when α_PSCCHAt 0.8, only 80% of the path loss can be compensated.

-X1: x1 denotes

And M is_PSCCHAnd M_PSSCHThe size of the frequency block allocated to transmitting PSCCH and PSCCH may be indicated separately. Also, ε is a parameter used for power boosting of the PSCCH. For example, when the PSCCH performs power boosting to keep its PSD 3dB higher than the PSCCH, epsilon may be 3. When PSCCH and PSCCH maintain the same PSD (or where no power boost is performed), epsilon may be 0. A fixed value may be used as the value of epsilon (i.e., epsilon is fixed to 3), or the value of epsilon may be set through RRC and system information of the base station. The value of epsilon can be preset when there is no base station. For example, in case of setting the value of epsilon, when configuring a unicast connection, V2X transmitting UE and receiving UE can receive the value of epsilon set through PC-5 RRC.

-X2: x2 denotes

And M is_PSCCH、M_PSSCHAnd ε may be the same as described above for X1.

-2 μ: 2 μmay be a parameter for compensating a Power Spectral Density (PSD) that varies according to a subcarrier interval. For example, the case of using a subcarrier spacing of 15kHz may indicate that μ ═ 0. Even if the same number of frequency blocks are used, when the subcarrier spacing is doubled to 30kHz, the PSD can be reduced by half compared to the case where the subcarrier spacing of 15kHz is used. Therefore, to compensate for the PSD, a power doubling is required. More specifically, for example, when two frequency blocks are used, 10log10(2x20) needs to be 3dB for a subcarrier spacing of 15kHz, while the transmit power needs to be increased to 10log10(2x21) 6dB for a subcarrier spacing of 30kHz in order to maintain the same PSD as for a subcarrier spacing of 15 kHz.

-PL: PL may indicate an estimated path loss value. The path loss value can be estimated by equation 2.

-P_Congestion: p included in equations 17 and 18_CongestionIs a parameter reflecting the congestion level of the V2X transmitting UE, and can indicate the most usable V2X transmitting UE according to the congestion levelA large transmission power. More specifically, when the base station determines that the congestion level is high in the resource pool configured by the base station, the base station may transmit P to V2X for the UE transmission through system information and RRC configuration_CongestionThe value is obtained. In another example, when configuring unicast link connection through PC-5RRC, V2X sending UE may receive P_CongestionThe set value of (2). In another example, V2X sending the P included in the pre-configured resource pool information may be used by the UE_CongestionThe value is obtained. P_CongestionThe unit of the value of (a) is [ dBm]In the range of 1[ dBm ] interval]Of (1) < 41[ dBm >]To 31[ dBm ]]。P_CongestionMay be associated with the priority of the PSSCH transmitted by the UE transmitted by V2X. That is, when the priority of V2X for transmitting the psch transmitted by the UE is high, even if the congestion level is high, P_CongestionMay also be high (e.g., 31 dBm)]) Since the transmission of the PSCCH and the PSCCH corresponding thereto should be successfully performed. On the other hand, when the priority of the PSCCH transmitted by the UE transmitted by V2X is low and the congestion level is high, P does not cause a problem because transmission failures of the PSCCH and the PSCCH corresponding thereto (or transmission may be dropped)_CongestionMay be low (e.g., -41 dBm]). At the same time, P_CongestionThe value of (c) may include a value of- ∞. Since the value indicates- ∞indbm, the value may be 10^ (- ∞/10) ^ 10^ 1/(10^ infinity) ≈ 0[ mW ^ 0 ] when the value is converted into a linear domain]. In equation 17, when P_CongestionWhen ═ infinity, the value may indicate P_PSCCH(i)＝X1+P_Congestion＝P_Congestion＝-∞[dBm]. As described above, it may indicate that in the linear domain, the transmit power of the PSCCH is 0 mW](i.e., PSCCH is not transmitted).

