WO2025010537A1

WO2025010537A1 - Channel state information feedback with time and frequency offset compensation

Info

Publication number: WO2025010537A1
Application number: PCT/CN2023/106329
Authority: WO
Inventors: Yushu Zhang; Jia-Hong Liou
Original assignee: Google Llc
Priority date: 2023-07-07
Filing date: 2023-07-07
Publication date: 2025-01-16

Abstract

This disclosure provides systems, methods and apparatuses for compensating for propagation delays and/or Doppler shifts that may affect signals transmitted by transmit and receive points (TRPs) located at different distances and directions from a user equipment (UE) 110. A network entity 120 configures signals for time and frequency offset measurement (306). The network entity or the UE measures the time and/or frequency offset for each TRP based on the configured signals (312). The network entity provides TCI states that inform the UE whether the network entity will pre-compensate for time and/or frequency offsets for different TRPs prior to coherent joint transmission to the UE (314). The network entity transmits CSI-RSs based on the indicated TCI states (316). The UE transmits CSI feedback that includes QCL parameters calculated based on the received CSI-RSs and whether the network entity has indicated it will perform pre-compensation for time and/or frequency offsets (320).

Description

CHANNEL STATE INFORMATION FEEDBACK WITH TIME AND FREQUENCY OFFSET COMPENSATION

TECHNICAL FIELD

Aspects of the present disclosure relate generally to wireless communication and techniques for determining channel state information feedback with time and frequency offset compensation.

BACKGROUND

The quality of service between a user equipment (UE) and a network entity (e.g., a base station) can be degraded by a number of factors, such as loss in signal strength, bandwidth limitations, interfering signals, and so forth. This is particularly true for UEs operating at a cell edge, which is frequently impacted by weak signal quality. One solution to address service degradation is to utilize multiple transmission and reception points (TRPs) for communicating with a UE. In a multi-TRP environment, a network entity such as a base station may have multiple TRPs, for example, macro-cells, small cells, pico-cells, femto-cells, remote radio heads, relay nodes, etc. located at different geographic locations within a cell. A network entity such as a base station coordinates joint scheduling, transmission, and reception for the multiple TRPs when communicating with a UE. The use of multiple TRPs may improve reliability, coverage, and network capacity. For example, a UE at a cell edge may be served by multiple TRPs for improved signal transmission and reception resulting in increased throughput for the UE. The joint scheduling and transmission of signals from a network entity via multiple TRPs may be referred to as “coherent joint transmission. ”

BRIEF SUMMARY

The systems, methods, and devices of this disclosure each have several innovative aspects, no single one of which is solely responsible for the desirable attributes disclosed herein.

One innovative aspect of the subject matter described in this disclosure can be implemented as a method for wireless communications by a first wireless device. The method may include communicating, with a second wireless device, one or more transmission configuration indication (TCI) states, each TCI state of the one or more TCI states indicating one or more quasi-co-location (QCL) parameters for each of a plurality of channel state information reference signals (CSI-RSs) . The method may further include communicating, with the second wireless device, the plurality of CSI-RSs having pre-compensation based on either or both a time offset and a frequency offset. The method may further include communicating, with the second wireless device, channel state information (CSI) feedback based on the plurality of CSI-RSs, the CSI feedback being based on a CSI report configuration.

Details of one or more implementations of the subject matter described in this disclosure are set forth in the accompanying drawings and the description below. Other features, aspects, and advantages will become apparent from the description, the drawings, and the claims.

BRIEF DESCRIPTION OF THE DRAWINGS

Note that the relative dimensions of the following figures may not be drawn to scale. Like reference numbers and designations in the various drawings indicate like elements. To easily identify the discussion of any particular element or act, the most significant digit or digits in a reference number refer to the figure number in which that element is first introduced.

Figure 1A is a conceptual diagram illustrating an example wireless system including a user equipment communicating with a network entity via multiple transmit/receive points using coherent joint transmission.

Figure 1B is a conceptual diagram illustrating further aspects of an example wireless system including a user equipment communicating with a network entity via multiple transmit/receive points using coherent joint transmission.

Figure 2 is a block diagram illustrating example configurations of a network entity and a user equipment.

Figure 3 is a sequence diagram illustrating example operations of a communications process for providing channel state information feedback with time and frequency offset compensation data determined by a network entity.

Figure 4 is a sequence diagram illustrating example operations of a communications process for providing channel state information feedback with time and frequency offset compensation data determined by a user equipment.

Figure 5 is a flow chart diagram illustrating example operations of a method for channel state information feedback based on signals having pre-compensated time and/or frequency offsets.

Figure 6A is a flow chart diagram illustrating example operations of a method for a UE to provide channel state information feedback where a network entity measures time and frequency offsets.

Figure 6B is a flow chart diagram illustrating example operations of a method for a UE to provide channel state information feedback where the UE measures time and frequency offsets.

Figure 7A is a flow chart diagram illustrating example operations of a method for a network entity to receive channel state information feedback where the network entity measures times and frequency offsets.

Figure 7B is a flow chart diagram illustrating example operations of a method for a network entity to receive channel state information feedback where a UE measures times and frequency offsets.

Figure 8A is a conceptual diagram illustrating example SRS resources for time and frequency offset measurement.

Figure 8B is a conceptual diagram illustrating example SRS resources for time and frequency offset measurement where the SRS symbols within a slot are from the same SRS resource.

Figure 8C illustrates an example resource grid for the multi-symbol SRS resource for time and/or frequency offset measurement.

Figure 9 is a conceptual diagram illustrating an example PUSCH transmission with data and uplink control information disabled.

DETAILED DESCRIPTION

The following description is directed to certain implementations for the purpose of describing the innovative aspects of this disclosure. However, a person having ordinary skill in the art will readily recognize that the teachings herein can be applied in a multitude of different ways. Some of the examples in this disclosure are based on wireless communication according to the 3rd Generation Partnership Project (3GPP) wireless standards, such as the 4th generation (4G) Long Term Evolution (LTE) and 5th generation (5G) New Radio (NR) standards. However, the described implementations can be implemented in any device, system, or network that is capable of transmitting and receiving radio frequency signals according to any of the wireless communication standards, including any of the Institute of Electrical and Electronics Engineers (IEEE) 802.11, 802.15, or 802.16 wireless standards, or other known signals that are used to communicate within a wireless, cellular, or internet of things (IOT) network, such as a system utilizing 3G, 4G, 5G, WiFi or future radio technology.

As discussed above, some wireless communication systems use coherent joint transmission in multiple TRP operations to improve signal quality for signals communicated between a network entity and a UE, thereby improving communication efficiency and throughput. A problem that may occur in multiple TRP operations is related to the fact that the TRPs may be located at different distances and directions from the UE. For example, the UE may receive signals from multiple TRPs, each at a different distance and different direction from the UE. This may result in different Doppler shifts associated with each signal received by the UE from the different TRPs. Additionally, the TRPs may not be fully synchronized with one another and/or may be at different distances from the UE and may result in different propagation delays associated with each signal received by the UE from the different TRPs. The lack of full synchronization between TRPs and/or the different propagation delays may result in different phase offsets for signals transmitted and received by the different TRPs with respect to the UE. This lack of synchronization may cause channel mismatches for CSI measurement, which may lead to performance degradation and user dissatisfaction.

Various aspects of this disclosure relate to techniques for compensating for propagation delays and/or Doppler shifts by measuring time and frequency offsets and pre-compensating for the offsets prior to transmitting a signal. In some aspects, the network entity may configure at least one signal for time and frequency offset measurement. The network entity or the UE may measure the time and/or frequency offset for each TRP based on the configured signal (s) . The network entity may provide one or more TCI states that inform the UE whether the network entity will pre-compensate for time and/or frequency offsets for different TRPs prior to coherent joint transmission to the UE. The network entity transmits CSI-RSs based on the indicated TCI states. The CSI-RS for tracking is the CSI-RS used for time and frequency offset tracking, which may be referred to as a tracking reference signal (TRS) in the discussion below. The UE transmits CSI feedback that includes QCL parameters calculated based on the received CSI-RSs and whether the network entity has indicated it will perform pre-compensation for time and/or frequency offsets.

To facilitate the CSI measurement based on the CSI-RS, the network entity may configure the antenna port quasi-co-location (QCL) property for the CSI-RS. The network entity may configure the source reference signal for the QCL indication for the CSI-RS as follows:

● A CSI-RS for tracking configured for QCL-TypeA and QCL-TypeD indication;

● A CSI-RS for tracking configured for QCL-TypeA indication and a CSI-RS for beam management configured for QCL-TypeD indication; or

● A synchronization signal block (SSB) configured for QCL-TypeC and QCL-TypeD indication.

The QCL types and the measurements associated with the different QCL types are defined as follows:

● 'typeA' : Doppler shift, Doppler spread, average delay, and delay spread.

● 'typeB' : Doppler shift and Doppler spread.

● 'typeC' : Doppler shift, average delay.

● 'typeD' : Spatial Receiving (Rx) parameter.

In some aspects, the network entity may configure and trigger at least one uplink signal for time and frequency offset measurement. The network entity may measure the time and/or frequency offset for each TRP after receiving the uplink signal. Then the network entity may provide one or more TCI states for each configured CSI-RS, which indicates whether the time and/or frequency offset has been pre-compensated or not. Then the network entity may transmit the configured CSI-RSs based on the indicated TCI states. The UE may transmit CSI feedback based on the received CSI-RSs.

In some other aspects, the network entity may configure at least two downlink reference signals for time and frequency offset measurement. In these other aspects, the UE may measure the time and/or frequency offset for each TRP based on the at least two downlink reference signals configured by the network entity. The UE may report the measured time offset and/or frequency offset to the network entity by Medium Access Control (MAC) Control Element (CE) or uplink control information (UCI) on Physical Uplink Control Channel (PUCCH) or Physical Uplink Shared Channel (PUSCH) . The network entity may use the time and/or frequency offset measured by the UE to perform pre-compensation based on the time and/or frequency offset prior to coherent joint transmission.

Particular implementations of the subject matter described in this disclosure may be implemented to realize one or more of the following potential advantages. A network entity and UE may cooperate to measure time and/or frequency offsets. Further, the network entity may inform the UE that the network entity will pre-compensate for the time and/or frequency offsets. Knowledge of the pre-compensation for time offsets and frequency offsets may enable the UE to provide more accurate CSI feedback to the network entity. This more accurate feedback may reduce the potential for channel mismatch between CSI measurement and downlink reception. This may result in improved the system performance and may facilitate the network entity and the UE to maintain correct synchronization of the communication channel while also utilizing multi-TRP and MIMO capabilities to improve communication, throughput, and signal coverage.

Figure 1A is a conceptual diagram illustrating an example wireless system including a user equipment communicating with a network entity via multiple transmit/receive points using coherent joint transmission. In the example shown in Figure 1A, wireless communication system 100 includes a UE 110 that wirelessly communicates with a network entity 120 via TRPs 122A-122D in a multi-TRP mode of operation. Although illustrated as a smartphone in Figure 1, the UE 110 may be implemented as any suitable computing or electronic device, such as a mobile communication device, a modem, cellular phone, gaming device, navigation device, media device, laptop computer, desktop computer, tablet computer, smart appliance, vehicle-based communication system, an Internet-of-things (IoT) device (e.g., sensor node, controller/actuator node, combination thereof) , and the like. Network entity 120 (e.g., base station, an Evolved Universal Terrestrial Radio Access Network Node B (E-UTRAN Node B) , evolved Node B, eNodeB, eNB, Next Generation Node B, gNode B, gNB, ng-eNB, access point, radio head or the like) may be implemented in a macrocell, microcell, small cell, picocell, or the like, or any combination thereof. The network entity 120 may be configured to use MIMO communication in which multiple TRPs (such as TRPs 122A-122D) associated with the network entity 120 are used to exchange wireless communication signals with UE 110.

In some aspects, the functionality, and thus the hardware components, of the network entity 120 may be distributed across multiple network nodes or devices and may be distributed in a manner to perform the functions described herein. As one example, the functionality of network entity 120 may be distributed across a radio unit (RU) , distributed unit (DU) , or central unit (CU) .

