阅读说明：本技术 用于非理想回程的多个pdsch的部分/完全重叠和dmrs端口的关联速率匹配 (Partial/full overlap of multiple PDSCHs and associated rate matching of DMRS ports for non-ideal backhaul ) 是由 A·马诺拉科斯 S·侯赛尼 M·霍什内维桑 J·孙 张晓霞 于 2019-10-08 设计创作，主要内容包括：本公开内容的某些方面提供了用于在多TRP情形中对PDSCH传输进行速率匹配的技术。在某些情况下,如果第一TRP和第二TRP有很少协调或没有协调,则每个TRP可以注意避免在另一TRP的DMRS资源上进行发送。在某些情况下,可以为每个TRP分配端口群组的DMRS端口的不同子集。(Certain aspects of the present disclosure provide techniques for rate matching PDSCH transmissions in multiple TRP scenarios. In some cases, if the first TRP and the second TRP have little or no coordination, each TRP may take care to avoid transmitting on the DMRS resource of the other TRP. In some cases, each TRP may be allocated a different subset of the DMRS ports of a port group.)

1. A method of wireless communication by a first Transmit Receive Point (TRP), comprising:

obtaining information on a first configuration indicating resources available for at least a second TRP for transmitting a demodulation reference signal (DMRS) for a Physical Downlink Shared Channel (PDSCH);

determining, based on the first configuration, that the DMRS or data transmission from the second TRP potentially overlaps with the DMRS or data transmission from the first TRP; and

based on the determination, rate matching is performed around the potential DMRS transmission of the second TRP when the PDSCH is transmitted to a User Equipment (UE).

2. The method of claim 1, wherein:

performing the rate matching assuming that the second TRP transmits on a DMRS port allocated according to the first configuration; and

according to the rate matching, the UE transmits Downlink Control Information (DCI) scheduling the PDSCH.

3. The method of claim 1, wherein the information about the first configuration is obtained from at least one of the UE or the second TRP.

4. The method of claim 1, wherein the information comprises at least one of: one or more DMRS port indices, DMRS port group indices, or Code Division Multiplexing (CDM) group indices.

5. The method of claim 1, wherein the DMRS ports allocated to each TRP are from the same DMRS port group.

6. The method of claim 1, further comprising:

receiving signaling indicating whether the first TRP and the second TRP transmit DMRS or data on non-overlapping resources, on potentially partially overlapping resources, or on potentially fully overlapping resources; and

performing the rate matching based on the determination only if the signaling indicates that the first TRP and the second TRP transmit DMRS on potentially partially or fully overlapping resources, or based on its own DMRS transmission only if the signaling indicates that the first TRP and the second TRP transmit DMRS or data on non-overlapping resources.

7. The method of claim 1, further comprising, for a case where the first TRP and the second TRP transmit DMRS on potentially overlapping resources:

the DMRS is transmitted subject to one or more constraints.

8. The method of claim 7, wherein the one or more constraints comprise:

the first TRP and the second TRP transmit DMRS using a different sequence than the second TRP.

9. The method of claim 8, wherein the different sequences are generated by applying different scrambling sequences.

10. The method of claim 7, wherein the one or more constraints are based on a maximum number of orthogonal ports and non-orthogonal service ports that can be transmitted as reported by the UE.

11. A method of wireless communication by a User Equipment (UE), comprising:

obtaining information on a first configuration indicating at least resources available for a first Transmission Reception Point (TRP) to transmit a demodulation reference signal (DMRS) for a Physical Downlink Shared Channel (PDSCH);

obtaining information on a second configuration indicating resources available for at least a second TRP for transmitting a DMRS for the PDSCH;

determining, based on the first configuration, that the DMRS or data transmission from the second TRP potentially overlaps with the DMRS or data transmission from the first TRP; and

based on the determination, performing rate matching when processing PDSCH transmissions that potentially overlap with DMRS transmissions from the first TRP and the second TRP.

12. The method of claim 11, wherein the rate matching is performed assuming that the second TRP is transmitted on a DMRS port allocated according to the first configuration.

13. The method of claim 11, further comprising:

providing information about the first configuration to the second TRP; and

providing information about the second configuration to the first TRP.

14. The method of claim 11, wherein:

the information about the first configuration is obtained from the first TRP; and

the information about the second configuration is obtained from the second TRP.

15. The method of claim 11, wherein the information comprises at least one of: one or more DMRS port indices, DMRS port group indices, or Code Division Multiplexing (CDM) group indices.

16. The method of claim 11, further comprising:

receiving signaling indicating whether the first TRP and the second TRP transmit DMRS or data on non-overlapping resources, on potentially partially overlapping resources, or on potentially fully overlapping resources; and

performing the rate matching based on the determination only if the signaling indicates that the first TRP and the second TRP transmit DMRS on potentially partially or fully overlapping resources.

17. The method of claim 11, further comprising, for a case where the first TRP and the second TRP transmit DMRS on potentially overlapping resources:

the DMRS is transmitted subject to one or more constraints.

18. The method of claim 17, wherein the one or more constraints comprise:

the first TRP and the second TRP use different sequences for DMRS transmission.

19. The method of claim 18, wherein the first TRP and the second TRP use different scrambling IDs to generate different DMRS sequences.

20. The method of claim 17, wherein the one or more constraints are based on a maximum number of orthogonal ports and non-orthogonal service ports that can be transmitted as reported by the UE.

21. An apparatus for wireless communication by a first Transmit Receive Point (TRP), comprising:

means for obtaining information on a first configuration indicating resources available for at least a second TRP for transmitting a demodulation reference signal (DMRS) for a Physical Downlink Shared Channel (PDSCH);

means for determining, based on the first configuration, that a DMRS or data transmission from the second TRP potentially overlaps with a DMRS or data transmission from the first TRP; and

means for performing rate matching around the potential DMRS transmission of the second TRP when transmitting the PDSCH to a User Equipment (UE) based on the determination.

22. The apparatus of claim 21, wherein the information comprises at least one of: one or more DMRS port indices, DMRS port group indices, or Code Division Multiplexing (CDM) group indices.

23. The apparatus of claim 21, wherein the DMRS ports allocated to each TRP are from the same DMRS port group.

24. The apparatus of claim 21, for a case where the first TRP and the second TRP transmit DMRS on potentially overlapping resources, further comprising:

means for transmitting the DMRS subject to one or more constraints.

25. The apparatus of claim 24, wherein the one or more constraints comprise:

the first TRP and the second TRP transmit DMRS using a different sequence than the second TRP.

26. The apparatus of claim 25, wherein the different sequences are generated by applying different scrambling sequences.

27. An apparatus of wireless communication by a User Equipment (UE), comprising:

means for obtaining information on a first configuration indicating at least resources available to a first Transmission Reception Point (TRP) for transmitting a demodulation reference signal (DMRS) for a Physical Downlink Shared Channel (PDSCH);

means for obtaining information on a second configuration indicating resources available for at least a second TRP for transmitting a DMRS for the PDSCH;

means for determining, based on the first configuration, that a DMRS or data transmission from the second TRP potentially overlaps with a DMRS or data transmission from the first TRP; and

means for performing rate matching when processing a PDSCH transmission potentially overlapping with DMRS transmissions from the first TRP and the second TRP based on the determination.

28. The apparatus of claim 27, wherein the rate matching is performed assuming that the second TRP is transmitted on a DMRS port allocated in accordance with the first configuration.

29. The apparatus of claim 27, wherein the information comprises at least one of: one or more DMRS port indices, DMRS port group indices, or Code Division Multiplexing (CDM) group indices.

30. The apparatus of claim 27, wherein the first TRP and the second TRP utilize different sequences for DMRS transmissions.

Technical Field

Aspects of the present disclosure relate to wireless communications, and more particularly, to techniques for rate matching around potentially overlapping demodulation reference signal (DMRS) resources in scenarios with multiple Transmit Receive Points (TRPs).

Background

Wireless communication systems are widely deployed to provide various telecommunication services such as telephony, video, data, messaging, broadcasting, and so on. These wireless communication systems may employ multiple-access techniques capable of supporting communication with multiple users by sharing the available system resources (e.g., bandwidth, transmit power, etc.). Examples of such multiple-access systems include third generation partnership project (3GPP) Long Term Evolution (LTE) systems, LTE-advanced (LTE-a) systems, Code Division Multiple Access (CDMA) systems, Time Division Multiple Access (TDMA) systems, Frequency Division Multiple Access (FDMA) systems, Orthogonal Frequency Division Multiple Access (OFDMA) systems, single carrier frequency division multiple access (SC-FDMA) systems, and time division synchronous code division multiple access (TD-SCDMA) systems, to name just a few.

