Trp beamforming for ue-assisted trp synchronization

Abstract

Certain aspects of the present disclosure provide techniques for deriving at least one of a timing offset or a phase offset between a first network entity and a second network entity based on downlink reference signals (RSs) transmitted from different network entities, such as transmission reception points (TRPs). Aspects of the present disclosure provide mechanisms that can help achieve synchronization of time and / or phase among TRPs. Such synchronization among TRPs can help enhance CJT-based communications and improve system performance and user experience.

Description

Technical Field

[0001] Various aspects of this disclosure relate to wireless communication, and more specifically, to techniques for synchronizing timing and / or phase offsets between network entities, such as transmit-receive points (TRPs). Background Technology

[0002] Wireless communication systems are widely deployed to provide a variety of telecommunications services, such as telephone, video, data, messaging, broadcasting, or other similar services. These wireless communication systems may employ multiple access technologies that enable communication with several users by sharing available wireless communication system resources.

[0003] Despite significant technological advancements in wireless communication systems over the years, challenges remain. For example, complex and dynamic environments can still attenuate or block signals between wireless transmitters and receivers. Therefore, there is a continuous expectation for improving the technical performance of wireless communication systems, including, for example: improving communication speed and data carrying capacity; improving the efficiency of shared communication media; reducing the power used by transmitters and receivers during communication; improving the reliability of wireless communication; avoiding redundant transmission and / or reception and related processing; improving the coverage area of ​​wireless communication; increasing the number and types of devices that can access the wireless communication system; increasing the ability of different types of devices to communicate with each other; and increasing the number and types of available wireless communication media. Therefore, there is a need for further improvements to wireless communication systems to overcome the aforementioned technical challenges and other obstacles. Summary of the Invention

[0004] One aspect provides a method for wireless communication at a user equipment (UE). The method includes: transmitting at least a first uplink reference signal (RS) and a second uplink RS via at least a first port and a second port; receiving at least a first downlink RS and a second downlink RS from a first network entity; receiving at least a third downlink RS and a fourth downlink RS from a second network entity; deriving at least one of a timing offset or a phase offset between the first network entity and the second network entity based on the first downlink RS, the second downlink RS, the third downlink RS, the fourth downlink RS, and the following assumptions: 1) the first downlink RS and the second downlink RS are transmitted from the first network entity using a first transmit beamforming derived from a first receive beamforming for the first uplink RS and the second uplink RS; and 2) the third downlink RS and the fourth downlink RS are transmitted from the second network entity using a second transmit beamforming derived from a second receive beamforming for the first uplink RS and the second uplink RS; and transmitting at least one of the timing offset or phase offset to at least one of the first network entity or the second network entity.

[0005] On the other hand, a method for wireless communication at a first network entity is provided. The method includes receiving at least a first uplink reference signal (RS) and a second uplink RS from a user equipment; at least: 1) transmitting a first downlink RS to the UE using a first transmit beamforming derived from a first receive beamforming for the first uplink RS, and 2) transmitting a second downlink RS to the UE using a second transmit beamforming derived from a second receive beamforming for the second uplink RS; and receiving indications of timing offsets and phase offsets for the first and second network entities, the timing offsets and phase offsets being derived by the UE based on the first downlink RS, the second downlink RS, a third downlink RS transmitted by the second network entity, and a fourth downlink RS transmitted by the second network entity.

[0006] Other aspects provide: an apparatus operable to, configured to, or otherwise adapted to perform one or more of the foregoing methods and / or those methods described elsewhere herein; a non-transitory computer-readable medium comprising instructions that, when executed by one or more processors of the apparatus (e.g., directly, indirectly, after preprocessing, or without preprocessing), cause the apparatus to perform the foregoing methods and those methods described elsewhere herein; a computer program product embodied on a computer-readable storage medium comprising: code for performing the foregoing methods and those methods described elsewhere herein; and / or an apparatus comprising components for performing the foregoing methods and those methods described elsewhere herein. By way of example, an apparatus may include a processing system, a device having a processing system, or a processing system cooperating via one or more networks.

[0007] For illustrative purposes, the following description and figures illustrate certain features. Attached Figure Description

[0008] The accompanying drawings depict certain features of the various aspects described herein and should not be considered as limiting the scope of this disclosure.

[0009] Figure 1 An example wireless communication network is depicted.

[0010] Figure 2 An example decomposed base station architecture is described.

[0011] Figure 3 Various aspects of the example base station and example user equipment are described.

[0012] Figure 4A , Figure 4B, Figure 4C and Figure 4D Various example aspects of data structures used in wireless communication networks are described.

[0013] Figure 5 An example predecoder matrix is ​​depicted.

[0014] Figure 6 An example of codebook-based (CB) channel state feedback (CSF) is described.

[0015] Figure 7 An example transmit-receive point (TRP) scenario for coherent joint transmission (CJT) is depicted.

[0016] Figure 8 An example of enhanced Type II (eType-II) Channel State Information (CSI) is depicted.

[0017] Figure 9 Examples of noncoherent joint transmission (NCJT) and coherent joint transmission (CJT) based on spatial division multiplexing (SDM) are depicted.

[0018] Figure 10 Example CJT and NCJT scenarios are depicted.

[0019] Figure 11 A timing diagram illustrating the timing offset between example TRPs is depicted.

[0020] Figure 12 A call flowchart illustrating an example UE-assisted TRP synchronization is depicted.

[0021] Figure 13 A call flowchart illustrating example UE-assisted TRP synchronization is depicted, where the UE has multiple transceivers / antennas.

[0022] Figure 14 A diagram illustrating example communication between a UE with multiple antennas and two TRPs is depicted.

[0023] Figure 15 A diagram illustrating example communication between a UE with multiple antennas and two TRPs with multiple antennas is shown.

[0024] Figure 16 An illustration depicts an example of TRP digital beamforming according to certain aspects of this disclosure.

[0025] Figure 17 A diagram illustrating an example link between CSI-RS and SRS for CSI-RS pre-decoding, according to certain aspects of this disclosure, is depicted.

[0026] Figure 18A method for wireless communication is described.

[0027] Figure 19 A method for wireless communication is described.

[0028] Figure 20 Various aspects of the example communication device are described. Detailed Implementation

[0029] This disclosure provides apparatus, methods, processing systems, and computer-readable media for synchronizing timing and / or phase offsets between network entities, such as transmit-receive points (TRPs).

[0030] In some systems, network entities (e.g., gNodeB (gNB)) may be associated with multiple Transmitter-Receiver Points (TRPs). TRPs may transmit signals simultaneously or concurrently on the same frequency channel (or transmit data via the Physical Downlink Shared Channel (PDSCH)). In such systems, User Equipment (UE) can communicate with more than one TRP using Coordinated Multipoint (CoMP) operation. CoMP operation can be based on Coherent Joint Transmission (CJT) or Non-CJT (NCJT).

[0031] During the CJT process, the gNB can be configured with multiple TRPs (e.g., up to four TRPs) to transmit Channel State Information (CSI) Reference Signals (RS). Each TRP can use a single antenna or multiple antennas to transmit the CSI-RS. The gNB can also be configured to receive CSI reports from the UE as feedback.

[0032] In some cases, the gNB may also transmit to the UE an indication of the maximum number of TRPs that can participate in CJT (e.g., The signaling of these TRPs. Each of these TRPs can transmit CSI-RS to the UE. The UE can transmit the number of TRPs from the maximum number of TRPs that can participate in CJT (e.g., N). Instructions for (e.g., via a size of TRP) (Bitmap). The UE can also be based on measurements from The CSI-RS of each TRP and the CSI feedback (e.g., indicating CSI information and the pre-decoder matrix to be used) are transmitted based on the N TRPs selected by the UE.

[0033] In some cases, CJT deployments may have non-ideal synchronization and backhaul conditions. In such cases, time misalignment and frequency / phase offset between TRPs can impact performance. Various aspects of this disclosure provide mechanisms that can facilitate time and / or phase synchronization between TRPs. Such synchronization between TRPs can help enhance CJT-based communication and improve system performance and user experience.

[0034] An introduction to wireless communication networks

[0035] The techniques and methods described herein can be used in a variety of wireless communication networks. While aspects may be described herein using terms commonly associated with 3G, 4G, and / or 5G wireless technologies, aspects of this disclosure are equally applicable to other communication systems and standards not explicitly mentioned herein.

[0036] Figure 1 An example of a wireless communication network 100 in which the aspects described herein can be implemented is depicted.

[0037] Generally, wireless communication network 100 includes various network entities (optionally, network elements or network nodes). Network entities are typically communication devices and / or communication functions performed by communication devices (e.g., user equipment (UE), base station (BS), components of the BS, servers, etc.). For example, various functions of the network and various devices associated with and interacting with the network can be considered network entities. Furthermore, wireless communication network 100 includes terrestrial aspects, such as terrestrial network entities (e.g., BS 102), and non-terrestrial aspects, such as satellite 140 and aircraft 145, which may include onboard network entities (e.g., one or more BSs) capable of communicating with other network elements (e.g., terrestrial BSs) and user equipment.

[0038] In the depicted example, wireless communication network 100 includes BS 102, UE 104 and one or more core networks (such as Evolved Packet Core (EPC) 160 and 5G Core (5GC) network 190) that interoperate to provide communication services over various communication links, including wired and wireless links.

[0039] Figure 1 Various example UE 104s are described, which may more generally include: cellular phones, smartphones, Session Initiation Protocol (SIP) phones, laptops, personal digital assistants (PDAs), satellite radios, global positioning systems, multimedia devices, video devices, digital audio players, cameras, game consoles, tablet computers, smart devices, wearable devices, vehicles, electricity meters, air pumps, large or small kitchen appliances, healthcare devices, implants, sensors / actuators, displays, Internet of Things (IoT) devices, always-on (AON) devices, edge processing devices, or other similar devices. UE 104 may also be more generally referred to as mobile devices, wireless devices, wireless communication devices, stations, mobile stations, subscriber stations, mobile subscriber stations, mobile units, subscriber units, wireless units, remote units, remote devices, access terminals, mobile terminals, wireless terminals, remote terminals, mobile phones, and others.

[0040] BS 102 communicates wirelessly with UE 104 via communication link 120 (e.g., sending or receiving signals to or from UE 104). Communication link 120 between BS 102 and UE 104 may include uplink (UL) transmission (also referred to as reverse link) from UE 104 to BS 102 and / or downlink (DL) transmission (also referred to as forward link) transmission from BS 102 to UE 104. In various aspects, communication link 120 may utilize multiple-input multiple-output (MIMO) antenna technologies, including spatial multiplexing, beamforming, and / or transmit diversity.