The UE 110 may communicate with network entity 120 and TRPs 122A-122D using wireless links (not shown in Fig. 1A) , which may be implemented as any suitable type of wireless link. The wireless links may include one or more wireless links (e.g., radio links) or bearers implemented using any suitable communication protocol or standard, or combination of communication protocols or standards, such as 3rd Generation Partnership Project Long-Term Evolution (3GPP LTE) , Fifth Generation New Radio (5G NR) , and so forth. Multiple wireless links may be aggregated in a carrier aggregation to provide a higher data rate for the UE 110.

The network entity 120 and TRPs 122A-122D support wireless communication with one or more UEs, such as UE 110, via radio frequency (RF) signaling using one or more applicable radio access technologies (RATs) as specified by one or more communications protocols or standards. The network entity 120 and the TRPs 122A-122D may employ any of a variety of RATs, such as operating as a NodeB (or base transceiver station (BTS) ) for a Universal Mobile Telecommunications System (UMTS) RAT (also known as “3G” ) , operating as an enhanced NodeB ( “eNB” ) for a Third Generation Partnership Project (3GPP) Long Term Evolution (LTE) RAT, operating as a 5G node B ( “gNB” ) for a 3GPP Fifth Generation (5G) New Radio (NR) RAT, and the like.

The network entity 120 and TRPs 122A-122D may be part of a radio access network (RAN) , for example, an Evolved Universal Terrestrial Radio Access Network, E-UTRAN, 5G NR RAN, or NR RAN. The network entity 120 may be connected to a core network 150. For example, the network entity 120 may connect to the core network 150 through an NG2 interface for control-plane signaling and using an NG3 interface for user-plane data communications when connecting to a 5G core network, or using an Si interface for control-plane signaling and user-plane data communications when connecting to an Evolved Packet Core (EPC) network. The network entity 120 may communicate using an Xn Application Protocol (XnAP) through an Xn interface or using an X2 Application Protocol (X2AP) through an X2 interface to exchange user-plane and control-plane data. The UE 110 may connect, via the core network 150, to one or more wide area networks (WANs) 160 or other packet data networks (PDNs) , such as the Internet.

Communications between network entity 120 and UE 110 utilize an uplink (UL) transmission path 112 for RF transmissions from the UE 110 to the network entity 120 and a downlink (DL) transmission path 114 for RF transmissions from the network entity 120 to the UE 110. As such, in the context of the UL transmission path 112, the UE 110 serves as the data sending device and the network entity 120 serves as the data receiving device, whereas in the context of the DL transmission path 114, the network entity 120 serves as the data sending device and the UE 110 serves as the data receiving device. UL transmission path 112 and DL transmission path 114 may utilize multiple communications channels for signal transmission. The multiple channels may each have different purposes.

UL transmission path 112 may include a Physical Uplink Shared Channel (PUSCH) , a Physical Uplink Control Channel (PUCCH) , and a Physical Random Access Channel (PRACH) . The PUSCH is used for the transmission of user data, such as voice data, video data, or text message data from UE 110 to network entity 120. Additionally, the PUSCH may be used to transmit control information (e.g., uplink control information (UCI) ) . The PUSCH may be shared by multiple UEs. The PUCCH is used for transmitting control information (e.g., UCI) from the UE to the network, such as channel quality feedback, scheduling requests, and acknowledgments. The PRACH is used for random access in the uplink direction, enabling the UE to access the system.

DL transmission path 114 may include one or more of a Physical Downlink Shared Channel (PDSCH) , a Physical Downlink Control Channel (PDCCH) , a Physical Broadcast Channel (PBCH) , or a paging channel. The PDSCH is used for transmission of user data from the network entity to the UE. The PDSCH may be shared by multiple UEs. As with the PUSCH, the data may be any type of information, such as voice data, video data, or text message data. The paging channel is used to notify the UE 110 that there is incoming traffic for it from the network entity 120.

UE 110 and network entity 120 may use channel state information (CSI) to optimize the quality of communications between the UE 110 and network entity 120 or a TRP. The network entity 120 may provide a CSI report configuration to the UE 110 for use in reporting the CSI to the network entity 120. For a CSI report, the UE may report at least one of rank indicator (RI) , precoder matrix indicator (PMI) , channel quality indicator (CQI) , and layer indicator (LI) . RI and PMI may be used to indicate the digital precoder, CQI may be used to indicate the signal-to-interference plus noise (SINR) status in order to assist the network entity 120 to determine the modulation and coding scheme (MCS) , and LI may be used to identify the strongest layer for the reported precoder indicated by RI and PMI.

The network entity 120 may configure the UE 110 to measure and report the CSI for coherent joint transmission (CJT) from multiple TRPs (e.g., TRPs 122A-122D) . The network entity 120 may configure the UE to measure and report the CSI based on a list of CSI reference signal (CSI-RS) resources. The network entity 120 transmits CSI-RS on the CSI-RS resources from the different TRPs 122A-122D as shown in Figure 1A. The UE 110 may analyze the CSI-RS for each TRP and calculate the various CSI parameters based on the analysis. The UE 110 may report the CSIs for each TRP to the network entity 120, which may use the reported CSIs to adjust various signal transmission parameters to attempt to optimize the communication between each TRP 122A-122D and UE 110.

In the example shown in Figure 1A, four TRPs 122A-122D are illustrated. However, a wireless communications system may more than four TRPs or less than four TRPs.

Figure 1B is a conceptual diagram illustrating further aspects of an example wireless communication system 140 including a UE communicating with a network entity via multiple transmit/receive points using coherent joint transmission. In the example illustrated in Figure 1B, wireless communication system 140 includes UE 110, network entity 120, and TRPs 122A and 122B of Figure 1A. Wireless communication system 140 may include other TRPs, including TRPs 122C and 122D of Figure 1A, which are not shown in Figure 1B in order to provide a clearer depiction of the techniques of the disclosure. Network entity 120 may be coupled to TRPs 122A and 122B via respective fronthaul networks 130A and 130B. For example, fronthaul networks 130A and 130B may be high performance networks such as fiber optic networks.

Network entity 120 may configure UE 110 for coherent joint transmission from TRPs 122A and 122B. In coherent joint transmission, the UE receives downlink signals from multiple TRPs (e.g., TRPs 122A and 122B) with antenna combining. As an example, assume that R TRPs are used for CJT of downlink signals. At a downlink resource element (RE) for a subcarrier k of a physical downlink shared channel (PDSCH) , the received signal Y_k in the frequency domain can be obtained as follows:
Y_k=H_kW_kX_k+N_k (1)

whereindicates the channel between the TRP j and the UE at RE_k; is the digital precoder from TRP j for RE_k; X_k is the modulated symbol at RE_k; N_k is the noise plus interference at RE_k. and T indicates the transpose of the matrix.

The locations of TRPs used for transmissions to the UE can affect various characteristics of the signals received by the UE from the TRPs. For instance, in the example shown in Figure 1B, the distance 124A between UE 110 and TRP 122A is less than the distance 124B between UE 110 and TRP 122B. As a result, wireless communications signals communicated between UE 110 and TRP 122A will take less time to travel than signals communicated between UE 110 and TRP 122B. In other words, the propagation delay between the UE 110 and the TRP 122A may be different (e.g., shorter) than the propagation delay between the UE 110 and the TRP 122B. Additionally, as shown in the example of Figure 1B, UE 110 may receive a signal from TRP 122A at a different angle than a signal from TRP 122B. In other words, the angle-of-arrival (AoA) of signals received from TRP 122A is different from the AoA of signals received from TRP 122B.

The different AoAs of TRPs used in signal transmission (for example, coherent joint transmissions) may result in different Doppler shifts for the different signals. This is because the Doppler shift generally depends on the receiving direction (e.g., AoA) for the downlink signal. In the example illustrated in Figure 1B, UE 110 receives signals from TRP 122A having a different AofA than signals received from TRP 122B. In some aspects, the channel with TRP-specific Doppler shifts may be calculated as follows:

whereindicates the Doppler shift between TRP j and the UE; Δ_t is the measurement time offset, e.g., the time offset between the CSI measurement and PDSCH reception; the function f () indicates the channel correlation factor. In one example, for a single-path channel, the function f () may be calculated as follows:

where λ is the waveform length.

Even though networks 130A and 130B may be high performance networks, there may be differences in the time it takes for control signals and/or data signals to reach different TRPs from network entity 120. This may result in TRPs 122A and 122B not being fully synchronized with respect to communications between the network entity 120 and the UE 110 via TRPs 122A and 122B. The possibility that the TRPs may not be fully synchronized and the existence of different propagation delays between different TRPs and the UE 110 may result in different time offsets for different REs. In some aspects, the channel with TRP-specific delay may be calculated as follows:

where τ_j indicates the relative time offset for TRP j with the first TRP as reference; f_k is the frequency for subcarrier k.

A problem with current systems is that the frequency offset and time offset with respect to signals arriving from different TRPs during CJT may cause channel mismatch for CSI measurement and PDSCH reception. This channel mismatch may lead to a degradation in communication performance between a UE and a network entity. A technique disclosed herein to address this lack of synchronization is for the network entity 120 to compensate for the time and frequency offsets of different TRPs (e.g., TRPs 122A and 122B) prior to transmission of a signal. Such compensation may be referred to as pre-compensation. The network entity 120 may be configured to transmit CSI-RSs from each TRP with pre-compensated time and frequency offsets. However, a technical problem with such pre-compensation relates to informing the UE that the network entity is performing pre-compensation so that the UE may provide correct CSI feedback to the network entity. A further technical problem is that the network entity and the UE may need to coordinate measurement of the time and frequency offset used for the pre-compensation.

Various aspects of the disclosure relate to techniques for compensating for propagation delays and Doppler shifts by measuring time and frequency offsets and pre-compensating for the offsets prior to transmitting a signal. The techniques include techniques for time and frequency offset measurement, reporting the time and frequency offsets, and calculating QCL parameters based on CSI-RSs and the status of pre-compensated time and frequency offsets.

In some implementations, the network entity 120 may measure time offsets and/or frequency offsets. In these implementations, the network entity 120 may configure at least one uplink signal for time and frequency offset measurement, and trigger the UE 110 to transmit the uplink signal. The network entity 120 entity may measure the time and/or frequency offset for each TRP after receiving the uplink signal from the UE 110. The network entity 120 may provide one or more TCI states for each configured CSI-RS, where the TCI states indicate whether the network entity 120 will pre-compensate for time and/or frequency offsets for different TRPs prior to transmission to the UE 110. Then the network entity transmits the configured CSI-RSs based on the indicated TCI state (s) . The UE transmits CJT-CSI feedback based on the received CSI-RSs.

In some other implementations, the UE 110 may measure time offsets and/or frequency offsets. In these implementations, the network entity 120 may configure at least two downlink reference signals for time and frequency offset measurement. The UE 110 may measure the time and frequency offset for each TRP based on the at least two downlink reference signals configured by the network entity 120. The UE 110 may report the measured time and/or frequency offset to the network entity 120 by MAC CE, or UCI on the PUCCH or PUSCH. The network entity 120 may use the time and/or frequency offset measured by the UE 110 to perform pre-compensation based on the time and/or frequency offset prior to transmission via TRPs 122A and 122B.

Further details of various techniques and aspects of disclosure are provided below with respect to Figures 2-5, 6A, 6B, 7A, and 7B.

Figure 2 is a block diagram illustrating example configurations of a network entity 120 and a UE 110. Note that the depicted hardware configurations represent the processing components and communication components related to measuring and reporting time and/or frequency offsets, pre-compensating for such time and/or frequency offsets, and configuring a UE to calculate and report QCL parameters for CJT feedback in accordance with the time and/or frequency offsets. The depicted hardware configurations may omit certain components well-understood to be frequently implemented in such electronic devices, such as displays, peripherals, power supplies, and the like.

The UE 110 includes antennas 202, a radio frequency front end (RF front end) 204, and radio-frequency transceivers (e.g., an LTE transceiver 206 and a 5G NR transceiver 208) for communicating with network entity 120 and/or one or more TRPs (e.g., TRPs 122A –122D of Figures 1A and 1B) .

The RF front end 204 includes one or more modems configured for the corresponding RAT(s) employed (for example, Third Generation Partnership Project (3GPP) Fifth Generation New Radio (5G NR) ) , one or more analog-to-digital converters (ADCs) , one or more digital-to-analog converters (DACs) , signal processors, and the like. In the example illustrated in Figure 2, the RF front end 204 of the UE 110 may couple or connect the LTE transceiver 206, and the 5G NR transceiver 208 to the antennas 202 to facilitate various types of wireless communication. The RF front end 204 operates, in effect, as a physical (PHY) transceiver interface to conduct and process signaling between the one or more processors 214 and the antennas 202 so as to facilitate various types of wireless communication.