In some examples, a wireless multiple-access communication system may include multiple Base Stations (BSs), each capable of supporting communication for multiple communication devices (otherwise referred to as User Equipments (UEs)) simultaneously. In an LTE or LTE-a network, a set of one or more base stations may define an enodeb (enb). In other examples (e.g., in a next generation, New Radio (NR), or 5G network), a wireless multiple-access communication system may include a plurality of Distributed Units (DUs) (e.g., Edge Units (EUs), Edge Nodes (ENs), Radio Heads (RHs), intelligent radio heads (SRHs), Transmit Receive Points (TRPs), etc.) in communication with a number of Central Units (CUs) (e.g., Central Nodes (CNs), Access Node Controllers (ANCs), etc.), wherein one or more sets of distributed units in communication with a central unit may define an access node (e.g., may be referred to as a base station, 5G NB, next generation node B (gbb or gnnodeb), TRP, etc.). A base station or distributed unit may communicate with a set of UEs on downlink channels (e.g., for transmissions from the base station or to the UEs) and uplink channels (e.g., for transmissions from the UEs to the base station or distributed unit).

These multiple access techniques have been employed in various telecommunications standards to provide a common protocol that enables different wireless devices to communicate at the urban, national, regional, and even global levels. New Radios (NR) (e.g., 5G) are one example of an emerging telecommunications standard. NR is a set of enhancements to the LTE mobile standard promulgated by 3 GPP. It is designed to better support mobile broadband internet access by improving spectral efficiency, reducing costs, improving services, utilizing new spectrum, and better integrating with other open standards using OFDMA and Cyclic Prefix (CP) on the Downlink (DL) and Uplink (UL). For this reason, NR supports beamforming, Multiple Input Multiple Output (MIMO) antenna technology, and carrier aggregation.

However, as the demand for mobile broadband access continues to increase, there is a need for further improvements in NR and LTE technologies. Preferably, these improvements should be applicable to other multiple access technologies and telecommunication standards that employ these technologies.

Disclosure of Invention

The systems, methods, and devices of the present disclosure each have several aspects, no single one of which is solely responsible for its desirable attributes. Without limiting the scope of the present disclosure as expressed by the claims that follow, some features will now be discussed briefly. After considering this discussion, and particularly after reading the section entitled "detailed description" one will understand how the features of this disclosure provide advantages that include improved communications between access points and stations in a wireless network.

Certain aspects provide a method for wireless communications by a User Equipment (UE). The method generally includes: obtaining information on a first configuration indicating resources available at least for a first Transmission Reception Point (TRP) for transmitting a demodulation reference signal (DMRS) for a Physical Downlink Shared Channel (PDSCH), obtaining information on a second configuration indicating resources available at least for a second TRP for transmitting a DMRS for a PDSCH, and, based on the first configuration, determining that a DMRS or data transmission from the second TRP potentially overlaps with a DMRS or data transmission from the first TRP, and, based on the determination, performing rate matching when processing PDSCH transmissions that potentially overlap with DMRS transmissions from the first TRP and the second TRP.

Certain aspects provide a method for wireless communication by a network entity (e.g., a first TRP). The method generally includes: obtaining information on a first configuration indicating resources available at least for a second TRP for transmitting a demodulation reference signal (DMRS) for a Physical Downlink Shared Channel (PDSCH), determining, based on the first configuration, that a DMRS or data transmission from the second TRP potentially overlaps with a DMRS or data transmission from the first TRP, and performing, based on the determination, rate matching around the potential DMRS transmission of the second TRP when transmitting the PDSCH to a User Equipment (UE).

Certain aspects of the present disclosure also provide various apparatuses, units, and computer-readable media capable of performing the above-described operations (or having instructions stored thereon for performing the above-described operations).

To the accomplishment of the foregoing and related ends, the one or more aspects comprise the features hereinafter fully described and particularly pointed out in the claims. The following description and the annexed drawings set forth in detail certain illustrative features of the one or more aspects. These features are indicative, however, of but a few of the various ways in which the principles of various aspects may be employed.

Brief description of the drawings

So that the manner in which the above recited features of the present disclosure can be understood in detail, a more particular description, briefly summarized above, may be had by reference to various aspects, some of which are illustrated in the appended drawings. It is to be noted, however, that the appended drawings illustrate only certain typical aspects of this disclosure and are therefore not to be considered limiting of its scope, for the description may admit to other equally effective aspects.

Fig. 1 is a block diagram conceptually illustrating an exemplary telecommunications system in accordance with certain aspects of the present disclosure.

Fig. 2 is a block diagram illustrating an example logical architecture of a distributed Radio Access Network (RAN) in accordance with certain aspects of the present disclosure.

Fig. 3 is a diagram illustrating an example physical architecture of a distributed RAN in accordance with certain aspects of the present disclosure.

Fig. 4 is a block diagram conceptually illustrating a design of an example Base Station (BS) and User Equipment (UE), in accordance with certain aspects of the present disclosure.

Fig. 5 is a diagram illustrating an example of a communication protocol stack for implementing certain aspects of the present disclosure.

Fig. 6 illustrates an example of a frame format for a New Radio (NR) system in accordance with certain aspects of the present disclosure.

Fig. 7 is a block diagram illustrating an example encoding chain in accordance with certain aspects of the present disclosure.

Fig. 8 is a diagram illustrating an exemplary multiple Transmit Receive Point (TRP) transmission scenario, in accordance with certain aspects of the present disclosure.

Fig. 9 illustrates an example of demodulation reference signal (DMRS) configuration.

Fig. 10 is a block diagram illustrating an example of Transmission Reception Points (TRPs) having overlapped Physical Downlink Shared Channel (PDSCH) resources.

Fig. 11 illustrates exemplary operations that may be performed by a User Equipment (UE) in accordance with aspects of the present disclosure.

Fig. 12 illustrates exemplary operations that may be performed by a network entity in accordance with aspects of the present disclosure.

Fig. 13 illustrates an example of a demodulation reference signal (DMRS) configuration in accordance with an aspect of the present disclosure.

To facilitate understanding, identical reference numerals have been used, where possible, to designate identical elements that are common to the figures. It is contemplated that elements disclosed in one aspect may be beneficially utilized on other aspects without specific recitation.

Detailed Description

Aspects of the present disclosure provide apparatuses, methods, processing systems, and computer-readable media for rate matching DMRS transmissions in multiple transmit receive point (multi-TRP) scenarios.

The following description provides examples, and does not limit the scope, applicability, or examples set forth in the claims. Changes may be made in the function and arrangement of elements discussed without departing from the scope of the disclosure. Various examples may omit, substitute, or add various procedures or components as appropriate. For example, the described methods may be performed in an order different than that described, and various steps may be added, omitted, or combined. Moreover, features described with respect to some examples may be combined in some other examples. For example, an apparatus may be implemented or a method may be practiced using any number of the aspects set forth herein. In addition, the scope of the present disclosure is intended to cover such an apparatus or method as implemented in other structure, functionality, or structure and function in addition to or in place of the various aspects of the present disclosure set forth herein. It should be understood that any aspect of the disclosure disclosed herein may be embodied by one or more elements of a claim. The word "exemplary" is used herein to mean "serving as an example, instance, or illustration. Any aspect described herein as "exemplary" is not necessarily to be construed as preferred or advantageous over other aspects.

The techniques described herein may be used for various wireless communication technologies such as LTE, CDMA, TDMA, FDMA, OFDMA, SC-FDMA and other networks. The terms "network" and "system" are generally used interchangeably. A CDMA network may implement radio technologies such as Universal Terrestrial Radio Access (UTRA), CDMA2000, and so on. UTRA includes wideband CDMA (wcdma) and other variants of CDMA. cdma2000 covers the IS-2000 standard, the IS-95 standard and the IS-856 standard. TDMA networks may implement radio technologies such as global system for mobile communications (GSM). An OFDMA network may implement radio technologies such as NR (e.g., 5G RA), evolved UTRA (E-UTRA), Ultra Mobile Broadband (UMB), IEEE 802.11(Wi-Fi), IEEE 802.16(WiMAX), IEEE 802.20, Flash-OFDMA, and the like. UTRA and E-UTRA are part of the Universal Mobile Telecommunications System (UMTS).

