阅读说明：本技术 在无线通信系统中生成信号的方法和设备 (Method and apparatus for generating signal in wireless communication system ) 是由 李润贞 金炳勋 尹硕铉 于 2019-04-16 设计创作，主要内容包括：提供了一种在无线通信系统中生成信号的方法和设备。在新无线电接入技术RAT中操作的用户设备UE基于载波的中心频率来生成用于参数集的信号,并发送所生成的信号。载波的中心频率基于网络所支持的最大子载波间距。(A method and apparatus for generating a signal in a wireless communication system are provided. A user equipment UE operating in a new radio access technology RAT generates a signal for a set of parameters based on a center frequency of a carrier and transmits the generated signal. The center frequency of the carrier is based on the maximum subcarrier spacing supported by the network.)

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

generating a signal for a set of parameters based on a center frequency of a carrier, wherein the center frequency of the carrier is based on a maximum subcarrier spacing supported by a network; and

the generated signal is transmitted.

2. The method according to claim 1, wherein the center frequency of the carrier is shifted with respect to the center frequency of the PRB grid of physical resource blocks of the maximum subcarrier spacing supported by the network.

3. The method according to claim 2, wherein the center frequencies of different sets of parameters are aligned to each other at the center frequency of the PRB grid of the maximum subcarrier spacing supported by the network.

4. The method of claim 1, wherein the center frequency of the carrier is determined based on an offset from point a and a number of resource blocks of the carrier.

5. The method of claim 1, further comprising receiving information about an offset between a center frequency of the carrier and a center frequency of a PRB grid for the maximum subcarrier spacing supported by the network.

6. A user equipment, UE, in a wireless communication system, the UE comprising:

a memory;

a transceiver; and

a processor operatively coupled to the memory and the transceiver and configured to:

generating a signal for a set of parameters based on a center frequency of a carrier, wherein the center frequency of the carrier is based on a maximum subcarrier spacing supported by a network; and is

Controlling the transceiver to transmit the generated signal.

7. The UE according to claim 6, wherein the center frequencies of the carriers are shifted with respect to the center frequency of the PRB grid of physical resource blocks of the maximum subcarrier spacing supported by the network.

8. The UE of claim 7, wherein center frequencies of different sets of parameters are aligned with each other at a center frequency of the PRB grid of the maximum subcarrier spacing supported by the network.

9. The UE of claim 6, wherein the center frequency of the carrier is determined based on an offset from point A and a number of resource blocks of the carrier.

10. The UE of claim 6, wherein the processor is further configured to control the transceiver to receive information regarding an offset between a center frequency of the carrier and a center frequency of a PRB grid of the maximum subcarrier spacing supported by the network.

Technical Field

The present invention relates to wireless communications, and more particularly, to a method and apparatus for generating a signal in a new Radio Access Technology (RAT).

Background

The 3 rd generation partnership project (3GPP) Long Term Evolution (LTE) is a technology that allows high-speed packet communication. Many schemes have been proposed for LTE purposes, including those aimed at reducing user and provider costs, improving quality of service, and extending and improving coverage and system capacity. As an upper layer requirement, the 3GPP LTE requires reduction of cost per bit, increase of service availability, flexible use of a frequency band, simple structure, open interface, and appropriate power consumption of a terminal.

The International Telecommunications Union (ITU) and 3GPP have begun to develop requirements and specifications for New Radio (NR) systems. The 3GPP has to identify and develop the technical components required for successful standardization of new RATs that will meet both the urgent market requirements and the longer term requirements set forth by the ITU radio sector (ITU-R) International Mobile Telecommunications (IMT) -2020 process in time. Furthermore, NR should be able to use any spectral band at least up to the 100GHz range that can be used for wireless communication even in the more distant future.

The goal of NR is a single technology framework that addresses all usage scenarios, requirements, and deployment scenarios, including enhanced mobile broadband (eMBB), large-scale machine type communication (mtc), ultra-reliable and low-latency communication (URLLC), and so on. NR should be inherently forward compatible.

Disclosure of Invention

Technical problem

NR supports multiple parameter sets corresponding to different subcarrier spacings. The present invention provides a method and apparatus for generating a signal considering a plurality of parameter sets in NR.

Technical scheme

In an aspect, a method performed by a User Equipment (UE) in a wireless communication system is provided. The method includes generating a signal for a parameter set based on a center frequency of a carrier and transmitting the generated signal. The center frequency of the carrier is based on the maximum subcarrier spacing supported by the network.

In another aspect, a User Equipment (UE) in a wireless communication system is provided. The UE includes a memory, a transceiver, and a processor operatively coupled to the memory and the transceiver. The processor is configured to generate a signal for the parameter set based on a center frequency of the carrier and control the transceiver to transmit the generated signal. The center frequency of the carrier is based on the maximum subcarrier spacing supported by the network.

Advantageous effects

In NR supporting a plurality of parameter sets, signals generated for the respective parameter sets may be aligned with each other.

Drawings

Fig. 1 shows an example of a wireless communication system to which the technical features of the present invention can be applied.

Fig. 2 shows another example of a wireless communication system to which the technical features of the present invention can be applied.

Fig. 3 shows an example of a frame structure to which the technical features of the present invention can be applied.

Fig. 4 shows another example of a frame structure to which the technical features of the present invention can be applied.

Fig. 5 illustrates an example of a subframe structure for minimizing delay of data transmission when TDD is used in NR.

Fig. 6 shows an example of a resource grid to which the technical features of the present invention can be applied.

Fig. 7 shows an example of a synchronization channel to which the technical features of the present invention can be applied.

Fig. 8 shows an example of a frequency allocation scheme to which the technical features of the present invention can be applied.

Fig. 9 illustrates an example of a plurality of BWPs to which technical features of the present invention can be applied.

Fig. 10 shows an example of aligning PRB grids of different parameter sets.

Fig. 11 illustrates an example of a method of generating a signal for a plurality of parameter sets according to an embodiment of the present invention.

Fig. 12 shows an example of a method of generating a signal for a plurality of parameter sets according to another embodiment of the present invention.

Fig. 13 illustrates a method of generating a signal by a UE according to an embodiment of the present invention.

Fig. 14 shows a wireless communication system implementing an embodiment of the present invention.