The antennas 202 of the UE 110 may include an array of multiple antennas that are configured similar to or different from each other and may be tuned to one or more frequency bands associated with a corresponding RAT. The antennas 202 and the RF front end 204 may be tuned to, and/or be tunable to, one or more frequency bands defined by the 3GPP LTE and 5G NR communication standards and implemented by the LTE transceiver 206, and/or the 5G NR transceiver 208. Additionally, the antennas 202, the RF front end 204, the LTE transceiver 206, and/or the 5G NR transceiver 208 may be configured to support beamforming for the transmission and reception of communications with the network entity 120 and/or with one or more TRPs (e.g., TRPs 122A -122D of Figures 1A and 1B) . By way of example and not limitation, the antennas 202 and the RF front end 204 may be implemented for operation in sub-gigahertz bands, sub-6 GHz bands, and/or above 6 GHz bands that are defined by the 3GPP LTE and 5G NR communication standards.

The UE 110 also includes processor (s) 214 and computer-readable storage media (CRM) 216. The processor 214 may include, for example, one or more central processing units, graphics processing units (GPUs) , or other application-specific integrated circuits (ASIC) , and the like. To illustrate, the processors 214 may include an application processor (AP) utilized by the UE 110 to execute an operating system and various user-level software applications, as well as one or more processors utilized by modems or a baseband processor of the RF front end 204.

CRM 216 may include any suitable memory or storage device such as random-access memory (RAM) , static RAM (SRAM) , dynamic RAM (DRAM) , non-volatile RAM (NVRAM) , read-only memory (ROM) , Flash memory, solid-state drive (SSD) or other mass-storage devices, and the like useable to store one or more sets of executable software instructions and associated data that manipulate the one or more processors 214 and other components of the UE 110 to perform the various functions described herein and attributed to the UE 110. The sets of executable software instructions include, for example, an operating system (OS) and various drivers (not shown) , and various software applications (not shown) , which are executable by processor (s) 214 to enable user-plane communication, control-plane signaling, and user interaction with the UE 110. The data 218 stored in the CRM 216 represents, for example, user data, multimedia data, beamforming codebooks, software application configuration information, and the like. Data 218 may include TCI state (s) 219 and QCL parameters 220. TCI state (s) 219 may be data representing one or more TCI states configured on the UE 110 by network entity 120. QCL parameters 220 may be data representing QCL parameters such as Doppler shift, Doppler spread, average delay, and/or delay spread.

CRM 216 also includes a communications controller 222. Alternately or additionally, the communications controller 222 may be implemented in whole or part as hardware logic or circuitry integrated with or separate from other components of the UE 110. In some aspects, communications controller 222 configures the RF front end 204, the LTE transceiver 206, and/or the 5G NR transceiver 208 to implement the techniques described herein for determining CSI feedback for CSI-RSs having time offsets and/or frequency offsets, and/or measuring time offsets and frequency offsets.

Turning to the hardware configuration of the network entity 120, it is noted that although Figure 2 illustrates an implementation of the network entity 120 as a single network node (for example, a 5G NR Node B, or “gNB” ) , the functionality, and thus the hardware components, of the network entity 120 instead may be distributed across multiple network nodes or devices and may be distributed in a manner to perform the functions described herein. As one example, the functionality of network entity 120 may be distributed across a radio unit (RU) , distributed unit (DU) , or central unit (CU) .

The network entity 120 includes antennas 252, a radio frequency front end (RF front end) 254, one or more LTE transceivers 256, and/or one or more 5G NR transceivers 258 for communicating with the UE 110. The RF front end 254 of the network entity 120 may couple or connect the LTE transceivers 256 and the 5G NR transceivers 258 to the antennas 252 to facilitate various types of wireless communication. Similar to RF front end 204, the RF front end 254 includes one or more modems, one or more ADCs, one or more DACs, and the like. RF front end 254 receives the one or more RF signals, for example, RF signals from UE 110, and pre-processes the one or more RF signals to generate data from the RF signals that is provided as input to processes and/or applications executing on network entity 120. This pre-processing may include, for example, power amplification, conversion of band-pass signaling to baseband signaling, initial analog-to-digital conversion, and the like.

The antennas 252 of the network entity 120 may be configured individually and/or as one or more arrays of multiple antennas. The antennas 252 and the RF front end 254 may be tuned to, and/or be tunable to, one or more frequency band defined by the 3GPP LTE and 5G NR communication standards, and implemented by the LTE transceivers 256, and/or the 5G NR transceivers 258. Additionally, the antennas 252, the RF front end 254, the LTE transceivers 256, and/or the 5G NR transceivers 258 may be configured to support beamforming, such as Massive-MIMO, for the transmission and reception of communications with any UE 110 in a UECS.

The network entity 120 also includes processor (s) 260 and computer-readable storage media (CRM) 262. The processor 260 may include, for example, one or more central processing units, graphics processing units (GPUs) , or other application-specific integrated circuits (ASIC) , and the like. To illustrate, the processors 260 may include an application processor (AP) utilized by the network entity 120 to execute an operating system and various user-level software applications, as well as one or more processors utilized by modems or a baseband processor of the RF front end 254 to enable communication with the UE 110.

CRM 262 may include any suitable memory or storage device such as random-access memory (RAM) , static RAM (SRAM) , dynamic RAM (DRAM) , non-volatile RAM (NVRAM) , read-only memory (ROM) , or Flash memory useable to store device data of the network entity 120. The device data may include data 264, which includes network scheduling data, radio resource management data, beamforming codebooks, software application configuration information, UE transmitter power levels, and/or TRP configuration data and the like. Data 264 may further include offsets 263, which may be time offsets and/or frequency offsets for TRPs that may be calculated by network entity 120 or received from UE 110 according to the techniques described herein.

CRM 262 also includes an RF resource manager 265. In some aspects, the RF resource manager 265 of the network entity 120 is implemented to perform various functions associated with allocating physical access (for example, resource blocks) or communication resources for the air interface of the network entity 120. The air interface of the network entity 120, may be partitioned or divided into various units (for example, frames, subframes, or slots) of one or more of bandwidth, time, symbols, or spatial layers. For example, within a framework of a 5G NR protocol, the RF resource manager 265 may allocate bandwidth and time intervals of access in resource blocks, each of which may be allocated in whole, or in part, to one or more channels for communicating with the UE 110. The channels may include one or more of a PRACH, a PUCCH, a PUSCH, a PDCCH, a PDSCH, a PBCH, or a paging channel. The resource blocks may include multiple subcarriers that each span a portion of a frequency domain of the resource blocks. The subcarriers may be further divided into resource elements, or orthogonal frequency-division multiplexing (OFDM) symbols, that each span a portion of a time domain of the subcarriers. Consequently, a resource block includes multiple OFDM symbols that may be grouped into subcarriers with other OFDM symbols having a common frequency bandwidth.

CRM 262 further includes network entity manager 266. Alternately or additionally, the network entity manager 266 may be implemented in whole or part as hardware logic or circuitry integrated with or separate from other components of the network entity 120. In at least some aspects, the network entity manager 266 configures the LTE transceivers 256 and the 5G NR transceivers 258 for communication with the UE 110, communication with TRPs (e.g., TRPs 122A-122D of Figures 1A and 1B) via fronthaul interface 267, as well as communication with a core network 150 (Figure 1A) .

In some aspects, the network entity 120 includes an inter-network entity station interface 268, such as an Xn and/or X2 interface, which the network entity manager 266 configures to exchange user-plane and control-plane data between another network entity, to manage the communication of the network entity 120 with the UE 110. The network entity 120 includes a core network interface 270 that the network entity manager 266 configures to exchange user-plane and control-plane data with core network functions and entities.

Figures 3-5, 6, 7A, and 7B describe various techniques for time offset and frequency offset measurement and reporting. In some examples that follow, the operations may be described as utilizing RRC signaling. Unless specified otherwise, RRC signaling may indicate a RRC reconfiguration message from the network entity to the UE, or a system information block (SIB) , where the SIB may be an existing SIB (e.g., SIB1) or a new SIB (e.g., SIB J, where J is an integer above 21) transmitted by the network entity.

Figure 3 is a sequence diagram illustrating example operations of a communications process 300 for providing channel state information feedback with time and frequency offset compensation data determined by a network entity. Although not illustrated for the sake of illustration clarity, various acknowledgements for messages illustrated in Figure 3 may be implemented to ensure reliable operations for measuring time and/or frequency offsets and providing CSI feedback.

At operation 302, the UE 110 may transmit or report to network entity 120 the UE’s capability (s) for supported configurations for CSI-RS for CSI feedback. In some aspects, UE 110 may communicate UE capability information to the network entity 120 during an initial communication session setup process between the UE 110 and the network entity 120. UE capability information may include supported frequency bands, radio access technologies, maximum transmission power, maximum data rates, and network protocols. In some implementations, the UE 110 may report UE capability information indicating whether the UE 110 supports TCI state configuration or QCL configuration for the CSI-RSs for CSI feedback, e.g., the UE may report whether it supports different TCI states or QCL parameters for the CSI-RSs for CSI feedback. The UE may further report whether it supports different configurations for some of the QCL parameters for the CSI-RSs for CJT-CSI feedback. In some aspects, such QCL parameters may include time-based parameters such as average delay and delay spread and/or frequency-based parameters such as Doppler delay and Doppler shift. The UE may further report the maximum number of different TCI states for the CSI-RSs for CJT-CSI feedback. In some aspects, the UE 110 may report a supported QCL configuration for the CSI-RSs for CSI measurement. Thus, the UE may report whether it supports CSI measurement based on time and/or frequency offset pre-compensation.

In the example of Figure 3, the UE 110 transmits UE capability information to network entity 120. In some implementations, the network entity may receive the UE capability from a core network (e.g., from an access and mobility management function (AMF) of the core network 150 of Figure 1A) . In some other implementations, the network entity receives the UE capability from another network entity (e.g., a gNB or eNB) .

At operation 304, the network entity 120 may, depending on the UE capability information received at operation 302, configure at least one CSI report configuration for CSI feedback. In some aspects, the network entity may configure the CSI report configuration with at least two CSI-RS resources. In some aspects, the network entity 120 may use Radio Resource Control (RRC) signaling to configure the CSI report. For example, the network entity 120 may transmit an RRCReconfiguration message to the UE 110 to specify the CSI report configuration.

At operation 306, the network entity 120 may further configure the UE 110 for at least one uplink signal for time offset and/or frequency offset measurement.

As a first example, the network entity may configure sounding reference signal (SRS) resources or SRS resource sets for time offset and/or frequency offset measurement. In some implementations, the network entity may configure dedicated SRS resource (s) or SRS resource set(s) for time and/or frequency offset measurement. In one example, the network entity may configure the dedicated SRS resources for time and/or frequency offset measurement by RRC signaling, e.g., configuring the RRC parameter usage as time-freq-offsetMeas. In some other implementations, the network entity 120 may measure the time and/or frequency offset based on the SRS resource (s) or SRS resource set (s) used for uplink codebook based transmission or antenna switching.

In some implementations, the network entity 120 configures at least two SRS resources in different slots, e.g., two consecutive slots, for the time offset and/or frequency offset measurement. The network entity 120 may configure the same resource elements (e.g., symbols) for the SRS resources within a slot. The network entity 120 may configure a common set of power control parameters for the two SRS resources. The UE 110 may transmit SRS on the configured SRS resources based on the same transmission power. In some examples, if the network entity configures or indicates two joint/UL TCI states for the two SRS resources respectively, the network entity 120 may ensure that the two joint/UL TCI states are associated/configured with the same set of power control parameters.

Figure 8A illustrates an example resource grid 800 for SRS resources for time and/or frequency offset measurement, where the SRS symbols within a slot are from the same SRS resource. In the example shown in Figure 8A, resource elements 804A in time slot 802A are symbols for a first SRS resource, SRS resource 1, and resource elements 804B in time slot 802B are symbols for a second SRS resource, SRS resource 2.