The resource pool information of the PSCCH may be configured from the base station or PC-5RRC, or may be pre-configured. In the configured (or pre-configured) resource pool, there may be a V2X resource allocation pattern where the V2X transmitting UE selects the resources for transmitting the PSCCH through a sensing process. The sensing procedure may indicate a procedure of decoding Sidelink Control Information (SCI) transmitted through the PSCCH and a procedure of measuring RSRP of a DMRS of the PSCCH associated with the PSCCH. The mode in which V2X transmits the UE to select resources through the sensing process may be referred to as mode 2. The V2X transmitting UE operating in mode-2 may perform decoding of the PSCCH to select PSCCH resources that may be occupied within a configured (or pre-configured) PSCCH resource pool or PSCCH resource region. Furthermore, the V2X transmitting UE may measure the congestion level of the PSCCH transmitted from each time slot within the PSCCH resource pool or PSCCH resource region. Similarly, a V2X transmitting UE operating in mode-2 may perform decoding of the PSCCH to select PSCCH resources that may be occupied within a configured (or pre-configured) PSCCH resource pool or PSCCH resource region, and may measure RSRP of DMRSs transmitted over the PSCCH. In addition, the V2X transmitting UE may measure the congestion level of the psch transmitted from each slot within the psch resource pool or psch resource region.

In the above-described pattern-2, the congestion level of the PSCCH or PSCCH may be measured by a ratio (B/a) between the total number of resources constituting the PSCCH resource pool (or PSCCH resource region) or PSCCH resource pool (or PSCCH resource region) and the number of resources occupied by other UEs. That is, a may be the total number of PSCCH resources that make up the PSCCH resource pool when measuring the congestion level of the PSCCH, and a may be the total number of PSCCH resources that make up the PSCCH resource pool when measuring the congestion level of the PSCCH. When measuring the congestion level of the PSCCH, B may be calculated by comparing the value of the Received Signal Strength Indicator (RSSI) of the PSCCH symbol with a critical value of the RSSI, which is set (or preset) by the base station or PC-5 RRC. For example, assuming that a PSCCH transmitted by each UE within a PSCCH resource pool is composed of x symbols, the total received power (x total received powers) of each symbol is obtained to obtain an average value of x symbols. Thus, the RSSI of the PSCCH transmitted by each UE can be measured. The V2X transmitting UE may compare the measured value of RSSI with a threshold value of RSSI set (or preset) by the base station or PC-5RRC, so that it may be determined that the corresponding PSCCH is occupied by other UEs when the measured value of RSSI is greater than the set threshold value of RSSI. Therefore, B may contain the corresponding PSCCH. Meanwhile, when the congestion level of the psch is measured, B may be calculated by comparing the RSSI value of the psch symbol with a critical value of RSSI set (or preset) by the base station or PC-5 RRC.

A measure of the level of congestion may be calculated during a certain period of time. For example, a and B may be measured for PSCCH resources (or PSCCH resources) that are present during a time period of an [ n-K, n-1] slot of a configured PSCCH resource pool (or PSCCH resource pool). Thus, the congestion level measured in n slots may indicate the congestion level measured for PSCCH resources (or PSCCH resources) present within the time period of an [ n-K, n-1] slot. A fixed value (or preset value) may be used as K, or K may also be set by the base station or PC-5 RRC.

In equations 17 and 18, when the ith PSCCH is transmitted, P is set for the slave base station or PC-5RRC_CongestionThe congestion level reflected in the value of (a) needs to define a congestion measurement time for obtaining the congestion level. For example, the base station or PC-5RRC may use the congestion level results measured before the k1 time slot or k2 symbol before the UE transmits the i-th PSCCH transmission of the UE. That is, P is calculated at the transmission power for PSCCH transmitted through the ith slot_CongestionMay indicate the congestion level measured at the i-kl slot or the congestion level measured k2 symbols before the first symbol of the PSCCH transmitted at the i slot. As described above, the congestion level measured at the i-K1 time slot may indicate a congestion level for a presence [ i-K1-K, i-K1-1]A congestion level measured for PSCCH resources over a time period. Further, the congestion level measured in the i-K2 symbol may indicate a congestion level for a packet present in [ i-K2-K, i-K2-1]A congestion level measured for PSCCH resources over a time period.