[0041] BS 102 may typically include: NodeB, enhanced NodeB (eNB), next-generation enhanced NodeB (ng-eNB), next-generation NodeB (gNB or gNodeB), access point, transceiver base station, radio base station, radio transceiver, transceiver functionality, transmit / receive point, and / or others. Each BS in BS 102 may provide communication coverage for a corresponding geographic coverage area 110, which may sometimes be referred to as a cell, and in some cases may overlap (e.g., a small cell 102' may have a coverage area 110' that overlaps with the coverage area 110 of a macro cell). For example, BS may provide communication coverage for macro cells (covering a relatively large geographic area), pico cells (covering a relatively small geographic area, such as a stadium), femtocells (covering a relatively small geographic area (e.g., a home)), and / or other types of cells.

[0042] Although BS 102 is described as a single communication device in various aspects, it can be implemented in a variety of configurations. For example, to give a few examples, one or more components of the base station can be decomposed, including a central unit (CU), one or more distributed units (DU), one or more radio units (RU), a near real-time (near RT) RAN intelligent controller (RIC), or a non-real-time (non-RT) RIC. In another example, various aspects of the base station can be virtualized. More generally, a base station (e.g., BS 102) can include components located at a single physical location or components located at various physical locations. In examples where the base station includes components located at various physical locations, the various components can each perform functions, such that the various components collectively achieve functionality similar to a base station located at a single physical location. In some aspects, a base station including components located at various physical locations can be referred to as a decomposed radio access network architecture (such as an open RAN (O-RAN) or virtualized RAN (VRAN) architecture). Figure 2 An example decomposed base station architecture is depicted and described.

[0043] Different BSs 102 within the wireless communication network 100 can also be configured to support different radio access technologies (such as 3G, 4G, and / or 5G). For example, a BS 102 configured for 4G LTE (collectively referred to as Evolved Universal Mobile Telecommunications System (UMTS) Terrestrial Radio Access Network (E-UTRAN)) can interface with EPC 160 via a first backhaul link 132 (e.g., S1 interface). A BS 102 configured for 5G (e.g., 5G NR or Next Generation RAN (NG-RAN)) can interface with 5GC 190 via a second backhaul link 184. BSs 102 can communicate directly or indirectly (e.g., via EPC 160 or 5GC 190) on a third backhaul link 134 (e.g., X2 interface), which can be wired or wireless.

[0044] Wireless communication network 100 can subdivide the electromagnetic spectrum into various categories, bands, channels, or other characteristics. In some aspects, subdivision is provided based on wavelength and frequency, where frequency may also be referred to as carrier, subcarrier, channel, tone, or subband. For example, 3GPP currently defines frequency range 1 (FR1) as including 410MHz to 7125MHz, which is often (interchangeably) referred to as “sub-6GHz”. Similarly, 3GPP currently defines frequency range 2 (FR2) as including 24,250MHz to 71,000MHz, which is sometimes (interchangeably) referred to as “millimeter wave” (“mmW” or “mmWave”). In some cases, FR2 can be further defined according to subranges (such as a first subrange FR2-1 including 24,250MHz to 52,600MHz and a second subrange FR2-2 including 52,600MHz to 71,000MHz). Base stations configured to communicate using mmWave / near mmWave radio bands (e.g., mmWave base stations such as BS 180) can utilize beamforming (e.g., 182) with UEs (e.g., 104) to improve path loss and range.

[0045] The communication link 120 between BS 102 and, for example, UE 104 can be via one or more carriers, which may have different bandwidths (e.g., 5MHz, 10MHz, 15MHz, 20MHz, 100MHz, 400MHz and / or other MHz) and may be aggregated in various ways. The carriers may be adjacent to each other or may not be adjacent to each other. The allocation of carriers may be asymmetric with respect to DL and UL (e.g., more or fewer carriers may be allocated to DL compared to UL).

[0046] Compared to lower-frequency communication, communication using higher frequency bands may have higher path loss and shorter range. Therefore, some base stations (e.g., Figure 1 The beamforming 182 of the BS 180 (180) with the UE 104 can be used to improve path loss and range. For example, the BS 180 and UE 104 may each include multiple antennas, such as antenna elements, antenna panels, and / or antenna arrays, to facilitate beamforming. In some cases, the BS 180 may transmit beamformed signals to the UE 104 in one or more transmit directions 182''. The UE 104 may receive beamformed signals from the BS 180 in one or more receive directions 182''. The UE 104 may also transmit beamformed signals to the BS 180 in one or more transmit directions 182''. The BS 180 may also receive beamformed signals from the UE 104 in one or more receive directions 182''. The BS 180 and UE 104 may then perform beamforming training to determine the optimal receive and transmit directions for each of the BS 180 and UE 104. It is worth noting that the transmit and receive directions of the BS 180 may be the same or different. Similarly, the sending and receiving directions of UE 104 can be the same or different.

[0047] The wireless communication network 100 also includes a Wi-Fi AP 150 that communicates with a Wi-Fi station (STA) 152 via a communication link 154 in, for example, unlicensed spectrum in 2.4 GHz and / or 5 GHz.

[0048] Some UEs 104 may use device-to-device (D2D) communication link 158 to communicate with each other. The D2D communication link 158 may use one or more sidelink channels, such as physical sidelink broadcast channel (PSBCH), physical sidelink discovery channel (PSDCH), physical sidelink shared channel (PSSCH), physical sidelink control channel (PSCCH), and / or physical sidelink feedback channel (PSFCH).

[0049] EPC 160 may include various functional components, including: Mobility Management Entity (MME) 162, other MMEs 164, Serving Gateway 166, Multimedia Broadcast Multicast Service (MBMS) Gateway 168, Broadcast Multicast Service Center (BM-SC) 170, and / or Packet Data Network (PDN) Gateway 172, as in the illustrated example. MME 162 may communicate with Home Subscriber Server (HSS) 174. MME 162 is the control node that handles signaling between UE 104 and EPC 160. Generally, MME 162 provides bearer and connectivity management.

[0050] Generally, user Internet Protocol (IP) packets are transmitted through Serving Gateway 166, which is itself connected to PDN Gateway 172. PDN Gateway 172 provides UE IP address allocation and other functions. PDN Gateway 172 and BM-SC 170 are connected to IP services 176, which may include, for example, the Internet, intranets, IP Multimedia Subsystem (IMS), packet-switched (PS) streaming services, and / or other IP services.

[0051] The BM-SC 170 provides functionality for MBMS user service dispatch and delivery. The BM-SC 170 can serve as an entry point for content provider MBMS transmissions, authorize and initiate MBMS bearer services within a Public Land Mobile Network (PLMN), and / or schedule MBMS transmissions. The MBMS Gateway 168 can distribute MBMS services to BS 102 within a Broadcast-Specific Service Single Frequency Network (MBSFN) area, and / or be responsible for session management (start / stop) and collecting eMBMS-related billing information.

[0052] 5GC 190 may include various functional components, including: Access and Mobility Management Function (AMF) 192, other AMFs 193, Session Management Function (SMF) 194, and User Plane Function (UPF) 195. AMF 192 may communicate with Unified Data Management (UDM) 196.

[0053] AMF 192 is the control node that handles signaling between UE 104 and 5GC 190. AMF 192 provides services such as Quality of Service (QoS) flow and session management.

[0054] Internet Protocol (IP) packets are transmitted via UPF 195, which connects to IP service 197 and provides UE IP address allocation and other functions for 5GC 190. IP service 197 may include, for example, the Internet, intranet, IMS, PS streaming service, and / or other IP services.

[0055] In various aspects, to give a few examples, network entities or network nodes can be implemented as aggregated base stations, decomposed base stations, components of base stations, integrated access and backhaul (IAB) nodes, relay nodes, and sidelink nodes.

[0056] Figure 2An example decomposed base station 200 architecture is depicted. The decomposed base station 200 architecture may include one or more central units (CUs) 210, which may communicate directly with the core network 220 via a backhaul link, or indirectly with the core network 220 through one or more decomposed base station units, such as a near real-time (near-RT) RAN Intelligent Controller (RIC) 225 via an E2 link, or a non-real-time (non-RT) RIC 215 associated with a Service Management and Orchestration (SMO) framework 205, or both. CUs 210 may communicate with one or more distributed units (DUs) 230 via corresponding midhaul links (such as F1 interfaces). DUs 230 may communicate with one or more radio units (RUs) 240 via corresponding fronthaul links. RUs 240 may communicate with a corresponding UE 104 via one or more radio frequency (RF) access links. In some specific implementations, UE 104 may be served simultaneously by multiple RUs 240.

[0057] Each unit in a cell (e.g., CU 210, DU 230, RU 240, and near-RT RIC 225, non-RT RIC 215, and SMO frame 205) may include or be coupled to one or more interfaces configured to receive or transmit signals, data, or information (collectively, signals) via a wired or wireless transmission medium. Each of the cells, or an associated processor or controller that provides instructions to the cell's communication interface, may be configured to communicate with one or more other cells via the transmission medium. For example, these cells may include a wired interface configured to receive signals or transmit signals to one or more other cells via a wired transmission medium. Additionally or alternatively, a cell may include a wireless interface that may include a receiver, transmitter, or transceiver (such as a radio frequency (RF) transceiver) configured to receive signals on a wireless transmission medium or transmit signals to one or more other cells, or both.

[0058] In some aspects, CU 210 can host one or more higher-level control functions. Such control functions may include Radio Resource Control (RRC), Packet Data Convergence Protocol (PDCP), or Service Data Adaptation Protocol (SDAP), etc. Each control function can be implemented using an interface configured to signal to other control functions hosted by CU 210. CU 210 can be configured to handle user plane functions (e.g., Central Unit-User Plane (CU-UP)), control plane functions (e.g., Central Unit-Control Plane (CU-CP)), or combinations thereof. In some implementations, CU 210 can be logically split into one or more CU-UP units and one or more CU-CP units. When implemented in an O-RAN configuration, CU-UP units can communicate bidirectionally with CU-CP units via an interface such as an E1 interface. CU 210 can be implemented to communicate with DU 230 for network control and signaling, as needed.

[0059] DU 230 may correspond to a logical unit that includes one or more base station functions for controlling the operation of one or more RU 240s. In some aspects, DU 230 may at least partially host one or more of the Radio Link Control (RLC) layer, Medium Access Control (MAC) layer, and one or more high physical (PHY) layers (such as modules for forward error correction (FEC) encoding and decoding, scrambling, modulation and demodulation, etc.) according to functional splits (such as those defined by the 3rd Generation Partnership Project (3GPP). In some aspects, DU 230 may also host one or more low PHY layers. Each layer (or module) may be implemented using an interface configured to communicate signals with other layers (and modules) hosted by DU 230 or with control functions hosted by CU 210.