Detailed Description

The technical features described below may be used by communication standards of the 3 rd generation partnership project (3GPP) standardization organization, communication standards of the Institute of Electrical and Electronics Engineers (IEEE), and the like. For example, communication standards of the 3GPP standardization organization include Long Term Evolution (LTE) and/or evolution of LTE systems. The evolution of the LTE system includes LTE-advanced (LTE-A), LTE-APro and/or 5G New Radio (NR). The IEEE organization for standardization's communication standards include Wireless Local Area Network (WLAN) systems such as IEEE 802.11 a/b/g/n/ac/ax. The above-described systems use various multiple access techniques, such as Orthogonal Frequency Division Multiple Access (OFDMA) and/or single carrier frequency division multiple access (SC-FDMA), for the Downlink (DL) and/or uplink (DL). For example, only OFDMA may be used for DL and only SC-FDMA may be used for UL. Alternatively, OFDMA and SC-FDMA can be used for DL and/or UL.

In this document, the terms "/" and "," should be interpreted as indicating "and/or". For example, the expression "a/B" may mean "a and/or B". Further, "A, B" may mean "a and/or B". Further, "a/B/C" may mean "A, B and/or at least one of C". Additionally, "A, B, C" may mean "at least one of A, B and/or C.

Furthermore, in this document, the term "or" should be interpreted as indicating "and/or". For example, the expression "a or B" may include 1) only a, 2) only B, and/or 3) both a and B. In other words, the term "or" in this document should be interpreted as indicating "additionally or alternatively".

Fig. 1 shows an example of a wireless communication system to which the technical features of the present invention can be applied. In particular, FIG. 1 illustrates a system architecture based on an evolved-UMTS terrestrial radio Access network (E-UTRAN). The above-mentioned LTE is part of an evolved-UTMS (E-UMTS) using E-UTRAN.

Referring to FIG. 1, a wireless communication system includes one or more user equipments (UEs; 10), an E-UTRAN, and an Evolved Packet Core (EPC). The UE 10 refers to a communication device carried by a user. The UE 10 may be fixed or mobile. The UE 10 may be referred to by another terminology, such as a Mobile Station (MS), a User Terminal (UT), a Subscriber Station (SS), a wireless device, etc.

The E-UTRAN consists of one or more Base Stations (BSs) 20. The BS 20 provides the E-UTRA user plane and control plane protocol ends towards the UE 10. The BS 20 is typically a fixed station that communicates with the UE 10. The BS 20 hosts functions such as inter-cell Radio Resource Management (RRM), Radio Bearer (RB) control, connection mobility control, radio admission control, measurement configuration/provisioning, dynamic resource allocation (scheduler), etc. A BS may be referred to as another term, e.g., evolved nodeb (enb), Base Transceiver System (BTS), Access Point (AP), etc.

Downlink (DL) denotes communication from the BS 20 to the UE 10. The Uplink (UL) denotes communication from the UE 10 to the BS 20. The Sidelink (SL) represents communication between the UEs 10. In DL, a transmitter may be a part of the BS 20 and a receiver may be a part of the UE 10. In the UL, the transmitter may be a part of the UE 10, and the receiver may be a part of the BS 20. In SL, the transmitter and receiver may be part of the UE 10.

The EPC includes a Mobility Management Entity (MME), a serving gateway (S-GW), and a Packet Data Network (PDN) gateway (P-GW). The MME hosts functions such as non-access stratum (NAS) security, idle state mobility handling, Evolved Packet System (EPS) bearer control, etc. The S-GW hosts functions such as mobility anchors and the like. The S-GW is a gateway with E-UTRAN as an endpoint. For convenience, the MME/S-GW 30 will be referred to herein simply as a "gateway," but it will be understood that this entity includes both an MME and an S-GW. The P-GW hosts functions such as UE Internet Protocol (IP) address assignment, packet filtering, etc. The P-GW is a gateway with the PDN as an end point. The P-GW is connected to an external network.

The UE 10 is connected to the BS 20 through a Uu interface. The UEs 10 are interconnected to each other by a PC5 interface. The BSs 20 are interconnected with each other through an X2 interface. The BS 20 is also connected to the EPC through an S1 interface, more specifically, to the MME through an S1-MME interface and to the S-GW through an S1-U interface. The S1 interface supports a many-to-many relationship between the MME/S-GW and the BS.

Fig. 2 shows another example of a wireless communication system to which the technical features of the present invention can be applied. In particular, fig. 2 shows a system architecture based on a 5G new radio access technology (NR) system. The entities used in the 5G NR system (hereinafter, simply referred to as "NR") may absorb some or all of the functions of the entities (e.g., eNB, MME, S-GW) introduced in fig. 1. The entity used in the NR system may be identified by the name "NG" to distinguish from LTE.

In the following description, for NR, reference may be made to 3GPP TS 38 sequences (3GPP TS 38.211, 38.212, 38.213, 38.214, 38.331, etc.) to facilitate understanding of the following description.

Referring to fig. 2, the wireless communication system includes one or more UEs 11, a next generation RAN (NG-RAN), and a 5 th generation core network (5 GC). The NG-RAN is composed of at least one NG-RAN node. The NG-RAN node is an entity corresponding to the BS 20 shown in fig. 1. The NG-RAN node consists of at least one gNB 21 and/or at least one NG-eNB 22. The gNB 21 provides NR user plane and control plane protocol ends towards the UE 11. The ng-eNB 22 provides the E-UTRA user plane and control plane protocol terminations towards the UE 11.

The 5GC includes an access and mobility management function (AMF), a User Plane Function (UPF), and a Session Management Function (SMF). The AMF hosts functions such as NAS security, idle state mobility handling, etc. The AMF is an entity that includes the functionality of a legacy MME. The UPF hosts functions such as mobility anchoring, Protocol Data Unit (PDU) handling. The UPF is an entity that includes the functionality of a conventional S-GW. SMF hosts functions such as UE IP address assignment, PDU session control.

The gNB and ng-eNB are interconnected to each other by an Xn interface. The gNB and NG-eNB are also connected to the 5GC over an NG interface, more specifically to the AMF over an NG-C interface and to the UPF over an NG-U interface.

Hereinafter, a frame structure/physical resource in NR is described.