Figure 8B illustrates an example resource grid 820 for SRS resources for time and/or frequency offset measurement, where each non-consecutive SRS symbol in a time slot is from a different SRS resource. In the example shown in Figure 8B, resource elements 804A in time slot 802A is a symbol for the first SRS resource, SRS resource 1, and resource elements 804B in time slot 802A is a symbol for the second SRS resource, SRS resource 2. Resource elements 804C in time slot 802B is a symbol for a third resource, SRS resource 3, and resource elements 804D in time slot 802B is a symbol for a fourth resource, SRS resource 4.

Returning to Figure 3, in some other implementations, the network entity 120 may configure one SRS resource with multiple symbols in one slot or in multiple slots for the time offset and/or frequency offset measurement. In one example, the network entity 120 configures the SRS resources with the same resource elements in consecutive or non-consecutive symbols. The network entity may configure the symbol index and slot index for each SRS symbol. The UE 110 may transmit all the symbols for the SRS resource based on the same transmission power.

Figure 8C illustrates an example resource grid 840 for the multi-symbol SRS resource for time and/or frequency offset measurement. In the example of Figure 8C, resource elements 804A are symbols for the first SRS resource, SRS resource 1. The symbols appear across multiple slots (e.g., slots 802A and 802B) and can be in consecutive order. For example, two symbols for SRS resource 1 are transmitted in slot 802A and one symbol for SRS resource 1 is transmitted in slot 802B.

Returning to Figure 3, as a second example, the network entity 120 may configure PRACH resources for time offset and/or frequency offset measurement. For example, the network entity 120 may configure the UE 110 with at least one PRACH resource (e.g., RA preamble, RACH occasion, etc. ) for time and/or frequency offset measurement. The network entity 120 may configure the PRACH resource by RRC signaling or trigger the PRACH transmission by MAC CE or downlink control information (DCI) .

In some implementations, the network entity 120 may trigger at least one PRACH resource by PDCCH. The network entity 120 may configure the PRACH resource (s) that is used for time and/or frequency offset measurement. Thus, the network entity 120 may configure there is no random access response (RAR) for the PRACH. That is, the UE may not need to monitor for a RAR after transmitting the RA preamble for the PRACH. The network entity 120 may indicate, in the DCI, whether the PRACH is a retransmission or not. If the PRACH is for retransmission, the UE 110 may apply a power ramping for the PRACH compared to the transmission power for the last transmission, where the power ramping step size may be predefined, e.g., 3dB, or configured/indicated by the network entity 120 via RRC signaling or the DCI. Alternatively, the network entity 120 may indicate the power ramping factor by the DCI. For example, for initial transmission, the network entity may indicate the power ramping factor as 0dB, and for retransmission, the network entity may indicate the power ramping factor greater than 0dB.

In some implementations, when more than one PRACH resource is indicated, the UE 110 applies the same transmission power for each of the PRACH resources. In some implementations, the network entity 120 may configure common power control parameters for the PRACH resources. In some other implementations, the UE 110 may determine the transmission power for the PRACH resources based on the power control parameters for the first PRACH resource.

In some implementations, the UE 110 may apply the same spatial transmission filter (e.g., transmission beam) for each of the PRACH resources. The network entity 120 receives the PRACH resources based on the same spatial reception filter (e.g., reception beam) .

As a third example, the network entity may configure PUSCH resources or PUCCH resources for time offset and/or frequency offset measurement. For example, the network entity 120 may measure the time offset and/or frequency offset based on the demodulation reference signal (DMRS) of the PUSCH or the PUCCH. The network entity 120 may trigger or schedule the PUSCH or PUCCH by DCI, or configure periodic or semi-persistent PUSCH or PUCCH by RRC signaling or MAC CE. The network entity 120 may indicate, in control signaling to trigger/schedule the PUSCH or PUCCH, whether only the DMRS for the PUSCH or PUCCH is triggered. The control signaling may be RRC signaling, a MAC CE, or DCI. If only the DMRS for PUSCH or PUCCH is triggered, the UE 110 may refrain from transmitting the data and/or UCI on the triggered PUSCH or PUCCH. In some other cases, for the PUSCH case, the network entity 120 may configure or indicate that the UE 110 is to only transmit the DMRS for a PUSCH and, if any, UCI multiplexed on resource elements of the PUSCH.

In one implementation, the network entity 120 may configure or indicate that the triggered/scheduled PUSCH is for DMRS only transmission by disabling all the codewords (e.g., indicating specific modulation and coding Scheme (MCS) index and redundant version (RV) index for all the codewords) . In another example, the network entity 120 may configure or indicate that the triggered/scheduled PUSCH is for DMRS only transmission by an explicit indicator field in the DCI. This explicit indicator field may be configurable by the network entity 120. In another example, the network entity 120 may configure a PUCCH resource without UCI, and trigger the PUCCH transmission on the PUCCH resource to trigger the DMRS for PUCCH only. In such examples, the network entity 120 may refrain from configuring or triggering a PUCCH resource for DMRS only, where the PUCCH resource for DMRS only has symbol length larger than one or two symbols.

Figure 9 illustrates an example resource grids for PUSCH with data and UCI disabled. In the example shown in Figure 9, resource grid 910 represents a resource grid having both DMRS and PUSCH data. Resource elements 806 represent DMRS, and resource elements 808 represent PUSCH data (or UCI) . Resource grid 920 represents a resource grid where PUSCH data and UCI are disabled. Thus, only resource elements 806 represent DMRS in resource grid 920. That is, only DMRS (associated with PUSCH) is transmitted in resource elements 806 for time offset and/or frequency offset measurement. Although not illustrated, it is understood that a similar resource grid may be implemented for a PUCCH with UCI disabled. In other words, only DMRS (associated with PUCCH) may be transmitted in resource elements for time offset and/or frequency offset measurement.

Returning to Figure 3, at operation 308, the network entity 120 triggers the UE 110 to transmit the uplink signal.

At operation 310, the UE transmits the triggered uplink signal. As discussed above, the uplink signal may include SRS, PRACH, or DMRS associated with PUCCH or PUSCH.

At operation 312, the network entity 120 may measure the time offset and/or frequency offset for each of the TRPs (e.g., TRPs 122A-122D) after receiving the uplink signal.

At operation 314, the network entity 120 may provide the transmission configuration indication (TCI) state (s) for each configured CSI-RS to the UE 110. The TCI state (s) may indicate whether the time and/or frequency offset has been pre-compensated or not. In some aspects, the network entity 120 may provide TCI state (s) that indicate time offset pre-compensation without frequency pre-compensation, frequency offset pre-compensation without time offset pre-compensation, both time offset and frequency offset pre-compensation (referred to as “full time and frequency offset pre-compensation” ) , or configurable time offset and frequency offset pre-compensation.

With respect to full time and frequency offset pre-compensation, in some aspects, the network entity 120 may configure or indicate a common TCI state for the CSI-RSs configured for CSI measurement in a CSI report configuration. The UE 110 may derive the QCL parameters for the CSI-RSs based on the indicated TCI state. In some other aspects, the network entity 120 may configure a common source reference signal, e.g., a common TRS, for QCL-TypeA indication for the TCI state (s) for the CSI-RSs. Thus, the network entity 120 may perform the time and frequency offset pre-compensation for the CSI-RSs, which leads to a common delay and/or Doppler property for all of the CSI-RSs. Table 1 below illustrates one example for the QCL parameter identification for the configured CSI-RSs with time and frequency offset pre-compensation.

Table 1

With respect to time offset pre-compensation without frequency pre-compensation, in some aspects, the network entity 120 may configure or indicate separate TCI states for each CSI-RS for the CSI-RSs configured for CSI measurement in a CSI report configuration. The network entity 120 may configure the UE 110 to derive the average delay and delay spread for the CSI-RSs based on one of the indicated TCI states or one common TCI (e.g., Common TCI) . The UE 110 may derive other QCL parameters, e.g., Doppler shift and Doppler spread, for the CSI-RSs based on the indicated TCI state for each CSI-RS or one indicated TCI state (e.g., Separate TCI) corresponding to the CSI-RS. Table 2 below illustrates one example for the QCL parameter identification for the configured CSI-RSs with time offset pre-compensation only.

Table 2

In some implementations, the TCI state for average delay and delay spread indication for all the CSI-RSs for CSI measurement in the CSI report configuration may be the TCI state applied to the first or last CSI-RS (or the first or last order to be configured in the CSI-RS resource set for CSI in RRC signaling) . In some other implementations, the TCI state for average delay and delay spread indication for all the CSI-RSs for CSI measurement in the CSI report configuration may be the TCI state applied to the CSI-RS with lowest or highest resource identifier (ID) . In some other implementations, the TCI state for average delay and delay spread indication for all the CSI-RSs for CSI measurement in the CSI report configuration may be the TCI state with lowest or highest TCI state ID. In some other implementations, the TCI state for average delay and delay spread indication for all the CSI-RSs for CSI measurement in the CSI report configuration is the first indicated or activated TCI state. In some other implementations, the TCI state for average delay and delay spread indication for all the CSI-RSs for CSI measurement in the CSI report configuration is configured by the network entity via RRC signaling, MAC CE, or DCI.

With respect to frequency offset pre-compensation without time offset pre-compensation, in some implementations, the network entity 120 may configure or indicate separate TCI states for each CSI-RS for the CSI-RSs configured for CSI measurement in a CSI report configuration. The network entity 120 may configure the UE 110 to derive the Doppler shift and Doppler spread for the CSI-RSs for CSI measurement based on one of the indicated TCI states or one common TCI (e.g., Common TCI) . The UE 110 may derive other QCL parameters, e.g., average delay and delay spread, for the CSI-RSs for CSI measurement based on the indicated TCI state (e.g., Separate TCI) for each CSI-RS. Table 3 below illustrates one example for the QCL parameter identification for the configured CSI-RSs with frequency offset pre-compensation only.

Table 3

In some implementations, the TCI state for Doppler shift and Doppler spread indication for all the CSI-RSs for CSI measurement in the CSI report configuration may be the TCI state applied to the first or last CSI-RS for the CSI-RSs for CSI measurement. In some other implementations, the TCI state for Doppler shift and Doppler spread indication for all the CSI-RSs for CSI measurement in the CSI report configuration may be the TCI state applied to the CSI-RS with lowest or highest resource identifier (ID) . In some other implementations, the TCI state for Doppler shift and Doppler spread indication for all the CSI-RSs for CSI measurement in the CSI report configuration is the TCI state with lowest or highest TCI state ID. In some other implementations, the TCI state for Doppler shift and Doppler spread for all the CSI-RSs for CSI measurement in the CSI report configuration is the first indicated TCI state. In some other implementations, the TCI state for Doppler shift and Doppler spread indication for all the CSI-RSs for CSI measurement in the CSI report configuration is configured by the network entity via RRC signaling, MAC CE, or DCI.

With respect to configurable time offset and frequency offset pre-compensation, in some implementations, the network entity 120 configures whether the UE 110 should derive each QCL parameter or each set of QCL parameters based on common or separate TCI states by RRC signaling, MAC CE, or DCI.

In some implementations, a new QCL-Type (e.g., QCL-TypeE) may be defined, which includes the QCL parameters, e.g., average delay, delay spread. For example, the QCL types and the measurements associated with the different QCL types are defined as follows:

● 'typeA' : Doppler shift, Doppler spread, average delay, and delay spread.

● 'typeB' : Doppler shift and Doppler spread.

● 'typeC' : Doppler shift, average delay.

● 'typeD' : Spatial Receiving (Rx) parameter.

● ‘typeE’ : average delay and delay spread.

The network entity 120 may configure or indicate the QCL-TypeB or QCL-TypeE for each TCI state applied to the CSI-RSs to indicate whether the UE 110 should derive the Doppler spread, Doppler shift, average delay, and/or delay spread based on the indicated TCI state.

In some implementations, the network entity 120 may refrain from configuring separate QCL parameters for average delay and delay spread for the TCI states for the CSI-RSs for CSI feedback with a common frequency domain (FD) basis report across the CSI-RSs.

In some other implementations, the network entity 120 may refrain from configuring separate QCL parameters for Doppler delay and Doppler shift for the TCI states for the CSI-RSs for CSI feedback with a common doppler domain (DD) basis report across the CSI-RSs.