Equation 16 may be applied to a mode (mode-1) in which the base station schedules V2X to transmit transmission resources of the UE by using Downlink Control Information (DCI) transmitted through the PDCCH. In another example, P of equation 17 is not set from the base station or PC-5RRC_CongestionWhen equation 16 can be applied, or when P of equation 18 is not set from the base station or PC-5RRC_RangeValue sum P_CongestionIn value, equation 16 may be applied.

When P is set from the base station or PC-5RRC_CongestionIn value, equation 17 may be applied. When P is set from the base station or PC-5RRC_RangeAnd P_CongestionEquation 18 may be applied. P may be omitted from equation 18_CongestionThe value is obtained. In thatIn this case, when P is set from the base station or PC-5RRC_RangeEquation 18 may be applied.

-P_Range: p of equation 18_RangeA transmission power value that satisfies the range requirement in V2X communication may be indicated. More specifically, the range requirement or range information may indicate a minimum distance that guarantees QoS (e.g., delay time, reliability, data transmission rate, etc.) of side link packets transmitted through unicast or multicast communication. In unicast or multicast V2X communications, the sending UE may receive information about the range transmitted from its upper layers (e.g., application layer). The range information may be expressed as a distance having a unit of meter (m) or may be expressed as an index. That is, the application layer may provide the range information to the application layer in units of meters (e.g., 100 m). In another example, the application layer may provide the AS layer with a scope index. In this case, the minimum distance may be mapped to each range index (i.e., index 1-100 m, index 2-200 m, etc.). Upon receiving the scope information, the AS layer may generate P mapped to the corresponding scope information_RangeThe value is obtained. For example, P corresponding to a 100m range (or range index 1) may be generated_RangeThe sum of values and P corresponding to a 200m range (or range index 2)_RangeThe value is obtained. In another example, when distance information transferred from an application layer is received, the AS layer may transfer the corresponding information to the RRC and generate P in the RRC_RangeThe value is obtained.

Meanwhile, referring to fig. 3, the V2X UE may be configured for whether to perform sidelink transmission power by using a downlink path loss with a base station or whether to perform sidelink transmission power by using a sidelink path loss between the V2X UEs. This information may be configured by a configuration of V2X transmitting UEs or V2X receiving path loss estimation signals that the UEs may use. More specifically, as illustrated in fig. 3, when the sidelink transmission power should be performed by using the downlink path loss with the base station, the V2X transmission UE and the V2X reception UE may be configured by the base station such that the path loss is estimated by using a downlink Synchronization Signal Block (SSB) or CSI-RS (i.e., the SSB or CSI-RS is configured as a path loss estimation signal). When performing sidelink transmit power by using sidelink path loss between V2X UEs, the V2X transmitting UE and the V2X receiving UE may be configured by the base station such that the path loss is estimated by using a sidelink reference signal (e.g., a sidelink CSI-RS transmitted over PSSCH or a DMRS transmitted over PSSCH) (i.e., the sidelink CSI-RS or DMRS is configured as a path loss estimation signal).

The sidelink resource pool information may include information on whether the mentioned downlink path loss value is applied to sidelink transmission power, whether an uplink path loss value is applied to sidelink transmission power, or whether any path loss estimation signal that may have the same meaning as it is used. For example, the base station may transmit information on the sidelink resource pool to the UE through system information or RRC configuration, and the information on the sidelink resource pool may include a setting parameter of a sidelink transmission power, which may be used in the corresponding resource pool. The parameter of the transmission power may include P mentioned in relation to equation 16, equation 17, and equation 18_{0_PSCCH}、α_PSCCHAnd PL (q). More specifically, PL (0) may indicate that the downlink path loss is applied, and may indicate that the downlink path loss is estimated by using SSB (q ═ 0). PL (1) may indicate that a downlink path loss is applied, and may indicate that the downlink path loss is estimated by using a downlink CSI-RS (q ═ 1). Further, PL (2) may indicate that a side link path loss is applied, and may indicate that the side link path loss is estimated by using a side link CSI-RS or a side link DMRS (q ═ 2). In another example, the use of SSBs, CSI-RS, sidelink CSI-RS, or sidelink DMRS for resource pool information may be explicitly written by system information or RRC configuration.