In LTE/LTE-a, one radio frame consists of 10 subframes, and one subframe consists of 2 slots. One subframe may have a length of 1ms and one slot may have a length of 0.5 ms. The time for transmitting one transport block by a higher layer to a physical layer (typically via one subframe) is defined as a Transmission Time Interval (TTI). The TTI may be the smallest unit of scheduling.

In NR, DL transmission and UL transmission are performed via a radio frame having a duration of 10 ms. Each radio frame includes 10 subframes. Thus, one subframe corresponds to 1 ms. Each radio frame is divided into two half-frames.

Unlike LTE/LTE-a, NR supports various parameter sets, and thus, the structure of a radio frame may vary. NR supports multiple subcarrier spacings in the frequency domain. Table 1 shows a number of parameter sets supported in NR. Each parameter set may be identified by an index μ.

[ Table 1]

Referring to table 1, the subcarrier spacing may be set to any one of 15, 30, 60, 120, and 240kHz, which is identified by an index μ. However, the subcarrier spacings shown in table 1 are merely exemplary, and the specific subcarrier spacings may vary. Thus, each subcarrier spacing (e.g., μ ═ 0,1.. 4) may be represented as a first subcarrier spacing, a second subcarrier spacing.

Referring to table 1, according to the subcarrier spacing, transmission of user data (e.g., Physical Uplink Shared Channel (PUSCH), Physical Downlink Shared Channel (PDSCH)) may not be supported. That is, transmission of user data may not be supported only in at least one particular subcarrier spacing (e.g., 240 kHz).

In addition, referring to table 1, according to subcarrier spacing, synchronization channels (e.g., Primary Synchronization Signal (PSS), Secondary Synchronization Signal (SSS), Physical Broadcast Channel (PBCH)) may not be supported. That is, the synchronization channel may not be supported only in at least one specific subcarrier spacing (e.g., 60 kHz).

One subframe includes N_symb ^subframe,μ＝N_symb ^slot*N_slot ^subframe,μOne consecutive OFDM symbol. In NR, the number of slots and the number of symbols included in one radio frame/subframe may be according to various parameter sets (i.e., various subcarrier spacings)) But is different.

Table 2 shows the number of OFDM symbols per slot (N) of each parameter set under a normal Cyclic Prefix (CP)_symb ^slot) Number of slots per radio frame (N)_symb ^frame,μ) And number of slots per subframe (N)_symb ^subframe,μ) Examples of (2).

[ Table 2]

Referring to table 2, when the first parameter set corresponding to μ ═ 0 is applied, one radio frame includes 10 subframes, one subframe includes one slot, and one slot is composed of 14 symbols.

Table 3 shows the number of OFDM symbols per slot (N) of each parameter set under the extended CP_symb ^slot) Number of slots per radio frame (N)_symb ^frame,μ) And number of slots per subframe (N)_symb ^subframe,μ) Examples of (2).

[ Table 3]

Referring to table 3, μ ═ 2 is supported only in the extended CP. One radio frame includes 10 subframes, one subframe includes 4 slots, and one slot is composed of 12 symbols.

In this specification, a symbol refers to a signal transmitted during a specific time interval. For example, a symbol may refer to a signal generated through OFDM processing. That is, the symbol in this specification may refer to an OFDM/OFDMA symbol, an SC-FDMA symbol, or the like. The CP may be located between the respective symbols.

Fig. 3 shows an example of a frame structure to which the technical features of the present invention can be applied. In fig. 3, the subcarrier spacing is 15kHz, which corresponds to μ ═ 0.

Fig. 4 shows another example of a frame structure to which the technical features of the present invention can be applied. In fig. 4, the subcarrier spacing is 30kHz, which corresponds to μ ═ 1.

Further, Frequency Division Duplexing (FDD) and/or Time Division Duplexing (TDD) may be applied to a wireless communication system to which embodiments of the present invention are applied. When TDD is applied, in LTE/LTE-a, UL subframes and DL subframes are allocated in units of subframes.

In NR, symbols in a slot may be classified into DL symbols (denoted by D), flexible symbols (denoted by X), and UL symbols (denoted by U). In a slot in a DL frame, the UE will assume that DL transmission occurs only in DL symbols or flexible symbols. In a slot in a UL frame, a UE should transmit only in UL symbols or flexible symbols. Flexible symbols may be referred to as another term, such as reserved symbols, other symbols, unknown symbols, and the like.

Table 4 shows an example of the slot format identified by the corresponding format index. The contents of table 4 may be applied to a specific cell in common, or may be applied to neighboring cells in common, or may be applied to respective UEs individually or differently.

[ Table 4]

For convenience of explanation, table 4 shows only a part of the slot formats actually defined in NR. Specific allocation schemes may be changed or added.

The UE may receive the slot format configuration via higher layer signaling (i.e., Radio Resource Control (RRC) signaling). Alternatively, the UE may receive the slot format configuration via Downlink Control Information (DCI) received on the PDCCH. Alternatively, the UE may receive the slot format configuration via a combination of higher layer signaling and DCI.

Fig. 5 illustrates an example of a subframe structure for minimizing delay of data transmission when TDD is used in NR. The subframe structure shown in fig. 5 may be referred to as a self-contained subframe structure.

Referring to fig. 5, a subframe includes a DL control channel in a first symbol and an UL control channel in a last symbol. The remaining symbols may be used for DL data transmission and/or for UL data transmission. According to the subframe structure, DL transmission and UL transmission may be sequentially performed in one subframe. Accordingly, the UE may receive DL data and transmit UL acknowledgement/negative acknowledgement (ACK/NACK) in a subframe. As a result, it may take less time to retransmit the data when a data transmission error occurs, thereby minimizing the delay of the final data transmission.

In a self-contained subframe structure, the transition from transmit mode to receive mode or from receive mode to transmit mode may require a time gap. For this, some symbols in the subframe structure at the time of switching from DL to UL may be set as a Guard Period (GP).

Fig. 6 shows an example of a resource grid to which the technical features of the present invention can be applied. The example shown in fig. 6 is a time-frequency resource grid used in NR. The example shown in fig. 6 may be applied to UL and/or DL.