In some implementations, the network entity 120 may perform pre-compensation for some, but not all, of the CSI-RSs for CSI measurement. The network entity 120 may configure whether the UE 110 should derive all or part of the QCL parameters based on a common TCI state or a separate TCI state indicated for each CSI-RS. Table 4 below illustrates one example for the time/frequency offset pre-compensation for part of CSI-RSs.

Table 4

In this example, the network entity 120 configures common QCL parameters (e.g., Common TCI) for CSI-RS resource 1 and CSI-RS resource 2. With respect to CSI-RS resource 3, the network entity 120 configures separate QCL parameters (e.g., Separate TCI) for average delay and delay spread, and common QCL parameters (e.g., Common TCI) for Doppler Shift and Doppler spread. With respect to CSI-RS resource 4, the network entity 120 configures separate QCL parameters (e.g., Separate TCI) for average delay, delay spread, Doppler shift, and Doppler spread.

As may be appreciated from the above, CSI-RSs having pre-compensation based on the time offset may share the same QCL parameters with respect to average delay and delay spread. CSI-RSs having pre-compensation based on the frequency offset may share the same QCL parameters with respect to Doppler delay and Doppler shift. CSI-RSs having pre-compensation based on both the time offset and frequency offset may share the same QCL parameters with respect to average delay, delay spread, Doppler delay and Doppler shift.

At operation 316, the network entity 120 transmits the configured CSI-RSs to the UE 110 with pre-compensation based on the indicated TCI state (s) .

At operation 318, the UE 110 determines CSI feedback (e.g., CJT-CSI feedback) based on the received CSI-RSs.

At operation 320, the UE 110 transmits the CSI feedback to the network entity 120.

Figure 4 is a sequence diagram illustrating example operations of a communications process 400 for providing channel state information feedback with time and frequency offset compensation data determined by a UE. Compared to the communications process 300 in Figure 3, the difference is that instead of using an uplink signal for time and frequency offset measurement, the time and frequency offset for each TRP is measured by the UE based on at least two downlink reference signals configured by the network entity. Although not illustrated for the sake of illustration clarity, various acknowledgements for messages illustrated in Figure 4 may be implemented to ensure reliable operations for measuring time and/or frequency offsets and providing CSI feedback.

At operation 302, like operation 302 of Figure 3, the UE 110 may transmit or report the UE’s capability (s) for supported configurations for CSI-RS for CSI feedback. In some aspects, the UE 110 may report a supported QCL configuration for the CSI-RSs for CJT-CSI measurement. Thus, the UE 110 may report whether it supports CSI measurement based on time and/or frequency offset pre-compensation. Additionally, in the example illustrated in Figure 4, the UE 110 may report capabilities related to the UE’s ability to measure time offsets and/or frequency offsets. For example, in some aspects, the UE 110 may report capability information indicating whether the UE supports time offset report or frequency offset report or both. The UE 110 may report UE capability information indicating at least one of the following:

● the maximum number of CSI-RS resource sets for time and/or frequency offset measurement.

● the maximum number of time and/or frequency offset reports.

● the minimum processing delay for the time and/or frequency offset measurement and report.

● the number of CSI processing unit (CPU) for each time and/or frequency offset measurement and report.

● the supported time domain behavior for the time and/or frequency offset report, e.g., aperiodic, semi-persistent, or periodic.

● the supported time domain behavior for the downlink reference signal for the time and/or frequency offset measurement, e.g., aperiodic, semi-persistent, or periodic.

The UE 110 may also report UE capability information indicating whether the UE supports UE-triggered or event-triggered report for time offset and/or frequency offset.

With respect to the minimum processing delay, the minimum processing delay for the time and/or frequency offset measurement and report may be predefined, e.g., Z1 and Z1’ as defined in 3GPP Technical Specification (TS) 38.214, section 5.4.

In some aspects, the number of CPUs for each time and/or frequency offset measurement and report may be predefined, e.g., 1 CPU per CSI-RS resource set or per CSI report configuration.

At operation 304, and as discussed above with respect to Figure 3 operation 304, the network entity 120 may, depending on the UE capability information received at operation 302, configure at least one CSI report configuration for CSI feedback. In some aspects, the network entity 120 may use Radio Resource Control (RRC) signaling to configure the CSI report. For example, the network entity 120 may transmit an RRCReconfiguration message to the UE 110 to configure the CSI report configuration. In some aspects, the network entity 120 may configure at least two CSI-RS resources as channel measurement resources (CMRs) .

At operation 406, the network entity 120 configures the UE 110 for time offset and/or frequency offset measurement for TRPs. For example, the network entity 120 configures the UE with at least two downlink reference signals for time and/or frequency measurement. The network entity may configure a list of CSI-RS resource sets, e.g., TRSs, for use by the UE 110 to measure the time offset and/or frequency offset.

At operation 408, the network entity 120 transmits the configured downlink reference signal (s) via multiple TRPs (e.g., two or more of TRPs 122A-122D of Figure 1A) .

At operation 409, a time offset and/or frequency offset report is triggered. In some aspects, the time offset report and/or frequency offset report (s) may be a UE-triggered or event-triggered report. The UE 110 may trigger the UE-triggered or event-triggered report in case the measured/observed time and/or frequency offset meets a criteria. As an example, in some implementations, the UE 110 may trigger the time and/or frequency offset report if the measured time and/or frequency offset change for a TRP (or multiple TRPs) is larger than a threshold, where the threshold may be predefined or configured by the network entity 120. In some aspects the time offset threshold value may be based on the cyclic prefix (CP) length (e.g., 1 CP or 0.5 CP) . In some aspects, the frequency offset threshold value may be based on the periodicity (T) of the CSI-RS or CSI report, e.g., 1/T. For example, for a 10ms periodicity, the frequency offset threshold may be 100Hz.

At operation 410, the UE 110 may measure the time and/or frequency offset for each of the TRPs used to provide the downlink signal to the UE 110.

At operation 412, the UE 110 may transmit the measured time and/or frequency offset report to the network entity 120. The UE 110 may report the time and/or frequency offsets via a MAC CE, or UCI on a PUCCH or PUSCH.

In some implementations, for a time offset report, the UE may report the time offset based on the unit of samples based on a reference subcarrier spacing or the subcarrier spacing for the active bandwidth part or millisecond. The reference subcarrier spacing may be predefined, e.g., 15kHz, or configured by the network entity by RRC signaling. In some other implementations, the UE 110 may report the time offset based on the phase offset for a reference subcarrier. The reference subcarrier may be configured by the network entity 120 via RRC signaling or may be predefined, e.g., the first subcarrier in the active bandwidth part, or the first subcarrier for the first resource block of the CSI-RS resource set (s) or the CSI-RS resource set (s) configured for time offset measurement.

In some implementations, for frequency offset report, the UE 110 may report the maximum Doppler shift or Doppler spread. In some other implementations, the UE may report the Doppler shift or the channel correlation factor for each subcarrier, each resource block, each sub-band, or for the whole bandwidth for the configured CSI-RS resources in the CSI-RS resource set. The UE may calculate the channel correlation factor based on the channel correlation for CSI-RS resources in the CSI-RS resource set.

In some aspects, the network entity 120 may configure the UE 110 to provide multiple CSI reports, for example, a CSI report for each TRP. The network entity 120 may configure R CSI report configurations for the time offset and frequency offset measurement report for R TRPs. The network entity 120 may configure whether the UE 110 reports the time offset and/or frequency offset for each CSI report configuration. The UE 110 may report the absolute time and frequency offset in the report.

In some other aspects, the network entity configures R-1 CSI report configurations for the time and frequency offset measurement report for R-1 TRPs. The network entity 120 may configure whether the UE 110 reports the time offset and/or frequency offset for each CSI report configuration. The UE 110 may report the relative or differential time and frequency offsets in the report, with the time offset and frequency offset for a reference CSI-RS resource set from a TRP as the reference. The network entity 120 may configure the reference CSI-RS resource set by RRC signaling, MAC CE, or DCI. In some aspects, the reference CSI-RS resource set may be a CSI-RS resource set containing the TRS, which is a QCL type source RS configured in one of the indicated TCI states, e.g., the first indicated TCI state or the TCI state with lowest identifier. In some other aspects, the reference CSI-RS resource set may be a CSI-RS resource set containing the TRS, which is a QCL type source RS configured in the second indicated TCI state or the TCI state with highest identifier.

In some aspects, network entity 120 may configure the UE 110 to provide a single report that applies to multiple TRPs. For example, the network entity 120 may configure a CSI report configuration for the time and/or frequency offset measurement report for R TRPs with R CSI-RS resource sets. The network entity may configure whether the UE 110 reports the time and/or frequency offset for the CSI report configuration.

In some implementations, the UE 110 reports R times and/or frequency offsets for the R CSI-RS resource sets, where each time offset and/or frequency offset corresponds to each CSI-RS resource set. Table 5 below illustrates one example for the time and/or frequency offset report.

Table 5

In some other implementations, the UE 110 may report R-1 time offsets and/or frequency offsets for the R CSI-RS resource sets, where each time and/or frequency offset indicates the relative time and/or frequency offset for a CSI-RS resource set compared to a first CSI-RS resource set. Table 6 below illustrates another example for the time offset and/or frequency offset report.

Table 6

At operation 314, and as discussed above with respect to Figure 3 operation 314, the network entity 120 may provide the transmission configuration indication (TCI) state (s) for each configured CSI-RS to the UE 110. The TCI state (s) may indicate whether the time offset and/or frequency offset for the CSI-RSs have been pre-compensated or not.

At operation 316, the network entity 120 transmits the configured CSI-RSs to the UE 110 based on the indicated TCI state (s) .

Figure 5 is a flow chart diagram illustrating example operations of a method 500 for channel state information feedback based on signals having pre-compensated time and/or frequency offsets. The example operations of method 500 may be performed, for example, by UE 110 or network entity 120 of Figures 1A, 1B, 2, 3, and 4. Because the operations of method 500 may be performed by a UE, network entity, or other device, the operations are described from the point of view of a “first wireless device” communicating with a “second wireless device. ” In some examples, the first wireless device may be a UE and the second wireless device may be a network entity. In other examples, the first wireless device may be a network entity and the second wireless device may be a UE. The role of the first wireless device and the second wireless device will be clear from the context of the discussion. Similarly, in some cases, the “communicating” will be the first wireless device receiving a signal from the second wireless device. In other cases, the “communicating” will be the first wireless device transmitting a signal to the second wireless device. Again, the specific type of communication involved will be clear from the context of the discussion.

At block 502, the first wireless device communicates, with the second wireless device, UE capability information. In cases where the first wireless device is a UE, the first wireless device (e.g., the UE 110) transmits UE capability information to the second wireless device (e.g., the network entity 120) as described above with reference to Figures 3 and 4, operation 302. In cases where the first wireless device is a network entity, the first wireless device (e.g., the network entity 120) receives the UE capability information from the second wireless device (e.g., the UE 120) as described above with reference to Figures 3 and 4, operation 302.

At block 514, the first wireless device communicates, with the second wireless device, one or more TCI states. In cases where the first wireless device is a UE, the first wireless device (e.g., the UE 110) receives the one or more TCI states from the second wireless device (e.g., the network entity 120) as described above with reference to Figures 3 and 4, operation 314. In cases where the first wireless device is a network entity, the first wireless device (e.g., the network entity 120) transmits the one or more TCI states to the second wireless device (e.g., the UE 110) as described above with reference to Figures 3 and 4, operation 314.

At block 516, the first wireless device communicates, with the second wireless device, configured CSI-RSs having pre-compensated time offset and/or frequency offset. In cases where the first wireless device is a UE, the first wireless device (e.g., the UE 110) receives the CSI-RSs having pre-compensated time offset and/or frequency offset from the second wireless device (e.g., the network entity 120) as described above with reference to Figures 3 and 4, operation 316. In cases where the first wireless device is a network entity, the first wireless device (e.g., the network entity 120) transmits the CSI-RSs having pre-compensated time offset and/or frequency offset to the second wireless device (e.g., the UE 110) as described above with reference to Figures 3 and 4, operation 316.

At block 520, the first wireless device communicates, with the second wireless device, CSI feedback based on the CSI-RSs. In cases where the first wireless device is a UE, the first wireless device (e.g., the UE 110) transmits the CSI feedback to the second wireless device (e.g., the network entity 120) as described above with reference to Figures 3 and 4, operation 320. In cases where the first wireless device is a network entity, the first wireless device (e.g., the network entity 120) receives the CSI feedback from the second wireless device (e.g., the UE 110) as described above with reference to Figures 3 and 4, operation 320.

