Alignment for user equipment-assisted coherent joint transmission with multiple transmission and reception points
UE-assisted coherent joint transmission techniques calculate and report inter-TRP timing and phase offsets using defined frequency domain references, enhancing synchronization and alignment for improved CJT performance in wireless communication systems.
Patent Information
- Application Number
- PCT/CN2024/106079
- Authority / Receiving Office
- WO · WO
- Patent Type
- Applications
- Current Assignee / Owner
- Filing Date
- 2024-07-18
- Publication Date
- 2026-01-22
AI Technical Summary
Existing wireless communication systems face challenges in aligning multiple transmission and reception points (TRPs) for coherent joint transmission (CJT) due to varying UE parameters in reporting inter-TRP timing and phase offsets, leading to inconsistent performance in CJT operations.
User Equipment (UE) assists in coherent joint transmission by calculating and reporting UE-derived inter-TRP timing and phase offsets based on received reference signals, using pre-coded or non-pre-coded CSI-RS, and aligning these offsets with a defined frequency domain reference point, such as a subcarrier, resource block, or subband, to synchronize TRPs for effective CJT.
The solution enhances the synchronization and alignment of multiple TRPs, improving the effectiveness and consistency of coherent joint transmission by accurately determining and reporting inter-TRP timing and phase offsets, thereby optimizing communication performance.
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Figure CN2024106079_22012026_PF_FP_ABST
Abstract
Description
ALIGNMENT FOR USER EQUIPMENT-ASSISTED COHERENT JOINT TRANSMISSION WITH MULTIPLE TRANSMISSION AND RECEPTION POINTS
[0001] FIELD OF TECHNOLOGY
[0002] The following relates to wireless communications, including alignment for user equipment (UE) -assisted coherent joint transmission with multiple transmission and reception points.BACKGROUND
[0003] Wireless communications systems are widely deployed to provide various types of communication content such as voice, video, packet data, messaging, broadcast, and so on. These systems may be capable of supporting communication with multiple users by sharing the available system resources (e.g., time, frequency, and power) . Examples of such multiple-access systems include fourth generation (4G) systems such as Long Term Evolution (LTE) systems, LTE-Advanced (LTE-A) systems, or LTE-A Pro systems, and fifth generation (5G) systems which may be referred to as New Radio (NR) systems. These systems may employ technologies such as code division multiple access (CDMA) , time division multiple access (TDMA) , frequency division multiple access (FDMA) , orthogonal FDMA (OFDMA) , or discrete Fourier transform spread orthogonal frequency division multiplexing (DFT-S-OFDM) . A wireless multiple-access communications system may include one or more base stations, each supporting wireless communication for communication devices, which may be known as user equipment (UE) .SUMMARY
[0004] 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.
[0005] A method for wireless communications by a user equipment (UE) is described. The method may include receiving control signaling indicating a configuration for an offset information report in a coherent joint transmission scheme, transmitting a first reference signal to both a first transmission and reception point (TRP) and a second TRP, receiving, from the first TRP and the second TRP, respective second reference signals that are respectively precoded based on the first reference signal, and transmitting the offset information report to the first TRP or the second TRP, or both, that indicates a UE-derived inter-TRP timing offset between the first TRP and the second TRP and a UE-derived inter-TRP phase offset between the first TRP and the second TRP based on receiving the respective second reference signals, where the UE-derived inter-TRP phase offset is based on the UE-derived inter-TRP timing offset and a reference frequency domain resource in accordance with the configuration for the offset information report.
[0006] A UE for wireless communications is described. The UE may include one or more memories storing processor executable code, and one or more processors coupled with the one or more memories. The one or more processors may individually or collectively be operable to execute the code to cause the UE to receive control signaling indicating a configuration for an offset information report in a coherent joint transmission scheme, transmit a first reference signal to both a first TRP and a second TRP, receive, from the first TRP and the second TRP, respective second reference signals that are respectively precoded based on the first reference signal, and transmit the offset information report to the first TRP or the second TRP, or both, that indicates a UE-derived inter-TRP timing offset between the first TRP and the second TRP and a UE-derived inter-TRP phase offset between the first TRP and the second TRP based on receiving the respective second reference signals, where the UE-derived inter-TRP phase offset is based on the UE-derived inter-TRP timing offset and a reference frequency domain resource in accordance with the configuration for the offset information report.
[0007] Another UE for wireless communications is described. The UE may include means for receiving control signaling indicating a configuration for an offset information report in a coherent joint transmission scheme, means for transmitting a first reference signal to both a first TRP and a second TRP, means for receiving, from the first TRP and the second TRP, respective second reference signals that are respectively precoded based on the first reference signal, and means for transmitting the offset information report to the first TRP or the second TRP, or both, that indicates a UE-derived inter-TRP timing offset between the first TRP and the second TRP and a UE-derived inter-TRP phase offset between the first TRP and the second TRP based on receiving the respective second reference signals, where the UE-derived inter-TRP phase offset is based on the UE-derived inter-TRP timing offset and a reference frequency domain resource in accordance with the configuration for the offset information report.
[0008] A non-transitory computer-readable medium storing code for wireless communications is described. The code may include instructions executable by one or more processors to receive control signaling indicating a configuration for an offset information report in a coherent joint transmission scheme, transmit a first reference signal to both a first TRP and a second TRP, receive, from the first TRP and the second TRP, respective second reference signals that are respectively precoded based on the first reference signal, and transmit the offset information report to the first TRP or the second TRP, or both, that indicates a UE-derived inter-TRP timing offset between the first TRP and the second TRP and a UE-derived inter-TRP phase offset between the first TRP and the second TRP based on receiving the respective second reference signals, where the UE-derived inter-TRP phase offset is based on the UE-derived inter-TRP timing offset and a reference frequency domain resource in accordance with the configuration for the offset information report.
[0009] In some examples of the method, UEs, and non-transitory computer-readable medium described herein, receiving the control signaling indicating the configuration may include operations, features, means, or instructions for receiving an indication of the reference frequency domain resource for the UE-derived inter-TRP phase offset.
[0010] In some examples of the method, UEs, and non-transitory computer-readable medium described herein, the reference frequency domain resource corresponds to a first subcarrier, resource block, or subband of a wideband configured for the UE and the UE-derived inter-TRP phase offset may be associated with the wideband.
[0011] In some examples of the method, UEs, and non-transitory computer-readable medium described herein, the reference frequency domain resource corresponds to a middle subcarrier, resource block, or subband of a wideband configured for the UE and the UE-derived inter-TRP phase offset may be associated with the wideband.
[0012] In some examples of the method, UEs, and non-transitory computer-readable medium described herein, the UE-derived inter-TRP timing offset corresponds to an average delay difference between the first TRP and the second TRP based on the respective second reference signals.
[0013] In some examples of the method, UEs, and non-transitory computer-readable medium described herein, the UE-derived inter-TRP timing offset corresponds to a delay difference between a first peak received power of the first TRP and a second peak received power of the second TRP based on the respective second reference signals.
[0014] In some examples of the method, UEs, and non-transitory computer-readable medium described herein, the configuration for the offset information report indicates that the UE-derived inter-TRP timing offset corresponds to an average delay difference between the first TRP and the second TRP based on the respective second reference signals or the UE-derived inter-TRP timing offset corresponds to a delay difference between a first peak received power of the first TRP and a second peak received power of the second TRP based on the respective second reference signals.
[0015] Some examples of the method, UEs, and non-transitory computer-readable medium described herein may further include operations, features, means, or instructions for measuring the respective second reference signals over respective frequency domain resources of one or more subbands to obtain a respective one or more UE-derived inter-TRP phase offsets for the one or more subbands.
[0016] Some examples of the method, UEs, and non-transitory computer-readable medium described herein may further include operations, features, means, or instructions for measuring the respective second reference signals over a wideband including one or more subbands to obtain a respective one or more UE-derived inter-TRP phase offsets for the one or more subbands.
[0017] In some examples of the method, UEs, and non-transitory computer-readable medium described herein, the configuration for the offset information report indicates to calculate the UE-derived inter-TRP phase offset based on frequency domain resources of a wideband or one or more subbands.