New Radios (NR) are emerging wireless communication technologies developed in conjunction with the 5G technology forum (5 GTF). 3GPP Long Term Evolution (LTE) and LTE-advanced (LTE-A) are versions of UMTS that use E-UTRA. UTRA, E-UTRA, UMTS, LTE-A, and GSM are described in documents from an organization named "third Generation partnership project" (3 GPP). cdma2000 and UMB are described in documents from an organization named "third generation partnership project 2" (3GPP 2). The techniques described herein may be used for the wireless networks and radio technologies described above, as well as other wireless networks and radio technologies. For clarity, although aspects may be described herein using terminology commonly associated with 3G and/or 4G wireless technologies, aspects of the disclosure may be applied in other generation-based communication systems, e.g., 5G and beyond, including NR technologies.

New Radio (NR) access (e.g., 5G technology) may support various wireless communication services, such as enhanced mobile broadband (eMBB) for broadband (e.g., 80MHz or higher), millimeter wave (mmW) for high carrier frequencies (e.g., 25GHz or higher), massive Machine Type Communication (MTC) for non-backward compatible MTC technologies, and/or critical tasks for ultra-reliable low latency communication (URLLC). These services may include latency and reliability requirements. These services may also have different Transmission Time Intervals (TTIs) to meet corresponding quality of service (QoS) requirements. In addition, these services may coexist in the same subframe.

Exemplary Wireless communication System

Fig. 1 illustrates an example wireless communication network 100 in which aspects of the disclosure may be performed. For example, the wireless communication network 100 may be a New Radio (NR) or 5G network.

As shown in fig. 1, wireless network 100 may include a plurality of Base Stations (BSs) 110 and other network entities. A BS may be a station that communicates with a User Equipment (UE). Each BS 110 may provide communication coverage for a particular geographic area. In 3GPP, the term "cell" can refer to a coverage area of a node B (nb) and/or a node B subsystem serving the coverage area, depending on the context in which the term is used. In NR systems, the terms "cell" and next generation node b (gnb), new radio base station (NR BS), 5G NB, Access Point (AP) or Transmission Reception Point (TRP) may be interchangeable. In some examples, the cell may not necessarily be stationary, and the geographic area of the cell may move according to the location of the mobile BS. In some examples, the base stations may be interconnected to each other and/or to one or more other base stations or network nodes (not shown in the figures) in the wireless communication network 100 through various types of backhaul interfaces, such as direct physical connections, wireless connections, virtual networks, etc., using any suitable transport network.

In general, any number of wireless networks may be deployed in a given geographic area. Each wireless network may support a particular Radio Access Technology (RAT) and may operate on one or more frequencies. A RAT may also be referred to as a radio technology, air interface, etc. Frequencies may also be referred to as carriers, subcarriers, frequency channels, tones, subbands, and the like. Each frequency may support a single RAT in a given geographic area in order to avoid interference between wireless networks of different RATs. In some cases, NR or 5G RAT networks may be deployed.

A Base Station (BS) may provide communication coverage for a macrocell, picocell, femtocell, and/or other types of cell. A macro cell may cover a relatively large geographic area (e.g., several kilometers in radius) and may allow unrestricted access by UEs with service subscriptions. A pico cell may cover a relatively small geographic area and may allow unrestricted access by UEs with service subscriptions. A femto cell may cover a relatively small geographic area (e.g., a home) and may allow restricted access by UEs having an association with the femto cell (e.g., UEs in a Closed Subscriber Group (CSG), UEs for users in the home), and so forth. The BS for the macro cell may be referred to as a macro BS. The BS for the pico cell may be referred to as a pico BS. The BS for the femto cell may be referred to as a femto BS or a home BS. In the example shown in fig. 1, BS 110a, BS 110b, and BS 110c may be macro BSs corresponding to macro cell 102a, macro cell 102b, and macro cell 102c, respectively. BS 110x may be a pico BS corresponding to pico cell 102 x. BSs 110y and 110z may be femto BSs corresponding to the femtocells 102y and 102z, respectively. A BS may support one or more (e.g., three) cells.

The wireless communication network 100 may also include relay stations. A relay station is a station that receives a transmission of data and/or other information from an upstream station (e.g., a BS or a UE) and sends the transmission of data and/or other information to a downstream station (e.g., a UE or a BS). The relay station may also be a UE that relays transmissions of other UEs. In the example shown in fig. 1, relay station 110r may communicate with BS 110a and UE 120r to facilitate communication between BS 110a and UE 120 r. A relay station may also be referred to as a relay BS, relay, etc.

The wireless communication network 100 may be a heterogeneous network including different types of BSs, e.g., macro BSs, pico BSs, femto BSs, relays, and the like. These different types of BSs may have different transmit power levels, different coverage areas, and different effects on interference in the wireless network 100. For example, a macro BS may have a high transmit power level (e.g., 20 watts), while a pico BS, a femto BS, and a relay may have a lower transmit power level (e.g., 1 watt).

The wireless communication network 100 may support synchronous or asynchronous operation. For synchronous operation, BSs may have similar frame timing, and transmissions from different BSs may be approximately aligned in time. For asynchronous operation, BSs may have different frame timings, and transmissions from different BSs may not be aligned in time. The techniques described herein may be used for both synchronous and asynchronous operations.

Network controller 130 may be coupled to a set of BSs and provide coordination and control for these BSs. Network controller 130 may communicate with BS 110 via a backhaul. BSs 110 may also communicate with each other (e.g., directly or indirectly) over a wireless or wired backhaul.

UEs 120 (e.g., 120x, 120y, etc.) may be dispersed throughout wireless network 100, and each UE may be stationary or mobile. A UE may also be referred to as a mobile station, a terminal, an access terminal, a subscriber unit, a station, a client device (CPE), a cellular telephone, a smartphone, a Personal Digital Assistant (PDA), a wireless modem, a wireless communication device, a handheld device, a laptop, a cordless telephone, a Wireless Local Loop (WLL) station, a tablet computer, a camera, a gaming device, a netbook, a smartbook, a ultrabook, an appliance, a medical device or medical equipment, a biometric sensor/device, a wearable device such as a smartwatch, a smart garment, smart glasses, a smart bracelet, a smart jewelry (e.g., a smart ring, a smart bracelet, etc.), an entertainment device (e.g., a music device, a video device, a satellite radio, etc.), a vehicle component or sensor, a smart meter/sensor, an industrial manufacturing equipment, a global positioning system device, a Wireless Local Loop (WLL) station, a tablet computer, Or any other suitable device configured to communicate via a wireless or wired medium. Some UEs may be considered Machine Type Communication (MTC) devices or evolved MTC (emtc) devices. MTC and eMTC UEs include, for example, a robot, a drone, a remote device, a sensor, a meter, a monitor, a location tag, etc., which may communicate with a BS, another device (e.g., a remote device), or some other entity. The wireless nodes may provide connectivity to or from a network (e.g., a wide area network such as the internet or a cellular network) via wired or wireless communication links. Some UEs may be considered internet of things devices, which may be narrowband internet of things devices.

Some wireless networks (e.g., LTE) employ Orthogonal Frequency Division Multiplexing (OFDM) on the downlink and single carrier frequency division multiplexing (SC-FDM) on the uplink. OFDM and SC-FDM partition the system bandwidth into multiple (K) orthogonal subcarriers, which are also commonly referred to as tones, bins, and so on. Each subcarrier may be modulated with data. Typically, modulation symbols are transmitted in the frequency domain using OFDM and in the time domain using SC-FDM. The spacing between adjacent subcarriers may be fixed, and the total number of subcarriers (K) may depend on the system bandwidth. For example, the spacing of the subcarriers may be 15kHz, and the minimum resource allocation (referred to as a "resource block" (RB)) may be 12 subcarriers (or 180 kHz). Thus, for a system bandwidth of 1.25, 2.5, 5, 10, or 20 megahertz (MHz), the nominal Fast Fourier Transform (FFT) size may be equal to 128, 256, 512, 1024, or 2048, respectively. The system bandwidth may also be divided into subbands. For example, a sub-band may cover 1.08MHz (i.e., 6 resource blocks), and may have 1, 2, 4, 8, or 16 sub-bands for a system bandwidth of 1.25, 2.5, 5, 10, or 20MHz, respectively.