Figure 6A is a flow chart diagram illustrating example operations of a method 600 for a UE to provide channel state information feedback where a network entity measures time and frequency offsets. The example operations of method 600 may be performed by a UE, for example, UE 110 of Figures 1A, 1B, 2, 3, and 4.

At block 602, and as described above with respect to Figures 3 and 4, operation 302, the UE transmits UE capability information to the network entity. In some aspects, the UE may communicate UE capability information to the network entity during an initial communication session setup process between the UE and the network entity 120. The UE capability information may include information indicating whether the UE supports TCI configuration or QCL configuration for the CSI-RSs for CSI feedback. The UE may report whether it supports CSI measurement based on time and/or frequency offset pre-compensation.

At block 604, and as described above with respect to Figures 3 and 4, operation 304, the UE receives from a network entity at least one CSI report configuration for CSI feedback.

At block 606, and as described above at Figure 3, operation 306, the UE may receive, from the network entity, a configuration for at least one uplink signal for time offset and/or frequency offset measurement.

At block 608, and as described above at Figure 3, operation 308, the UE receives a trigger to transmit the uplink signal.

At block 610, and as described above at Figure 3, operation 310, the UE transmits the triggered uplink signal.

At block 614, and as described above at Figure 3, operation 314, the UE receives, from the network entity, one or more TCI states for each configured CSI-RS to the UE 110. The TCI state (s) may indicate whether the time offsets and/or frequency offsets have been pre-compensated or not with respect to CSI-RSs received from the network entity. In some aspects, the one or more TCI states may indicate that the CSI-RSs have time offset pre-compensation without frequency pre-compensation, frequency offset pre-compensation without time offset pre-compensation, both time offset and frequency offset pre-compensation, or configurable time offset and frequency offset pre-compensation.

At block 616, and as described above at Figure 3, operation 316, the UE receives the configured CSI-RSs having pre-compensation based on the indicated TCI state (s)

At block 618, and as described above at Figure 3, operation 318, the UE determines CSI feedback based on the received CSI-RSs.

At block 620, and as described above at Figure 3, operation 320, the UE transmits the CSI feedback to the network entity.

Figure 6B is a flow chart diagram illustrating example operations of a method 650 for a UE to provide channel state information feedback where the UE measures time and frequency offsets. The example operations of method 650 may be performed by a UE, for example, UE 110 of Figures 1A, 1B, 2, 3, and 4.

Blocks 602 and 604 of Figure 6B are as described above with respect to Figure 6A.

At block 607, and as described above at Figure 4, operation 406, the UE receives from the network entity 120 a configuration for time offset and/or frequency offset measurement for TRPs. For example, the UE may be configured with at least two downlink reference signals for time and/or frequency measurement. The UE may also receive a list of CSI-RS resource sets, e.g., TRSs, for use by the UE to measure the time offset and/or frequency offset.

At block 609, and as described above at Figure 4, operation 408, the UE receives, from the network entity, the configured downlink reference signal (s) via multiple TRPs.

At block 611, and as described above at Figure 4, operation 410, the UE may measure the time and/or frequency offset for each of the TRPs used to provide the receiving the downlink signal to the UE.

At block 613, and as described above at Figure 4, operation 412, the UE may report the measured time and/or frequency offset to the network entity. The UE may report the time and/or frequency offsets via a MAC CE, or UCI on a PUCCH or PUSCH.

Block 614-620 of Figure 6B are as described above with respect to Figure 6A.

Figure 7A is a flow chart diagram illustrating example operations of a method 700 for a network entity to receive channel state information feedback where the network entity measures times and frequency offsets. The example operations of method 700 may be performed by a network entity, for example, network entity 120 of Figures 1A, 1B, 2, 3, and 4.

At block 702, and as described above with respect to Figures 3 and 4, operation 302, the network entity may receive UE capability information from a UE. In some aspects, the network entity may receive UE capability information from the UE during an initial communication session setup process between the UE and the network entity. The UE capability information may include information indicating whether the UE supports TCI configuration or QCL configuration for the CSI-RSs for CSI feedback. The UE capability information may indicate whether or not the UE supports CSI measurement based on time and/or frequency offset pre-compensation.

At block 704, and as described above with respect to Figures 3 and 4, operation 304, the network entity transmits, to the UE, at least one CSI report configuration for CSI feedback.

At block 706, and as described above at Figure 3, operation 306, the network entity may transmit, to the UE, a configuration for at least one uplink signal for time offset and/or frequency offset measurement.

At block 708, and as described above at Figure 3, operation 308, the network entity transmits, to the UE, a trigger to transmit the uplink signal.

At block 710, and as described above at Figure 3, operation 310, the network entity receives the triggered uplink signal from the UE.

At block 712, the network entity measures the time offset and/or frequency offset based on the uplink signal.

At block 714, and as described above at Figure 3, operation 314, the network entity transmits, to the UE, one or more TCI states for each configured CSI-RS. The TCI state (s) may indicate whether the time offsets and/or frequency offsets have been pre-compensated or not with respect to CSI-RSs received from the network entity. In some aspects, the one or more TCI states may indicate that the CSI-RSs have time offset pre-compensation without frequency pre-compensation, frequency offset pre-compensation without time offset pre-compensation, both time offset and frequency offset pre-compensation, or configurable time offset and frequency offset pre-compensation.

At block 716, and as described above at Figure 3, operation 316, the network entity transmits the configured CSI-RSs having pre-compensation based on the indicated TCI state (s)

At block 620, and as described above at Figure 3, operation 320, the network entity receives CSI feedback from the UE.

Figure 7B is a flow chart diagram illustrating example operations of a method 750 for a network entity to receive channel state information feedback where a UE measures times and frequency offsets. The example operations of method 750 may be performed by a network entity, for example, network entity 120 of Figures 1A, 1B, 2, 3, and 4.

Blocks 702 and 704 of Figure 7B are as described above with respect to Figure 7A.

At block 705, and as described above at Figure 4, operation 406, the network entity configures the UE for time offset and/or frequency offset measurement for TRPs. For example, the network entity may configure the UE with at least two downlink reference signals for time and/or frequency measurement. The network entity may also provide to the UE a list of CSI-RS resource sets, e.g., TRSs, for use by the UE to measure the time offset and/or frequency offset.

At block 707, and as described above at Figure 4, operation 408, the network entity transmits, to the UE, the configured downlink reference signals via multiple TRPs.

At block 709, and as described above at Figure 4, operation 412, the network entity may receive, from the UE, a report of the time offsets and/or frequency offsets measured by the UE. The network entity may receive report via a MAC CE, or UCI on a PUCCH or PUSCH.

Block 714, 716, and 720 of Figure 7B are as described above with respect to Figure 7A.

It is noted that throughout this disclosure, an expression of “X/Y” may include meaning of “X or Y” . It is noted that throughout this disclosure, an expression of “X/Y” may include meaning of “X and Y” . It is noted that throughout this disclosure, an expression of “X/Y” may include meaning of “X and/or Y” . It is noted that throughout this disclosure, an expression of “ (A) B”or “B (A) ” may include concept of “only B” . It is noted that throughout this disclosure, an expression of “ (A) B” or “B (A) ” may include concept of “A+B” or “B+A” .

It is noted that some or all of the foregoing or the following implementations can be jointly combined or formed to be a new or another one implementation.

It is noted that the foregoing or the following techniques can be used to solve at least (but not limited to) the issue (s) or scenario (s) mentioned in this disclosure.

The following additional considerations may apply to the foregoing and the following discussions.

It is noted that any two or more than two of the foregoing or the following paragraphs, (sub) -bullets, points, actions, or claims described in each method/technique/implementation may be combined logically, reasonably, and properly to form a specific method.

It is noted that any sentence, paragraph, (sub) -bullet, point, action, or claim described in each of the foregoing or the following technique (s) /implementation (s) /concept (s) may be implemented independently and separately to form a specific method. Dependency, such as “based on”, “more specifically” , “where” or etc., in technique (s) /implementation (s) /concept (s) mentioned in this disclosure is just one possible implementation which would not restrict the specific method.

Certain techniques are described in this disclosure as including logic or a number of components or modules. Modules may be software modules (such as code stored on non-transitory machine-readable medium) or hardware modules. A hardware module is a tangible unit capable of performing certain operations and may be configured or arranged in a certain manner. A hardware module can comprise dedicated circuitry or logic that is permanently configured (such as a special-purpose processor, such as a field programmable gate array (FPGA) or an application-specific integrated circuit (ASIC) ) to perform certain operations. A hardware module may also comprise programmable logic or circuitry (for example, as encompassed within a general-purpose processor or other programmable processor) that is temporarily configured by software to perform certain operations. The decision to implement a hardware module in dedicated and permanently configured circuitry, or in temporarily configured circuitry (for example, configured by software) may be driven by cost and time considerations.

Figures 1A, 1B, 2, 3, 4, 5, 6A, 6B, 7A, 7B, 8A, 8B, 8C, and 9, and the operations described herein are examples meant to aid in understanding example implementations and should not be used to limit the potential implementations or limit the scope of the claims. Some implementations might include additional operations, fewer operations, operations in parallel or in a different order, and some operations differently.

The foregoing disclosure provides illustration and description but is not intended to be exhaustive or to limit the aspects to the precise form disclosed. Modifications and variations may be made in light of the above disclosure or may be acquired from practice of the aspects. While the aspects of the disclosure have been described in terms of various examples, any combination of aspects from any of the examples is also within the scope of the disclosure. The examples in this disclosure are provided for pedagogical purposes. Alternatively, or in addition to the other examples described herein, examples include any combination of the following implementation options (enumerated as clauses for clarity) .

CLAUSES

Clause 1. A method for wireless communications by a first wireless device, including: communicating, with a second wireless device, one or more transmission configuration indication (TCI) states, each TCI state of the one or more TCI states indicating one or more quasi-co-location (QCL) parameters for each of a plurality of channel state information reference signals (CSI-RSs) ; communicating, with the second wireless device, the plurality of CSI-RSs having pre-compensation based on either or both a time offset and a frequency offset; and communicating, with the second wireless device, channel state information (CSI) feedback based on the plurality of CSI-RSs, the CSI feedback being based on a CSI report configuration.

Clause 2. The method of clause 1, where the one or more QCL parameters include first QCL parameters associated with an average delay or delay spread, and second QCL parameters associated with a Doppler delay or a Doppler shift, and where communicating the one or more TCI states includes communicating a common TCI state for all of the plurality of CSI-RSs, the common TCI state indicating that the first wireless device is to determine the first QCL parameters and the second QCL parameters based on the plurality of CSI-RSs having pre-compensation based on both the time offset and the frequency offset.

Clause 3. The method of clause 1, where the one or more QCL parameters include first QCL parameters and second QCL parameters; and where communicating the one or more TCI states includes: communicating a common TCI state for all of the plurality of CSI-RSs, the common TCI state indicating that the first wireless device is to determine the first QCL parameters based on the plurality of CSI-RSs having pre-compensation based on the time offset; and communicating separate TCI states for each of the plurality of CSI-RSs, each of the separate TCI states indicating that the first wireless device is to determine the second QCL parameters based on the plurality of CSI-RSs not having pre-compensation based on the frequency offset.

Clause 4. The method of clause 1, where the one or more QCL parameters include first QCL parameters and second QCL parameters; and where communicating the one or more TCI states includes: communicating a common TCI state for all of the plurality of CSI-RSs, the common TCI state indicating that the first wireless device is to determine the second QCL parameters based on the plurality of CSI-RSs having pre-compensation based on the frequency offset; and communicating separate TCI states for each of the plurality of CSI-RSs, each of the separate TCI states indicating that the first wireless device is to determine the first QCL parameters based on the plurality of CSI-RSs not having pre-compensation based on the time offset.

Clause 5. The method of clause 1, where the one or more QCL parameters include first QCL parameters and second QCL parameters; where communicating the one or more TCI states includes: communicating a common TCI state for a first subset of the plurality of CSI-RSs, the common TCI state indicating that the first wireless device is to determine the first QCL parameters and the second QCL parameters based on the plurality of CSI-RSs having pre-compensation based on both the time offset and the frequency offset; and communicating separate TCI states, each separate TCI state corresponding to a CSI-RS of a second subset of the plurality of CSI-RSs, each of the separate TCI states indicating that the CSI-RS corresponding to the TCI state does not have pre-compensation based on either or both the time offset and the frequency offset.