[0060] Lower-layer functionality can be implemented by one or more RU 240s. In some deployments, the RU240 controlled by the DU 230 may correspond to a logical node that hosts RF processing functions or low-PHY layer functions (such as performing Fast Fourier Transform (FFT), Inverse FFT (iFFT), digital beamforming, or Physical Random Access Channel (PRACH) extraction and filtering, or both, at least in part based on functional decomposition (such as lower-layer functional decomposition). In such architectures, the RU 240 may be implemented to handle over-the-air (OTA) communications with one or more UE 104s. In some specific implementations, the real-time and non-real-time aspects of control plane and user plane communications with the RU 240 may be controlled by the corresponding DU 230. In some scenarios, this configuration allows the DU 230 and CU 210 to be implemented in a cloud-based RAN architecture (such as a vRAN architecture).

[0061] SMO framework 205 can be configured to support RAN deployment and provisioning of both non-virtualized and virtualized network elements. For non-virtualized network elements, SMO framework 205 can be configured to support the deployment of dedicated physical resources for RAN coverage requirements, which can be managed via operation and maintenance interfaces such as the O1 interface. For virtualized network elements, SMO framework 205 can be configured to interact with a cloud computing platform such as Open Cloud (O-Cloud) 290 to perform network element lifecycle management (such as instantiating virtualized network elements) via a cloud computing platform interface such as the O2 interface. Such virtualized network elements may include, but are not limited to, CU 210, DU 230, RU 240, and near-RT RIC 225. In some implementations, SMO framework 205 can communicate with hardware aspects of the 4G RAN, such as Open eNB (O-eNB) 211, via the O1 interface. Additionally, in some implementations, SMO framework 205 can communicate directly with one or more RU 240s via the O1 interface. SMO framework 205 may also include a non-RT RIC 215 configured to support the functionality of SMO framework 205.

[0062] The non-RT RIC 215 can be configured to include logical functions that enable non-real-time control and optimization of RAN elements and resources, including artificial intelligence / machine learning (AI / ML) workflows for model training and updates, or policy-based guidance for applications / features in the near-RT RIC 225. The non-RT RIC 215 can be coupled to or communicate with the near-RT RIC 225, such as via an A1 interface. The near-RT RIC 225 can be configured to include logical functions that enable near real-time control and optimization of RAN elements and resources via an interface, such as via an E2 interface, through data collection and actions, connecting one or more CU 210s, one or more DU 230s, or both, and O-eNBs to the near-RT RIC 225.

[0063] In some implementations, to generate AI / ML models to be deployed in the near-RT RIC 225, the non-RT RIC 215 may receive parameters or external enrichment information from an external server. This information can be utilized by the near-RT RIC 225 and may be received from non-network data sources or network functions at the SMO framework 205 or the non-RT RIC 215. In some examples, the non-RT RIC 215 or the near-RT RIC 225 may be configured to tune RAN behavior or performance. For example, the non-RT RIC 215 may monitor long-term trends and patterns in performance and employ AI / ML models to perform corrective actions via the SMO framework 205 (such as reconfiguration via O1) or by creating RAN management policies (such as A1 policies).

[0064] Figure 3 Various aspects of examples BS 102 and UE 104 are described.

[0065] Generally, BS 102 includes various processors (e.g., 320, 330, 338, and 340), antennas 334a to 334t (collectively referred to as 334), transceivers 332a to 332t (collectively referred to as 332) including modulators and demodulators, and other aspects that enable the wireless transmission of data (e.g., data source 312) and the wireless reception of data (e.g., data sink 339). For example, BS 102 can transmit and receive data between BS 102 and UE 104. BS 102 includes a controller / processor 340 that can be configured to implement the various wireless communication-related functions described herein.

[0066] Generally, UE 104 includes various processors (e.g., 358, 364, 366, and 380), antennas 352a to 352r (collectively referred to as 352), transceivers 354a to 354r (collectively referred to as 354) including modulators and demodulators, and other aspects that enable the wireless transmission of data (e.g., retrieval from data source 362) and the wireless reception of data (e.g., provision to data sink 360). UE 104 includes a controller / processor 380 that can be configured to implement the various wireless communication-related functions described herein.

[0067] Regarding example downlink transmission, BS 102 includes a transmission processor 320 that can receive data from data source 312 and control information from controller / processor 340. The control information may be for a Physical Broadcast Channel (PBCH), Physical Control Format Indicator Channel (PCFICH), Physical HARQ Indicator Channel (PHICH), Physical Downlink Control Channel (PDCCH), Group Shared PDCCH (GC PDCCH), and / or others. In some examples, this data may be for a Physical Downlink Shared Channel (PDSCH).

[0068] The transmitter processor 320 can process data and control information (e.g., encoding and symbol mapping) to obtain data symbols and control symbols, respectively. The transmitter processor 320 can also generate reference symbols (such as those for the primary synchronization signal (PSS), secondary synchronization signal (SSS), PBCH demodulation reference signal (DMRS), and channel state information reference signal (CSI-RS)).

[0069] The transmit (TX) multiple-input multiple-output (MIMO) processor 330 can perform spatial processing (e.g., pre-decoding) on ​​data symbols, control symbols, and / or reference symbols where applicable, and can provide the output symbol stream to the modulators (MODs) in transceivers 332a to 332t. Each modulator in transceivers 332a to 332t can process the corresponding output symbol stream to obtain an output sample stream. Each modulator can further process (e.g., convert to analog, amplify, filter, and up-convert) the output sample stream to obtain a downlink signal. The downlink signal from the modulators in transceivers 332a to 332t can be transmitted via antennas 334a to 334t, respectively.

[0070] To receive downlink transmissions, UE 104 includes antennas 352a to 352r that receive downlink signals from BS 102 and provide the received signals to demodulators (DEMODs) in transceivers 354a to 354r, respectively. Each demodulator in transceivers 354a to 354r can adjust (e.g., filter, amplify, down-convert, and digitize) the corresponding received signal to obtain an input sample. Each demodulator can further process the input sample to obtain the received symbols.

[0071] The MIMO detector 356 acquires received symbols from all demodulators in transceivers 354a-354r, performs MIMO detection on the received symbols where applicable, and provides the detected symbols. The receive processor 358 processes the detected symbols (e.g., demodulation, deinterleaving, and decoding), provides the decoded data of UE 104 to data sink 360, and provides the decoded control information to controller / processor 380.

[0072] Regarding example uplink transmission, UE 104 also includes a transmit processor 364 that receives and processes data from data source 362 (e.g., for PUSCH) and control information from controller / processor 380 (e.g., for Physical Uplink Control Channel (PUCCH)). Transmit processor 364 may also generate reference symbols for reference signals (e.g., for Sounding Reference Signal (SRS)). Symbols from transmit processor 364 may be pre-decoded by TX MIMO processor 366 where applicable, further processed by modulators in transceivers 354a to 354r (e.g., for SC-FDM), and transmitted to BS 102.

[0073] At BS 102, uplink signals from UE 104 can be received by antennas 334a to 334t, processed by demodulators in transceivers 332a to 332t, detected by MIMO detector 336 where applicable, and further processed by receiver processor 338 to obtain decoded data and control information transmitted by UE 104. Receiver processor 338 can provide the decoded data to data sink 339 and the decoded control information to controller / processor 340.

[0074] Memory 342 and memory 382 can store data and program code for BS 102 and UE 104, respectively.

[0075] Scheduler 344 can schedule UE to send data on the downlink and / or uplink.

[0076] In various respects, BS 102 can be described as transmitting and receiving various types of data associated with the methods described herein. In these contexts, “transmitting” can refer to various mechanisms that output data, such as from data source 312, scheduler 344, memory 342, transmit processor 320, controller / processor 340, TX MIMO processor 330, transceivers 332a to 332t, antennas 334a to 334t, and / or other aspects described herein. Similarly, “receiving” can refer to various mechanisms that acquire data, such as from antennas 334a to 334t, transceivers 332a to 332t, RX MIMO detector 336, controller / processor 340, receive processor 338, scheduler 344, memory 342, and / or other aspects described herein.

[0077] In various respects, UE 104 can also be described as transmitting and receiving various types of data associated with the methods described herein. In these contexts, “transmitting” can refer to various mechanisms that output data, such as from data source 362, memory 382, ​​transmit processor 364, controller / processor 380, TX MIMO processor 366, transceivers 354a to 354t, antennas 352a to 352t, and / or other aspects described herein. Similarly, “receiving” can refer to various mechanisms that acquire data, such as from antennas 352a to 352t, transceivers 354a to 354t, RX MIMO detector 356, controller / processor 380, receive processor 358, memory 382, ​​and / or other aspects described herein.

[0078] In some respects, one or more processors may be configured to perform various operations (such as those associated with the methods described herein) and respectively send (output) data to another interface configured to send data or receive (obtain) data from another interface configured to receive data.

[0079] Figure 4A , Figure 4B , Figure 4C and Figure 4D Describes the use of wireless communication networks (such as Figure 1 All aspects of the data structure of the wireless communication network 100.

[0080] Specifically, Figure 4A Figure 400 is an example of the first subframe within a 5G (e.g., 5G NR) frame structure. Figure 4B Figure 430 illustrates an example of a DL channel within a 5G subframe. Figure 4C Figure 450 illustrates an example of the second subframe within a 5G frame structure, and Figure 4D Figure 480 illustrates an example of a UL channel within a 5G subframe.

[0081] Wireless communication systems can utilize Orthogonal Frequency Division Multiplexing (OFDM) with a cyclic prefix (CP) on both the uplink and downlink. Such systems can also support half-duplex operation using Time Division Duplex (TDD). OFDM and Single-Carrier Frequency Division Multiplexing (SC-FDM) will (e.g., as...) Figure 4B and Figure 4D The system bandwidth (as depicted in the text) is divided into multiple orthogonal subcarriers. Each subcarrier can be modulated with data. Modulation symbols can be transmitted in the frequency domain using OFDM and / or in the time domain using SC-FDM.

[0082] Wireless communication frame structures can be frequency division duplex (FDD), where for a specific set of subcarriers, subframes within that set are dedicated to either deep (DL) or ultra-low (UL). Wireless communication frame structures can also be time division duplex (TDD), where for a specific set of subcarriers, subframes within that set are dedicated to both DL and UL.