In another example, when there is no base station, V2X sends a setting parameter that the UE can receive the sidelink transmit power from the pre-configured resource pool information. In this case, the V2X UE may obtain the above-mentioned transmit power parameter from the pre-configured resource pool information.

In another example, regardless of whether a base station exists, when a unicast connection with a V2X receiving UE is configured, the V2X transmitting UE may perform PC-5RRC configuration. The parameter of the sidelink transmission power may be set when the parameter of the sidelink transmission power is set from the PC-5RRC (case where the sidelink resource pool information does not include the sidelink transmission power parameter), or when the information on the sidelink resource pool is configured from the PC-5RRC (case where the sidelink resource pool information includes the sidelink transmission power parameter).

In equations 16, 17 and 18, P is applied when the downlink path loss is applied or when the side link path loss is applied_{0_PSCCH}And alpha_PSCCHMay be set to have different values. That is, when the UE applies downlink path loss, P_{0_PSCCH}And alpha_PSCCHCan be set to A1 and B1, respectively, P when UE applies sidelink path loss_{0_PSCCH}And alpha_PSCCHMay be set to a2 and B2, respectively. In a scenario where the sidelink and the Uu link (i.e., downlink and uplink) share a frequency, sidelink transmit power control may be performed in order to reduce interference caused by sidelink transmission in an uplink signal received by a base station, and thus a downlink path loss value may be applied. In contrast, in a scenario where the sidelink and the Uu link do not share a frequency, since the sidelink quality is guaranteed and unnecessary high transmission power is not used, a sidelink path loss value may be applied to reduce power consumption.

Meanwhile, unlike the above example, the V2X UE may receive all of the sidelink transmit power parameter when the downlink path loss value is applied and the sidelink transmit power parameter when the sidelink path loss value is applied. That is, the V2X UE may receive all of the following from the base station through system information or RRC, or through PC-5RRC of the UE: p that can be used when applying downlink path loss values_{0_PSCCH}And alpha_PSCCHAnd a type of path loss estimation signal (SSB or downlink CSI-RS) used to estimate downlink path loss; and P that can be used when applying side link path loss values_{0_PSCCH}And alpha_PSCCHAnd a type of a side link path loss estimation signal (side link CSI-RS or side link DMRS) for estimating a side link path loss.

As described aboveThe resource pool information may include sidelink transmit power parameter information, including P_{0_PSCCH}And alpha_PSCCHAnd a type of path loss estimation signal used to estimate path loss. More specifically, all of the following (i.e., SSB or downlink CSI-RS and sidelink CSI-RS or sidelink DMRS are configured) may be configured in the resource pool information: p that can be used when applying downlink path loss values_{0_PSCCH_DL}And alpha_{PSCCH_DL}And a type of path loss estimation signal used to estimate the downlink path loss; and P that can be used when applying side link path loss values_{0_PSSCH_SL}And alpha_{PSSCH_SL}And a type of side link path loss estimation signal used to estimate the side link path loss.

In another example, the path loss index set in the resource pool information may indicate a type of a path loss estimation signal for estimating a path loss (e.g., when q-0 indicates SSB, q-1 indicates a downlink CSI-RS, and q-2 indicates a side link CSI-RS or a side link DMRS, q-0 and q-2 or q-1 and q-2 are both set).

When the V2X UE receives all the sidelink transmit power parameters when the downlink path loss value is applied and the sidelink transmit power parameters when the sidelink path loss value is applied, the V2X UE can calculate the PSCCH transmit power by equation 19 or equation 20.

P_PSCCH(i)＝X1+min{Pcmax(i),10log10(X2*2^μ)+min{P1,P2}}[dBm]

.. equation 19

P_PSCCH(i)＝X1+min{Pcmax(i),min{P3,P4}}[dBm].. equation 20

Each parameter of equations 19 and 20 may indicate the following.

Pcmax (i) X1, X2 and 2^μThe same as described in equation 16.