Clause 6. The method of any of clauses 1-5, further including communicating a configuration of the one or more TCI states via at least one of radio resource control (RRC) signaling, a medium access control (MAC) control element (CE) , or a downlink control information (DCI) .

Clause 7. The method of any of clauses 1-6, further including communicating, with the second wireless device, a CSI report configuration indicating the plurality of CSI-RSs to be used for CSI feedback.

Clause 8. The method of any of clauses 1-7, further including communicating, with the second wireless device, UE capability information, the UE capability information including at least one of: a first capability indicator indicating support for different TCI states for the plurality of CSI-RSs for CSI feedback; a second capability indicator indicating support for different QCL parameters for the plurality CSI-RSs; a maximum number of different TCI states for the plurality of CSI-RSs; a third capability indicator indicating support for separate TCI states for the plurality of CSI-RSs, the separate TCI states identifying the QCL parameters; a fourth capability indicator indicating support for reporting either or both the time offset and the frequency offset; a maximum number of CSI-RS resource sets for either or both time offset measurement and frequency offset measurement; a maximum number of offset reports; a minimum processing delay for the offset report; a number of CSI processing unit (CPU) for each offset report; a first supported time domain behavior for the offset report; or a second supported time domain behavior for a downlink reference signal for either or both the time offset measurement and the frequency offset measurement.

Clause 9. The method of any of clauses 1-8, further including calculating the one or more QCL parameters for one or more of the plurality of CSI-RSs, the QCL parameters being selected based on one or more indicators in the one or more TCI states for the one or more of the plurality of CSI-RSs.

Clause 10. The method of clause 9, where the one or more indicators include a first indicator indicating whether the first wireless device is to calculate a first QCL parameter from one of the one or more TCI states, the first QCL parameter including at least one of an average delay or a delay spread.

Clause 11. The method of clause 9, where the one or more indicators include a second indicator indicating whether the first wireless device is to calculate a second QCL parameter from one of the one or more the TCI states, the second QCL parameter including at least one of a Doppler delay or a Doppler shift.

Clause 12. The method of any of clauses 1-11, further including: receiving, from the second wireless device, a configuration of at least one uplink signal resource for either or both time offset measurement and frequency offset measurement.

Clause 13. The method of clause 12, where the at least one uplink signal resource includes at least one of a physical uplink shared channel (PUSCH) resource, a physical uplink control channel (PUCCH) resource, a sounding reference signal (SRS) resource, an SRS resource set, or one or more physical random access channel (PRACH) resources.

Clause 14. The method of clause 12, further including: receiving, from the second wireless device, a trigger indicator; and in response to receiving the trigger indicator, transmitting, to the second wireless device, an uplink signal via the at least one uplink signal resource.

Clause 15. The method of clause 14, where the uplink signal includes one of a PUSCH transmission or a PUCCH transmission, where the trigger indicator includes an indicator to cause the first wireless device to disable data or uplink control information (UCI) for the uplink signal, and where either or both the time offset and the frequency offset are based on a demodulation reference signal (DMRS) associated with the one of the PUSCH transmission or PUCCH transmission.

Clause 16. The method of any of clauses 1-11, further including: receiving, from the second wireless device, a configuration of at least one downlink reference resource for offset measurements; receiving, from the second wireless device, one or more signals via the at least one downlink reference resource; calculating, by the first wireless device, either or both the time offset and the frequency offset based on the one or more signals received via the at least one downlink reference resource; and transmitting, to the second wireless device, a report including either or both the time offset and the frequency offset.

Clause 17. The method of clause 16, where the at least one downlink reference resource includes one or more one second CSI-RSs configured as one or more tracking reference signals (TRSs) , where calculating either or both the time offset and the frequency offset includes calculating either or both the time offset and the frequency offset based on the one or more TRSs.

Clause 18. The method of clause 16, where transmitting the report includes transmitting a plurality of reports, where each report of the plurality of reports for a corresponding transmit and receive point (TRP) , each report including either or both the time offset and the frequency offset for the corresponding TRP.

Clause 19. The method of clause 16, where the report includes entries for a plurality of TRPs, each entry including either or both the time offset and the frequency offset for a corresponding TRP of the plurality of TRPs.

Clause 20. The method of clause 1, further including: transmitting, to the second wireless device, a configuration of at least one uplink signal resource for either or both time offset measurement and frequency offset measurement; transmitting, to the second wireless device, a trigger indicator; and receiving, from the second wireless device, a signal via the at least one uplink signal resource.

Clause 21. The method of clause 20, further including calculating, by the first wireless device, either or both the time offset and the frequency offset based on the signal received from the second wireless device via the at least one uplink signal resource.

Clause 22. The method of any of clauses 1-21, where one or more of the plurality of CSI-RSs having pre-compensation based on the time offset include first CSI-RSs that share same first QCL parameters with respect to average delay and delay spread, where one or more of the plurality of CSI-RSs having pre-compensation based on the frequency offset include second CSI-RSs that share same second QCL parameters with respect to Doppler delay and Doppler shift, and where one or more of the plurality of CSI-RSs having pre-compensation based on both the time offset and frequency offset include third CSI-RSs that share the same first and second QCL parameters.

Clause 23. An apparatus, including: a communication unit; and a processing system configured to control the communication unit to implement any one of the methods of clauses 1-22.

Another innovative aspect of the subject matter described in this disclosure can be implemented as a wireless communication device of a UE or a network entity. The wireless communication device may include at least one interface and a processing system communicatively coupled with the at least one interface. The processing system may be configured to implement any one of the above clauses.

Another innovative aspect of the subject matter described in this disclosure can be implemented as a portable electronic device including a wireless communication device, a plurality of antennas coupled to the at least one transceiver to wirelessly transmit signals output from the at least one transceiver and a housing that encompasses the wireless communication device, the at least one transceiver and at least a portion of the plurality of antennas. The wireless communication device may include at least one interface and a processing system communicatively coupled with the at least one interface. The processing system may be configured to implement any one of the above clauses.

Another innovative aspect of the subject matter described in this disclosure can be implemented as a machine-readable medium having processor-readable instructions stored therein that, when executed by a processing system of a UE or network element, cause the UE or network element to implement any one of the above clauses.

Another innovative aspect of the subject matter described in this disclosure can be implemented as an apparatus. The apparatus may include means for implementing any one of the above clauses.

As used herein, the term “component” is intended to be broadly construed as hardware, firmware, or a combination of hardware and software. As used herein, a processor is implemented in hardware, firmware, or a combination of hardware and software. As used herein, the phrase “based on” is intended to be broadly construed to mean “based at least in part on. ”

Some aspects are described herein in connection with thresholds. As used herein, satisfying a threshold may refer to a value being greater than the threshold, greater than or equal to the threshold, less than the threshold, less than or equal to the threshold, equal to the threshold, not equal to the threshold, or the like.

As used herein, a phrase referring to “at least one of” or “one or more of” a list of items refers to any combination of those items, including single members. For example, “at least one of: a, b, or c” is intended to cover the possibilities of: a only, b only, c only, a combination of a and b, a combination of a and c, a combination of b and c, and a combination of a and b and c.

In this disclosure, the term "can" indicates a capability, or alternatively indicates a possible implementation option. The term "may" indicates a permission or a possible implementation option.

The various illustrative components, logic, logical blocks, modules, circuits, operations and algorithm processes described in connection with the implementations disclosed herein may be implemented as electronic hardware, firmware, software, or combinations of hardware, firmware or software, including the structures disclosed in this specification and the structural equivalents thereof. The interchangeability of hardware, firmware and software has been described generally, in terms of functionality, and illustrated in the various illustrative components, blocks, modules, circuits and processes described above. Whether such functionality is implemented in hardware, firmware or software depends upon the particular application and design constraints imposed on the overall system.

The hardware and data processing apparatus used to implement the various illustrative components, logics, logical blocks, modules and circuits described in connection with the aspects disclosed herein may be implemented or performed with a general purpose single-or multi-chip processor, a digital signal processor (DSP) , an application specific integrated circuit (ASIC) , a field programmable gate array (FPGA) or other programmable logic device (PLD) , discrete gate or transistor logic, discrete hardware components, or any combination thereof designed to perform the functions described herein. A general-purpose processor may be a microprocessor, or any conventional processor, controller, microcontroller, or state machine. A processor also may be implemented as a combination of computing devices, for example, a combination of a DSP and a microprocessor, multiple microprocessors, one or more microprocessors in conjunction with a DSP core, or any other such configuration. In some implementations, particular processes, operations and methods may be performed by circuitry that is specific to a given function.

As described above, in some aspects implementations of the subject matter described in this specification can be implemented as software. For example, various functions of components disclosed herein, or various blocks or steps of a method, operation, process or algorithm disclosed herein can be implemented as one or more modules of one or more computer programs. Such computer programs can include non-transitory processor-or computer-executable instructions encoded on one or more tangible processor-or computer-readable storage media for execution by, or to control the operation of, data processing apparatus including the components of the devices described herein. By way of example, and not limitation, such storage media may include RAM, ROM, EEPROM, CD-ROM or other optical disk storage, magnetic disk storage or other magnetic storage devices, or any other medium that may be used to store program code in the form of instructions or data structures. Combinations of the above should also be included within the scope of storage media. When implemented in software, the techniques can be provided as part of the operating system, a library used by multiple applications, a particular software application, etc. The software can be executed by one or more general-purpose processors or one or more special-purpose processors.

As used herein, the terms “user device” , “user equipment” (for example, UE 110) , “wireless communication device” , “mobile communication device” , “communication device” , or “mobile device” refer to any one or all of cellular telephones, smartphones, portable computing devices, personal or mobile multi-media players, laptop computers, tablet computers, smartbooks, Internet-of-Things (IoT) devices, palm-top computers, wireless electronic mail receivers, multimedia Internet enabled cellular telephones, wireless gaming controllers, display sub-systems, driver assistance systems, vehicle controllers, vehicle system controllers, vehicle communication system, infotainment systems, vehicle telematics systems or subsystems, vehicle display systems or subsystems, vehicle data controllers, point-of-sale (POS) terminals, health monitoring devices, drones, cameras, media-streaming dongles or another personal media devices, wearable devices such as smartwatches, wireless hotspots, femtocells, broadband routers or other types of routers, and similar electronic devices which include a programmable processor and memory and circuitry configured to perform operations as described herein. Further, the user device in some cases may be embedded in an electronic system such as the head unit of a vehicle or an advanced driver assistance system (ADAS) . Still further, a mobile-internet device (MID) . Depending on the type, the user device can include one or more general-purpose processors, a computer-readable memory, a user interface, one or more network interfaces, one or more sensors, etc.

Various modifications to the implementations described in this disclosure may be readily apparent to persons having ordinary skill in the art, and the generic principles defined herein may be applied to other implementations without departing from the spirit or scope of this disclosure. Thus, the claims are not intended to be limited to the implementations shown herein but are to be accorded the widest scope consistent with this disclosure, the principles and the novel features disclosed herein.

Additionally, various features that are described in this specification in the context of separate implementations also can be implemented in combination in a single implementation. Conversely, various features that are described in the context of a single implementation also can be implemented in multiple implementations separately or in any suitable subcombination. As such, although features may be described above as acting in particular combinations, and even initially claimed as such, one or more features from a claimed combination can in some cases be excised from the combination, and the claimed combination may be directed to a subcombination or variation of a subcombination.

Similarly, while operations are depicted in the drawings in a particular order, this should not be understood as requiring that such operations be performed in the particular order shown or in sequential order, or that all illustrated operations be performed, to achieve desirable results. Further, the drawings may schematically depict one or more example processes in the form of a flowchart or flow diagram. However, other operations that are not depicted can be incorporated in the example processes that are schematically illustrated. For example, one or more additional operations can be performed before, after, simultaneously, or between any of the illustrated operations. In some circumstances, multitasking and parallel processing may be advantageous. Moreover, the separation of various system components in the implementations described above should not be understood as requiring such separation in all implementations, and it should be understood that the described program components and systems can generally be integrated together in a single software product or packaged into multiple software products. Additionally, other implementations are within the scope of the following claims. In some cases, the actions recited in the claims can be performed in a different order and still achieve desirable results.