[0083] exist Figure 4A and Figure 4C In this example, the wireless communication frame structure is TDD, where D stands for DL, U for UL, and X is flexibly used between DL and UL. The UE can be configured using a time slot format (dynamically via DL control information (DCI) or semi-statically / statically via Radio Resource Control (RRC) signaling) through the received Time Slot Format Indicator (SFI). In the depicted example, a 10ms frame is divided into 10 equal-sized 1ms subframes. Each subframe may include one or more time slots. In some examples, each time slot may include 7 or 14 symbols, depending on the time slot format. Subframes may also include micro-slots, which typically have fewer symbols than the entire time slot. Other wireless communication technologies may have different frame structures and / or different channels.

[0084] In some respects, the number of time slots within a subframe is based on the time slot configuration and parameter set. For example, for time slot configuration 0, different parameter sets (μ) 0 to 6 allow 1, 2, 4, 8, 16, 32, and 64 time slots per subframe, respectively. For time slot configuration 1, different parameter sets 0 to 2 allow 2, 4, and 8 time slots per subframe, respectively. Therefore, for time slot configuration 0 and parameter set μ, there are 14 symbols per time slot and 2µ time slots per subframe. The subcarrier spacing and symbol length / duration are functions of the parameter set. The subcarrier spacing can be equal to... kHz, where μ is the parameter set from 0 to 6. Therefore, the parameter set... It has a subcarrier spacing of 15 kHz and a parameter set It has a subcarrier spacing of 960 kHz. The symbol length / duration is negatively correlated with the subcarrier spacing. Figure 4A , Figure 4B , Figure 4C and Figure 4D It provides slot configuration 0 with 14 symbols per slot and parameter set with 4 slots per subframe. Example: The time slot duration is 0.25 ms, the subcarrier spacing is 60 kHz, and the symbol duration is approximately 16.67 μs.

[0085] like Figure 4A , Figure 4B , Figure 4C and Figure 4DAs depicted, the resource grid can be used to represent the frame structure. Each time slot includes a resource block (RB) (also known as a physical RB (PRB)) extending for, for example, 12 consecutive subcarriers. The resource grid is divided into multiple resource elements (REs). The number of bits carried by each RE depends on the modulation scheme.

[0086] like Figure 4A As illustrated in the example, some REs in the RE carry information for the UE (e.g., Figure 1 and Figure 3 The reference (pilot) signal (RS) of the UE (104) may include a demodulation RS (DMRS) and / or a channel state information reference signal (CSI-RS) for channel estimation at the UE. The RS may also include a beam measurement RS (BRS), a beam refinement RS (BRRS), and / or a phase tracking RS (PT-RS).

[0087] Figure 4B Examples of various DL channels within a subframe of a frame are illustrated. The Physical Downlink Control Channel (PDCCH) carries the DCI within one or more Control Channel Elements (CCEs), each CCE comprising, for example, nine RE groups (REGs), each REG comprising, for example, four consecutive REs in an OFDM symbol.

[0088] The Primary Synchronization Signal (PSS) can be located within symbol 2 of a specific subframe of the frame. The PSS is generated by the UE (e.g., Figure 1 and Figure 3 104) is used to determine subframe / symbol timing and physical layer identifier.

[0089] The Supplemental Synchronization Signal (SSS) can be located in symbol 4 of a specific subframe of a frame. The SSS is used by the UE to determine the physical layer cell identifier group number and radio frame timing.

[0090] Based on the Physical Layer Identifier and Physical Layer Cell Identifier Group Number, the UE can determine the Physical Cell Identifier (PCI). Based on the PCI, the UE can determine the location of the aforementioned DMRS. The Physical Broadcast Channel (PBCH), carrying the Master Information Block (MIB), can be logically grouped with the PSS and SSS to form a Synchronization Signal (SS) / PBCH block. The MIB provides the number of RBs and the System Frame Number (SFN) in the system bandwidth. The Physical Downlink Shared Channel (PDSCH) carries user data, broadcast system information (such as System Information Block (SIB)) not transmitted via the PBCH, and / or paging messages.

[0091] like Figure 4CAs illustrated, some REs in the REs carry DMRS for channel estimation at the base station (indicated as R for a particular configuration, but other DMRS configurations are possible). The UE can transmit DMRS for PUCCH and DMRS for PUSCH. PUSCH DMRS can be transmitted, for example, in the first or second symbol preceding the PUSCH. PUCCH DMRS can be transmitted in different configurations depending on whether a short or long PUCCH is being transmitted and depending on the specific PUCCH format used. UE104 can transmit a Sounding Reference Signal (SRS). SRS can be transmitted, for example, in the last symbol of a subframe. SRS can have a comb structure, and the UE can transmit SRS on one of the comb teeth. SRS can be used by the base station for channel quality estimation to enable frequency-dependent scheduling of the UL.

[0092] Figure 4D Examples of various UL channels within a subframe of a frame are illustrated. The PUCCH can be located as indicated in one configuration. The PUCCH carries uplink control information (UCI), such as scheduling requests, channel quality indicators (CQI), pre-decoding matrix indicators (PMI), rank indicators (RI), and HARQ ACK / NACK feedback. The PUSCH carries data and may additionally be used to carry buffer status reports (BSR), power clearance reports (PHR), and / or UCI.

[0093] Channel State Information (CSI) Feedback Coefficient Report Overview

[0094] As mentioned above, a User Equipment (UE) can be configured for Channel State Information (CSI) reporting, for example, by receiving a CSI configuration message from a Base Station (BS). In some cases, the UE can be configured to report at least the Type II pre-decoder across the frequency division (FD) units of the configuration. For example, for layer... pre-decoder matrix This includes using spatial compression to report the W1 matrix of a subset of the selected beams and using FD cells across configurations to report (for cross-polarization) the linear combination coefficients for the selected beams (2L). matrix: ,in , Where b i It is the selected beam, c i It is the set of linear combination coefficients (i.e., entries of the matrix), L is the number of selected spatial beams, and N3 corresponds to the number of frequency units (e.g., subbands, resource blocks (RBs), etc.). In some configurations, L is configured via radio resource control (RRC). The precoder is based on a linear combination of digital Fourier transform (DFT) beams. Type II codebooks can improve multi-user (MU) multiple-input multiple-output (MIMO) performance. In some configurations where two polarizations are considered, the size of the matrix is 2L×N3.

[0095] In some cases, a UE may be configured to report FD compressed precoder feedback to reduce the overhead of CSI reports. As Figure 5 depicted, for a layer (where ) the precoder matrix ( ) may use an FD compression matrix to compress the matrix size of the precoder matrix to 2L×M (where M is configured and conveyed by the network via RRC or downlink control information (DCI) in a CSI configuration message, and M<N3), which is given as:

[0096] where the precoder matrix (not shown) has P=2N1N2 rows (spatial domain, number of ports) and N3 columns (frequency domain compression units including RBs or reporting subbands), and where M bases are independently selected for each of layer 0 and layer 1. Matrix 520 includes linear combination coefficients (amplitude and co-phase), where each element represents a coefficient for a tap of a beam. As shown, matrix 520 is defined by a size of 2L×M, where one row corresponds to one spatial beam in a (not shown) of size P×2L (where L is configured by a network entity via RRC), and one entry therein represents a coefficient for one tap of the spatial beam. A UE may be configured to report (e.g., a CSI report) a subset K0<2LM of the linear combination coefficients of matrix 520. For example, the UE may report K exemplified as shaded squares <K0 coefficients (where K NZ,i <K0 coefficients (where K NZ,i corresponds to the maximum number of non-zero coefficients for layer- (where or 1), and K0 is configured by the network via RRC) (unreported coefficients are set to zero). In some configurations, the entries in matrix 520 correspond to Row 530 of matrix 530. In the example shown, at layer 0... Matrix 520 and at layer 1 Both matrix 450 and matrix 450 are 2L×M.

[0097] Matrix 530 consists of basis vectors (each row being a basis vector) used to perform compression in the frequency domain. In the example shown, at layer 0... Matrix 530 and at layer 1 Both matrices 560 and 560 include M=4 FD bases (instantiated as shaded rows) from N3 candidate DFT bases. In some configurations, the UE can report via CSI reporting. The matrix is ​​a subset of the basis for selection. Specifically, M bases are selected at layer 0 and layer 1. That is, the M bases selected at layer 0 can be the same as, partially overlap with, or not overlap with the M bases selected at layer 1.

[0098] The pre-decoded matrix indicator (PMI) codebook is a dictionary of PMI entries. In this way, using the PMI codebook, each PMI component from a predefined set can be mapped to a bit sequence reported by the user equipment (UE). The network entity receiving the bit sequence (e.g., as channel state feedback (CSF)) can then obtain the corresponding PMI from the reported bit sequence.

[0099] How the UE calculates the PMI is left to the UE's specific implementation. However, how the UE reports the PMI should follow the format defined in the codebook, so that both the UE and the network entity know how to map the PMI components to the reported bit sequence.

[0100] Figure 6 An example codebook-based CSF 600 is depicted. As depicted, the UE can first perform channel estimation (at 602) based on the Channel State Information (CSI) Reference Signal (RS) to estimate the channel H. The CSI calculation box 604 can generate a bit sequence. . As illustrated, the bit sequence It can be generated to find PMI components from a predefined PMI codebook used for radio channel H or pre-decoder W (at box 606), and map the PMI components to bit sequences via box 608. This mapping from a predefined set of PMI components serves as a form of quantization. The UE transmits the bit sequence via box 610. Send to BS (e.g., in a CSI report).

[0101] like Figure 6 As described, at the network entity side, the network entity receives the bit sequence reported by the UE. Then, the network entity follows the codebook to use the reported bit sequence. To obtain each PMI component, and at box 612, use each PMI component (obtained from the codebook) to reconstruct the actual PMI to recover the radio channel H or pre-decoder W.

[0102] Figure 7 Various scenarios 700 for coherent joint transmission (CJT) are depicted. These scenarios are referred to as: Scenario 1A, where co-located transmitter-receiver points (TRPs) / panels (within a site) have the same orientation; and Scenario 1B, where panels have different orientations (sectors). Another scenario (Scenario 2) may involve distributed TRPs (between sites).

[0103] Figure 8 Example 800 of Enhanced Type II (eType-II) CSI is depicted. In this example 800, for each layer, the number of spans is... The pre-decoder for each (PMI-) subband is matrix: .