Although aspects of the examples described in this application may be associated with LTE technology, aspects of the disclosure may be applicable to other wireless communication systems, such as NRs. NR may utilize OFDM with CP on the uplink and downlink and include support for half-duplex operation using TDD. Beamforming may be supported and beam directions may be dynamically configured. MIMO transmission with precoding may also be supported. MIMO configuration in DL may support up to 8 transmit antennas with multi-layer DL transmission of up to 8 streams and up to 2 streams per UE. Multi-layer transmission with up to 2 streams per UE may be supported. Aggregation of multiple cells may be supported with up to 8 serving cells.

In some examples, access to the air interface may be scheduled, where a scheduling entity (e.g., a base station) allocates resources for communication between some or all of the devices and apparatuses within its service area or cell. The scheduling entity may be responsible for scheduling, allocating, reconfiguring, and releasing resources for one or more subordinate entities. That is, for scheduled communications, the subordinate entity employs the resources allocated by the scheduling entity. The base station is not the only entity that can act as a scheduling entity. In some examples, a UE may serve as a scheduling entity and may schedule resources for one or more subordinate entities (e.g., one or more other UEs), and the other UEs may utilize the resources scheduled by the UE for wireless communications. In some examples, the UE may serve as a scheduling entity in a point-to-point (P2P) network and/or in a mesh network. In the mesh network example, in addition to communicating with the scheduling entity, the UEs may also communicate directly with each other.

In fig. 1, a solid line with double arrows indicates desired transmissions between a UE and a serving BS, which is a BS designated to serve the UE on the downlink and/or uplink. The thin dashed line with double arrows represents interfering transmissions between the UE and the BS.

Fig. 2 illustrates an exemplary logical architecture of a distributed Radio Access Network (RAN)200, which may be implemented in the wireless communication network 100 shown in fig. 1. The 5G access node 206 may include an Access Node Controller (ANC) 202. ANC 202 may be a Central Unit (CU) of distributed RAN 200. The backhaul interface to the next generation core network (NG-CN)204 may terminate at ANC 202. The backhaul interface to the neighbor next generation access node (NG-AN)210 may terminate at ANC 202. ANC 202 may include one or more Transmit Receive Points (TRPs) 208 (e.g., cells, BSs, gnbs, etc.).

TRP 208 may be a Distributed Unit (DU). The TRP 208 may be connected to a single ANC (e.g., ANC 202) or more than one ANC (not shown). For example, for RAN sharing, radio as a service (RaaS), AND service-specific AND deployments, the TRP 208 may be connected to more than one ANC. TRPs 208 may each include one or more antenna ports. TRP 208 may be configured to provide services to UEs individually (e.g., dynamic selection) or jointly (e.g., joint transmission).

The logical architecture of the distributed RAN 200 may support a fronthaul (frontaul) solution across different deployment types. For example, the logical architecture may be based on transport network capabilities (e.g., bandwidth, latency, and/or jitter).

The logical architecture of the distributed RAN 200 may share features and/or components with LTE. For example, a next generation access node (NG-AN)210 may support dual connectivity with NRs and may share a common fronthaul for LTE and NRs.

The logical architecture of the distributed RAN 200 may enable cooperation between the TRPs 208, e.g., within the TRP and/or across the TRP via the ANC 202. The interface between TRPs may not be used.

The logical functions may be dynamically distributed in the logical architecture of the distributed RAN 200. As described in more detail with reference to fig. 5, a Radio Resource Control (RRC) layer, a Packet Data Convergence Protocol (PDCP) layer, a Radio Link Control (RLC) layer, a Medium Access Control (MAC) layer, and a Physical (PHY) layer may be appropriately disposed at a DU (e.g., TRP 208) or a CU (e.g., ANC 202).

Fig. 3 illustrates an example physical architecture of a distributed Radio Access Network (RAN)300 in accordance with aspects of the present disclosure. A central core network unit (C-CU)302 may host core network functions. C-CUs 302 may be centrally deployed. The C-CU 302 functions may be offloaded (e.g., to Advanced Wireless Services (AWS)) in an effort to handle peak capacity.

Central RAN unit (C-RU)304 may host one or more ANC functions. Alternatively, C-RU 304 may host the core network functions locally. C-RU 304 may have a distributed deployment. The C-RU 304 may be near the edge of the network.

DU 306 may host one or more TRPs (edge node (EN), Edge Unit (EU), Radio Head (RH), Smart Radio Head (SRH), etc.). The DU may be located at the edge of a Radio Frequency (RF) enabled network.

Fig. 4 illustrates exemplary components of BS 110 and UE 120 (as shown in fig. 1) that may be used to implement aspects of the present disclosure. For example, antennas 452, processors 466, 458, 464, and/or controller/processor 480 of UE 120, and/or antennas 434, processors 420, 430, 438, and/or controller/processor 440 of BS 110 may be used to perform various techniques and methods described herein.

At BS 110, a transmit processor 420 may receive data from a data source 412 and control information from a controller/processor 440. The control information may be for a Physical Broadcast Channel (PBCH), a Physical Control Format Indicator Channel (PCFICH), a physical hybrid ARQ indicator channel (PHICH), a Physical Downlink Control Channel (PDCCH), a group common PDCCH (gc PDCCH), etc. The data may be for a Physical Downlink Shared Channel (PDSCH), etc. Processor 420 may process (e.g., encode and symbol map) the data and control information to obtain data symbols and control symbols, respectively. Processor 420 may also generate reference symbols, e.g., for Primary Synchronization Signals (PSS), Secondary Synchronization Signals (SSS), and cell-specific reference signals (CRS). A Transmit (TX) multiple-input multiple-output (MIMO) processor 430 may perform spatial processing (e.g., precoding) on the data symbols, the control symbols, and/or the reference symbols, if applicable, and may provide output symbol streams to Modulators (MODs) 432a through 432 t. Each modulator 432 may process a respective output symbol stream (e.g., for OFDM, etc.) to obtain an output sample stream. Each modulator may further process (e.g., convert to analog, amplify, filter, and upconvert) the output sample stream to obtain a downlink signal. Downlink signals from modulators 432a through 432t may be transmitted via antennas 434a through 434t, respectively.

At UE 120, antennas 452a through 452r may receive the downlink signals from base station 110 and may provide received signals to demodulators (DEMODs) in transceivers 454a through 454r, respectively. Each demodulator 454 may condition (e.g., filter, amplify, downconvert, and digitize) a respective received signal to obtain input samples. Each demodulator may further process the input samples (e.g., for OFDM, etc.) to obtain received symbols. A MIMO detector 456 may obtain received symbols from all demodulators 454a through 454r (if applicable), perform MIMO detection on the received symbols, and provide detected symbols. A receive processor 458 may process (e.g., demodulate, deinterleave, and decode) the detected symbols, provide decoded data for the UE 120 to a data sink 460, and provide decoded control information to a controller/processor 480.

On the uplink, at UE 120, a transmit processor 464 may receive and process data from a data source 462 (e.g., for the Physical Uplink Shared Channel (PUSCH)) and control information from a controller/processor 480 (e.g., for the Physical Uplink Control Channel (PUCCH)). The transmit processor 464 may also generate reference symbols for a reference signal (e.g., for a Sounding Reference Signal (SRS)). The symbols from transmit processor 464 may be precoded by a TX MIMO processor 466 if applicable, further processed by demodulators in transceivers 454a through 454r (e.g., for SC-FDM, etc.), and transmitted to base station 110. At BS 110, the uplink signals from UE 120 may be received by antennas 434, processed by modulators 432, detected by a MIMO detector 436 (if applicable), and further processed by a receive processor 438 to obtain decoded data and control information transmitted by UE 120. Receive processor 438 may provide decoded data to a data sink 439 and decoded control information to controller/processor 440.

Controllers/processors 440 and 480 may direct the operation at base station 110 and UE 120, respectively. Processor 440 and/or other processors and modules at BS 110 may perform or direct the performance of the processes for the techniques described herein. Memories 442 and 482 may store data and program codes for BS 110 and UE 120, respectively. A scheduler 444 may schedule UEs for data transmission on the downlink and/or uplink.