The foregoing disclosure provides illustration and description but is not intended to be exhaustive or to limit the aspects to the precise form disclosed. Modifications and variations may be made in light of the above disclosure or may be acquired from practice of the aspects. While the aspects of the disclosure have been described in terms of various examples, any combination of aspects from any of the examples is also within the scope of the disclosure. The examples in this disclosure are provided for pedagogical purposes.

As used herein, the terms “component” and “module” are intended to be broadly construed as hardware, firmware, or a combination of hardware and software. As used herein, a processor is implemented in hardware, firmware, or a combination of hardware and software. As used herein, the phrase “based on” is intended to be broadly construed to mean “based at least in part on. ”

The hardware and data processing apparatus used to implement the various illustrative components, logics, logical blocks, modules and circuits described in connection with the aspects disclosed herein may be implemented or performed with processing circuitry, examples of which include a general purpose single-or multi-chip processor, a digital signal processor (DSP) , an application specific integrated circuit (ASIC) , a field programmable gate array (FPGA) or other programmable logic device (PLD) , discrete gate or transistor logic, discrete hardware components, or any combination thereof designed to perform the functions described herein. A general-purpose processor may be a microprocessor, or any conventional processor, controller, microcontroller, or state machine. A processor also may be implemented as a combination of computing devices, for example, a combination of a DSP and a microprocessor, multiple microprocessors, one or more microprocessors in conjunction with a DSP core, or any other such configuration. In some implementations, particular processes, operations and methods may be performed by circuitry that is specific to a given function.

As described above, in some aspects implementations of the subject matter described in this specification can be implemented as software. For example, various functions of components disclosed herein, or various blocks or steps of a method, operation, process or algorithm disclosed herein can be implemented as one or more modules of one or more computer programs. Such computer programs can include non-transitory processor-or computer-executable instructions encoded on one or more tangible processor-or computer-readable storage media for execution by, or to control the operation of, data processing apparatus including the components of the devices described herein. By way of example, and not limitation, such storage media may include RAM, ROM, EEPROM, CD-ROM or other optical disk storage, magnetic disk storage or other magnetic storage devices, or any other medium that may be used to store program code in the form of instructions or data structures. Combinations of the above should also be included within the scope of storage media.

As used herein, the terms “user equipment” , “wireless communication device” , “mobile communication device” , “communication device” , or “mobile device” refer to any one or all of cellular telephones, smartphones, portable computing devices, personal or mobile multi-media players, laptop computers, tablet computers, smartbooks, Internet-of-Things (IoT) devices, palm-top computers, wireless electronic mail receivers, multimedia Internet enabled cellular telephones, wireless gaming controllers, display sub-systems, driver assistance systems, vehicle controllers, vehicle system controllers, vehicle communication system, infotainment systems, vehicle telematics systems or subsystems, vehicle display systems or subsystems, vehicle data controllers or routers, and similar electronic devices which include a processing circuitry such as a programmable processor, memory, and other circuitry configured to perform operations as described herein.

Various modifications to the implementations described in this disclosure may be readily apparent to persons having ordinary skill in the art, and the generic principles defined herein may be applied to other implementations without departing from the scope of this disclosure. Thus, the claims are not intended to be limited to the implementations shown herein but are to be accorded the widest scope consistent with this disclosure, the principles and the novel features disclosed herein.

Similarly, while operations are depicted in the drawings in a particular order, this should not be understood as requiring that such operations be performed in the particular order shown or in sequential order, or that all illustrated operations be performed, to achieve desirable results. Further, the drawings may schematically depict one or more example processes in the form of a flowchart or flow diagram. However, other operations that are not depicted can be incorporated in the example processes that are schematically illustrated. For example, one or more additional operations can be performed before, after, simultaneously, or between any of the illustrated operations. In some circumstances, multitasking and parallel processing may be advantageous. Moreover, the separation of various system components in the implementations described above should not be understood as requiring such separation in all implementations, and should be understood that the described program components and systems can generally be integrated together in a single software product or packaged into multiple software products. Additionally, other implementations are within the scope of the following claims. In some cases, the actions recited in the claims can be performed in a different order and still achieve desirable results.

Claims

A method for wireless communications by a first wireless device, comprising:

communicating, with a second wireless device, one or more transmission configuration indication (TCI) states, each TCI state of the one or more TCI states indicating one or more quasi-co-location (QCL) parameters for each of a plurality of channel state information reference signals (CSI-RSs) ;

communicating, with the second wireless device, the plurality of CSI-RSs having pre-compensation based on either or both a time offset and a frequency offset; and

communicating, with the second wireless device, channel state information (CSI) feedback based on the plurality of CSI-RSs, the CSI feedback being based on a CSI report configuration.
The method of claim 1,

wherein the one or more QCL parameters include first QCL parameters associated with an average delay or delay spread, and second QCL parameters associated with a Doppler delay or a Doppler shift, and

wherein communicating the one or more TCI states comprises communicating a common TCI state for all of the plurality of CSI-RSs, the common TCI state indicating that the first wireless device is to determine the first QCL parameters and the second QCL parameters based on the plurality of CSI-RSs having pre-compensation based on both the time offset and the frequency offset.
The method of claim 1,

wherein the one or more QCL parameters include first QCL parameters and second QCL parameters; and

wherein communicating the one or more TCI states comprises:

communicating a common TCI state for all of the plurality of CSI-RSs, the common TCI state indicating that the first wireless device is to determine the first QCL parameters based on the plurality of CSI-RSs having pre-compensation based on the time offset; and

communicating separate TCI states for each of the plurality of CSI-RSs, each of the separate TCI states indicating that the first wireless device is to determine the second QCL parameters based on the plurality of CSI-RSs not having pre-compensation based on the frequency offset.
The method of claim 1,

wherein the one or more QCL parameters include first QCL parameters and second QCL parameters; and

wherein communicating the one or more TCI states comprises:

communicating a common TCI state for all of the plurality of CSI-RSs, the common TCI state indicating that the first wireless device is to determine the second QCL parameters based on the plurality of CSI-RSs having pre-compensation based on the frequency offset; and

communicating separate TCI states for each of the plurality of CSI-RSs, each of the separate TCI states indicating that the first wireless device is to determine the first QCL parameters based on the plurality of CSI-RSs not having pre-compensation based on the time offset.
The method of claim 1,

wherein the one or more QCL parameters include first QCL parameters and second QCL parameters;

wherein communicating the one or more TCI states comprises:

communicating a common TCI state for a first subset of the plurality of CSI-RSs, the common TCI state indicating that the first wireless device is to determine the first QCL parameters and the second QCL parameters based on the plurality of CSI-RSs having pre-compensation based on either or both the time offset and the frequency offset; and

communicating separate TCI states, each separate TCI state corresponding to a CSI-RS of a second subset of the plurality of CSI-RSs, each of the separate TCI states indicating that the CSI-RS corresponding to the TCI state does not have pre-compensation based on either or both the time offset and the frequency offset.
The method of any of claims 1-5, further comprising communicating a configuration of the one or more TCI states via at least one of radio resource control (RRC) signaling, a medium access control (MAC) control element (CE) , or a downlink control information (DCI) .
The method of any of claims 1-6, further comprising communicating, with the second wireless device, a CSI report configuration indicating the plurality of CSI-RSs to be used for CSI feedback.
The method of any of claims 1-7, further comprising communicating, with the second wireless device, user equipment (UE) capability information, the UE capability information comprising at least one of:

a first capability indicator indicating support for different TCI states for the plurality of CSI-RSs for CSI feedback;

a second capability indicator indicating support for different QCL parameters for the plurality of CSI-RSs;

a maximum number of different TCI states for the plurality of CSI-RSs;

a third capability indicator indicating support for separate TCI states for the plurality of CSI-RSs, the separate TCI states identifying the QCL parameters;

a fourth capability indicator indicating support for reporting either or both the time offset and the frequency offset;

a maximum number of CSI-RS resource sets for either or both time offset measurement and frequency offset measurement;

a maximum number of offset reports;

a minimum processing delay for the offset report;

a number of CSI processing unit (CPU) for each offset report;

a first supported time domain behavior for the offset report; or

a second supported time domain behavior for a downlink reference signal for either or both the time offset measurement and the frequency offset measurement.
The method of any of claims 1-8, wherein:

one or more of the plurality of CSI-RSs having pre-compensation based on the time offset include first CSI-RSs that share same first QCL parameters with respect to average delay and delay spread;

one or more of the plurality of CSI-RSs having pre-compensation based on the frequency offset include second CSI-RSs that share same second QCL parameters with respect to Doppler delay and Doppler shift; and

one or more of the plurality of CSI-RSs having pre-compensation based on both the time offset and frequency offset include third CSI-RSs that share the same first and second QCL parameters.
The method of any of claims 1-9, further comprising calculating the one or more QCL parameters for one or more of the plurality of CSI-RSs, the QCL parameters being selected based on one or more indicators in the one or more TCI states for the one or more of the plurality of CSI-RSs; wherein the first wireless device includes a UE and the second wireless device includes a network entity.
The method of claim 10, wherein the one or more indicators include a first indicator indicating whether the first wireless device is to calculate a first QCL parameter from one of the one or more TCI states, the first QCL parameter comprising at least one of an average delay or a delay spread.
The method of claim 10, wherein the one or more indicators include a second indicator indicating whether the first wireless device is to calculate a second QCL parameter from one of the one or more the TCI states, the second QCL parameter comprising at least one of a Doppler delay or a Doppler shift.
The method of any of claims 1-12, further comprising:

receiving, from the second wireless device, a configuration of at least one uplink signal resource for either or both time offset measurement and frequency offset measurement, wherein the first wireless device includes a UE and the second wireless device includes a network entity.
The method of claim 13, wherein the at least one uplink signal resource comprises at least one of a physical uplink shared channel (PUSCH) resource, a physical uplink control channel (PUCCH) resource, a sounding reference signal (SRS) resource, an SRS resource set, or one or more physical random access channel (PRACH) resources.
The method of claim 13, further comprising:

receiving, from the second wireless device, a trigger indicator; and

in response to receiving the trigger indicator, transmitting, to the second wireless device, an uplink signal via the at least one uplink signal resource.
The method of claim 15,

wherein the uplink signal comprises one of a PUSCH transmission or a PUCCH transmission,

wherein the trigger indicator includes an indicator to cause the first wireless device to disable data or uplink control information (UCI) for the uplink signal, and

wherein either or both the time offset and the frequency offset are based on a demodulation reference signal (DMRS) associated with the one of the PUSCH transmission or PUCCH transmission.
The method of any of claims 1-12, further comprising:

receiving, from the second wireless device, a configuration of at least one downlink reference resource for offset measurements;

receiving, from the second wireless device, one or more signals via the at least one downlink reference resource;

calculating, by the first wireless device, either or both the time offset and the frequency offset based on the one or more signals received via the at least one downlink reference resource; and

transmitting, to the second wireless device, a report including either or both the time offset and the frequency offset, wherein the first wireless device includes a user equipment (UE) and the second wireless device includes a network entity.
The method of claim 17, wherein the at least one downlink reference resource comprises one or more one second CSI-RSs configured as one or more tracking reference signals (TRSs) , wherein calculating either or both the time offset and the frequency offset comprises calculating either or both the time offset and the frequency offset based on the one or more TRSs.
The method of claim 17, wherein transmitting the report comprises transmitting a plurality of reports, wherein each report of the plurality of reports for a corresponding transmit and receive point (TRP) , each report including either or both the time offset and the frequency offset for the corresponding TRP.
The method of claim 17, wherein the report includes entries for a plurality of TRPs, each entry comprising either or both the time offset and the frequency offset for a corresponding TRP of the plurality of TRPs.
The method of claim 1, further comprising:

transmitting, to the second wireless device, a configuration of at least one uplink signal resource for either or both time offset measurement and frequency offset measurement;

transmitting, to the second wireless device, a trigger indicator; and

receiving, from the second wireless device, a signal via the at least one uplink signal resource wherein the first wireless device includes a network entity and the second wireless device includes a UE.
The method of claim 21, further comprising calculating, by the first wireless device, either or both the time offset and the frequency offset based on the signal received from the second wireless device via the at least one uplink signal resource.
An apparatus, comprising:

a communication unit; and

a processing system configured to control the communication unit to implement any one of the methods of claims 1-22.