[0018] A method for wireless communications by a first TRP is described. The method may include transmitting control signaling indicating a configuration for an offset information report in a coherent joint transmission scheme with a second TRP, receiving a first reference signal from a UE, transmitting, to the UE, a second reference signal that is precoded based on the first reference signal, receiving the offset information report from the UE, where the offset information report indicates a UE-derived inter-TRP timing offset between the first TRP and the second TRP and a UE-derived inter-TRP phase offset between the first TRP and the second TRP that is based on the UE-derived inter-TRP timing offset and a reference frequency domain resource in accordance with the configuration for the offset information report, and transmitting an indication of the UE-derived inter-TRP phase offset and the UE-derived inter-TRP timing offset to the second TRP.
[0019] A first TRP for wireless communications is described. The first TRP may include one or more memories storing processor executable code, and one or more processors coupled with the one or more memories. The one or more processors may individually or collectively be operable to execute the code to cause the first TRP to transmit control signaling indicating a configuration for an offset information report in a coherent joint transmission scheme with a second TRP, receive a first reference signal from a UE, transmit, to the UE, a second reference signal that is precoded based on the first reference signal, receive the offset information report from the UE, where the offset information report indicates a UE-derived inter-TRP timing offset between the first TRP and the second TRP and a UE-derived inter-TRP phase offset between the first TRP and the second TRP that is based on the UE-derived inter-TRP timing offset and a reference frequency domain resource in accordance with the configuration for the offset information report, and transmit an indication of the UE-derived inter-TRP phase offset and the UE-derived inter-TRP timing offset to the second TRP.
[0020] Another first TRP for wireless communications is described. The first TRP may include means for transmitting control signaling indicating a configuration for an offset information report in a coherent joint transmission scheme with a second TRP, means for receiving a first reference signal from a UE, means for transmitting, to the UE, a second reference signal that is precoded based on the first reference signal, means for receiving the offset information report from the UE, where the offset information report indicates a UE-derived inter-TRP timing offset between the first TRP and the second TRP and a UE-derived inter-TRP phase offset between the first TRP and the second TRP that is based on the UE-derived inter-TRP timing offset and a reference frequency domain resource in accordance with the configuration for the offset information report, and means for transmitting an indication of the UE-derived inter-TRP phase offset and the UE-derived inter-TRP timing offset to the second TRP.
[0021] A non-transitory computer-readable medium storing code for wireless communications is described. The code may include instructions executable by one or more processors to transmit control signaling indicating a configuration for an offset information report in a coherent joint transmission scheme with a second TRP, receive a first reference signal from a UE, transmit, to the UE, a second reference signal that is precoded based on the first reference signal, receive the offset information report from the UE, where the offset information report indicates a UE-derived inter-TRP timing offset between the first TRP and the second TRP and a UE-derived inter-TRP phase offset between the first TRP and the second TRP that is based on the UE-derived inter-TRP timing offset and a reference frequency domain resource in accordance with the configuration for the offset information report, and transmit an indication of the UE-derived inter-TRP phase offset and the UE-derived inter-TRP timing offset to the second TRP.
[0022] In some examples of the method, first TRPs, and non-transitory computer-readable medium described herein, transmitting the control signaling indicating the configuration may include operations, features, means, or instructions for transmitting an indication of the reference frequency domain resource for a determination of the UE-derived inter-TRP phase offset.
[0023] In some examples of the method, first TRPs, and non-transitory computer-readable medium described herein, the configuration for the offset information report indicates to calculate the UE-derived inter-TRP phase offset based on frequency domain resources of a wideband radio frequency spectrum band or one or more subbands.
[0024] A method for wireless communications by a UE is described. The method may include receiving control signaling indicating a configuration for an offset information report in a coherent joint transmission scheme, transmitting a first reference signal to a first TRP and to a second TRP, receiving, from the first TRP and the second TRP, respective second frequency-domain (FD) -non-precoded reference signals, and transmitting the offset information report to the first TRP or the second TRP, or both, where the offset information report indicates a UE-derived inter-TRP phase offset between the first TRP and the second TRP or a UE-derived inter-TRP delay offset between the first TRP and the second TRP, or both, based on receiving the respective second FD-non-precoded reference signals and in accordance with the configuration for the offset information report.
[0025] A UE for wireless communications is described. The UE may include one or more memories storing processor executable code, and one or more processors coupled with the one or more memories. The one or more processors may individually or collectively be operable to execute the code to cause the UE to receive control signaling indicating a configuration for an offset information report in a coherent joint transmission scheme, transmit a first reference signal to a first TRP and to a second TRP, receive, from the first TRP and the second TRP, respective second frequency-domain (FD) -non-precoded reference signals, and transmit the offset information report to the first TRP or the second TRP, or both, where the offset information report indicates a UE-derived inter-TRP phase offset between the first TRP and the second TRP or a UE-derived inter-TRP delay offset between the first TRP and the second TRP, or both, based on receiving the respective second FD-non-precoded reference signals and in accordance with the configuration for the offset information report.
[0026] Another UE for wireless communications is described. The UE may include means for receiving control signaling indicating a configuration for an offset information report in a coherent joint transmission scheme, means for transmitting a first reference signal to a first TRP and to a second TRP, means for receiving, from the first TRP and the second TRP, respective second frequency-domain (FD) -non-precoded reference signals, and means for transmitting the offset information report to the first TRP or the second TRP, or both, where the offset information report indicates a UE-derived inter-TRP phase offset between the first TRP and the second TRP or a UE-derived inter-TRP delay offset between the first TRP and the second TRP, or both, based on receiving the respective second FD-non-precoded reference signals and in accordance with the configuration for the offset information report.
[0027] A non-transitory computer-readable medium storing code for wireless communications is described. The code may include instructions executable by one or more processors to receive control signaling indicating a configuration for an offset information report in a coherent joint transmission scheme, transmit a first reference signal to a first TRP and to a second TRP, receive, from the first TRP and the second TRP, respective second frequency-domain (FD) -non-precoded reference signals, and transmit the offset information report to the first TRP or the second TRP, or both, where the offset information report indicates a UE-derived inter-TRP phase offset between the first TRP and the second TRP or a UE-derived inter-TRP delay offset between the first TRP and the second TRP, or both, based on receiving the respective second FD-non-precoded reference signals and in accordance with the configuration for the offset information report.
[0028] Some examples of the method, UEs, and non-transitory computer-readable medium described herein may further include operations, features, means, or instructions for averaging a phase measurement of the respective second FD-non-precoded reference signals using a subset of antenna ports of the UE to obtain the inter-TRP phase offset.
[0029] Some examples of the method, UEs, and non-transitory computer-readable medium described herein may further include operations, features, means, or instructions for selecting the subset of antenna ports of the UE based on receiving the respective second FD-non-precoded reference signals, where the offset information report indicates the subset of antenna ports used for a determination of the UE-derived inter-TRP phase offset.
[0030] Some examples of the method, UEs, and non-transitory computer-readable medium described herein may further include operations, features, means, or instructions for receiving a control signal indicating the subset of antenna ports to use for a determination the UE-derived inter-TRP phase offset based on the first reference signal, where the UE-derived inter-TRP phase offset may be based on the subset of antenna ports.
[0031] In some examples of the method, UEs, and non-transitory computer-readable medium described herein, the configuration for the offset information report indicates the subset of antenna ports of the UE.
[0032] In some examples of the method, UEs, and non-transitory computer-readable medium described herein, the UE-derived inter-TRP phase offset may be based on the UE-derived inter-TRP delay offset.
[0033] In some examples of the method, UEs, and non-transitory computer-readable medium described herein, receiving the control signaling indicating the configuration may include operations, features, means, or instructions for receiving an indication of a reference frequency domain resource, where the UE-derived inter-TRP phase offset may be based on the reference frequency domain resource in accordance with the configuration for the offset information report.
[0034] In some examples of the method, UEs, and non-transitory computer-readable medium described herein, the offset information report indicates the UE-derived inter-TRP delay offset.
[0035] In some examples of the method, UEs, and non-transitory computer-readable medium described herein, the UE-derived inter-TRP delay offset corresponds to an average delay difference between the first TRP and the second TRP based on the respective second FD-non-precoded reference signals.
[0036] In some examples of the method, UEs, and non-transitory computer-readable medium described herein, the UE-derived inter-TRP delay offset corresponds to a delay difference between a first peak received power of the first TRP and a second peak received power of the second TRP based on the respective second FD-non-precoded reference signals.