Referring to fig. 6, a plurality of slots are included in one subframe in the time domain. Specifically, when represented according to a value of "μ," a "14 · 2 μ" symbol may be represented in the resource grid. In addition, one Resource Block (RB) may occupy 12 consecutive subcarriers. One RB may be referred to as a Physical Resource Block (PRB), and 12 Resource Elements (REs) may be included in each PRB. The number of allocable RBs may be determined based on the minimum and maximum values. The number of allocable RBs may be individually configured according to a parameter set ("μ"). The number of allocatable RBs may be configured to the same value for UL and DL or may be configured to different values for UL and DL.

Hereinafter, cell search in NR is described.

The UE may perform cell search in order to acquire time and/or frequency synchronization with a cell and acquire a cell Identifier (ID). Synchronization channels such as PSS, SSS, and PBCH may be used for cell search.

Fig. 7 shows an example of a synchronization channel to which the technical features of the present invention can be applied. Referring to fig. 7, the PSS and SSS may include one symbol and 127 subcarriers. The PBCH may include 3 symbols and 240 subcarriers.

PSS is used for Synchronization Signal (SS)/PBCH block symbol timing acquisition. The PSS indicates 3 hypotheses for the cell ID identification. SSS is used for cell ID identification. The SSS indicates 336 hypotheses. Thus, 1008 physical layer cell IDs may be configured by PSS and SSS.

The SS/PBCH block may be repeatedly transmitted according to a predetermined pattern within a 5ms window. For example, when L SS/PBCH blocks are transmitted, SS/PBCH block #1 to SS/PBCH block # L may all contain the same information, but may be transmitted through beams in different directions. That is, a quasi-co-location (QCL) relationship may not be applied to SS/PBCH blocks within a 5ms window. The beam used to receive the SS/PBCH block may be used in subsequent operations (e.g., random access operations) between the UE and the network. The SS/PBCH block may be repeated at a specific period. The repetition period may be individually configured according to the parameter set.

Referring to fig. 7, the PBCH has a bandwidth of 20 RBs for 2/4 th symbols and 8 RBs for 3 rd symbols. The PBCH includes a demodulation reference signal (DM-RS) for decoding the PBCH. The frequency domain for the DM-RS is determined according to the cell ID. Unlike LTE/LTE-a, since no cell-specific reference signal (CRS) is defined in NR, a special DM-RS is defined for decoding PBCH (i.e., PBCH-DMRS). The PBCH-DMRS may contain information indicating SS/PBCH block index.

The PBCH performs various functions. For example, the PBCH may perform the function of broadcasting a Master Information Block (MIB). System Information (SI) is divided into a minimum SI and other SIs. The minimum SI may be divided into MIB and system information block type-1 (SIB 1). The minimum SI other than the MIB may be referred to as a remaining minimum SI (rmsi). That is, RMSI may refer to SIB 1.

The MIB includes information required to decode the SIB 1. For example, the MIB may include information on subcarrier spacing applied to the SIB1 (and MSG2/4, other SIs used in the random access procedure), information on frequency offset between SS/PBCH blocks and subsequently transmitted RBs, information on bandwidth of PDCCH/SIB, and information for decoding the PDCCH (e.g., information on search space/control resource set (CORESET)/DM-RS, etc., which will be described later). The MIB may be transmitted periodically and the same information may be repeatedly transmitted during an 80ms time interval. SIB1 may be repeatedly transmitted through the PDSCH. The SIB1 includes control information for initial access by the UE and information for decoding another SIB.

Hereinafter, a DL control channel in NR is described.

The search space for the PDCCH corresponds to an aggregation of control channel candidates for which the UE performs blind decoding. In LTE/LTE-a, the search space for PDCCH is divided into a Common Search Space (CSS) and a UE-specific search space (USS). The size of each search space and/or the size of a Control Channel Element (CCE) included in the PDCCH is determined according to a PDCCH format.

In NR, a Resource Element Group (REG) and a CCE for PDCCH are defined. In NR, the concept of CORESET is defined. Specifically, one REG corresponds to 12 REs, i.e., one RB is transmitted through one OFDM symbol. Each REG includes a DM-RS. One CCE includes a plurality of REGs (e.g., 6 REGs). The PDCCH may be transmitted through a resource consisting of 1, 2, 4, 8, or 16 CCEs. The number of CCEs may be determined according to an aggregation level. That is, one CCE when the aggregation level is 1, 2 CCEs when the aggregation level is 2, 4 CCEs when the aggregation level is 4, 8 CCEs when the aggregation level is 8, and 16 CCEs when the aggregation level is 16 may be included in the PDCCH for a specific UE.

CORESET is a set of resources used to control signal transmission. CORESET may be defined over 1/2/3 OFDM symbols and multiple RBs. In LTE/LTE-a, the number of symbols for PDCCH is defined by Physical Control Format Indicator Channel (PCFICH). However, PCFICH is not used in NR. Instead, the number of symbols for CORESET may be defined by the RRC message (and/or PBCH/SIB 1). In addition, in LTE/LTE-a, since the frequency bandwidth of the PDCCH is the same as the entire system bandwidth, there is no signaling regarding the frequency bandwidth of the PDCCH. In NR, the frequency domain of CORESET may be defined by RRC messages (and/or PBCH/SIB1) in units of RBs.

The base station may send information about CORESET to the UE. For example, information about the CORESET configuration may be sent for each CORESET. Via the information on the CORESET configuration, at least one of a duration (e.g., 1/2/3 symbols), a frequency domain resource (e.g., an RB set), a REG-to-CCE mapping type (e.g., whether interleaving is applied), a precoding granularity, a REG bundling size (when the REG-to-CCE mapping type is interleaving), an interleaver size (when the REG-to-CCE mapping type is interleaving), and a DMRS configuration (e.g., a scrambling ID) of the corresponding CORESET may be transmitted. Bundling of two or six REGs may be performed when interleaving is applied to allocate CCEs to a 1 symbol CORESET. Bundling of two or six REGs may be performed for a two symbol CORESET, and time-first mapping may be applied. Bundling of three or six REGs may be performed for a three symbol CORESET, and time-first mapping may be applied. When performing REG bundling, the UE may assume the same precoding for the corresponding bundling units.