[0104] Among them, space separation (SD) base (Direct Fourier Transform (DFT) basis) is matrix, It is shared by all floors. (Number of Tx antennas - of which) and Oversampling is configured by Radio Resource Control (RRC), L={2,4,6} (number of beams) is configured by RRC, and FD base... (DFT basis) is matrix, It is layer-specific, and M (the number of FD bases) is rank-pair-specific, that is, for rank = {1, 2}, And for rank = {3, 4}, , or It's configured with RRC. Coefficient matrix. for The matrix is ​​layer-specific. For each layer, the UE can report up to [number missing]. There are non-zero coefficients, among which It's configured with RRC. Across all tiers, the UE can report up to... There are 10 non-zero coefficients, where unreported coefficients can be set to zero.

[0105] Figure 9 An example scenario 900 for noncoherent joint transmission (NCJT) based on spatial multiplexing (SDM) is depicted, in which data is pre-decoded separately on different TRPs. Figure 9An example CJT is also depicted, where data is pre-decoded in a fully joint manner. Depending on an option, the data can be pre-decoded using separate pre-decoders with in-phase and amplitude coefficients. It is also possible that in-phase / in-amplitude coefficients are implicitly accommodated within the pre-decoder (therefore, the equations can appear indistinguishably from the NCJT case). Port diagrams for the first option of NCJT, CJT, and the second option of CJT are also depicted. Figure 10 Examples of CJT and NCJT scenarios 1000.

[0106] Aspects related to TRP beamforming for UE-assisted TRP synchronization

[0107] This disclosure provides apparatus, methods, processing systems, and computer-readable media for synchronizing timing and / or phase offsets between network entities, such as transmit-receive points (TRPs).

[0108] Some aspects of this disclosure relate to MIMO in UE-assisted CJT mTRP operation. Other aspects provide UE reporting techniques for CJT deployments under non-ideal synchronization and backhaul conditions. These techniques are particularly applicable to TDD in frequency range 1 (FR1). Such techniques can provide advantages in scenarios involving inter-TRP time misalignment and frequency / phase offset measurements (e.g., with legacy CSI-RS designs) and reporting on the PUSCH (e.g., independent aperiodic).

[0109] Some CJT-TDD scenarios may exhibit channel reciprocity issues. These issues can be understood when considering TDD systems, where SRS probes used for DL ​​channel measurements are based on reciprocity, assuming the downlink channel ( ) and uplink channel ( ) are reciprocal (e.g., transpose of each other): .

[0110] For CJT mTRP, there are multiple downlink channels (e.g., ) and multiple uplink channels ( Assuming there are two TRPs (TRP2 and TRP1), the expansion is as follows: .

[0111] However, for distributed TRPs with their own independent clock sources, the measured UL channel (including Tx and Rx phases) is measured via SRS. , This can be represented as: .

[0112] Measured DL channel for potential PDSCH ( , (including the phases of Tx and Rx) can be expressed as: .

[0113] In the above equation, Rx is misaligned. Tx misalignment (For example, for TRP or UE) includes two items: 1) Timing offset (represented as ) and 2) phase shift (represented as In the frequency domain (e.g., in different subcarriers) k Rx misaligned at (location) Tx misalignment They can be represented as and : ;as well as .

[0114] To achieve reciprocity-based SRS channel detection, the following conditions may need to be met: , in This is a constant shared by TRP (e.g., it can be unknown). The following can be derived: (at each subcarrier k) .

[0115] To achieve SRS reciprocity in the CJT-TDD system, the Rx-Tx timing offset between TRPs can be eliminated. ) and phase shift ( It can be represented by the following equation: ;as well as .

[0116] In the above equation, timing offset Channel propagation delay may be excluded, and phase offset may be excluded. Channel phase may not be included.

[0117] For reference Figure 11 To understand timing offset, Figure 11 Timing diagram 1100 depicts the timing offset between exemplary TRPs. For simplicity, it can be assumed (and in the equations below) that both TRPs are single propagation paths.

[0118] As illustrated at 1102, the channel estimate (ChanEst) via the uplink (e.g., by the network) has a power density distribution (PDP), where the TRP2-to-1 delay is expressed as: .

[0119] As illustrated at 1104, the channel “seen” via the downlink (e.g., by the UE) has a PDP, where the TRP2-to-1 delay is represented as (e.g., different from the ChanEst via the uplink above): .

[0120] In some cases, with the aid of a UE, the TRP can be synchronized based on feedback regarding timing and / or phase offset.

[0121] Figure 12 A call flowchart 1200 illustrating an example UE-assisted TRP synchronization is depicted.

[0122] As illustrated at 1202, the UE may send UL-RS (e.g., SRS) to TRP1 and TRP2. The reception at TRP1 and TRP2 can be represented as follows: ; , Wherein, at subcarrier k, for the receiver side (e.g., TRP or UE): , And at subcarrier k, for the transmitter side (e.g., TRP or UE): .

[0123] In some cases, SRS can be transmitted using only a single transceiver of the UE. This is relatively common, for example, if phase coherence cannot be guaranteed between the transceivers of the UE.

[0124] As illustrated at 1204 and 1206, each TRP may send a corresponding DL-RS, such as a single-port CSI-RS, to the UE. In this case, each CSI-RS may be based on at least the phase of the corresponding received SRS (e.g., phase conjugate). and ) to pre-decode.

[0125] CSI-RS pre-decoding can help ensure that channel propagation delay and channel phase are canceled out, and for , No effect, indicated as: ;as well as .

[0126] As illustrated at 1208, the UE can (e.g., on multiple subcarriers) calculate: .

[0127] This method ensures that the phase of the UE's Rx-Tx uncertainty is canceled out, and only the timing offset and phase offset between TRPs remain: , .

[0128] In some cases, the timing and phase offsets between two TRPs (TRPs) It can be achieved by using subcarriers k=1,…,K across the entire bandwidth. To estimate.

[0129] As illustrated at 1210, the estimated This can be reported to one of the TRPs (e.g., TRP2) to synchronize with another TRP (e.g., TRP1), as illustrated at 1212. In other words, one or both TRPs can adjust transmit and / or receiver parameters to account for timing and / or phase offsets.

[0130] Figure 13 A call flowchart 1300 illustrating example UE-assisted TRP synchronization is depicted, wherein the UE has multiple ( A Transceiver / antenna.

[0131] As illustrated at 1302, the UE can utilize its respective A One transceiver / antenna transmits to TRP1 and TRP2. A >1 SRS (e.g., or A >1 port). The reception at TRP1 and TRP2 can be represented as follows: (at TRP1), and (At TRP2).

[0132] As illustrated at 1304 and 1306 respectively, TRP1 and TRP2 can each send to the UE. A >1 corresponding single-port CSI-RS, where each CSI-RS is pre-decoded based on the corresponding received SRS (e.g., port). For example, the CSI-RS can be generated at TRP1 by Pre-decoding, and by TRP2 Pre-decoding. The corresponding reception from TRP1 (e.g., and similar to TRP2) can be represented as shown in the table below (e.g., dimension 1). A × A ):

[0133] As illustrated at 1308, the UE can operate on multiple subcarriers (e.g., based on the total from each TRP). Calculate (each received signal item) And it can export the timing offset between TRPs ( ) and phase shift ( These calculations may vary significantly depending on the UE implementation (e.g., example algorithms are described below).

[0134] As illustrated at 1310, the estimated It can be reported to one of the TRPs (e.g., TRP2) to synchronize to another TRP (e.g., TRP1), as illustrated at 1312.

[0135] Figure 14 Figure 1400 illustrates an example communication between a UE with multiple antennas and two TRPs. In the figure, the numbers in brackets [1] and [2] correspond to the antenna indices of the two antennas (ports or transceivers). The illustrated example assumes antenna [1] and antenna [2]. As illustrated at 1402, the link between TRP1 and antenna [1] of the UE can be represented as follows: As illustrated at 1404, the link between TRP1 and the UE's antenna [2] can be represented as follows: Similarly, as illustrated at 1406 and 1408 respectively, the link between TRP2 and the UE's antenna [1] can be represented as follows: And the link between TRP2 and the UE's antenna [2] can be represented as .

[0136] The link between TRP1 and the UE (e.g., antenna 1 and antenna 2 respectively) can be represented by the following equation: ;as well as .

[0137] The "diagonal" terms from TRP1 can be represented by the following equation (for example, where each term cancels out the corresponding channel phase): ------(1)and ------(2)

[0138] The "off-diagonal" term from TRP1 can be represented by the following equation: ------(3a) ------(3b)

[0139] As shown below, equations (3a) × (3b) cancel out the channel phase: ------(3)

[0140] The link between TRP2 and the UE generates items similar to those in TRP2 (e.g., “diagonal” items (1’), (2’) and “off-diagonal” items (3a’) × (3b’). (3')). The Rx-Tx phase uncertainty of the UE antenna / transceiver [1] and [2] can be expressed by equation (1) respectively. ×(1)or(2) ×(2)or(3) × (3') (for example, or in combination using these equations) to cancel each other out.

[0141] Figure 15 A diagram illustrating example communication between a UE with multiple antennas and two TRPs with multiple antennas is shown.

[0142] The link between TRP1 and the UE (e.g., antenna 1 and antenna 2 respectively) can be represented by the following equation: Size is P×1; and Its size is P×1.

[0143] The "diagonal" terms can be represented by the following equation (for example, where each term cancels out the corresponding channel phase): ------(1)and ------(2)

[0144] The "off-diagonal" term can be represented by the following equation: ------(3a;and ------(3b)

[0145] Therefore, (3a) × (3b) (3) It cancels out channel phase (e.g., similar to the reference above). Figure 14 The equation described.

[0146] The link between TRP2 and the UE generates items similar to those in TRP2 (e.g., “diagonal” items (1’), (2’) and “off-diagonal” items (3a’) × (3b’). (3')). The Rx-Tx phase uncertainty of the UE antenna / transceiver [1] and [2] can be expressed by equation (1) respectively. ×(1)or(2) ×(2)or(3) × (3') (for example, or in combination using these equations) to cancel each other out.

[0147] According to various aspects of this disclosure, beamforming (e.g., digital beamforming) can be employed (at the TRP) to improve the signal-to-noise ratio (SNR) of these techniques for UE-assisted TRP synchronization in CJT-TDD. Furthermore, these techniques can allow for the calculation of Rx-Tx timing offsets between TRPs (e.g., ) and phase shift (e.g., This can offset channel propagation delay and channel phase, while improving SNR.

[0148] Figure 16 Figure 1600 illustrates an example TRP digital beamforming application at TRP1 according to certain aspects of this disclosure. Although not shown, similar beamforming can be utilized at TRP2. The techniques for implementing beamforming are described below.