Fig. 5 illustrates a diagram 500 of an example for implementing a communication protocol stack in accordance with an aspect of the present disclosure. The illustrated communication protocol stack may be implemented by a device operating in a wireless communication system (e.g., a system supporting uplink-based mobility), such as a 5G system. Diagram 500 shows a communication protocol stack that includes a Radio Resource Control (RRC) layer 510, a Packet Data Convergence Protocol (PDCP) layer 515, a Radio Link Control (RLC) layer 520, a Medium Access Control (MAC) layer 525, and a Physical (PHY) layer 530. In various examples, the layers of the protocol stack may be implemented as separate modules of software, portions of a processor or ASIC, portions of non-collocated devices connected by a communication link, or various combinations thereof. The collocated and non-collocated implementations may be used, for example, in a protocol stack of a network access device (e.g., AN, CU, and/or DU) or UE.

A first option 505-a illustrates a separate implementation of a protocol stack, wherein the implementation of the protocol stack is separated between a central network access device (e.g., ANC 202 in fig. 2) and a distributed network access device (e.g., DU 208 in fig. 2). In the first option 505-a, the RRC layer 510 and the PDCP layer 515 may be implemented by a central unit, while the RLC layer 520, the MAC layer 525 and the PHY layer 530 may be implemented by DUs. In various examples, a CU and a DU may be collocated or non-collocated. The first option 505-a may be useful in a macrocell, microcell, or picocell deployment.

A second option 505-b illustrates a unified implementation of a protocol stack, wherein the protocol stack is implemented in a single network access device. In a second option, the RRC layer 510, PDCP layer 515, RLC layer 520, MAC layer 525, and PHY layer 530 may all be implemented by AN. The second option 505-b may be useful in, for example, a femtocell deployment.

Whether the network access device implements part or all of a protocol stack, the UE may implement the entire protocol stack (e.g., RRC layer 510, PDCP layer 515, RLC layer 520, MAC layer 525, and PHY layer 530) as shown at 505-c.

In LTE, the basic Transmission Time Interval (TTI), or packet duration, is a 1ms subframe. In NR, one subframe is still 1ms, but the basic TTI is called a slot. One subframe contains a variable number of slots (e.g., 1, 2, 4, 8, 16, … slots), depending on the subcarrier spacing. NR RB is 12 consecutive frequency subcarriers. NR may support a basic subcarrier spacing of 15KHz and other subcarrier spacings may be defined relative to the basic subcarrier spacing, e.g., 30KHz, 60KHz, 120KHz, 240KHz, etc. The symbol and slot lengths scale with the subcarrier spacing. The CP length also depends on the subcarrier spacing.

Fig. 6 is a diagram showing an example of a frame format 600 for NR. The transmission timeline for each of the downlink and uplink may be divided into units of radio frames. Each radio frame may have a predetermined duration (e.g., 10ms) and may be divided into 10 subframes, each subframe being 1ms, with indices of 0 through 9. Each subframe may include a variable number of slots, depending on the subcarrier spacing. Each slot may include a variable number of symbol periods (e.g., 7 or 14 symbols), depending on the subcarrier spacing. The symbol periods in each slot may be assigned an index. Mini-slots, which may be referred to as a sub-slot structure, refer to transmission time intervals (e.g., 2,3, or 4 symbols) having a duration less than one slot.

Each symbol in a slot may indicate a link direction (e.g., DL, UL, or flexible) for data transmission, and the link direction for each subframe may be dynamically switched. The link direction may be based on the slot format. Each slot may include DL/UL data as well as DL/UL control information.

In NR, a Synchronization Signal (SS) block/physical broadcast channel (SS/PBCH) block (also referred to as a Synchronization Signal Block (SSB)) is transmitted. The SS/PBCH block includes a PSS, a SSS, and two symbols PBCH. The SS/PBCH block may be transmitted in a fixed slot location (e.g., symbols 2-5 as shown in fig. 6). The PSS and SSS may be used by the UE for cell search and acquisition. The PSS may provide half-frame timing and the SS may provide CP length and frame timing. The PSS and SSS may provide the cell identity. The PBCH carries some basic system information, e.g., downlink system bandwidth, timing information within the radio frame, SS burst set periodicity, system frame number, etc. The SS/PBCH blocks may be organized into SS bursts to support beam scanning. Further system information such as Remaining Minimum System Information (RMSI), System Information Blocks (SIBs), Other System Information (OSI) may be transmitted on the Physical Downlink Shared Channel (PDSCH) in certain subframes.

In some cases, two or more subordinate entities (e.g., UEs) may communicate with each other using sidelink signals. Practical applications for such sidelink communications may include public safety, proximity services, UE-to-network relay, vehicle-to-vehicle (V2V) communications, internet of everything (IoE) communications, internet of things communications, mission critical grid, and/or various other suitable applications. In general, a sidelink signal may refer to a signal transmitted from one subordinate entity (e.g., UE1) to another subordinate entity (e.g., UE2) without relaying the communication through a scheduling entity (e.g., UE or BS), even though the scheduling entity may be used for scheduling and/or control purposes. In some examples, the sidelink signals may be transmitted using licensed spectrum (as opposed to wireless local area networks that typically use unlicensed spectrum).

The UE may operate in various radio resource configurations, including configurations associated with transmitting pilots using a dedicated set of resources (e.g., a Radio Resource Control (RRC) dedicated state, etc.) or configurations associated with transmitting pilots using a common set of resources (e.g., an RRC common state, etc.). When operating in the RRC dedicated state, the UE may select a dedicated set of resources for transmitting pilot signals to the network. When operating in the RRC common state, the UE may select a common set of resources for transmitting pilot signals to the network. In either case, the pilot signals transmitted by the UE may be received by one or more network access devices (such as AN or DU or portions thereof). Each receiving network access device may be configured to receive and measure pilot signals transmitted on a set of common resources and also receive and measure pilot signals transmitted on a set of dedicated resources allocated to the UE, the network access device being a member of a monitoring set of network access devices for the UE. The measurements may be used by one or more receiving network access devices or CUs to which the receiving network access devices send measurements of pilot signals to identify serving cells for the UEs or initiate changes to the serving cells of one or more of the UEs.

Some systems perform coding on some physical channels. For example, some systems perform Low Density Parity Check (LDPC) coding. LDPC involves encoding using a base graph with variable nodes corresponding to system information bits and parity bits and associated check nodes. The encoding may involve lifting the base graph and the interconnect edges in the base graph using a cyclic integer lift value. The base graph is associated with a code rate, sometimes referred to as a mother code rate. For example, a first base map (referred to as BG1, with N-3K) may have a rate of 1/3, and a second base map (referred to as BG2, with N-5K) may have a rate of 1/5. Rate matching may be performed, for example, based on available transmission resources at the transmitting device to achieve different code rates. Puncturing may be performed to discard one or more information bits. One goal of rate matching is to select specific bits to be transmitted within a Transmission Time Interval (TTI). Rate matching may involve various operations such as sub-block interleaving, bit collection, and clipping. In some examples, polarization coding or other coding may be used.

Fig. 7 is a block diagram illustrating an example encoding chain in accordance with certain aspects of the present disclosure. As shown in fig. 7, for example, if the TB size is greater than a threshold, the Transport Block (TB) is segmented into one or more Code Blocks (CBs). The CB is then encoded. The coded bit sequence for the CB includes information bits and parity bits. After encoding (and before constellation mapping), rate matching is performed on the encoded bits. Each CB may be separately coded and rate matched.

Exemplary multiple TRP Transmission

Advanced systems support multiple-input multiple-output (mimo) communications through deployment of enhanced multiple Transmit Receive Points (TRPs) and/or TRPs with multiple antenna panels.

In a multi-TRP scenario, multiple TRPs (e.g., two TRPs) may transmit data to the same UE, where the data may belong to the same TB/CB (e.g., the same information bits, but could be different coded bits) or different TBs (e.g., different information bits are transmitted from multiple TRPs). The UE considers the transmissions from both TRPs and decodes the transmissions accordingly. In some examples, transmissions from multiple TRPs are simultaneous (e.g., in the same slot, mini-slot, and/or in the same symbol), but span different Resource Blocks (RBs) and/or different layers. The number of layers and/or modulation orders from each TRP may be the same or different. In some examples, the transmissions from the TRP may be at different times (e.g., in two consecutive mini-slots or time slots). In some examples, the transmission from the TRP may be a combination of the above.