In NR, a search space for PDCCH is divided into CSS and USS. The search space may be configured in CORESET. As an example, one search space may be defined in one CORESET. In this case, CORESET for CSS and CORESET for USS may be configured separately. As another example, multiple search spaces may be defined in one CORESET. That is, the CSS and the USS may be configured in the same CORESET. In the following examples, CSS means CORESET configuring CSS, USS means CORESET configuring USS. Since the USS may be indicated by an RRC message, the UE may require an RRC connection to decode the USS. The USS may include control information assigned to PDSCH decoding of the UE.

Since it is necessary to decode the PDCCH even when RRC configuration is not completed, CSS should be defined. For example, CSS may be defined when a PDCCH for decoding a PDSCH conveying SIB1 is configured or when a PDCCH for receiving MSG2/4 is configured in a random access procedure. Similar to LTE/LTE-a, in NR, the PDCCH may be scrambled by a Radio Network Temporary Identifier (RNTI) for a specific purpose.

Resource allocation in NR is described.

In NR, a certain number (e.g., up to 4) of bandwidth parts (BWPs) may be defined. BWP (or carrier BWP) is a set of contiguous PRBs and may be represented by contiguous subsets of common rbs (crbs). Individual RBs in the CRB may be represented by CRB1, CRB2, etc. from CRB 0.

Fig. 8 shows an example of a frequency allocation scheme to which the technical features of the present invention can be applied.

Referring to fig. 8, a plurality of BWPs may be defined in a CRB trellis. The reference point of the CRB grid (which may be referred to as a common reference point, a start point, etc.) is referred to as so-called "point a" in the NR. Point a is indicated by RMSI (i.e., SIB 1). Specifically, the frequency offset between the frequency band transmitting the SS/PBCH block and point a may be indicated by RMSI. Point a corresponds to the center frequency of CRB 0. Further, in NR, a point a may be a point at which a variable "k" indicating the frequency band of RE is set to zero. A plurality of BWPs shown in fig. 8 are configured as one cell (e.g., primary cell (PCell)). The plurality of BWPs may be individually or collectively configured for each cell.

Referring to fig. 8, each BWP may be defined by a size and a starting point from CRB 0. For example, a first BWP (i.e., BWP #0) may be defined by a starting point by an offset from CRB0, and the size of BWP #0 may be determined by the size of BWP # 0.

A specific number (e.g., up to four) of BWPs may be configured for the UE. Even if multiple BWPs are configured, only a certain number (e.g., one) of BWPs may be enabled per cell for a given period of time. However, when the UE is configured with a Supplemental Uplink (SUL) carrier, up to four BWPs may be additionally configured on the SUL carrier and one BWP may be enabled for a given time. The number of configurable BWPs and/or the number of enabled BWPs may be configured jointly or separately for UL and DL. In addition, the parameter set and/or CP for DL BWP and/or the parameter set and/or CP for UL BWP may be configured to the UE via DL signaling. The UE may receive PDSCH, PDCCH, Channel State Information (CSI) RS and/or tracking RS (trs) on active DL BWP only. In addition, the UE may send PUSCH and/or Physical Uplink Control Channel (PUCCH) only on active UL BWP.

Fig. 9 illustrates an example of a plurality of BWPs to which technical features of the present invention can be applied.

Referring to fig. 9, 3 BWPs may be configured. The first BWP may span a 40MHz frequency band and may apply a subcarrier spacing of 15 kHz. The second BWP may span the 10MHz band and may apply a subcarrier spacing of 15 kHz. The third BWP may span the 20MHz band and may apply a subcarrier spacing of 60 kHz. The UE may configure at least one BWP among the 3 BWPs as an active BWP, and may perform UL and/or DL data communication via the active BWP.

The time resource may be indicated in a manner of indicating a time difference/offset based on a transmission time point of a PDCCH allocating a DL or UL resource. For example, the starting point of the PDSCH/PUSCH corresponding to the PDCCH and the number of symbols occupied by the PDSCH/PUSCH may be indicated.

Carrier Aggregation (CA) is described. Similar to LTE/LTE-A, CA may be supported in the NR. That is, contiguous or non-contiguous Component Carriers (CCs) may be aggregated to increase bandwidth, and thus, bit rate. Each CC may correspond to a (serving) cell, and each CC/cell may be divided into a Primary Serving Cell (PSC)/primary CC (pcc) or a Secondary Serving Cell (SSC)/secondary CC (scc).

Table 5 shows the spectrum utilization in the frequency band below 6 GHz. The frequency band below 6GHz may be referred to as frequency range 1(FR 1). Table 5 shows the number of RBs according to the bandwidth supported by FR 1.

[ Table 5]

Table 6 shows the spectrum utilization efficiency in a frequency band lower than millimeter wave (mmWave). The frequency band below mmWave may be referred to as frequency range 2(FR 2). Table 6 shows the number of RBs according to the bandwidth supported by FR 2.

[ Table 6]

PRB utilization is the set of PRBs that fall within the UE or BS channel bandwidth and do not violate minimum protection.

Table 7 shows the minimum guard size (kHz) of FR 1. Table 7 shows the minimum guard size according to the bandwidth supported by FR 1. Protection is set from the last PRB to the channel bandwidth edge on each side of the carrier.

[ Table 7]

Table 8 shows the minimum guard size (kHz) of FR 2. Table 8 shows the minimum guard size according to the bandwidth supported by FR 2.

[ Table 8]

The actual spectrum utilization depends on the RB alignment in the channel and may result in 1RB less than the number in tables 5 and 6.

In order to efficiently support different parameter sets, in NR, it is assumed that subcarriers 0 of the respective parameter sets are aligned. It is also desirable to align the PRB grids of different sets of parameters while maximizing spectral efficiency (and thus satisfying the required minimum guard band) and balancing the guard bands symmetrically.

Fig. 10 shows an example of aligning PRB grids of different parameter sets. Referring to fig. 10, different examples of 25RB alignment of a first set of parameters corresponding to a 15kHz subcarrier spacing and 11RB alignment of a second set of parameters corresponding to a 30kHz subcarrier spacing are shown. The PRB grid for a subcarrier spacing of 30kHz may be shifted to align 25 RBs for a subcarrier spacing of 15kHz with 11 RBs for a subcarrier spacing of 30 kHz. In this regard, it may be discussed whether all PRB grid shifts for all subcarrier spacings above the reference subcarrier spacing are supported and whether there are further constraints on PRB alignment for different subcarrier spacings.