[0037] In some examples of the method, UEs, and non-transitory computer-readable medium described herein, the configuration for the offset information report indicates that the UE-derived inter-TRP delay offset corresponds to an average delay difference between the first TRP and the second TRP based on the respective second FD-non-precoded reference signals or the UE-derived inter-TRP delay offset corresponds to a delay difference between a first peak received power of the first TRP and a second peak received power of the second TRP based on the respective second FD-non-precoded reference signals.
[0038] Some examples of the method, UEs, and non-transitory computer-readable medium described herein may further include operations, features, means, or instructions for measuring the respective second FD-non-precoded reference signals over respective frequency domain resources of one or more subbands to obtain a respective one or more UE-derived inter-TRP phase offsets for the one or more subbands.
[0039] A method for wireless communications by a first TRP is described. The method may include transmitting control signaling indicating a configuration for an offset information report in a coherent joint transmission scheme with a second TRP, receiving a first reference signal from a UE, transmitting, to the UE, a second FD-non-precoded reference signal, receiving the offset information report from the UE based on transmitting the second FD-non-precoded reference signal, where the offset information report indicates a UE-derived inter-TRP phase offset between the first TRP and the second TRP, and transmitting an indication of the UE-derived inter-TRP phase offset to the second TRP.
[0040] A first TRP for wireless communications is described. The first TRP may include one or more memories storing processor executable code, and one or more processors coupled with the one or more memories. The one or more processors may individually or collectively be operable to execute the code to cause the first TRP to transmit control signaling indicating a configuration for an offset information report in a coherent joint transmission scheme with a second TRP, receive a first reference signal from a UE, transmit, to the UE, a second FD-non-precoded reference signal, receive the offset information report from the UE based on transmitting the second FD-non-precoded reference signal, where the offset information report indicates a UE-derived inter-TRP phase offset between the first TRP and the second TRP, and transmit an indication of the UE-derived inter-TRP phase offset to the second TRP.
[0041] Another first TRP for wireless communications is described. The first TRP may include means for transmitting control signaling indicating a configuration for an offset information report in a coherent joint transmission scheme with a second TRP, means for receiving a first reference signal from a UE, means for transmitting, to the UE, a second FD-non-precoded reference signal, means for receiving the offset information report from the UE based on transmitting the second FD-non-precoded reference signal, where the offset information report indicates a UE-derived inter-TRP phase offset between the first TRP and the second TRP, and means for transmitting an indication of the UE-derived inter-TRP phase offset to the second TRP.
[0042] A non-transitory computer-readable medium storing code for wireless communications is described. The code may include instructions executable by one or more processors to transmit control signaling indicating a configuration for an offset information report in a coherent joint transmission scheme with a second TRP, receive a first reference signal from a UE, transmit, to the UE, a second FD-non-precoded reference signal, receive the offset information report from the UE based on transmitting the second FD-non-precoded reference signal, where the offset information report indicates a UE-derived inter-TRP phase offset between the first TRP and the second TRP, and transmit an indication of the UE-derived inter-TRP phase offset to the second TRP.
[0043] Some examples of the method, first TRPs, and non-transitory computer-readable medium described herein may further include operations, features, means, or instructions for transmitting a control signal indicating a subset of antenna ports to use for a determination of the UE-derived inter-TRP phase offset based on the first reference signal, where the UE-derived inter-TRP phase offset may be based on the subset of antenna ports.
[0044] In some examples of the method, first TRPs, and non-transitory computer-readable medium described herein, the UE-derived inter-TRP phase offset may be based on a UE-derived inter-TRP delay offset between the first TRP and the second TRP based on receiving the first reference signal and transmitting the second FD-non-precoded reference signal.
[0045] In some examples of the method, first TRPs, and non-transitory computer-readable medium described herein, the configuration for the offset information report indicates that the UE-derived inter-TRP delay offset corresponds to an average delay difference between the first TRP and the second TRP based on the second FD-non- precoded reference signal or the UE-derived inter-TRP delay offset corresponds to a delay difference between a first peak received power of the first TRP and a second peak received power of the second TRP based on the second FD-non-precoded reference signal.
[0046] In some examples of the method, first TRPs, and non-transitory computer-readable medium described herein, the offset information report indicates a subset of antenna ports of the UE used to calculate the UE-derived inter-TRP phase offset based on transmitting the second FD-non-precoded reference signal.
[0047] 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. Note that the relative dimensions of the following figures may not be drawn to scale.BRIEF DESCRIPTION OF THE DRAWINGS
[0048] FIG. 1 shows an example of a wireless communications system that supports alignment for user equipment (UE) -assisted coherent joint transmission with multiple transmission and reception points in accordance with one or more aspects of the present disclosure.
[0049] FIG. 2 shows an example of a wireless communications system that supports alignment for UE-assisted coherent joint transmission with multiple transmission and reception points in accordance with one or more aspects of the present disclosure.
[0050] FIG. 3 shows an example of a process flow that supports alignment for UE-assisted coherent joint transmission with multiple transmission and reception points in accordance with one or more aspects of the present disclosure.
[0051] FIG. 4 shows an example of a process flow that supports alignment for UE-assisted coherent joint transmission with multiple transmission and reception points in accordance with one or more aspects of the present disclosure.
[0052] FIGs. 5 and 6 show block diagrams of devices that support alignment for UE-assisted coherent joint transmission with multiple transmission and reception points in accordance with one or more aspects of the present disclosure.
[0053] FIG. 7 shows a block diagram of a communications manager that supports alignment for UE-assisted coherent joint transmission with multiple transmission and reception points in accordance with one or more aspects of the present disclosure.
[0054] FIG. 8 shows a diagram of a system including a device that supports alignment for UE-assisted coherent joint transmission with multiple transmission and reception points in accordance with one or more aspects of the present disclosure.
[0055] FIGs. 9 and 10 show block diagrams of devices that support alignment for UE-assisted coherent joint transmission with multiple transmission and reception points in accordance with one or more aspects of the present disclosure.
[0056] FIG. 11 shows a block diagram of a communications manager that supports alignment for UE-assisted coherent joint transmission with multiple transmission and reception points in accordance with one or more aspects of the present disclosure.
[0057] FIG. 12 shows a diagram of a system including a device that supports alignment for UE-assisted coherent joint transmission with multiple transmission and reception points in accordance with one or more aspects of the present disclosure.
[0058] FIGs. 13 through 16 show flowcharts illustrating methods that support alignment for UE-assisted coherent joint transmission with multiple transmission and reception points in accordance with one or more aspects of the present disclosure.DETAILED DESCRIPTION
[0059] Some wireless communication systems may provide for coherent joint transmission (CJT) . A network entity may enable multiple transmission and reception points (TRPs) that transmit signaling over a same time and frequency resources to a user equipment (UE) . To support CJT, the UE may provide inter-TRP time misalignment and phase offset measurement and reporting. The UE may transmit an uplink reference signal, such as a sounding reference signal (SRS) , to each TRP. In response, the UE may receive a downlink reference signal, such as a channel state information reference signal (CSI-RS) , from each TRP. The communications between the UE and each TRP may have associated phase and time differences or offsets. The UE may calculate the offsets between each of the TRPs based on the received CSI-RSs and report the calculated offsets to one of the TRPs. For example, the UE may calculate an inter-TRP phase offset and an inter-TRP timing offset between a first TRP and a second TRP, and the UE may report the inter-TRP phase offset and an inter-TRP timing offset to the second TRP. The second TRP may use the inter-TRP phase offset and an inter-TRP timing offset from the UE to synchronize with the first TRP.
[0060] In a first scheme, the UE may receive pre-coded CSI-RS from each TRP, and the CSI-RS precoding may ensure that channel propagation delay and channel phase are canceled out from the determination of inter-TRP phase offset and an inter-TRP timing offset. The UE may report the inter-TRP timing offset to one of the TRPs for the TRPs to synchronize for CJT. In a second scheme, the UE may receive non-precoded CSI-RS from each TRP, such that the channel propagation delay and channel phase are not canceled out. The non-precoded CSI-RS may not be precoded in the frequency domain, or be frequency domain (FD) -non-precoded CSI-RS, as the precoding (e.g., z1) conjugate may be applied for each frequency domain subcarrier. The UE may report an inter-TRP phase offset as observed by the UE. The network may determine an inter-TRP phase offset observed by the network, and determine an inter-TRP phase offset based on a difference between the inter-TRP phase offset observed by the UE and the inter-TRP phase offset observed by the network to cancel out the downlink and uplink channel phases. For either scheme, the techniques to determine the inter-TRP phase offset and inter-TRP timing offset have variables that may change across implementations. If, for example, different UEs use different parameters to generate offset information, the offset information reports from these UEs may have varied effectiveness in assisting CJT with multiple TRPs.