Fig. 8 is a diagram illustrating an exemplary multiple TRP transmission scenario in accordance with certain aspects of the present disclosure. In the illustrated example, multiple TRPs (TRP a and TRP B) may communicate with the same UE at the same/different times in a transparent manner to improve reliability and/or increase throughput. For example, TRP a and TRP B may jointly transmit PDCCH/PDSCH/reference signals (e.g., DMRS) to the same UE. Similarly, on the uplink, the UE may transmit PUCCH/PUSCH/reference signals (e.g., SRS) to the TRP.

TRP a and TRP B may communicate via a backhaul connection. Ideally, to allow dynamic coordination between multiple TRPs for multiple TRP transmissions, the backhaul allows communication between multiple TRPs with effectively zero delay and infinite capacity. Unfortunately, many backhaul connections are not ideal, with limited capacity and considerable delay (e.g., 5ms delay or even longer), which may prevent dynamic coordination between multiple TRPs. In these cases, coordination among multiple TRPs may be limited to, for example, semi-static coordination.

In a multiple TRP scenario, one Downlink Control Information (DCI) may schedule one or more multiple PDSCH transmissions (from multiple TRPs). The DCI may be transmitted by one or more TRPs.

In some cases, multiple DCIs may schedule multiple (e.g., 2, 4, or more) PDSCH transmissions. In this case, each DCI may be transmitted by one TRP and schedule the corresponding PDSCH (in terms of that TRP). In this case, it may be assumed that each PDSCH contains one QCL hypothesis.

Exemplary partial/full overlap of multiple PDSCH transmissions for non-ideal backhaul and associated rate matching of DMRS ports

Aspects of the present disclosure provide some enhancements for multiple TRP and/or multi-panel transmission. As will be described in more detail below, in the case where DMRS transmissions of two TRPs potentially collide and those TRPs do not have an ideal backhaul, each TRP may perform rate matching around the DMRS transmission of the other TRP. In other words, since such TRPs are not well coordinated, they cannot ensure that they are signaling to the UE DMRS ports that are orthogonal and do not collide in the time/frequency resource grid. Performing rate matching around DMRS transmissions may result in improved reliability and robustness with non-ideal backhaul mechanisms in the case of potential collisions.

For multiple TRP scenarios, there are various possible DMRS configurations. For example, fig. 9 illustrates an example of demodulation reference signal (DMRS) configuration.

Effectively, each TRP may be assigned a different DMRS port group or configuration. As shown, for a first type of DMRS configuration, there are effectively 4 DMRS ports (ports 0-3) with a length of 1 symbol or 8 DMRS ports assuming a length of 2 symbols. As shown, for the second type of DMRS configuration, there are effectively 6 DMRS ports (ports 0-5) with a length of 1 symbol or 12 DMRS ports (ports 0-11) assuming a length of 2 symbols. As shown, Code Division Multiplexing (CDM) may be used in the time domain (where the same frequency resources are used).

One challenge in a multiple TRP scenario is how to address rate matching behavior when multiple PDSCH transmissions are partially or fully overlapping in situations where multiple TRPs are not coordinated or coordination limited (e.g., due to non-ideal backhaul). This can be understood by considering 2 gbb scenarios, where the gbb (acting as TRP) has relatively little (or no) coordination, but still good synchronization (OFDM symbol level synchronization).

In this case, it may be assumed that both the gNB/TRP are transmitted to the UE on the same OFDM symbol with physical PRBs that are partially/fully overlapping PDSCH resources, as shown in fig. 10. It may also be assumed that the gNB transmits DMRS on the same OFDM symbol.

If the gnbs have good coordination, they may be able to coordinate to ensure that they are signaling DMRS ports that are orthogonal and do not collide in the time/frequency resource grid to the UE.

However, if the gNB does not have good coordination (e.g., due to non-ideal backhaul), the DMRS of a first TRP may at least partially collide with the DMRS of another TRP.

Aspects of the present disclosure provide mechanisms that can help a UE and multiple TRPs coordinate rate matching around DMRSs for partially or fully overlapping PDSCH transmissions with little or no coordination across TRPs.

Fig. 11 illustrates exemplary operations 1100 for wireless communications by a User Equipment (UE) in accordance with aspects of the present disclosure. For example, operation 1100 may be performed by UE 120 shown in fig. 1 and 4.

1100 begins at 1102 by obtaining information regarding a first configuration indicating resources available at least to a first Transmit Receive Point (TRP) for transmitting a demodulation reference signal (DMRS) for a Physical Downlink Shared Channel (PDSCH). At 1104, the UE obtains information regarding a second configuration indicating resources available for at least a second TRP for transmitting a DMRS for a PDSCH. At 1106, the UE determines, based on the first configuration, that the DMRS or data transmission from the second TRP potentially overlaps with the DMRS or data transmission from the first TRP.

At 1108, based on the determination, the UE performs rate matching when processing PDSCH transmissions that potentially overlap with DMRS transmissions from the first TRP and the second TRP. In some cases, the grant for PDSCH transmission received by the UE from each TRP may take into account rate matching (e.g., the TRP may schedule PDSCH transmissions to account for potential overlap in DMRS transmissions from the two TRPs).

Fig. 12 illustrates example operations 1200 for wireless communication through a first TRP in accordance with aspects of the present disclosure. For example, operation 1200 may be performed by BS/gNB110 shown in fig. 1 and 4 to configure a UE to perform rate matching according to the operations of fig. 11 described above.

Operations 1200 begin at 1202 by obtaining information regarding a first configuration indicating resources available for at least a second TRP to transmit a demodulation reference signal (DMRS) for a Physical Downlink Shared Channel (PDSCH). At 1204, based on the first configuration, the first TRP determines that the DMRS or data transmission from the second TRP potentially overlaps with the DMRS or data transmission from the first TRP.

At 1206, based on the determination, the first TRP performs rate matching around a potential DMRS transmission of the second TRP when transmitting the PDSCH transmission to the User Equipment (UE). In some cases, the grant for PDSCH transmission received by the UE from each TRP may take into account rate matching (e.g., the TRP may schedule PDSCH transmissions to account for potential overlap in DMRS transmissions from 2 TRPs.

As described above, the techniques presented herein may allow a UE and multiple TRPs to coordinate rate matching for partial/full overlapping PDSCH transmissions with little or no coordination across TRPs.

If the TRP has relatively little (or no) coordination, the UE to be scheduled from each TRP may be configured to have various information regarding the DMRS configuration of each TRP according to one or more of the following alternatives.

In a first alternative, the UE may be configured with a port index/index to be used by each TRP for DMRS transmissions. For example, port {0,1} may be used for DMRS from TRP1, while port {2,3} may be used for DMRS from TRP 2.

In a second alternative, the UE may be configured with a DMRS port group index (e.g., group 0/1/2/3). In a third alternative, the UE may be configured with a CDM port group index (e.g., group 0/1/2/3). In other words, the TRP may always be transmitted within a respective subset of ports.

If the subset of DMRS ports for each TRP are from the same DMRS group, each port may have the same port parameters, which may help each TRP rate match around potential DMRS transmissions from another port.

If the TRPs are not coordinated at all, the UE may report this information to each TRP. For example, to assist with rate matching, a UE may signal to one TRP which ports/CDM groups/DMRS port groups are used by another TRP.

Whether reported by the UE or backhaul communication, each TRP may be signaled by the DMRS ports/DMRS groups/CDM groups used by other TRPs.

In some cases, each TRP may be able to rate match their respective PDSCH, even though PDSCH collisions may not ultimately exist, assuming that the assigned DMRS ports of the remaining TRPs are always transmitting DMRSs (e.g., a worst case assumption). When processing PDSCH transmissions from multiple TRPs, the UE may take similar actions to perform rate matching.

In some cases, there may be indications exchanged between the various modes. In the first mode, TRPs are assumed to be always non-overlapping in frequency/time, such as shown in fig. 13, where each TRP is allocated a different PRB. In this case, orthogonal resources are transmitted, and therefore, the gNB need not insist on transmitting in a specific subset of DMRS ports. In this case, signaling of DMRS ports/CDM port groups/subsets of DMRS port groups may not be required. This mode may be a default mode of operation for new UEs and for legacy gNB/UE PDSCH rate matching.

In the second mode, the TRPs can partially overlap in frequency/time. The techniques described above may be applied if the pattern is signaled to the UE. In other words, the gNB/TRP and the UE may assume that the PDSCH is rate matched in all PRBs where DMRS collisions could potentially occur, regardless of whether collisions actually occur (as described above, this may be considered a worst case assumption).