When considering different PRB grids between different parameter sets, the fundamental frequency may be considered in terms of baseband signal generation. The fundamental frequency may be a half-point of the carrier bandwidth per a given set of parameters or the lowest subcarrier of the individual carriers per a given set of parameters. Alternatively, the base frequency may also be the half-point of the active BWP for a UE per a given set of parameters or the lowest subcarrier of the active BWP for a UE per a given set of parameters. The FFT may assume zero or a center frequency for the fundamental frequency.

In NR, due to various scenarios such as BWP operation, broadband operation, multiple parameter sets, etc., signal generation/reception may be based on center frequencies of the respective devices, rather than aligned center frequencies (e.g., center frequencies of carriers as in LTE). However, in order to compensate for the phase, a common reference between the network and the UE may still be required. The common reference may be absolute frequency 0 or a starting frequency of the respective frequency region or a set of fixed values per frequency range (e.g. for FR1, 0, for FR2, 24000MHz) or a starting frequency of the respective frequency band.

In other words, the signal may be generated by pre-compensating for an offset between a center frequency of the transmitter and a reference frequency based on the common reference. For convenience of the following description, the center frequency of the transmitter may be referred to as "F0" and the basic frequency of baseband signal generation may be referred to as "d 0".

Considering multiple parameter sets, depending on the scenario, the PRB grid (i.e., guard band) may not be fixed relative to the location of the SS/PBCH block for each parameter set. For example, referring to FIG. 10 shown above, if a 15kHz subcarrier spacing PRB grid has a larger guard band on the left, it may be desirable to use (2) for a 30kHz subcarrier spacing PRB grid to balance the symmetric guard band. On the other hand, if a 15kHz subcarrier spacing PRB grid has a larger guard band on the right side, it is advisable to use (3) for a 30kHz subcarrier spacing PRB grid. In other words, the optimal PRB trellis mapping may be different according to the frequency band in order to balance the guard bands of the respective parameter sets. Depending on the situation, the offset between point a (the point where subcarriers 0 of all parameter sets are aligned) and the lowest subcarrier (or the center subcarrier) of the individual carriers of a given parameter set may be different.

According to an embodiment of the present invention, in signal generation for a plurality of parameter sets, the following two methods may be considered.

(1) The method comprises the following steps: f0 for each parameter set may be aligned. Alternatively, d0 for each parameter set may be aligned. For example, F0 or d0 of the respective parameter sets may be aligned with each other by using the center frequency of the minimum or maximum subcarrier spacing supported by the network or the frequency band as a common reference.

(2) The method 2 comprises the following steps: f0 or d0 of each parameter set may be determined based on the PRB grid of each parameter set. Thus, F0 or d0 for each parameter set may differ between different parameter sets. The F0 or d0 of the respective parameter sets may not be aligned with each other.

Fig. 11 illustrates an example of a method of generating a signal for a plurality of parameter sets according to an embodiment of the present invention. In that

In fig. 11, it is assumed that the subcarrier spacing supported by the network or bandwidth is 15kHz, 30kHz, 60kHz, and the maximum subcarrier spacing supported by the network or bandwidth is 60 kHz. The SS/PBCH block may be transmitted using a subcarrier spacing of 15 KHz. A PRB grid may be generated for each parameter set, and at point a, subcarrier 0 is aligned in the PRB grid for all parameter sets. Referring to fig. 11, the center frequency (F0) of the PRB network of each parameter set and/or the reference frequency (d0) of the baseband signal generation of each parameter set may be aligned based on the common reference of the signal generation of each new parameter set. Referring to fig. 11, a center frequency of a subcarrier spacing of 60kHz, which is a maximum subcarrier spacing supported by a network or a bandwidth, may be used as a common reference. That is, in a PBB grid of sub-carrier spacing less than 60kHz (i.e., 30kHz or 15kHz sub-carrier spacing), the center frequency may be shifted/aligned based on the center frequency of the sub-carrier spacing of 60 kHz. From the center frequency d0 of each parameter set, a reference frequency for baseband signal generation may be determined (d 0). Alternatively, in a PBB grid of sub-carrier spacing less than 60kHz (i.e., 30kHz or 15kHz sub-carrier spacing), the reference frequency (d0) of baseband signal generation may be shifted/aligned based on the center frequency of the sub-carrier spacing of 60 kHz.

Fig. 12 shows an example of a method of generating a signal for a plurality of parameter sets according to another embodiment of the present invention. In fig. 12, it is assumed that the subcarrier spacing supported by the network or bandwidth is 15kHz, 30kHz, 60kHz, and the maximum subcarrier spacing supported by the network or bandwidth is 60 kHz. The SS/PBCH block may be transmitted using a subcarrier spacing of 15 KHz. A PRB grid may be generated for each parameter set, and at point a, subcarrier 0 is aligned in the PRB grid for all parameter sets. Referring to fig. 12, the center frequencies (F0) of the PRB networks of the respective parameter sets and/or the reference frequencies (d0) of the baseband signal generation of the respective parameter sets are not aligned with each other. In other words, F0 or d0 of each parameter set may be determined based on the PRB grid of each parameter set. Unlike fig. 11, in a PBB grid of sub-carrier spacing less than 60kHz (i.e., 30kHz or 15kHz sub-carrier spacing), the center frequency and/or reference frequency of baseband signal generation is not shifted/aligned based on the center frequency of the sub-carrier spacing of 60 kHz.

Method 1 has the benefit of center frequency alignment between different parameter sets. That is, baseband signal generation may be performed based on the aligned center frequencies. The method can be effectively used for Frequency Division Multiplexing (FDM) between different parameter sets and for fast Time Division Multiplexing (TDM) between different parameter sets. However, method 1 requires determining a common reference frequency between different parameter sets and potentially may require compensating for different center frequencies of the respective parameter sets.