[0061] Techniques described herein provide for aligning parameters for UE-assisted CJT with multiple TRPs. These techniques provide for determining a frequency-domain reference point associated with the inter-TRP phase offset in a wideband radio frequency spectrum band. The reference point may be a first, middle, or configurable frequency domain unit (e.g., subband, resource block, or subcarrier) of the wideband radio frequency spectrum band. The techniques may provide definitions for the inter- TRP timing offset. For example, the inter-TRP timing offset may correspond to an average delay difference between the TRPs, a delay difference between peak powers of the TRPs, or be configurable. If the UE is configured to report an inter-TRP phase offset and / or inter-TRP timing offset for one or more subbands of a wideband radio frequency spectrum band, the inter-TRP phase offset and the inter-TRP timing offset may be measured on frequency domain resources of either the subbands or across the entire wideband radio frequency spectrum band. The UE may use multiple antenna ports to transmit the SRS or receive the CSI-RS, or both, and determine the inter-TRP timing offset and inter-TRP phase offset. A network entity may indicate which antenna ports the UE is to use to determine the offset information, or the UE may indicate which antenna ports the UE has used to determine the offset information.
[0062] Aspects of the disclosure are initially described in the context of wireless communications systems. Aspects of the disclosure are further illustrated by and described with reference to apparatus diagrams, system diagrams, and flowcharts that relate to alignment for UE-assisted coherent joint transmission with multiple transmission and reception points.
[0063] FIG. 1 shows an example of a wireless communications system 100 that supports alignment for UE-assisted coherent joint transmission with multiple transmission and reception points in accordance with one or more aspects of the present disclosure. The wireless communications system 100 may include one or more devices, such as one or more network devices (e.g., network entities 105) , one or more UEs 115, and a core network 130. In some examples, the wireless communications system 100 may be a Long Term Evolution (LTE) network, an LTE-Advanced (LTE-A) network, an LTE-A Pro network, a New Radio (NR) network, or a network operating in accordance with other systems and radio technologies, including future systems and radio technologies not explicitly mentioned herein.
[0064] The network entities 105 may be dispersed throughout a geographic area to form the wireless communications system 100 and may include devices in different forms or having different capabilities. In various examples, a network entity 105 may be referred to as a network element, a mobility element, a radio access network (RAN) node, or network equipment, among other nomenclature. In some examples, network entities 105 and UEs 115 may wirelessly communicate via communication link (s) 125 (e.g., a radio frequency (RF) access link) . For example, a network entity 105 may support a coverage area 110 (e.g., a geographic coverage area) over which the UEs 115 and the network entity 105 may establish the communication link (s) 125. The coverage area 110 may be an example of a geographic area over which a network entity 105 and a UE 115 may support the communication of signals according to one or more radio access technologies (RATs) .
[0065] The UEs 115 may be dispersed throughout a coverage area 110 of the wireless communications system 100, and each UE 115 may be stationary, or mobile, or both at different times. The UEs 115 may be devices in different forms or having different capabilities. Some example UEs 115 are illustrated in FIG. 1. The UEs 115 described herein may be capable of supporting communications with various types of devices in the wireless communications system 100 (e.g., other wireless communication devices, including UEs 115 or network entities 105) , as shown in FIG. 1.
[0066] As described herein, a node of the wireless communications system 100, which may be referred to as a network node, or a wireless node, may be a network entity 105 (e.g., any network entity described herein) , a UE 115 (e.g., any UE described herein) , a network controller, an apparatus, a device, a computing system, one or more components, or another suitable processing entity configured to perform any of the techniques described herein. For example, a node may be a UE 115. As another example, a node may be a network entity 105. As another example, a first node may be configured to communicate with a second node or a third node. In one aspect of this example, the first node may be a UE 115, the second node may be a network entity 105, and the third node may be a UE 115. In another aspect of this example, the first node may be a UE 115, the second node may be a network entity 105, and the third node may be a network entity 105. In yet other aspects of this example, the first, second, and third nodes may be different relative to these examples. Similarly, reference to a UE 115, network entity 105, apparatus, device, computing system, or the like may include disclosure of the UE 115, network entity 105, apparatus, device, computing system, or the like being a node. For example, disclosure that a UE 115 is configured to receive information from a network entity 105 also discloses that a first node is configured to receive information from a second node.
[0067] In some examples, network entities 105 may communicate with a core network 130, or with one another, or both. For example, network entities 105 may communicate with the core network 130 via backhaul communication link (s) 120 (e.g., in accordance with an S1, N2, N3, or other interface protocol) . In some examples, network entities 105 may communicate with one another via backhaul communication link (s) 120 (e.g., in accordance with an X2, Xn, or other interface protocol) either directly (e.g., directly between network entities 105) or indirectly (e.g., via the core network 130) . In some examples, network entities 105 may communicate with one another via a midhaul communication link 162 (e.g., in accordance with a midhaul interface protocol) or a fronthaul communication link 168 (e.g., in accordance with a fronthaul interface protocol) , or any combination thereof. The backhaul communication link (s) 120, midhaul communication links 162, or fronthaul communication links 168 may be or include one or more wired links (e.g., an electrical link, an optical fiber link) or one or more wireless links (e.g., a radio link, a wireless optical link) , among other examples or various combinations thereof. A UE 115 may communicate with the core network 130 via a communication link 155.
[0068] One or more of the network entities 105 or network equipment described herein may include or may be referred to as a base station 140 (e.g., a base transceiver station, a radio base station, an NR base station, an access point, a radio transceiver, a NodeB, an eNodeB (eNB) , a next-generation NodeB or giga-NodeB (either of which may be referred to as a gNB) , a 5G NB, a next-generation eNB (ng-eNB) , a Home NodeB, a Home eNodeB, or other suitable terminology) . In some examples, a network entity 105 (e.g., a base station 140) may be implemented in an aggregated (e.g., monolithic, standalone) base station architecture, which may be configured to utilize a protocol stack that is physically or logically integrated within one network entity (e.g., a network entity 105 or a single RAN node, such as a base station 140) .
[0069] In some examples, a network entity 105 may be implemented in a disaggregated architecture (e.g., a disaggregated base station architecture, a disaggregated RAN architecture) , which may be configured to utilize a protocol stack that is physically or logically distributed among multiple network entities (e.g., network entities 105) , such as an integrated access and backhaul (IAB) network, an open RAN (O-RAN) (e.g., a network configuration sponsored by the O-RAN Alliance) , or a virtualized RAN (vRAN) (e.g., a cloud RAN (C-RAN) ) . For example, a network entity 105 may include one or more of a central unit (CU) , such as a CU 160, a distributed unit (DU) , such as a DU 165, a radio unit (RU) , such as an RU 170, a RAN Intelligent Controller (RIC) , such as an RIC 175 (e.g., a Near-Real Time RIC (Near-RT RIC) , a Non-Real Time RIC (Non-RT RIC) ) , a Service Management and Orchestration (SMO) system, such as an SMO system 180, or any combination thereof. An RU 170 may also be referred to as a radio head, a smart radio head, a remote radio head (RRH) , a remote radio unit (RRU) , or a TRP. One or more components of the network entities 105 in a disaggregated RAN architecture may be co-located, or one or more components of the network entities 105 may be located in distributed locations (e.g., separate physical locations) . In some examples, one or more of the network entities 105 of a disaggregated RAN architecture may be implemented as virtual units (e.g., a virtual CU (VCU) , a virtual DU (VDU) , a virtual RU (VRU) ) .