In the third mode, TRPs may (completely) overlap only in frequency/time. There are multiple options for this mode. For example, in the first option, the same solution as in the case where TRP may be completely overlapped.

In the second option, where the following constraints (one or a combination may apply) may apply as well as multiple options, collisions of DMRS ports/CDM port groups/DMRS port groups may occur across different TRPs.

For example, according to the first option, different TRPs may transmit DMRSs having different sequences. For example, different sequences may be generated using different scrambling IDs from the colliding DMRS ports/CDM groups/DMRS port groups of each of the colliding TRPs.

According to a third option, the UE reports the maximum number of orthogonal ports + non-orthogonal service ports that can be sent. For example, assume one TRP uses port 0 and the other TRP uses ports 0, 2 with a different scrambling ID/scrambling sequence for port 0. This results in 3 ports (1 from TRP1 and 2 from TRP2) being effectively sent to the UE. The UE would then need to report that it is capable of supporting this mode of operation: 1 port from one TRP and another port transmitted from another TRP which is non-orthogonal to the port transmitted from another TRP.

It is also possible to configure the timeslot/mini-timeslot sets for potential multiple TRP transmissions, wherein the above described scheme applies when some other timeslot/mini-timeslot sets are for a single TRP transmission from TRP1 and some other timeslot/mini-timeslot sets are for a single TRP transmission from TRP 2. For that set of slots/mini-slots with a pre-configured single TRP transmission, transmitting a TRP only requires rate matching around its own DMRS port, and not around the DMRS ports used by other TRPs.

Exemplary embodiments

Example 1: a method of wireless communication by a first Transmit Receive Point (TRP), comprising: obtaining information on a first configuration indicating resources available at least for a second TRP for transmitting a demodulation reference signal (DMRS) for a Physical Downlink Shared Channel (PDSCH), determining, based on the first configuration, that a DMRS or data transmission from the second TRP potentially overlaps with a DMRS or data transmission from the first TRP, and, based on the determination, performing rate matching around the potential DMRS transmission of the second TRP when transmitting the PDSCH to a User Equipment (UE).

Example 2: the method of embodiment 1, wherein the rate matching is performed assuming that the second TRP is transmitted on a DMRS port allocated according to the first configuration; and, according to the rate matching, the UE transmits Downlink Control Information (DCI) scheduling the PDSCH.

Example 3: the method according to any of embodiments 1-2, wherein the information about the first configuration is obtained from at least one of the UE or the second TRP.

Example 4: the method according to any of embodiments 1-3, wherein the information comprises at least one of: one or more DMRS port indices, DMRS port group indices, or Code Division Multiplexing (CDM) group indices.

Example 5: the method according to any one of embodiments 1-4, wherein the DMRS ports allocated to each TRP are from the same DMRS port group.

Example 6: the method according to any of embodiments 1-5, further comprising: receiving signaling indicating whether the first TRP and the second TRP transmit DMRS or data on non-overlapping resources, on potentially partially overlapping resources, or on potentially fully overlapping resources, and performing the rate matching based on the determination only if the signaling indicates that the first TRP and the second TRP transmit DMRS or data on potentially partially or fully overlapping resources, or based on its own DMRS transmission only if the signaling indicates that the first TRP and the second TRP transmit DMRS or data on non-overlapping resources.

Example 7: the method according to any of embodiments 1-6, further comprising, for a case where the first TRP and the second TRP transmit DMRS on potentially overlapping resources: the DMRS is transmitted subject to one or more constraints.

Example 8: the method of embodiment 7, wherein the one or more constraints comprise: the first TRP and the second TRP transmit DMRS using a different sequence than the second TRP.

Example 9: the method of embodiment 8, wherein the different sequences are generated by applying different scrambling sequences.

Example 10: the method of any of embodiments 1-9, wherein the one or more constraints are based on a maximum number of orthogonal ports and non-orthogonal service ports that can be transmitted as reported by the UE.

Example 11: a method of wireless communication by a User Equipment (UE), comprising: obtaining information on a first configuration indicating resources available at least for a first Transmission Receiving Point (TRP) to transmit a demodulation reference signal (DMRS) for a Physical Downlink Shared Channel (PDSCH), obtaining information on a second configuration indicating resources available at least for a second TRP to transmit a DMRS for a PDSCH, determining that a DMRS or data transmission from the second TRP potentially overlaps with a DMRS or data transmission from the first TRP based on the first configuration, and performing rate matching when processing PDSCH transmissions that potentially overlap with DMRS transmissions from the first TRP and the second TRP based on the determination.

Example 12: the method of embodiment 11, wherein the rate matching is performed assuming that the second TRP is transmitted on a DMRS port allocated according to the first configuration.

Example 13: the method of any of embodiments 11-12, further comprising: providing information about the first configuration to the second TRP, and providing information about the second configuration to the first TRP.

Example 14: the method according to any of embodiments 11-13, wherein the information about the first configuration is obtained from the first TRP and the information about the second configuration is obtained from the second TRP.

Example 15: the method according to any of embodiments 11-14, wherein the information comprises at least one of: one or more DMRS port indices, DMRS port group indices, or Code Division Multiplexing (CDM) group indices.

Example 16: the method of any of embodiments 11-15, further comprising: receiving signaling indicating whether the first TRP and the second TRP transmit DMRS or data on non-overlapping resources, on potentially partially overlapping resources, or on potentially fully overlapping resources, and performing the rate matching based on the determination only if the signaling indicates that the first TRP and the second TRP transmit DMRS on potentially partially or fully overlapping resources.

Example 17: the method according to any of embodiments 11-16, further comprising, for a case where the first TRP and the second TRP transmit DMRS on potentially overlapping resources: the DMRS is transmitted subject to one or more constraints.

Example 18: the method of embodiment 17, wherein the one or more constraints comprise: the first TRP and the second TRP use different sequences for DMRS transmission.

Example 19: the method of embodiment 18, wherein the first TRP and the second TRP use different scrambling IDs to generate different DMRS sequences.

Example 20: the method of any of embodiments 11-19, wherein the one or more constraints are based on a maximum number of orthogonal ports and non-orthogonal service ports that can be transmitted as reported by the UE.

Example 21: an apparatus for wireless communication by a first Transmit Receive Point (TRP), comprising: means for obtaining information about a first configuration indicating resources available at least for a second TRP for transmitting a demodulation reference signal (DMRS) for a Physical Downlink Shared Channel (PDSCH), means for determining, based on the first configuration, that a DMRS or data transmission from the second TRP potentially overlaps with a DMRS or data transmission from the first TRP, and means for performing, based on the determination, rate matching around the potential DMRS transmission of the second TRP when transmitting the PDSCH to a User Equipment (UE).

Example 22: the apparatus of embodiment 21, wherein the information comprises at least one of: one or more DMRS port indices, DMRS port group indices, or Code Division Multiplexing (CDM) group indices.

Example 23: the apparatus according to any one of embodiments 21-22, wherein the DMRS ports allocated to each TRP are from the same DMRS port group.

Example 24: the apparatus according to any one of embodiments 21-23, further comprising, for a case where the first TRP and the second TRP transmit DMRS on potentially overlapping resources: means for transmitting the DMRS subject to one or more constraints.

Example 25: the apparatus of embodiment 24, wherein the one or more constraints comprise: the first TRP and the second TRP transmit DMRS using a different sequence than the second TRP.

Example 26: the apparatus of embodiment 25, wherein the different sequences are generated by applying different scrambling sequences.

Example 27: an apparatus of wireless communication by a User Equipment (UE), comprising: the apparatus includes means for obtaining information regarding a first configuration indicating resources available at least to a first Transmit Receive Point (TRP) for transmitting a demodulation reference signal (DMRS) for a Physical Downlink Shared Channel (PDSCH), means for obtaining information regarding a second configuration indicating resources available at least to a second TRP for transmitting a DMRS for a PDSCH, means for determining, based on the first configuration, that DMRS or data transmissions from the second TRP potentially overlap with DMRS or data transmissions from the first TRP, and means for performing rate matching when processing PDSCH transmissions that potentially overlap with DMRS or data transmissions from the first TRP and the second TRP based on the determination.

Example 28: the apparatus of embodiment 27, wherein the rate matching is performed assuming that the second TRP is transmitted on a DMRS port allocated according to the first configuration.

Example 29: the apparatus of any of embodiments 27-28, wherein the information comprises at least one of: one or more DMRS port indices, DMRS port group indices, or Code Division Multiplexing (CDM) group indices.