-P1: p1 indicates the transmit power when the downlink path loss value is applied, which may be P1 ═ P_{0_PSCCH_DL}+α_{PSCCH_DL*}PL (q). The index q indicating the path loss may be omitted from P1.

-P2: p2 indicates the applicationThe transmission power at the side link path loss value may be P2 ═ P_{0_PSCCH_SL}+α_{PSCCH_SL*}PL (q). The index q indicating the path loss may be omitted from P2.

-P3: p3 indicates the transmit power when the downlink path loss value is applied, which may be P3 ═ P1+10log10(X2 × 2)^μ). The index q indicating the path loss may be omitted from P3.

-P4: p4 indicates the transmit power when the sidelink path loss value is applied, which may be P4 ═ P2+10log10(X2 × 2)^μ). The index q indicating the path loss may be omitted from P4.

Although not shown in equations 19 and 20, P may be included in equations 19 and 20 as shown in equations 17 and 18_CongestionAnd P_Range. More specifically, equation 19 may be expressed as equation 21.

P_PSCCH(i)＝X1+min{Pcmax(i),P_Congestion,P_Range,10log10(X2*2^μ)+min{P1,P2}}[dBm].. equation 21

Equation 21 shows P_CongestionAnd P_RangeAll inclusive, but P may be omitted from equation 21_CongestionAnd P_RangeOne of them.

Similarly, equation 20 may be expressed as equation 22.

P_PSCCH(i)＝X1+min{Pcmax(i),P_Congestion,P_Range,min{P3,P4}}[dBm]

.. equation 22

Equation 22 shows P_CongestionAnd P_RangeAll inclusive, but P as shown in equation 21_CongestionAnd P_RangeOne of which may be omitted from equation 22.

Equation 16, equation 17, equation 18, equation 19, equation 20, equation 21, and equation 22 are equations for determining the transmit power value of the PSCCH. Similarly, the transmit power value of the PSSCH can be calculated, but the transmit power of the PSSCH can be calculated in two parts. The first part is the transmit power of the PSCCH corresponding to K1 symbols in fig. 13, and may indicate the transmit power at the PSCCH and PSCCHPSCCH transmit power in symbols during frequency division multiplexing. It can be defined as P_PSSCH-1(i) In that respect The second part is the transmit power of the PSCCH corresponding to K2 symbols in fig. 13 and may indicate the PSCCH transmit power in symbols during which the PSCCH is not frequency division multiplexed. It can be defined as P_PSSCH-2(i)。P_PSSCH-1(i) May be defined by changing X1 defined in each of equation 16, equation 17, equation 18, equation 19, equation 20, equation 21, and equation 22 to X1-epsilon. Taking equation 21 as an example, when equation 21 is used for PSCCH transmit power, P may be calculated as shown in equation 23_PSSCH-1(i)。

P_PSSCH-1(i)＝X1-ε+min{Pcmax(i),P_Congestion,P_Range,10log10(X2*2^μ)+min{P1,P2}}[dBm]… equation 23

The parameters defined in equation 23 may be the same as those described in equation 21. When equation 16, equation 17, equation 18, equation 19, equation 20, or equation 22 is used to calculate the PSCCH transmit power value, X1 defined in each equation is changed to X1-epsilon, so that it is possible to derive a value for calculating P_PSSCH-1(i) Equation (c) of (c). In addition, in order to calculate P by modifying equation 23_PSSCH-1(i) Equation 22 may be used to apply P_PSSCH-1(i)＝X1-ε+min{Pcmax(i),P_Congestion,P_Range,min{P3,P4}}[dBm]。

The transmit power equations for the first part of the PSCCH and PSCCH that make up the K1 symbols in fig. 13 have been described. Based on this, a transmit power value (P) for calculating the second part with respect to the psch may be defined by considering the following_PSSCH-2(i) Equation of (c).