[0070] The split of functionality between a CU 160, a DU 165, and an RU 170 is flexible and may support different functionalities depending on which functions (e.g., network layer functions, protocol layer functions, baseband functions, RF functions, or any combinations thereof) are performed at a CU 160, a DU 165, or an RU 170. For example, a functional split of a protocol stack may be employed between a CU 160 and a DU 165 such that the CU 160 may support one or more layers of the protocol stack and the DU 165 may support one or more different layers of the protocol stack. In some examples, the CU 160 may host upper protocol layer (e.g., layer 3 (L3) , layer 2 (L2) ) functionality and signaling (e.g., Radio Resource Control (RRC) , service data adaptation protocol (SDAP) , Packet Data Convergence Protocol (PDCP) ) . The CU 160 (e.g., one or more CUs) may be connected to a DU 165 (e.g., one or more DUs) or an RU 170 (e.g., one or more RUs) , or some combination thereof, and the DUs 165, RUs 170, or both may host lower protocol layers, such as layer 1 (L1) (e.g., physical (PHY) layer) or L2 (e.g., radio link control (RLC) layer, medium access control (MAC) layer) functionality and signaling, and may each be at least partially controlled by the CU 160. Additionally, or alternatively, a functional split of the protocol stack may be employed between a DU 165 and an RU 170 such that the DU 165 may support one or more layers of the protocol stack and the RU 170 may support one or more different layers of the protocol stack. The DU 165 may support one or multiple different cells (e.g., via one or multiple different RUs, such as an RU 170) . In some cases, a functional split between a CU 160 and a DU 165 or between a DU 165 and an RU 170 may be within a protocol layer (e.g., some functions for a protocol layer may be performed by one of a CU 160, a DU 165, or an RU 170, while other functions of the protocol layer are performed by a different one of the CU 160, the DU 165, or the RU 170) . A CU 160 may be functionally split further into CU control plane (CU-CP) and CU user plane (CU-UP) functions. A CU 160 may be connected to a DU 165 via a midhaul communication link 162 (e.g., F1, F1-c, F1-u) , and a DU 165 may be connected to an RU 170 via a fronthaul communication link 168 (e.g., open fronthaul (FH) interface) . In some examples, a midhaul communication link 162 or a fronthaul communication link 168 may be implemented in accordance with an interface (e.g., a channel) between layers of a protocol stack supported by respective network entities (e.g., one or more of the network entities 105) that are in communication via such communication links.
[0071] In some wireless communications systems (e.g., the wireless communications system 100) , infrastructure and spectral resources for radio access may support wireless backhaul link capabilities to supplement wired backhaul connections, providing an IAB network architecture (e.g., to a core network 130) . In some cases, in an IAB network, one or more of the network entities 105 (e.g., network entities 105 or IAB node (s) 104) may be partially controlled by each other. The IAB node (s) 104 may be referred to as a donor entity or an IAB donor. A DU 165 or an RU 170 may be partially controlled by a CU 160 associated with a network entity 105 or base station 140 (such as a donor network entity or a donor base station) . The one or more donor entities (e.g., IAB donors) may be in communication with one or more additional devices (e.g., IAB node (s) 104) via supported access and backhaul links (e.g., backhaul communication link (s) 120) . IAB node (s) 104 may include an IAB mobile termination (IAB-MT) controlled (e.g., scheduled) by one or more DUs (e.g., DUs 165) of a coupled IAB donor. An IAB-MT may be equipped with an independent set of antennas for relay of communications with UEs 115 or may share the same antennas (e.g., of an RU 170) of IAB node (s) 104 used for access via the DU 165 of the IAB node (s) 104 (e.g., referred to as virtual IAB-MT (vIAB-MT) ) . In some examples, the IAB node (s) 104 may include one or more DUs (e.g., DUs 165) that support communication links with additional entities (e.g., IAB node (s) 104, UEs 115) within the relay chain or configuration of the access network (e.g., downstream) . In such cases, one or more components of the disaggregated RAN architecture (e.g., the IAB node (s) 104 or components of the IAB node (s) 104) may be configured to operate according to the techniques described herein.
[0072] For instance, an access network (AN) or RAN may include communications between access nodes (e.g., an IAB donor) , IAB node (s) 104, and one or more UEs 115. The IAB donor may facilitate connection between the core network 130 and the AN (e.g., via a wired or wireless connection to the core network 130) . That is, an IAB donor may refer to a RAN node with a wired or wireless connection to the core network 130. The IAB donor may include one or more of a CU 160, a DU 165, and an RU 170, in which case the CU 160 may communicate with the core network 130 via an interface (e.g., a backhaul link) . The IAB donor and IAB node (s) 104 may communicate via an F1 interface according to a protocol that defines signaling messages (e.g., an F1 AP protocol) . Additionally, or alternatively, the CU 160 may communicate with the core network 130 via an interface, which may be an example of a portion of a backhaul link, and may communicate with other CUs (e.g., including a CU 160 associated with an alternative IAB donor) via an Xn-C interface, which may be an example of another portion of a backhaul link.
[0073] IAB node (s) 104 may refer to RAN nodes that provide IAB functionality (e.g., access for UEs 115, wireless self-backhauling capabilities) . A DU 165 may act as a distributed scheduling node towards child nodes associated with the IAB node (s) 104, and the IAB-MT may act as a scheduled node towards parent nodes associated with IAB node (s) 104. That is, an IAB donor may be referred to as a parent node in communication with one or more child nodes (e.g., an IAB donor may relay transmissions for UEs through other IAB node (s) 104) . Additionally, or alternatively, IAB node (s) 104 may also be referred to as parent nodes or child nodes to other IAB node (s) 104, depending on the relay chain or configuration of the AN. The IAB-MT entity of IAB node (s) 104 may provide a Uu interface for a child IAB node (e.g., the IAB node (s) 104) to receive signaling from a parent IAB node (e.g., the IAB node (s) 104) , and a DU interface (e.g., a DU 165) may provide a Uu interface for a parent IAB node to signal to a child IAB node or UE 115.
[0074] For example, IAB node (s) 104 may be referred to as parent nodes that support communications for child IAB nodes, or may be referred to as child IAB nodes associated with IAB donors, or both. An IAB donor may include a CU 160 with a wired or wireless connection (e.g., backhaul communication link (s) 120) to the core network 130 and may act as a parent node to IAB node (s) 104. For example, the DU 165 of an IAB donor may relay transmissions to UEs 115 through IAB node (s) 104, or may directly signal transmissions to a UE 115, or both. The CU 160 of the IAB donor may signal communication link establishment via an F1 interface to IAB node (s) 104, and the IAB node (s) 104 may schedule transmissions (e.g., transmissions to the UEs 115 relayed from the IAB donor) through one or more DUs (e.g., DUs 165) . That is, data may be relayed to and from IAB node (s) 104 via signaling via an NR Uu interface to MT of IAB node (s) 104 (e.g., other IAB node (s) ) . Communications with IAB node (s) 104 may be scheduled by a DU 165 of the IAB donor or of IAB node (s) 104.
[0075] In the case of the techniques described herein applied in the context of a disaggregated RAN architecture, one or more components of the disaggregated RAN architecture may be configured to support test as described herein. For example, some operations described as being performed by a UE 115 or a network entity 105 (e.g., a base station 140) may additionally, or alternatively, be performed by one or more components of the disaggregated RAN architecture (e.g., components such as an IAB node, a DU 165, a CU 160, an RU 170, an RIC 175, an SMO system 180) .
[0076] A UE 115 may include or may be referred to as a mobile device, a wireless device, a remote device, a handheld device, or a subscriber device, or some other suitable terminology, where the “device” may also be referred to as a unit, a station, a terminal, or a client, among other examples. A UE 115 may also include or may be referred to as a personal electronic device such as a cellular phone, a personal digital assistant (PDA) , a tablet computer, a laptop computer, or a personal computer. In some examples, a UE 115 may include or be referred to as a wireless local loop (WLL) station, an Internet of Things (IoT) device, an Internet of Everything (IoE) device, or a machine type communications (MTC) device, among other examples, which may be implemented in various objects such as appliances, vehicles, or meters, among other examples.
[0077] The UEs 115 described herein may be able to communicate with various types of devices, such as UEs 115 that may sometimes operate as relays, as well as the network entities 105 and the network equipment including macro eNBs or gNBs, small cell eNBs or gNBs, or relay base stations, among other examples, as shown in FIG. 1.