[0149] In the first step, TRP1 receives SRS from the UE. For example, from the UE transceiver [1], the SRS reception at TRP1 can be described as follows: , The size is P×1, where P is the number of TXRUs / ports of TRP1, and the index p=1,…,P. TRP can perform optimal digital beamforming for Rx on all transceivers a=1,…,A of the UE, using the highest signal strength. The search, in which: , And expressed as: The size is P×1. Virtual ports can be formed by combining / summing all P ports of the TRP. For example, for a UE transceiver [1], the equation can be: .

[0150] In the second step, the same digital beam used for receiving (Rx) can be applied for transmitting TRP1. For example, for a single-port CSI-RS based on the pre-decoded conjugate of the SRS received from the UE transceiver [1]: Its size is P×1.

[0151] The equations for the TRP1-UE link can be determined in the following steps. For the first step, TRP1 receives SRS from the UE (e.g., two SRS / ports transmitted by the UE's two antennas / transceivers): Size is P×1; and Its size is P×1.

[0152] The virtual receiver port can be defined by the following equation: scalar; , scalar.

[0153] The second step is to enable the UE to receive the corresponding transmitted CSI-RS from TRP1, which may involve "diagonal" entries (e.g., where each entry cancels out channel phase): ------(1)and ------(2) And the "off-diagonal" term, which can be described by the following equation: ------(3a;and ------(3b)

[0154] Therefore, (3a) × (3b) (3) Can cancel channel phase (similar to the above reference) Figure 15 The calculation described.

[0155] The “TRP2 to UE” link can generate items similar to TRP2 (“diagonal” items (1’), (2’) and “off-diagonal” items (3a’) × (3b’). (3')). In this context, the "diagonal" and "non-diagonal" items can be described as above.

[0156] In the third step, the Rx-Tx phase uncertainty of the UE antenna / transceiver [1] and [2] can be solved by equation (1). ×(1)or(2) ×(2)or(3) ×(3) to offset, or by using these equations in combination to offset.

[0157] Figure 17 Figure 1700 illustrates an example link between CSI-RS and SRS for CSI-RS pre-decoding, according to certain aspects of this disclosure.

[0158] For CJT-TDD, for N-based TRP UE-assisted TRP synchronization of CSI-RSs of the set with inter-TRP phase / timing offset reports, wherein each CSI-RS from each set is linked to an SRS (port) (i.e., the CSI-RS is pre-decoded based on the ChanEst received from the linked SRS (port) to offset channel phase and channel propagation delay), and the UE can expect any CSI-RS to be transmitted via a Tx port associated with the Rx port used to receive the linked SRS (port).

[0159] In some cases, the UE may assume that, for the network side, the transmit (Tx) port and the associated receive (Rx) port have the same "port-to-antenna element" pre-decoding (i.e., the same digital / hybrid beamforming). ).

[0160] (For example, the Rx pre-decoding of the SRS from the UE transceiver / antenna [1] can be as follows:) , in This is the descrambled original reception (i.e., UL chanEst). The CSI Tx pre-decoding can be defined as: , in This is the CSI-RS sequence (data) to be sent.

[0161] Transmissions from any of the CSI-RSs can also be pre-decoded based on at least the phase of the reception of the linked SRS. For example, pre-decoding can be based on the conjugate of the reception of the SRS via the virtual port of the associated TRP (or equivalently, via each transceiver (receiver) of the associated TRP).

[0162] In some cases, all CSI-RS transmissions may be single-port only. The number of CSI-RS in each set can be represented as "A" (A also represents the number of UE transceivers / antennas), where each CSI-RS is linked to each of all A SRS (or A ports) (i.e., pre-decoded based on at least (conjugate) phase of the received SRS (ports) linked to).

[0163] According to one option, the UE may assume that CSI-RS within the same set (TRP) have the same Tx port (e.g., the same virtual port (digital / hybrid beam)). According to the second option, it is configurable whether the CSI-RS within the same UE set (TRP) have the same Tx port or different Tx ports (e.g., different virtual ports (digital / hybrid beam)). From the perspective of UE implementation, if different Tx ports are configured for different SRS (or ports, i.e., UE transceivers / antennas), the UE may not be able to use "off-diagonal" terms to cancel channel phase (e.g., as shown in the derivation described below).

[0164] In this case, for the “TRP1 – UE” link, the first step may involve the following equations: Its size is P×1; Its size is P×1.

[0165] For virtual port 1: scalar; , scalar.

[0166] For virtual port 2: scalar; , scalar.

[0167] The second step may involve "diagonal" terms (each of which cancels out the channel phase): ------(1) .

[0168] For the "non-diagonal" item: ------(3a;and ------(3b)

[0169] In the above equation, the term is: .

[0170] They may not be mutually dependent.

[0171] Example Operation

[0172] Figure 18 This shows the user equipment (UE) (such as Figure 1 and Figure 3 An example of a method 1800 for wireless communication at UE 104.

[0173] Method 1800 begins at step 1805, transmitting at least a first uplink reference signal (RS) and a second uplink RS via at least a first port and a second port. In some cases, this step refers to the operation of referencing... Figure 20 The circuitry and / or code described for transmitting, or that can be executed by the circuitry and / or the code.

[0174] Method 1800 then proceeds to step 1810, receiving at least a first downlink RS and a second downlink RS from the first network entity. In some cases, this step refers to the operation as described in reference... Figure 20 The circuitry and / or code described for receiving, or that can be executed by the circuitry and / or the code.

[0175] Method 1800 then proceeds to step 1815, receiving at least a third downlink RS and a fourth downlink RS from the second network entity. In some cases, this step refers to the operation as described in reference [reference needed]. Figure 20 The circuitry and / or code described for receiving, or that can be executed by the circuitry and / or the code.

[0176] Method 1800 then proceeds to step 1820, deriving at least one of the timing offset or phase offset between the first network entity and the second network entity based on the first downlink RS, the second downlink RS, the third downlink RS, the fourth downlink RS, and the following assumptions: 1) the first downlink RS and the second downlink RS are transmitted from the first network entity using a first transmit beamforming derived from a first receive beamforming for the first uplink RS and the second uplink RS, and 2) the third downlink RS and the fourth downlink RS are transmitted from the second network entity using a second transmit beamforming derived from a second receive beamforming for the first uplink RS and the second uplink RS. In some cases, the operation of this step refers to or may be derived from, as referenced Figure 20 The circuitry and / or code used for export are executed.

[0177] Method 1800 then proceeds to step 1825, sending at least one of a timing offset or a phase offset to at least one of the first network entity or the second network entity. In some cases, this step refers to the operation as described in reference... Figure 20 The circuitry and / or code described for transmitting, or that can be executed by the circuitry and / or the code.

[0178] In some respects, at least one of the timing offset or phase offset is derived based on the following assumptions: the first downlink RS is transmitted via a first transmit port associated with a first receive port used by the first network entity to receive the first uplink RS, and the second downlink RS is transmitted via a second transmit port associated with a second receive port used by the first network entity to receive the second uplink RS; and the third downlink RS is transmitted via a third transmit port associated with a third receive port used by the second network entity to receive the first uplink RS, and the fourth downlink RS is transmitted via a fourth transmit port associated with a fourth receive port used by the second network entity to receive the second uplink RS.

[0179] In some respects, the first transmit port and the first receive port are associated with first port-to-antenna element pre-decoding; the second transmit port and the second receive port are associated with second port-to-antenna element pre-decoding; the third transmit port and the third receive port are associated with third port-to-antenna element pre-decoding; and the fourth transmit port and the fourth receive port are associated with fourth port-to-antenna element pre-decoding.

[0180] In some respects, the first and second transmitting ports are the same; and the third and fourth transmitting ports are the same.

[0181] In some respects, the first and second transmitting ports are different; and the third and fourth transmitting ports are different.

[0182] In some aspects, method 1800 further includes receiving signaling indicating whether the first transmitting port and the second transmitting port are the same. In some cases, this step refers to the operation as described in reference... Figure 20 The circuitry and / or code described for receiving, or that can be executed by the circuitry and / or the code.

[0183] In some respects, the first uplink RS and the second uplink RS include a sounding reference signal (SRS).

[0184] In some respects, the first downlink RS and the second downlink RS include channel state information (CSI) RS.

[0185] In one aspect, method 1800 or any aspect thereof may be made by means of a device (such as...) Figure 20 The communication device 2000 is used to perform the method 1800, which includes various components capable of operating, being configured, or adapted to perform the method. The communication device 2000 is described in further detail below.

[0186] It should be noted that Figure 18This is merely one example of a method, and other methods that include fewer, additional, or alternative steps may also be consistent with this disclosure.

[0187] Figure 19 It is shown in the first network entity (such as Figure 1 and Figure 3 (BS 102) or as relative to Figure 2 An example of the method of wireless communication at the decomposed base station discussed in 1900.

[0188] Method 1900 begins at step 1905, receiving at least a first uplink reference signal (RS) and a second uplink RS from the user equipment. In some cases, this step refers to the operation as reference... Figure 20 The circuitry and / or code described for receiving, or that can be executed by the circuitry and / or the code.

[0189] Method 1900 then proceeds to step 1910, at least: 1) transmitting a first downlink RS to the UE using a first transmit beamforming derived from a first receive beamforming for a first uplink RS, and 2) transmitting a second downlink RS to the UE using a second transmit beamforming derived from a second receive beamforming for a second uplink RS. In some cases, the operation of this step refers to, as referenced Figure 20 The circuitry and / or code described for transmitting, or that can be executed by the circuitry and / or the code.

[0190] Method 1900 then proceeds to step 1915, receiving indications of timing and phase offsets for the first and second network entities, the timing and phase offsets being derived by the UE based on the first downlink RS, the second downlink RS, the third downlink RS transmitted by the second network entity, and the fourth downlink RS transmitted by the second network entity. In some cases, this step refers to the operation as described in reference... Figure 20 The circuitry and / or code described for receiving, or that can be executed by the circuitry and / or the code.

[0191] In some respects, the indication is received from the UE.

[0192] In some respects, the instructions are received from a second network entity.

[0193] In some respects, the first downlink RS is transmitted via a first transmit port associated with a first receive port used by the first network entity to receive the first uplink RS; and the second downlink RS is transmitted via a second transmit port associated with a second receive port used by the first network entity to receive the second uplink RS.

[0194] In some respects, the first transmit port and the first receive port are associated with first port-to-antenna element pre-decoding; and the second transmit port and the second receive port are associated with second port-to-antenna element pre-decoding.

[0195] In some respects, the first transmitting port and the second transmitting port are the same.

[0196] In some respects, the first transmitting port and the second transmitting port are different.

[0197] In some aspects, method 1900 further includes sending signaling indicating whether the first transmitting port and the second transmitting port are the same. In some cases, this step refers to the operation as described in reference... Figure 20 The circuitry and / or code described for transmitting, or that can be executed by the circuitry and / or the code.