In the current NR specification, point a (where the subcarriers 0 of the respective parameter set PRB grid are aligned) is indicated to the UE, as well as the offset between point a and the lowest subcarrier of the carriers of a given parameter set and the number of RBs of the carrier. In order to determine the common reference frequency, a specific rule may be required. For example, the common reference frequency may be the center frequency of the PRB grid for the maximum or minimum subcarrier spacing supported by the network in the same frequency band. Alternatively, the common reference frequency may be the center frequency of a PRB grid of fixed subcarrier spacing (e.g., 15kHz for FR1, 60kHz for FR 2). If the center frequency of the PRB grid of the largest or smallest subcarrier spacing is used as the common reference frequency, the difference between the calculated center frequency and the common reference frequency for each parameter set may need to be signaled or calculated. The center frequency of each parameter set may be calculated based on the lowest subcarrier of the parameter set and the number of RBs of the carrier. In other words, the center of the PRB grid for a carrier may be the calculated center frequency derived from the offset between point a and the lowest subcarrier of the carrier and the number of RBs of the carrier.

If the supported parameter sets for all carriers are not signaled, the difference between the center frequency of the individual parameter sets and the common reference frequency may need to be signaled. Different signaling may be required depending on which is used as a reference. For example, if the center frequency of the PRB pattern of the minimum subcarrier spacing is used as the common reference frequency, if the maximum subcarrier spacing is 4 × the minimum subcarrier spacing, the difference of the respective parameter sets may be { -6, -3,0,3,6 }. If the center frequency of the PRB mesh of the largest subcarrier spacing is used as the common reference frequency, the difference of the parameter sets may be-12, -6,0,6,12 if the largest subcarrier spacing is 4 x the smallest subcarrier spacing. If the maximum subcarrier spacing is greater than 4 x the minimum subcarrier spacing, then method 1 may require a different value such as-1.5, which may be undesirable. In this case, it may be necessary to use method 2. The same set of values may be required if the lowest subcarrier of the carriers is used as d 0.

When using method 1, the signal generation and up-conversion may have the following options.

(1) Option 1: the "d 0" for signal generation of the parameter set may be compensated/determined based on the common reference frequency. To allow for the same upconversion frequency, the signal generation of the various parameter sets may determine d0 based on a common reference frequency, i.e., an aligned center frequency (F0). This option may be understood as mapping resources based on a common reference frequency as the supported parameter set, rather than based on a virtual center of the calculation of the PRB grid for the respective parameter set. From the perspective of resource mapping, the subcarrier index of d0 may be different according to whether an offset is applied. To use this option, transmission of the SS/PBCH block and/or the RMSI should not take this offset into account, or should assume an offset value of zero, when no PRB grid information for the respective parameter set is given before RMSI reception. However, this may lead to confusion for RMSI transmission after the UE has received explicit signaling of carrier information and/or parameter set specific offset values. Thus, it may be assumed that the parameter set specific offset does not apply to all transmissions in the initial DL BWP and/or to SS/PBCH block/RMSI transmissions prior to RMSI reception in the initial DL BWP and/or RMSI-only transmissions (e.g., RMSI update, initial access).

Alternatively, the PRB grid for the parameter set of the RMSI may be used as a reference. In case RMSI is also monitored in UE-specific BWP, the parameter set used for RMSI may be the parameter set used in the initial DL BWP. Thus, there is no ambiguity in reading the RMSI, and the SS/PBCH block can be sent without any consideration of multiple parameter sets. The offset may be determined assuming that the center of the calculation of the PRB grid for the set of parameters of the RMSI is the common reference frequency. In this case, the offset value may be { -12, -9, -6, -3,0,3,6,9,12} if the maximum subcarrier spacing is not greater than the minimum subcarrier spacing supported by the 4 x network or band.

Similar problems may occur with other options as will be described below, which may be mitigated using similar schemes.

(2) Option 2: the signal generation for a parameter set "d 0" may be based on its own parameter set only, without considering any compensation/offset for alignment between different parameter sets. For each parameter set, different upconversion frequencies may be used, such that a common reference frequency (different upconversion frequencies) is usedI.e. different f_base+f_gap ^u) For each parameter set. For example, if the center frequency is 2GHz, then 2GHz + is shifted by the subcarrier spacing [ kHz ] based on the difference between the calculated center frequency and the common reference frequency]May be used for up-conversion of a given set of parameters. This option may also require handling different methods between the RMSI and other channels, as discussed for option 1. That is, the common reference frequency may be determined based on a set of parameters for the RMSI. In other words, this option assumes f in the up-conversion_TXThe center frequencies (calculated for the respective parameter sets) are the same across multiple parameter sets (and determined based on the reference parameter sets), and when f0 is determined on the receiver side, f0 for the respective parameter sets is calculated as f0_base+Δ^u(parameter set specific offset) where f0_baseMay be common to all parameter sets and determined based on a reference parameter set. May perform f per OFDM symbol_TX-f_RXPhase compensation between them.

(3) Option 3: the "d 0" used for signal generation may be based on its own parameter set only and the up-conversion frequency for each parameter set may also be fixed. The gaps between the calculated center frequencies of the respective parameter sets and the common reference frequency and the digital rotator may be used to compensate for this value. In other words, Δ^uThe (parameter set specific offset) can be applied separately from the resource mapping and up-conversion. In other words, f can be targeted at the transmitting side_TX(center frequencies calculated for respective parameter sets) — f_base+Δ^uThe phase compensation of the respective parameter sets is done (parameter set specific offset). Similar operations on the receiver side may also be performed.

(4) Option 4: the "d 0" used for signal generation may be based on its own parameter set only and the up-conversion frequency for each parameter set may also be fixed. From the receiver's perspective, the center frequencies of the various parameter sets may potentially be different (i.e., similar to option 2), and the transmitter may compensate for the difference between the center frequencies of the various parameter sets and the actual center frequencies for the parameter sets. At the receiver side, the calculated center frequencies of the respective parameter sets may be used for up-conversion/phase compensation.

The receiver may consider similar options and option 3 may use digital de-rotation instead of rotation.

To achieve the different options described above, the following may be considered.

In the baseband signal generation, different offset values may be applied for each parameter set. The offset value may be determined per each respective parameter set based on information or explicit signaling of the carrier (including its own) of the parameter set indicated as described above. To avoid ambiguity in the RMSI reception, the parameter set used in the initial DL BWP may be used as a reference.