[0078] The UEs 115 and the network entities 105 may wirelessly communicate with one another via the communication link (s) 125 (e.g., one or more access links) using resources associated with one or more carriers. The term “carrier” may refer to a set of RF spectrum resources having a defined PHY layer structure for supporting the communication link (s) 125. For example, a carrier used for the communication link (s) 125 may include a portion of an RF spectrum band (e.g., a bandwidth part (BWP) ) that is operated according to one or more PHY layer channels for a given RAT (e.g., LTE, LTE-A, LTE-A Pro, NR) . Each PHY layer channel may carry acquisition signaling (e.g., synchronization signals, system information) , control signaling that coordinates operation for the carrier, user data, or other signaling. The wireless communications system 100 may support communication with a UE 115 using carrier aggregation or multi-carrier operation. A UE 115 may be configured with multiple downlink component carriers and one or more uplink component carriers according to a carrier aggregation configuration. Carrier aggregation may be used with both frequency division duplexing (FDD) and time division duplexing (TDD) component carriers. Communication between a network entity 105 and other devices may refer to communication between the devices and any portion (e.g., entity, sub-entity) of a network entity 105. For example, the terms “transmitting, ” “receiving, ” or “communicating, ” when referring to a network entity 105, may refer to any portion of a network entity 105 (e.g., a base station 140, a CU 160, a DU 165, a RU 170) of a RAN communicating with another device (e.g., directly or via one or more other network entities, such as one or more of the network entities 105) .
[0079] In some examples, such as in a carrier aggregation configuration, a carrier may have acquisition signaling or control signaling that coordinates operations for other carriers. A carrier may be associated with a frequency channel (e.g., an evolved universal mobile telecommunication system terrestrial radio access (E-UTRA) absolute RF channel number (EARFCN) ) and may be identified according to a channel raster for discovery by the UEs 115. A carrier may be operated in a standalone mode, in which case initial acquisition and connection may be conducted by the UEs 115 via the carrier, or the carrier may be operated in a non-standalone mode, in which case a connection is anchored using a different carrier (e.g., of the same or a different RAT) .
[0080] The communication link (s) 125 of the wireless communications system 100 may include downlink transmissions (e.g., forward link transmissions) from a network entity 105 to a UE 115, uplink transmissions (e.g., return link transmissions) from a UE 115 to a network entity 105, or both, among other configurations of transmissions. Carriers may carry downlink or uplink communications (e.g., in an FDD mode) or may be configured to carry downlink and uplink communications (e.g., in a TDD mode) .
[0081] A carrier may be associated with a particular bandwidth of the RF spectrum and, in some examples, the carrier bandwidth may be referred to as a “system bandwidth” of the carrier or the wireless communications system 100. For example, the carrier bandwidth may be one of a set of bandwidths for carriers of a particular RAT (e.g., 1.4, 3, 5, 10, 15, 20, 40, or 80 megahertz (MHz) ) . Devices of the wireless communications system 100 (e.g., the network entities 105, the UEs 115, or both) may have hardware configurations that support communications using a particular carrier bandwidth or may be configurable to support communications using one of a set of carrier bandwidths. In some examples, the wireless communications system 100 may include network entities 105 or UEs 115 that support concurrent communications using carriers associated with multiple carrier bandwidths. In some examples, each served UE 115 may be configured for operating using portions (e.g., a sub-band, a BWP) or all of a carrier bandwidth.
[0082] Signal waveforms transmitted via a carrier may be made up of multiple subcarriers (e.g., using multi-carrier modulation (MCM) techniques such as orthogonal frequency division multiplexing (OFDM) or discrete Fourier transform spread OFDM (DFT-S-OFDM) ) . In a system employing MCM techniques, a resource element may refer to resources of one symbol period (e.g., a duration of one modulation symbol) and one subcarrier, in which case the symbol period and subcarrier spacing may be inversely related. The quantity of bits carried by each resource element may depend on the modulation scheme (e.g., the order of the modulation scheme, the coding rate of the modulation scheme, or both) , such that a relatively higher quantity of resource elements (e.g., in a transmission duration) and a relatively higher order of a modulation scheme may correspond to a relatively higher rate of communication. A wireless communications resource may refer to a combination of an RF spectrum resource, a time resource, and a spatial resource (e.g., a spatial layer, a beam) , and the use of multiple spatial resources may increase the data rate or data integrity for communications with a UE 115.
[0083] One or more numerologies for a carrier may be supported, and a numerology may include a subcarrier spacing (Δf) and a cyclic prefix. A carrier may be divided into one or more BWPs having the same or different numerologies. In some examples, a UE 115 may be configured with multiple BWPs. In some examples, a single BWP for a carrier may be active at a given time and communications for the UE 115 may be restricted to one or more active BWPs.
[0084] The time intervals for the network entities 105 or the UEs 115 may be expressed in multiples of a basic time unit which may, for example, refer to a sampling period of Ts=1 / (Δfmax·Nf) seconds, for which Δfmax may represent a supported subcarrier spacing, and Nf may represent a supported discrete Fourier transform (DFT) size. Time intervals of a communications resource may be organized according to radio frames each having a specified duration (e.g., 10 milliseconds (ms) ) . Each radio frame may be identified by a system frame number (SFN) (e.g., ranging from 0 to 1023) .
[0085] Each frame may include multiple consecutively-numbered subframes or slots, and each subframe or slot may have the same duration. In some examples, a frame may be divided (e.g., in the time domain) into subframes, and each subframe may be further divided into a quantity of slots. Alternatively, each frame may include a variable quantity of slots, and the quantity of slots may depend on subcarrier spacing. Each slot may include a quantity of symbol periods (e.g., depending on the length of the cyclic prefix prepended to each symbol period) . In some wireless communications systems, such as the wireless communications system 100, a slot may further be divided into multiple mini-slots associated with one or more symbols. Excluding the cyclic prefix, each symbol period may be associated with one or more (e.g., Nf) sampling periods. The duration of a symbol period may depend on the subcarrier spacing or frequency band of operation.
[0086] A subframe, a slot, a mini-slot, or a symbol may be the smallest scheduling unit (e.g., in the time domain) of the wireless communications system 100 and may be referred to as a transmission time interval (TTI) . In some examples, the TTI duration (e.g., a quantity of symbol periods in a TTI) may be variable. Additionally, or alternatively, the smallest scheduling unit of the wireless communications system 100 may be dynamically selected (e.g., in bursts of shortened TTIs (sTTIs) ) .
[0087] Physical channels may be multiplexed for communication using a carrier according to various techniques. A physical control channel and a physical data channel may be multiplexed for signaling via a downlink carrier, for example, using one or more of time division multiplexing (TDM) techniques, frequency division multiplexing (FDM) techniques, or hybrid TDM-FDM techniques. A control region (e.g., a control resource set (CORESET) ) for a physical control channel may be defined by a set of symbol periods and may extend across the system bandwidth or a subset of the system bandwidth of the carrier. One or more control regions (e.g., CORESETs) may be configured for a set of the UEs 115. For example, one or more of the UEs 115 may monitor or search control regions for control information according to one or more search space sets, and each search space set may include one or multiple control channel candidates in one or more aggregation levels arranged in a cascaded manner. An aggregation level for a control channel candidate may refer to an amount of control channel resources (e.g., control channel elements (CCEs) ) associated with encoded information for a control information format having a given payload size. Search space sets may include common search space sets configured for sending control information to UEs 115 (e.g., one or more UEs) or may include UE-specific search space sets for sending control information to a UE 115 (e.g., a specific UE) .
[0088] A network entity 105 may provide communication coverage via one or more cells, for example a macro cell, a small cell, a hot spot, or other types of cells, or any combination thereof. The term “cell” may refer to a logical communication entity used for communication with a network entity 105 (e.g., using a carrier) and may be associated with an identifier for distinguishing neighboring cells (e.g., a physical cell identifier (PCID) , a virtual cell identifier (VCID) ) . In some examples, a cell also may refer to a coverage area 110 or a portion of a coverage area 110 (e.g., a sector) over which the logical communication entity operates. Such cells may range from smaller areas (e.g., a structure, a subset of structure) to larger areas depending on various factors such as the capabilities of the network entity 105. For example, a cell may be or include a building, a subset of a building, or exterior spaces between or overlapping with coverage areas 110, among other examples.