[0198] In some respects, the first uplink RS and the second uplink RS include a sounding reference signal (SRS).

[0199] In some respects, the first downlink RS and the second downlink RS include channel state information (CSI) RS.

[0200] In one aspect, method 1900 or any aspect thereof may be made by means of a device (such as...) Figure 20 The communication device 2000 is used to perform the method 1900, which includes various components capable of operating, being configured, or adapted to perform the method. The communication device 2000 is described in further detail below.

[0201] It should be noted that Figure 19 This is merely one example of a method, and other methods that include fewer, additional, or alternative steps may also be consistent with this disclosure.

[0202] Example communication device

[0203] Figure 20 Various aspects of the example communication device 2000 are described. In some aspects, the communication device 2000 is user equipment, such as those mentioned above. Figure 1 and Figure 3 The UE 104 is described. In some respects, the communication device 2000 is a network entity, such as... Figure 1 and Figure 3 BS 102 or as about Figure 2 The decomposed base station under discussion.

[0204] The communication device 2000 includes a processing system 2005 coupled to a transceiver 2055 (e.g., a transmitter and / or receiver). In some aspects (e.g., when the communication device 2000 is a network entity), the processing system 2005 may be coupled to a network interface 2065, which is configured to communicate via a communication link (such as, as described herein, regarding...). Figure 2 The described backhaul link, midhaul link, and / or fronthaul link acquire and transmit signals for the communication device 2000. Transceiver 2055 is configured to transmit and receive signals for the communication device 2000, such as the various signals described herein, via antenna 2060. Processing system 2005 may be configured to perform processing functions for the communication device 2000, including processing signals received by the communication device 2000 and / or to be transmitted by the communication device.

[0205] The processing system 2005 includes one or more processors 2010. In various aspects, the one or more processors 2010 may represent one or more of a receive processor 358, a transmit processor 364, a TX MIMO processor 366, and / or a controller / processor 380, as per [reference to...]. Figure 3 As described. In various respects, one or more processors 2010 may represent one or more of the following: receive processor 338, transmit processor 320, TX MIMO processor 330, and / or controller / processor 340, as per [reference to...]. Figure 3 As described. One or more processors 2010 are coupled to a computer-readable medium / memory 2030 via a bus 2050. In some aspects, the computer-readable medium / memory 2030 is configured to store instructions (e.g., computer-executable code) that, when executed by one or more processors 2010, cause one or more processors 2010 to perform actions regarding Figure 18 The described method 1800 or any aspect thereof; and relative to Figure 19 The method 1900 described herein or any aspect thereof. It should be noted that references to processors performing the functions of communication device 2000 may include one or more processors 2010 performing those functions of communication device 2000.

[0206] In the depicted example, computer-readable medium / memory 2030 stores code (e.g., executable instructions), such as code 2035 for transmitting, code 2040 for receiving, and code 2045 for exporting. Processing the code 2035 for transmitting, the code 2040 for receiving, and the code 2045 for exporting enables the communication device 2000 to perform operations related to... Figure 18 The described method 1800 or any aspect thereof; and relative to Figure 19The method described in 1900 or any aspect thereof.

[0207] One or more processors 2010 include circuitry configured to implement (e.g., execute) code stored in computer-readable medium / memory 2030, including circuitry 2015 for transmitting, circuitry 2020 for receiving, and circuitry 2025 for deriving. Processing using the circuitry 2015 for transmitting, the circuitry 2020 for receiving, and the circuitry 2025 for deriving enables the communication device 2000 to perform operations related to... Figure 18 The described method 1800 or any aspect thereof; and relative to Figure 19 The method described in 1900 or any aspect thereof.

[0208] The various components of the communication device 2000 provide parts for performing: about Figure 18 The described method 1800 or any aspect thereof; and relative to Figure 19 The described method 1900 or any aspect thereof. For example, components for transmitting, conveying, or outputting for transmission may include... Figure 3 The transceiver 354 and / or antenna 352 of UE 104 illustrated herein Figure 3 The transceiver 332 and / or antenna 334 of BS 102 illustrated herein Figure 20 The communication device 2000 includes a transceiver 2055 and an antenna 2060. Components for receiving or acquiring data may include... Figure 3 The transceiver 354 and / or antenna 352 of UE 104 illustrated herein Figure 3 The transceiver 332 and / or antenna 334 of BS 102 illustrated herein Figure 20 The transceiver 2055 and antenna 2060 of the communication equipment 2000.

[0209] Example Terms

[0210] Specific implementation examples are described in the following numbered clauses: Clause 1: A method for wireless communication at a user equipment (UE), the method comprising: transmitting at least a first uplink reference signal (RS) and a second uplink RS via at least a first port and a second port; receiving at least a first downlink RS and a second downlink RS from a first network entity; receiving at least a third downlink RS and a fourth downlink RS from a second network entity; deriving at least one of a timing offset or a phase offset between the first network entity and the second network entity based on the first downlink RS, the second downlink RS, the third downlink RS, the fourth downlink RS and the following assumptions: 1) the first downlink RS and the second downlink RS are transmitted from the first network entity using a first transmit beamforming derived from a first receive beamforming for the first uplink RS and the second uplink RS, and 2) the third downlink RS and the fourth downlink RS are transmitted from the second network entity using a second transmit beamforming derived from a second receive beamforming for the first uplink RS and the second uplink RS; and transmitting at least one of the timing offset or the phase offset to at least one of the first network entity or the second network entity.

[0211] Clause 2: According to the method of Clause 1, the at least one of the timing offset or the phase offset is derived based on the following assumptions: the first downlink RS is transmitted via a first transmit port associated with a first receive port used by the first network entity to receive the first uplink RS, and the second downlink RS is transmitted via a second transmit port associated with a second receive port used by the first network entity to receive the second uplink RS; and the third downlink RS is transmitted via a third transmit port associated with a third receive port used by the second network entity to receive the first uplink RS, and the fourth downlink RS is transmitted via a fourth transmit port associated with a fourth receive port used by the second network entity to receive the second uplink RS.

[0212] Clause 3: The method according to Clause 2, wherein the first transmit port and the first receive port are associated with a first port-to-antenna element pre-decoding; the second transmit port and the second receive port are associated with a second port-to-antenna element pre-decoding; the third transmit port and the third receive port are associated with a third port-to-antenna element pre-decoding; and the fourth transmit port and the fourth receive port are associated with a fourth port-to-antenna element pre-decoding.

[0213] Clause 4: The method described in Clause 2, wherein the first transmitting port and the second transmitting port are the same; and the third transmitting port and the fourth transmitting port are the same.

[0214] Clause 5: The method described in Clause 2, wherein the first transmitting port and the second transmitting port are different; and the third transmitting port and the fourth transmitting port are different.

[0215] Clause 6: The method according to Clause 2 further includes receiving signaling indicating whether the first transmitting port and the second transmitting port are the same.

[0216] Clause 7: The method according to any one of Clauses 1 to 6, wherein the first uplink RS and the second uplink RS include a sounding reference signal (SRS).

[0217] Clause 8: The method according to any one of Clauses 1 to 7, wherein the first downlink RS and the second downlink RS include channel state information (CSI) RS.

[0218] Clause 9: A method for wireless communication at a first network entity, the method comprising: receiving at least a first uplink reference signal (RS) and a second uplink RS from a user equipment; at least: 1) transmitting a first downlink RS to the UE using a first transmit beamforming derived from a first receive beamforming for the first uplink RS, and 2) transmitting a second downlink RS to the UE using a second transmit beamforming derived from a second receive beamforming for the second uplink RS; and receiving indications of timing offsets and phase offsets for the first network entity and the second network entity, the timing offsets and phase offsets being derived by the UE based on the first downlink RS, the second downlink RS, a third downlink RS transmitted by the second network entity, and a fourth downlink RS transmitted by the second network entity.

[0219] Clause 10: The method described in Clause 9, wherein the instruction is received from the UE.

[0220] Clause 11: The method according to any one of Clauses 9 to 10, wherein the instruction is received from the second network entity.

[0221] Clause 12: The method according to any one of Clauses 9 to 11, wherein the first downlink RS is transmitted via a first transmit port associated with a first receive port used by the first network entity to receive the first uplink RS; and the second downlink RS is transmitted via a second transmit port associated with a second receive port used by the first network entity to receive the second uplink RS.

[0222] Clause 13: The method according to Clause 12, wherein the first transmit port and the first receive port are associated with a first port-to-antenna element pre-decoding; and the second transmit port and the second receive port are associated with a second port-to-antenna element pre-decoding.

[0223] Clause 14: The method described in Clause 12, wherein the first transmitting port and the second transmitting port are the same.

[0224] Clause 15: The method described in Clause 12, wherein the first transmitting port and the second transmitting port are different.

[0225] Clause 16: The method according to Clause 12 further includes sending signaling indicating whether the first sending port and the second sending port are the same.

[0226] Clause 17: The method according to any one of Clauses 9 to 16, wherein the first uplink RS and the second uplink RS include a sounding reference signal (SRS).

[0227] Clause 18: The method according to any one of Clauses 9 to 17, wherein the first downlink RS and the second downlink RS include channel state information (CSI) RS.

[0228] Clause 19: An apparatus comprising: at least one memory including executable instructions; and at least one processor configured to execute the executable instructions and cause the apparatus to perform the method according to any combination of Clauses 1 to 18.

[0229] Clause 20: An apparatus comprising: a component for performing the method described in any combination of Clauses 1 to 18.

[0230] Clause 21: A non-transitory computer-readable medium comprising executable instructions that, when executed by at least one processor of the device, cause the device to perform the method according to any combination of Clauses 1 to 18.

[0231] Clause 22: A computer program product embodied on a computer-readable storage medium, the computer-readable storage medium including code for performing the methods described in any combination of Clauses 1 to 18.

[0232] Additional Notes

[0233] The foregoing description is provided to enable any person skilled in the art to practice the various aspects described herein. The examples discussed herein do not limit the scope, applicability, or aspects set forth in the claims. Various modifications to these aspects will be apparent to those skilled in the art, and the general principles defined herein may be applied to other aspects. For example, the function and arrangement of the elements discussed may be changed without departing from the scope of this disclosure. Various processes or components may be omitted, substituted, or added as appropriate in the various examples. For example, the described methods may be performed in a different order than described, and various actions may be added, omitted, or combined. Furthermore, features described with respect to some examples may be combined in some other examples. For example, any number of aspects set forth herein may be used to implement an apparatus or practice. Moreover, the scope of this disclosure is intended to cover such apparatuses or methods practiced using other structures, functionalities, or structures and functionalities that complement or replace the various aspects of this disclosure set forth herein. It should be understood that any aspect of the disclosure herein may be embodied by one or more elements of the claims.