As shown in fig. 13, when the number of symbols used by a single V2X transmitting UE to transmit the ith PSCCH and PSCCH is K1+ K2, each symbol constituting K1+ K2 symbols should have the same transmission power. When the transmission power of each symbol is not the same, inefficient use of resources may occur because a guard portion (or gap) for power transients is required between symbols where the transmission power changes. Further, when the transmission power level between symbols is changed, the receiving side changes due to the phase between symbolsThe reception performance of the corresponding symbol may be degraded. Therefore, the transmission power of K1 symbols where PSCCH and PSCCH are frequency division multiplexed and the transmission power of K2 symbols where PSCCH only is transmitted should be kept equal. To this end, a transmission power value (P) for the second part of the psch may be determined by equation 24_PSSCH-2(i))。

P_PSSCH-2(i)＝P_PSCCH(i)+P_PSSCH-1(i)[dBm]… equation 24

The parameters of equation 24 are the same as those mentioned in equation 16, equation 17, equation 18, equation 19, equation 20, equation 21, equation 22, and equation 23. In equation 24, P_PSCCH(i) And P_PSSCH-1(i) May be less than the value of pcmax (i), which is the maximum transmit power of the UE (i.e., P;)_PSCCH(i)<Pcmax (i) and P_PSSCH-1(i)<Pcmax (i), but P_PSSCH-2(i) Is P_PSCCH(i) And P_PSSCH-1(i) And, it may be greater than Pcmax (i). In this case, P may be recalculated by equations 25 and 26_PSSCH-2(i)。

P'_PSSCH-2(i)＝min{Pcmax(i),P_PSSCH-2(i)}[dBm].. equation 25

P'_PSSCH-2(i)＝δ·P_PSSCH-2(i)[dBm].. equation 26

In equation 26, δ is a scaling factor and may be greater than 0 and less than or equal to 1. To satisfy P_PSSCH-2(i) Pcmax (i), the value of δ may be set by the transmitting UE.

At P 'through equation 25'_PSSCH-2(i) In the case of Pcmax (i), P is proved as described above_PSCCH(i)+P_PSSCH-1(i)＝P_PSSCH-2(i)>Pcmax (i). That is, due to P_PSSCH-2(i) Limited by Pcmax (i) and the transmit power is thus changed, so P_PSCCH(i)+P_PSSCH-1(i) Should be changed so that the K1 symbols and the K2 symbols can use the same transmission power. To this end, beta. P_PSCCH(i)+P_PSSCH-1(i)]Is used to scale down the sum of the transmit powers such that P is satisfied_PSCCH(i)+P_PSSCH-1(i) Pcmax (i) or less. Beta isThe scale factor may be greater than 0 and less than or equal to 1. In another example, as described in equations 12 and 13, P_PSSCH-2(i) At a transmission power of P_PSCCH(i) And P_PSSCH-1(i) And P can be updated_PSCCH(i) And P_PSSCH-1(i) Each of the transmit power values. That is, when P is_PSCCH(i) And P_PSSCH-1(i) Are defined as P'_PSCCH(i) And P'_PSSCH-1(i) When they are of P'_PSCCH(i)＝10log10[X1*Y/(X1+X2)]And P'_PSSCH-1(i)＝10log10[X2*Y/(X1+X2)](equation 13). X1 and X2 are the same as defined in equation 12, Y may indicate that Y ═ 10^ P_PSSCH-2(i)/10]。

Similarly, when P is_PSSCH-2(i) Is changed to P 'by equation 26'_PSSCH-2(i) At transmission power of, P_PSCCH(i)+P_PSSCH-1(i) Should be changed so that the same transmission power can be used for K1 symbols and K2 symbols. For this purpose, as described above, β · [ P ]_PSCCH(i)+P_PSSCH-1(i)]Is used to scale down P_PSCCH(i)+P_PSSCH-1(i) Of the transmitted power of, or of varying P_PSSCH-2(i) At a transmission power value of P_PSCCH(i) And P_PSSCH-1(i) Is redistributed and P_PSCCH(i) And P_PSSCH-1(i) May thus be updated.