[0089] A macro cell generally covers a relatively large geographic area (e.g., several kilometers in radius) and may allow unrestricted access by the UEs 115 with service subscriptions with the network provider supporting the macro cell. A small cell may be associated with a network entity 105 operating with lower power (e.g., a base station 140 operating with lower power) relative to a macro cell, and a small cell may operate using the same or different (e.g., licensed, unlicensed) frequency bands as macro cells. Small cells may provide unrestricted access to the UEs 115 with service subscriptions with the network provider or may provide restricted access to the UEs 115 having an association with the small cell (e.g., the UEs 115 in a closed subscriber group (CSG) , the UEs 115 associated with users in a home or office) . A network entity 105 may support one or more cells and may also support communications via the one or more cells using one or multiple component carriers.
[0090] In some examples, a carrier may support multiple cells, and different cells may be configured according to different protocol types (e.g., MTC, narrowband IoT (NB-IoT) , enhanced mobile broadband (eMBB) ) that may provide access for different types of devices.
[0091] In some examples, a network entity 105 (e.g., a base station 140, an RU 170) may be movable and therefore provide communication coverage for a moving coverage area, such as the coverage area 110. In some examples, coverage areas 110 (e.g., different coverage areas) associated with different technologies may overlap, but the coverage areas 110 (e.g., different coverage areas) may be supported by the same network entity (e.g., a network entity 105) . In some other examples, overlapping coverage areas, such as a coverage area 110, associated with different technologies may be supported by different network entities (e.g., the network entities 105) . The wireless communications system 100 may include, for example, a heterogeneous network in which different types of the network entities 105 support communications for coverage areas 110 (e.g., different coverage areas) using the same or different RATs.
[0092] The wireless communications system 100 may support synchronous or asynchronous operation. For synchronous operation, network entities 105 (e.g., base stations 140) may have similar frame timings, and transmissions from different network entities (e.g., different ones of the network entities 105) may be approximately aligned in time. For asynchronous operation, network entities 105 may have different frame timings, and transmissions from different network entities (e.g., different ones of network entities 105) may, in some examples, not be aligned in time. The techniques described herein may be used for either synchronous or asynchronous operations.
[0093] Some UEs 115, such as MTC or IoT devices, may be relatively low cost or low complexity devices and may provide for automated communication between machines (e.g., via Machine-to-Machine (M2M) communication) . M2M communication or MTC may refer to data communication technologies that allow devices to communicate with one another or a network entity 105 (e.g., a base station 140) without human intervention. In some examples, M2M communication or MTC may include communications from devices that integrate sensors or meters to measure or capture information and relay such information to a central server or application program that uses the information or presents the information to humans interacting with the application program. Some UEs 115 may be designed to collect information or enable automated behavior of machines or other devices. Examples of applications for MTC devices include smart metering, inventory monitoring, water level monitoring, equipment monitoring, healthcare monitoring, wildlife monitoring, weather and geological event monitoring, fleet management and tracking, remote security sensing, physical access control, and transaction-based business charging.
[0094] Some UEs 115 may be configured to employ operating modes that reduce power consumption, such as half-duplex communications (e.g., a mode that supports one-way communication via transmission or reception, but not transmission and reception concurrently) . In some examples, half-duplex communications may be performed at a reduced peak rate. Other power conservation techniques for the UEs 115 may include entering a power saving deep sleep mode when not engaging in active communications, operating using a limited bandwidth (e.g., according to narrowband communications) , or a combination of these techniques. For example, some UEs 115 may be configured for operation using a narrowband protocol type that is associated with a defined portion or range (e.g., set of subcarriers or resource blocks (RBs) ) within a carrier, within a guard-band of a carrier, or outside of a carrier.
[0095] The wireless communications system 100 may be configured to support ultra-reliable communications or low-latency communications, or various combinations thereof. For example, the wireless communications system 100 may be configured to support ultra-reliable low-latency communications (URLLC) . The UEs 115 may be designed to support ultra-reliable, low-latency, or critical functions. Ultra-reliable communications may include private communication or group communication and may be supported by one or more services such as push-to-talk, video, or data. Support for ultra-reliable, low-latency functions may include prioritization of services, and such services may be used for public safety or general commercial applications. The terms ultra-reliable, low-latency, and ultra-reliable low-latency may be used interchangeably herein.
[0096] In some examples, a UE 115 may be configured to support communicating directly with other UEs (e.g., one or more of the UEs 115) via a device-to-device (D2D) communication link, such as a D2D communication link 135 (e.g., in accordance with a peer-to-peer (P2P) , D2D, or sidelink protocol) . In some examples, one or more UEs 115 of a group that are performing D2D communications may be within the coverage area 110 of a network entity 105 (e.g., a base station 140, an RU 170) , which may support aspects of such D2D communications being configured by (e.g., scheduled by) the network entity 105. In some examples, one or more UEs 115 of such a group may be outside the coverage area 110 of a network entity 105 or may be otherwise unable to or not configured to receive transmissions from a network entity 105. In some examples, groups of the UEs 115 communicating via D2D communications may support a one-to-many (1: M) system in which each UE 115 transmits to one or more of the UEs 115 in the group. In some examples, a network entity 105 may facilitate the scheduling of resources for D2D communications. In some other examples, D2D communications may be carried out between the UEs 115 without an involvement of a network entity 105.
[0097] In some systems, a D2D communication link 135 may be an example of a communication channel, such as a sidelink communication channel, between vehicles (e.g., UEs 115) . In some examples, vehicles may communicate using vehicle-to- everything (V2X) communications, vehicle-to-vehicle (V2V) communications, or some combination of these. A vehicle may signal information related to traffic conditions, signal scheduling, weather, safety, emergencies, or any other information relevant to a V2X system. In some examples, vehicles in a V2X system may communicate with roadside infrastructure, such as roadside units, or with the network via one or more network nodes (e.g., network entities 105, base stations 140, RUs 170) using vehicle-to-network (V2N) communications, or with both.
[0098] The core network 130 may provide user authentication, access authorization, tracking, Internet Protocol (IP) connectivity, and other access, routing, or mobility functions. The core network 130 may be an evolved packet core (EPC) or 5G core (5GC) , which may include at least one control plane entity that manages access and mobility (e.g., a mobility management entity (MME) , an access and mobility management function (AMF) ) and at least one user plane entity that routes packets or interconnects to external networks (e.g., a serving gateway (S-GW) , a Packet Data Network (PDN) gateway (P-GW) , or a user plane function (UPF) ) . The control plane entity may manage non-access stratum (NAS) functions such as mobility, authentication, and bearer management for the UEs 115 served by the network entities 105 (e.g., base stations 140) associated with the core network 130. User IP packets may be transferred through the user plane entity, which may provide IP address allocation as well as other functions. The user plane entity may be connected to IP services 150 for one or more network operators. The IP services 150 may include access to the Internet, Intranet (s) , an IP Multimedia Subsystem (IMS) , or a Packet-Switched Streaming Service.
[0099] The wireless communications system 100 may operate using one or more frequency bands, which may be in the range of 300 megahertz (MHz) to 300 gigahertz (GHz) . Generally, the region from 300 MHz to 3 GHz is known as the ultra-high frequency (UHF) region or decimeter band because the wavelengths range from approximately one decimeter to one meter in length. UHF waves may be blocked or redirected by buildings and environmental features, which may be referred to as clusters, but the waves may penetrate structures sufficiently for a macro cell to provide service to the UEs 115 located indoors. Communications using UHF waves may be associated with smaller antennas and shorter ranges (e.g., less than one hundred kilometers) compared to communications using the smaller frequencies and longer waves of the high frequency (HF) or very high frequency (VHF) portion of the spectrum below 300 MHz.
[0100] The wireless communications system 100 may also operate using a super high frequency (SHF) region, which may be in the range of 3 GHz to 30 GHz, also known as the centimeter band, or using an extremely high frequency (EHF) region of the spectrum (e.g., from 30 GHz to 300 GHz) , also known as the millimeter band. In some examples, the wireless communications system 100 may support millimeter wave (mmW) communications between the UEs 115 and the network entities 105 (e.g., base stations 140, RUs 170) , and EHF antennas of the respective devices may be smaller and more closely spaced than UHF antennas. In some examples, such techniques may facilitate using antenna arrays within a device. The propagation of EHF transmissions, however, may be subject to even greater attenuation and shorter range than SHF or UHF transmissions. The techniques disclosed herein may be employed across transmissions that use one or more different frequency regions, and designated use of bands across these frequency regions may differ by country or regulating body.