Example 30: the apparatus according to any one of embodiments 27-29, wherein the first TRP and the second TRP use different sequences for DMRS transmission.

The methods disclosed herein comprise one or more steps or actions for achieving these methods. The method steps and/or actions may be interchanged with one another without departing from the scope of the claims. In other words, unless a specific order of steps or actions is specified, the order and/or use of specific steps and/or actions may be modified without departing from the scope of the claims.

As used herein, a phrase referring to "at least one of a list of items" refers to any combination of those items, including a single member. For example, "at least one of a, b, or c" is intended to encompass any combination of a, b, c, a-b, a-c, b-c, and a-b-c, as well as multiples of the same element (e.g., a-a-a, a-a-b, a-a-c, a-b-b, a-c-c, b-b-b, b-b-c, c-c, and c-c-c, or any other order of a, b, and c).

As used herein, the term "determining" encompasses a wide variety of actions. For example, "determining" can include calculating, computing, processing, deriving, investigating, looking up (e.g., looking up in a table, a database or another data structure), determining or the like. Also, "determining" may include receiving (e.g., receiving information), accessing (e.g., accessing data in a memory), and the like. Also, "determining" may include resolving, selecting, choosing, establishing, and the like.

The previous description is provided to enable any person skilled in the art to practice the various aspects described herein. Various modifications to these aspects will be readily apparent to those skilled in the art, and the generic principles defined herein may be applied to other aspects. Thus, the claims are not intended to be limited to the aspects shown herein, but is to be accorded the full scope consistent with the language claims, wherein reference to an element in the singular is not intended to mean "one and only one" unless specifically so stated, but rather "one or more. The term "some" means one or more unless specifically stated otherwise. All structural and functional equivalents to the elements of the various aspects described throughout this disclosure that are known or later come to be known to those of ordinary skill in the art are expressly incorporated herein by reference and are intended to be encompassed by the claims. Furthermore, nothing disclosed herein is intended to be dedicated to the public regardless of whether such disclosure is explicitly recited in the claims. Any claim material is not to be construed in accordance with the provisions of 35 U.S.C. No claim element should be construed in accordance with the provisions of 35 u.s.c. § 112(f), unless the element is explicitly stated using the phrase "module for … …", or in the case of method claims, the element is explicitly stated using the phrase "step for … …".

The various operations of the above-described methods may be performed by any suitable means capable of performing the corresponding functions. The unit may include various hardware and/or software components and/or modules, including but not limited to a circuit, an Application Specific Integrated Circuit (ASIC), or a processor. Generally, in the case of operations shown in the figures, those operations may have corresponding functional module components. For example, the various operations shown in fig. 11 and 12 may be performed by various processors shown in fig. 4.

The various illustrative logical blocks, modules, and circuits described in connection with the disclosure may be implemented or performed with a general purpose processor, a Digital Signal Processor (DSP), an Application Specific Integrated Circuit (ASIC), a Field Programmable Gate Array (FPGA) or other Programmable Logic Device (PLD), discrete gate or transistor logic, discrete hardware components, or any combination thereof designed to perform the functions described herein. A general-purpose processor may be a microprocessor, but, in the alternative, the processor may be any commercially available processor, controller, microcontroller or state machine. A processor may also be implemented as a combination of computing devices, e.g., a combination of a DSP and a microprocessor, a plurality of microprocessors, one or more microprocessors in conjunction with a DSP core, or any other such configuration.

If implemented in hardware, an exemplary hardware configuration may include a processing system in the wireless node. The processing system may be implemented with a bus architecture. The bus may include any number of interconnecting buses and bridges depending on the specific application of the processing system and the overall design constraints. A bus may link various circuits together, including a processor, a machine-readable medium, and a bus interface. A bus interface may be used to connect a network adapter or the like to the processing system via the bus. The network adapter may be used to implement signal processing functions of the PHY layer. In the case of a user terminal 120 (see fig. 1), a user interface (e.g., keyboard, display, mouse, joystick, etc.) may also be connected to the bus. The bus may also link various other circuits such as timing sources, peripherals, voltage regulators, power management circuits, and the like, which are well known in the art, and therefore, will not be described any further. The processor may be implemented with one or more general and/or special purpose processors. Examples include microprocessors, microcontrollers, DSP processors, and other circuits capable of executing software. Those skilled in the art will recognize how best to implement the described functionality for a processing system, depending on the particular application and the overall design constraints imposed on the overall system.

If implemented in software, the functions may be stored on or transmitted over as one or more instructions or code by a computer-readable medium. Software should be construed broadly to mean instructions, data, or any combination thereof, whether referring to software, firmware, middleware, microcode, hardware description languages, or others. Computer-readable media includes both computer storage media and communication media including any medium that facilitates transfer of a computer program from one place to another. The processor may be responsible for managing the bus and general processing, including executing software modules stored on a machine-readable storage medium. A computer readable storage medium may be coupled to the processor such that the processor can read information from, and write information to, the storage medium. In the alternative, the storage medium may be integral to the processor. By way of example, the machine-readable medium may comprise a transmission line, a carrier wave modulated by data, and/or a computer-readable storage medium having stored thereon instructions separate from the wireless node, all of which may be accessed by a processor through a bus interface. Alternatively or additionally, the machine-readable medium or any portion thereof may be integrated into a processor, for example, as may be the case with a cache and/or a general register file. Examples of a machine-readable storage medium may include, for example, RAM (random access memory), flash memory, ROM (read only memory), PROM (programmable read only memory), EPROM (erasable programmable read only memory), EEPROM (electrically erasable programmable read only memory), registers, a magnetic disk, an optical disk, a hard drive, or any other suitable storage medium, or any combination thereof. The machine-readable medium may be embodied in a computer program product.

A software module may comprise a single instruction, or many instructions, and may be distributed over several different code segments, among different programs, and across multiple storage media. The computer readable medium may include a plurality of software modules. The software modules include instructions that, when executed by a device such as a processor, cause the processing system to perform various functions. The software modules may include a sending module and a receiving module. Each software module may reside on a single storage device or be distributed across multiple storage devices. For example, a software module may be loaded into RAM from a hard disk drive when a triggering event occurs. During execution of the software module, the processor may load some instructions into the cache to increase access speed. One or more caches may then be loaded into a general register file for execution by the processor. When referring to the functions of the following software modules, it should be understood that the functions are performed by a processor when instructions are executed from the software modules.

Also, any connection is properly termed a computer-readable medium. For example, if the software is transmitted from a website, server, or other remote source using a coaxial cable, fiber optic cable, twisted pair, Digital Subscriber Line (DSL), or wireless technologies such as Infrared (IR), radio, and microwave, then the definition of medium includes the coaxial cable, fiber optic cable, twisted pair, DSL, or wireless technologies such as infrared, radio, and microwave. Disk and disc, as used herein, includes Compact Disc (CD), laser disc, optical disc, Digital Versatile Disc (DVD), floppy disk andoptical disks, where magnetic disks usually reproduce data magnetically, while optical disks reproduce data optically with lasers. Thus, in some aspects, computer-readable media may comprise non-transitory computer-readable media (e.g., tangible media). Further, for other aspects, the computer-readable medium may comprise a transitory computer-readable medium (e.g., a signal). Combinations of the above should also be included within the scope of computer-readable media.

Accordingly, certain aspects may comprise a computer program product for performing the operations presented herein. For example, such a computer program product may include a computer-readable medium having instructions stored (and/or encoded) thereon, the instructions being executable by one or more processors to perform the operations described herein. For example, the instructions are for performing the operations described herein as well as the operations shown in fig. 11 and/or fig. 12.

Further, it should be appreciated that modules and/or other suitable means for performing the methods and techniques described herein may be downloaded and/or otherwise obtained by a user terminal and/or base station as appropriate. For example, such a device may be coupled to a server to facilitate communicating means for performing the methods described herein. Alternatively, the various methods described herein may be provided via storage means (e.g., RAM, ROM, a physical storage medium such as a Compact Disc (CD) or floppy disk) such that the user terminal and/or base station is able to obtain the various methods upon coupling or providing the storage unit to the device. Further, any other suitable technique for providing the methods and techniques described herein to a device may be used.

It is to be understood that the claims are not limited to the precise configuration and components described above. Various modifications, changes and variations may be made in the arrangement, operation and details of the methods and apparatus described above without departing from the scope of the claims.