In the baseband signal generation, no offset value may be applied. The upconversion frequency f0 may be determined per set of parameters^u(i.e., f)_base+f_gap ^u). F0 for each parameter set^uThe value may be determined based on information or explicit signaling of the carrier (including its own) of the parameter set indicated as described above. To avoid ambiguity in the RMSI reception, the parameter set used in the initial DL BWP may be used as a reference.

In baseband signal generation/up-conversion, no offset value may be applied and the common reference frequency may be used for up-conversion. However, the UE may need to shift the offset determined based on information or explicit signaling of the carrier (including its own) of the parameter set indicated as described above for a given parameter set. How the UE/gNB implements this shift may depend on the UE/gNB implementation. To avoid ambiguity in the RMSI reception, the parameter set used in the initial DL BWP may be used as a reference.

In baseband signal generation/up-conversion, no offset value may be applied and the common reference frequency may be used for up-conversion. The transmitter may compensate for any offset between the calculated center frequency of each parameter set and the center frequency of the parameter set used so that the receiver may use the calculated center frequency of each parameter set as a phase compensated transmitter frequency reference.

The gNB and the UE may employ different options among the above options. For example, the gNB may generate the baseband signal taking into account the parameter set specific offset, while the UE may not use any parameter set specific offset in signal generation. This difference can be compensated by an up-converter or digital derotator, as in options (2) or (3) above. In other words, parameter set features in the up-conversion may be introducedF0 (i.e., f0)^u) And f0 may or may not be the same between different parameter sets, depending on how the UE implementation compensates for the differences. How the UE computes the parameter set specific f0 may depend on the UE implementation.

Fig. 13 illustrates a method of generating a signal by a UE according to an embodiment of the present invention. The invention described above (specifically, method 1) can be applied to this embodiment.

In step S1300, the UE generates a signal for the parameter set based on the center frequency of the carrier. The center frequency of the carrier may be based on the maximum subcarrier spacing supported by the network. The center frequency of the carrier is shifted with respect to the center frequency of the PRB grid of the maximum subcarrier spacing supported by the network. The center frequencies of the different sets of parameters may be aligned with each other at the center frequency of the PRB grid for the largest subcarrier spacing supported by the network. The center frequency of the carrier may be determined based on the offset from point a and the number of resource blocks of the carrier. Further, the UE may receive information about an offset between a center frequency of the carrier and a center frequency of a PRB grid of a maximum subcarrier spacing supported by the network.

In step S1310, the UE transmits the generated signal.

According to an embodiment of the invention shown in fig. 13, signals for different parameter sets may be generated and aligned with each other. That is, based on the center frequency of the PRB grid for the maximum subcarrier spacing supported by the network, the center frequency or reference frequency of the baseband signal used to generate the PRB grid for the smaller subcarrier spacing may be shifted.

Fig. 14 shows a wireless communication system implementing an embodiment of the present invention.

The UE 1400 includes a processor 1410, a memory 1420, and a transceiver 1430. The processor 1410 may be configured to implement the proposed functions, procedures and/or methods described in this specification. Layers of radio interface protocols may be implemented in the processor 1410. In particular, the processor 1410 is configured to generate a signal for the parameter set based on a center frequency of the carrier. The center frequency of the carrier may be based on the maximum subcarrier spacing supported by the network. The center frequency of the carrier is shifted with respect to the center frequency of the PRB grid of the maximum subcarrier spacing supported by the network. The center frequencies of the different sets of parameters may be aligned with each other at the center frequency of the PRB grid for the largest subcarrier spacing supported by the network. The center frequency of the carrier may be determined based on the offset from point a and the number of resource blocks of the carrier. Further, the processor 1410 may be further configured to control the transceiver 1430 to receive information regarding an offset between a center frequency of the carrier and a center frequency of a PRB grid for a maximum subcarrier spacing supported by the network.

The processor 1410 is configured to control the transceiver 1430 to transmit the generated signal.

The memory 1420 is operatively coupled to the processor 1410 and stores various information for operating the processor 1410. The transceiver 1430 is operatively coupled to the processor 1410 and transmits and/or receives radio signals to and/or from the network node 1500.

Network node 1500 includes a processor 1510, a memory 1520, and a transceiver 1530. The processor 1510 may be configured to implement the proposed functions, procedures, and/or methods described in this specification. Layers of the radio interface protocol may be implemented in the processor 1510. The memory 1520 is operatively coupled to the processor 1510 and stores various information for operating the processor 1510. The transceiver 1530 is operatively coupled to the processor 1510 and transmits and/or receives radio signals to and/or from the UE 1400.

Processors 1410, 1510 may include Application Specific Integrated Circuits (ASICs), other chipsets, logic circuitry, and/or data processing devices. The memories 1420, 1520 may include read-only memory (ROM), random-access memory (RAM), flash memory, memory cards, storage media, and/or other storage devices. The transceivers 1430, 1530 may include baseband circuitry to process radio frequency signals. When an embodiment is implemented in software, the techniques described herein may be implemented with modules (e.g., procedures, functions, and so on) that perform the functions described herein. The modules may be stored in the memories 1420, 1520 and executed by the processors 1410, 1510. The memories 1420, 1520 may be implemented within the processors 1410, 1510 or external to the processors 1410, 1510, in which case those may be communicatively coupled to the processors 1410, 1510 via various means as is known in the art.

According to an embodiment of the invention shown in fig. 14, signals for different sets of parameters may be generated and aligned with each other. That is, based on the center frequency of the PRB grid for the maximum subcarrier spacing supported by the network, the center frequency or reference frequency of the baseband signal used to generate the PRB grid for the smaller subcarrier spacing may be shifted.

In view of the exemplary systems described herein, methodologies that may be implemented in accordance with the disclosed subject matter are described with reference to various flow diagrams. While, for purposes of simplicity of explanation, the methodologies are shown and described as a series of steps or blocks, it is to be understood and appreciated that the claimed subject matter is not limited by the order of steps or blocks, as some steps may occur in different orders or concurrently with other steps from that shown and described herein. Further, those of skill in the art will understand that the steps illustrated in the flowcharts are not exclusive and that other steps may be included or one or more steps in the example flowcharts may be deleted without affecting the scope of the present disclosure.