[0234] The various exemplary logic blocks, modules, and circuits described in this disclosure can be implemented or executed using a general-purpose processor, graphics processing unit (GPU), neural processing unit (NPU), digital signal processor (DSP), ASIC, field-programmable gate array (FPGA) or other programmable logic device (PLD), discrete gate or transistor logic unit, discrete hardware component, or any combination thereof designed to perform the functions described herein. While the general-purpose processor may be a microprocessor, in alternative embodiments, the processor may be any commercially available processor, controller, microcontroller, or state machine. The processor may also be implemented as a combination of computing devices, such as a combination of a DSP and a microprocessor, multiple microprocessors, one or more microprocessors working in conjunction with a DSP core, a system-on-a-chip (SoC), or any other such configuration.

[0235] As used herein, "processor," "at least one processor," or "one or more processors" generally refers to a single processor configured to perform one or more operations, or multiple processors configured to collectively perform one or more operations. In the case of multiple processors, the execution of one or more operations may be divided among different processors, but one processor may perform multiple operations, and multiple processors may collectively perform a single operation. Similarly, "memory," "at least one memory," or "one or more memory" generally refers to a single memory configured to store data and / or instructions, or multiple memories configured to collectively store data and / or instructions.

[0236] In some cases, instead of actually transmitting signals, a device (e.g., a wireless node or device) may have an interface for outputting signals for transmission. For example, a processor may output signals to a radio frequency (RF) front-end via a bus interface for transmission. Therefore, components for output may include such an interface as an alternative (or addition) to a transmitter or transceiver. Similarly, instead of actually receiving signals, a device (e.g., a wireless node or device) may have an interface for receiving signals from another device. For example, a processor may receive (or acquire) signals from an RF front-end for reception via a bus interface. Therefore, components for acquisition may include such an interface as an alternative (or addition) to a receiver or transceiver.

[0237] The components for sending, receiving, and exporting may include one or more processors, such as those mentioned above. Figure 20 One or more of the processors described.

[0238] As used in this article, the phrase “at least one of” in a list of items refers to any combination of these items, including a single member. For example, “at least one of a, b, or c” is intended to cover a, b, c, ab, ac, bc, and abc, as well as any combination with multiple identical elements (e.g., aa, aaa, aab, aac, abb, acc, bb, bbb, bbc, cc, and ccc, or any other ordering of a, b, and c).

[0239] As used herein, the term "determine" encompasses a wide variety of actions. For example, "determine" can include calculation, operation, processing, deduction, investigation, lookup (e.g., searching in a table, database, or other data structure), assertion, etc. Additionally, "determine" can include receiving (e.g., receiving information), accessing (e.g., accessing data in memory), etc. Furthermore, "determine" can include parsing, selecting, picking, building, etc.

[0240] The methods disclosed herein include one or more actions for implementing the methods. These actions may be interchanged without departing from the scope of the claims. In other words, unless a specific order of actions is specified, the order and / or use of a particular action may be modified without departing from the scope of the claims. Furthermore, the various operations of the methods described above may be performed by any suitable component capable of performing the corresponding function. This component may include various hardware and / or software components and / or modules, including but not limited to circuits, application-specific integrated circuits (ASICs), or processors. Software should be broadly interpreted as instructions, instruction sets, code, code segments, program code, programs, subroutines, software modules, applications, software applications, software packages, routines, subroutines, objects, executables, threads of execution, procedures, or functions, whether referred to as software, firmware, middleware, microcode, hardware description languages, or other terms.

[0241] The following claims are not intended to be limited to the aspects shown herein, but should be given the full scope consistent with the language of the claims. Within the claims, unless specifically stated otherwise, reference to the singular form of an element is not intended to mean “one and only one,” but rather “one or more.” Unless specifically stated otherwise, the term “some” refers to one or more. No element of any claim shall be interpreted in accordance with 35 USC §112(f) unless that element is explicitly stated using the phrase “for a component of.” All structural and functional equivalents of the elements throughout the various aspects described herein that are known to a person of ordinary skill in the art, or will later be known, are expressly incorporated herein by reference and are intended to be covered by the claims. Furthermore, nothing disclosed herein is intended to be offered to the public, whether or not such disclosure is explicitly recited in the claims.

Claims

1. An apparatus for wireless communication at a user equipment (UE), the apparatus comprising: Memory, the memory including instructions; and One or more processors, individually or in any combination, are configured to execute the instructions and cause the device to: At least a first uplink reference signal (RS) and a second uplink RS are transmitted via at least a first port and a second port; Receive at least a first downlink RS and a second downlink RS from the first network entity; Receive at least a third downlink RS and a fourth downlink RS from the second network entity; Based on the first downlink RS, the second downlink RS, the third downlink RS, the fourth downlink RS, and the following assumptions, at least one of the timing offset or phase offset between the first network entity and the second network entity is derived: 1) the first downlink RS and the second downlink RS are transmitted from the first network entity using a first transmit beamforming derived from a first receive beamforming for the first uplink RS and the second uplink RS, and 2) the third downlink RS and the fourth downlink RS are transmitted from the second network entity using a second transmit beamforming derived from a second receive beamforming for the first uplink RS and the second uplink RS; as well as Send at least one of the timing offset or the phase offset to at least one of the first network entity or the second network entity.

2. The apparatus of claim 1, wherein at least one of the timing offset or the phase offset is derived based on the following assumption: The first downlink RS is transmitted via a first transmit port associated with a first receive port used by the first network entity to receive the first uplink RS, and the second downlink RS is transmitted via a second transmit port associated with a second receive port used by the first network entity to receive the second uplink RS; and The third downlink RS is transmitted via a third transmit port associated with a third receive port used by the second network entity to receive the first uplink RS, and the fourth downlink RS is transmitted via a fourth transmit port associated with a fourth receive port used by the second network entity to receive the second uplink RS.

3. The apparatus according to claim 2, wherein: The first transmitting port and the first receiving port are associated with the first port to antenna element pre-decoding; The second transmit port and the second receive port are associated with the second port to antenna element pre-decoding; The third transmitting port and the third receiving port are associated with pre-decoding from the third port to the antenna element; and The fourth transmit port and the fourth receive port are associated with the fourth port-to-antenna element pre-decoding.

4. The apparatus according to claim 2, wherein: The first transmitting port and the second transmitting port are the same; and The third transmission port and the fourth transmission port are the same.

5. The apparatus according to claim 2, wherein: The first transmitting port and the second transmitting port are different; and The third transmission port and the fourth transmission port are different.

6. The apparatus of claim 2, wherein the one or more processors are further configured individually or in any combination to execute the instructions and cause the apparatus to receive signaling instructing the following: Whether the first sending port and the second sending port are the same.

7. The apparatus of claim 1, wherein the first uplink RS and the second uplink RS include a sounding reference signal (SRS).

8. The apparatus of claim 1, wherein the first downlink RS and the second downlink RS include a single-port channel state information (CSI) RS.

9. An apparatus for wireless communication at a first network entity, the apparatus comprising: Memory, the memory including instructions; and One or more processors, individually or in any combination, are configured to execute the instructions and cause the device to: Receive at least a first uplink reference signal (RS) and a second uplink RS from the user equipment; At least: 1) transmitting a first downlink RS to the UE using a first transmit beamforming derived from a first receive beamforming for the first uplink RS, and 2) transmitting a second downlink RS to the UE using a second transmit beamforming derived from a second receive beamforming for the second uplink RS; as well as The UE receives indications of timing offsets and phase offsets for the first network entity and the second network entity, the timing offsets and phase offsets being derived by the UE based on the first downlink RS, the second downlink RS, the third downlink RS transmitted by the second network entity, and the fourth downlink RS transmitted by the second network entity.

10. The apparatus of claim 9, wherein the instruction is received from the UE.

11. The apparatus of claim 9, wherein the instruction is received from the second network entity.

12. The apparatus according to claim 9, wherein: The first downlink RS is transmitted via a first transmit port associated with a first receive port used by the first network entity to receive the first uplink RS; and The second downlink RS is transmitted via a second transmit port associated with a second receive port used by the first network entity to receive the second uplink RS.

13. The apparatus according to claim 12, wherein: The first transmitting port and the first receiving port are associated with the first port-to-antenna element pre-decoding; and The second transmit port and the second receive port are associated with the second port to antenna element pre-decoding.

14. The apparatus of claim 12, wherein the first transmitting port and the second transmitting port are the same.

15. The apparatus of claim 12, wherein the first transmitting port and the second transmitting port are different.

16. The apparatus of claim 12, wherein the one or more processors are further configured individually or in any combination to execute the instructions and cause the apparatus to send signaling instructing the following: Whether the first sending port and the second sending port are the same.

17. The apparatus of claim 9, wherein the first uplink RS and the second uplink RS comprise a sounding reference signal (SRS).

18. The apparatus of claim 9, wherein the first downlink RS and the second downlink RS comprise a single-port channel state information (CSI) RS.

19. A method for conducting wireless communication at a user equipment (UE), the method comprising: At least a first uplink reference signal (RS) and a second uplink RS are transmitted via at least a first port and a second port; Receive at least a first downlink RS and a second downlink RS from the first network entity; Receive at least a third downlink RS and a fourth downlink RS from the second network entity; Based on the first downlink RS, the second downlink RS, the third downlink RS, the fourth downlink RS, and the following assumptions, at least one of the timing offset or phase offset between the first network entity and the second network entity is derived: 1) the first downlink RS and the second downlink RS are transmitted from the first network entity using a first transmit beamforming derived from a first receive beamforming for the first uplink RS and the second uplink RS, and 2) the third downlink RS and the fourth downlink RS are transmitted from the second network entity using a second transmit beamforming derived from a second receive beamforming for the first uplink RS and the second uplink RS; as well as Send at least one of the timing offset or the phase offset to at least one of the first network entity or the second network entity.

20. The method of claim 19, wherein at least one of the timing offset or the phase offset is derived based on the following assumption: The first downlink RS is transmitted via a first transmit port associated with a first receive port used by the first network entity to receive the first uplink RS, and the second downlink RS is transmitted via a second transmit port associated with a second receive port used by the first network entity to receive the second uplink RS; and The third downlink RS is transmitted via a third transmit port associated with a third receive port used by the second network entity to receive the first uplink RS, and the fourth downlink RS is transmitted via a fourth transmit port associated with a fourth receive port used by the second network entity to receive the second uplink RS.

Images