The transmission power parameter used in equation 16, equation 17, equation 18, equation 19, equation 20, equation 21, equation 22, equation 23, equation 24, and equation 26 may use a value set to the transmitting UE by the base station or may use a value preset in the UE through the methods mentioned in fig. 8 to 12. For example, a UE existing outside the coverage of the base station may not receive the set transmit power parameter from the base station. Thus, these UEs may use preset values for the parameters. The set point may comprise 0, 0dB or 0 dBm. The preset value may indicate a value input in the UE in the factory, or may indicate a value set by the base station when the UE once exists within the coverage of the base station (the UE is now located outside the coverage of the base station).

In another example, even if the UE exists within the coverage of the base station, parameter exchange between UEs that are to perform unicast/multicast communication may not be performed when no UE pairing is formed for performing unicast communication (e.g., before the PC5RRC configuration is completed), or before a UE packet for performing multicast communication is formed. The transmitting UE for unicast and multicast communications may not set the sidelink transmit power value based on the sidelink path loss estimate. For this, for the above parameters, the UE may use a preset value or a value transmitted from the base station through RRC configuration and system information of the base station. The parameter values used at this time may be different from those used after the PC5RRC configuration. The pl (q) used by the transmitting UE prior to PC5RRC configuration may indicate a pathloss value for the Uu link between the base station and the transmitting UE, rather than a side link pathloss value. Further, when the UE uses preset parameters, each parameter may include a value of 0, 0dB, or 0 dBm.

Fig. 14 shows a flow chart of the operation of a V2X UE for sidelink transmit power control in accordance with an embodiment of the present disclosure.

Referring to fig. 14, the V2X transmitting UE may determine whether the V2X transmitting UE exists within the coverage of the base station (fig. 1A) or whether the V2X transmitting UE exists outside the coverage of the base station (fig. 1C). When it is determined whether the V2X transmitting UE exists within the coverage of the base station, the UE may obtain information on a sidelink resource pool in operation 1401. For example, when recognizing that the UE exists within the coverage of the base station, the UE may obtain information on the sidelink resource pool through RRC configuration or system information transmitted by the base station. In contrast, when recognizing that the UE exists outside the coverage of the base station, the UE may obtain information on the sidelink resource pool through system information pre-configured in the UE.

When information on the resource pool is obtained from the base station or information on the pre-configured resource pool is obtained, the UE may obtain information on a sidelink transmission power parameter included in the sidelink resource pool information in operation 1402. The sidelink transmission power parameter included in the sidelink resource pool information may include at least one of the following parameters.

-P₀: parameters for ensuring link quality of a receiving UE

- α: α is a parameter for securing a path loss value, and its value is between 0 and 1.

-number of RBs: with respect to the parameter of the frequency block size, the UE may transmit the sidechain control information and the data information using the above frequency block

-subcarrier spacing: parameter regarding subcarrier spacing for transmitting sidelink control information and data information

-a reference signal for path loss estimation. That is, the reference signal may indicate a synchronization signal transmitted through a downlink of the base station or a DMRS of a Physical Broadcast Channel (PBCH) transmitted through a downlink of the base station, or may indicate a parameter indicating which signal the UE uses to estimate a path loss among side-link reference signals transmitted through a side-link between UEs.

Parameters regarding a multiplexing method of the sidelink control channel and the sidelink data channel (for example, information regarding whether the channel is time-divided and transmitted as shown in fig. 8, 9, and 12, or information regarding whether the channel is frequency-divided and transmitted as shown in fig. 10 and 11).

In operation 1403, V2X sends the UE to set the transmit power of the sidelink control channel and the sidelink data channel using the information on the parameters. In operation 1404, the V2X transmitting UE transmits the link control channel and the sidelink data channel at the transmitting side using the set transmission power value.

Fig. 15 is a diagram illustrating a UE configuration according to an embodiment of the present disclosure.

Referring to fig. 15, a UE according to an embodiment may include a transceiver 1520 and a controller 1510, the controller 1510 being configured to control the entire operation of the UE. The transceiver 1520 may include a transmitter 1521 and a receiver 1523.

The transceiver 1520 may transmit/receive signals to/from other network entities.

The controller 1510 may control the UE to perform one action of the above-described embodiments. Meanwhile, the controller 1510 and the transceiver 1520 do not have to be implemented as separate modules, and may be implemented as a single element in the form of a single chip. Further, the controller 1510 and the transceiver 1520 may be electrically connected to each other. For example, the controller 1510 may be circuitry, dedicated circuitry, or at least one processor. Further, the operation of the UE may be achieved by providing a storage device storing the corresponding program code to any element in the UE.

Fig. 16 is a diagram showing a base station configuration according to an embodiment of the present disclosure.

Referring to fig. 16, a base station according to an embodiment may include a transceiver 1620 and a controller 1610, and the controller 1610 is configured to control the entire operation of the base station. The transceiver 1620 may include a transmitter 1621 and a receiver 1623.

The transceiver 1620 may transmit/receive signals to/from other network entities.

The controller 1610 may control the base station to perform one action of the above-described embodiment. Meanwhile, the controller 1610 and the transceiver 1620 do not have to be implemented as separate modules, and may be implemented as a single element in the form of a single chip. In addition, the controller 1610 and the transceiver 1620 may be electrically connected to each other. For example, the controller 1610 may be a circuit, a dedicated circuit, or at least one processor. Further, the operation of the base station may be implemented by providing any of the elements in the base station with a memory device storing the corresponding program code.

It should be noted that the configuration diagrams, the example diagrams of the control/data signal transmission method, the example diagram of the operation procedure, and the configuration diagrams shown in fig. 1A to 1D, fig. 2A and 2B, fig. 3 to 16 are not intended to limit the scope of the present disclosure. That is, all elements, entities, or operations described in fig. 1A to 1D, fig. 2A and 2B, fig. 3 to 16 should not be construed as essential elements for implementing the present disclosure, and only some elements may be used for implementing the present disclosure within a range not to impair the nature of the present disclosure.

The above-described operations of the base station or the UE may be implemented by providing a storage device storing a corresponding program code to any element in the base station or the UE. That is, the controller of the base station or UE may perform the above-described operations by a processor or Central Processing Unit (CPU) reading and executing program codes stored in a storage device. The methods according to the embodiments of the present disclosure defined by the appended claims or disclosed herein may be implemented in hardware, software, or a combination of hardware and software.

When the methods are implemented by software, a computer-readable storage medium for storing one or more programs (software modules) may be provided. One or more programs stored in the computer-readable storage medium may be configured to be executed by one or more processors in the electronic device. The at least one program may include instructions for causing the electronic device to perform methods in accordance with various embodiments of the present disclosure as defined by the appended claims or disclosed herein.

Programs (software modules or software) may be stored in non-volatile memory including random access memory and flash memory, Read Only Memory (ROM), Electrically Erasable Programmable Read Only Memory (EEPROM), magnetic disk storage devices, compact disc-ROM (CD-ROM), Digital Versatile Discs (DVD), or other types of optical storage devices or magnetic tape. Alternatively, any combination of some or all of them may form a memory storing a program. Further, a plurality of such memories may be included in the electronic device.

Further, the program may be stored in an attachable storage device that can access the electronic device through a communication network such as the internet, an intranet, a Local Area Network (LAN), a wide area network (WLAN), and a Storage Area Network (SAN), or a combination thereof. Such a storage device may be accessible through an external port to an electronic device implementing an embodiment of the present disclosure. Furthermore, a separate storage device on the communication network may access the electronic device that performs embodiments of the present disclosure.

In the above detailed embodiments of the present disclosure, elements included in the present disclosure are expressed in the singular or plural according to the presented detailed embodiments. However, for convenience of description, the singular or plural expressions appropriate for the proposed cases are selected, and the present disclosure is not limited to the singular or plural elements. Elements expressed in the plural may be arranged in the singular, or elements expressed in the singular may be arranged in the plural.

While the disclosure has been shown and described with reference to various embodiments thereof, it will be understood by those skilled in the art that various changes in form and details may be made therein without departing from the spirit and scope of the disclosure as defined by the appended claims and their equivalents.

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Method and apparatus for controlling UE transmission power in wireless communication system

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