[0101] The wireless communications system 100 may utilize both licensed and unlicensed RF spectrum bands. For example, the wireless communications system 100 may employ License Assisted Access (LAA) , LTE-Unlicensed (LTE-U) RAT, or NR technology using an unlicensed band such as the 5 GHz industrial, scientific, and medical (ISM) band. While operating using unlicensed RF spectrum bands, devices such as the network entities 105 and the UEs 115 may employ carrier sensing for collision detection and avoidance. In some examples, operations using unlicensed bands may be based on a carrier aggregation configuration in conjunction with component carriers operating using a licensed band (e.g., LAA) . Operations using unlicensed spectrum may include downlink transmissions, uplink transmissions, P2P transmissions, or D2D transmissions, among other examples.
[0102] A network entity 105 (e.g., a base station 140, an RU 170) or a UE 115 may be equipped with multiple antennas, which may be used to employ techniques such as transmit diversity, receive diversity, multiple-input multiple-output (MIMO) communications, or beamforming. The antennas of a network entity 105 or a UE 115 may be located within one or more antenna arrays or antenna panels, which may support MIMO operations or transmit or receive beamforming. For example, one or more base station antennas or antenna arrays may be co-located at an antenna assembly, such as an antenna tower. In some examples, antennas or antenna arrays associated with a network entity 105 may be located at diverse geographic locations. A network entity 105 may include an antenna array with a set of rows and columns of antenna ports that the network entity 105 may use to support beamforming of communications with a UE 115. Likewise, a UE 115 may include one or more antenna arrays that may support various MIMO or beamforming operations. Additionally, or alternatively, an antenna panel may support RF beamforming for a signal transmitted via an antenna port.
[0103] The network entities 105 or the UEs 115 may use MIMO communications to exploit multipath signal propagation and increase spectral efficiency by transmitting or receiving multiple signals via different spatial layers. Such techniques may be referred to as spatial multiplexing. The multiple signals may, for example, be transmitted by the transmitting device via different antennas or different combinations of antennas. Likewise, the multiple signals may be received by the receiving device via different antennas or different combinations of antennas. Each of the multiple signals may be referred to as a separate spatial stream and may carry information associated with the same data stream (e.g., the same codeword) or different data streams (e.g., different codewords) . Different spatial layers may be associated with different antenna ports used for channel measurement and reporting. MIMO techniques include single-user MIMO (SU-MIMO) , for which multiple spatial layers are transmitted to the same receiving device, and multiple-user MIMO (MU-MIMO) , for which multiple spatial layers are transmitted to multiple devices.
[0104] Beamforming, which may also be referred to as spatial filtering, directional transmission, or directional reception, is a signal processing technique that may be used at a transmitting device or a receiving device (e.g., a network entity 105, a UE 115) to shape or steer an antenna beam (e.g., a transmit beam, a receive beam) along a spatial path between the transmitting device and the receiving device. Beamforming may be achieved by combining the signals communicated via antenna elements of an antenna array such that some signals propagating along particular orientations with respect to an antenna array experience constructive interference while others experience destructive interference. The adjustment of signals communicated via the antenna elements may include a transmitting device or a receiving device applying amplitude offsets, phase offsets, or both to signals carried via the antenna elements associated with the device. The adjustments associated with each of the antenna elements may be defined by a beamforming weight set associated with a particular orientation (e.g., with respect to the antenna array of the transmitting device or receiving device, or with respect to some other orientation) .
[0105] A network entity 105 or a UE 115 may use beam sweeping techniques as part of beamforming operations. For example, a network entity 105 (e.g., a base station 140, an RU 170) may use multiple antennas or antenna arrays (e.g., antenna panels) to conduct beamforming operations for directional communications with a UE 115. Some signals (e.g., synchronization signals, reference signals, beam selection signals, or other control signals) may be transmitted by a network entity 105 multiple times along different directions. For example, the network entity 105 may transmit a signal according to different beamforming weight sets associated with different directions of transmission. Transmissions along different beam directions may be used to identify (e.g., by a transmitting device, such as a network entity 105, or by a receiving device, such as a UE 115) a beam direction for later transmission or reception by the network entity 105.
[0106] Some signals, such as data signals associated with a particular receiving device, may be transmitted by a transmitting device (e.g., a network entity 105 or a UE 115) along a single beam direction (e.g., a direction associated with the receiving device, such as another network entity 105 or UE 115) . In some examples, the beam direction associated with transmissions along a single beam direction may be determined based on a signal that was transmitted along one or more beam directions. For example, a UE 115 may receive one or more of the signals transmitted by the network entity 105 along different directions and may report to the network entity 105 an indication of the signal that the UE 115 received with a highest signal quality or an otherwise acceptable signal quality.
[0107] In some examples, transmissions by a device (e.g., by a network entity 105 or a UE 115) may be performed using multiple beam directions, and the device may use a combination of digital precoding or beamforming to generate a combined beam for transmission (e.g., from a network entity 105 to a UE 115) . The UE 115 may report feedback that indicates precoding weights for one or more beam directions, and the feedback may correspond to a configured set of beams across a system bandwidth or one or more sub-bands. The network entity 105 may transmit a reference signal (e.g., a cell-specific reference signal (CRS) , a channel state information reference signal (CSI-RS) ) , which may be precoded or unprecoded. The UE 115 may provide feedback for beam selection, which may be a precoding matrix indicator (PMI) or codebook-based feedback (e.g., a multi-panel type codebook, a linear combination type codebook, a port selection type codebook) . Although these techniques are described with reference to signals transmitted along one or more directions by a network entity 105 (e.g., a base station 140, an RU 170) , a UE 115 may employ similar techniques for transmitting signals multiple times along different directions (e.g., for identifying a beam direction for subsequent transmission or reception by the UE 115) or for transmitting a signal along a single direction (e.g., for transmitting data to a receiving device) .
[0108] A receiving device (e.g., a UE 115) may perform reception operations in accordance with multiple receive configurations (e.g., directional listening) when receiving various signals from a transmitting device (e.g., a network entity 105) , such as synchronization signals, reference signals, beam selection signals, or other control signals. For example, a receiving device may perform reception in accordance with multiple receive directions by receiving via different antenna subarrays, by processing received signals according to different antenna subarrays, by receiving according to different receive beamforming weight sets (e.g., different directional listening weight sets) applied to signals received at multiple antenna elements of an antenna array, or by processing received signals according to different receive beamforming weight sets applied to signals received at multiple antenna elements of an antenna array, any of which may be referred to as “listening” according to different receive configurations or receive directions. In some examples, a receiving device may use a single receive configuration to receive along a single beam direction (e.g., when receiving a data signal) . The single receive configuration may be aligned along a beam direction determined based on listening according to different receive configuration directions (e.g., a beam direction determined to have a highest signal strength, highest signal-to-noise ratio (SNR) , or otherwise acceptable signal quality based on listening according to multiple beam directions) .
[0109] The wireless communications system 100 may be a packet-based network that operates according to a layered protocol stack. In the user plane, communications at the bearer or PDCP layer may be IP-based. An RLC layer may perform packet segmentation and reassembly to communicate via logical channels. A MAC layer may perform priority handling and multiplexing of logical channels into transport channels. The MAC layer also may implement error detection techniques, error correction techniques, or both to support retransmissions to improve link efficiency. In the control plane, an RRC layer may provide establishment, configuration, and maintenance of an RRC connection between a UE 115 and a network entity 105 or a core network 130 supporting radio bearers for user plane data. A PHY layer may map transport channels to physical channels.
[0110] The UEs 115 and the network entities 105 may support retransmissions of data to increase the likelihood that data is received successfully. Hybrid automatic repeat request (HARQ) feedback is one technique for increasing the likelihood that data is received correctly via a communication link (e.g., the communication link (s) 125, a D2D communication link 135) . HARQ may include a combination of error detection (e.g., using a cyclic redundancy check (CRC) ) , forward error correction (FEC) , and retransmission (e.g., automatic repeat request (ARQ) ) . HARQ may improve throughput at the MAC layer in relatively poor radio conditions (e.g., low signal-to-noise conditions) . In some examples, a device may support same-slot HARQ feedback, in which case the device may provide HARQ feedback in a specific slot for data received via a previous symbol in the slot. In some other examples, the device may provide HARQ feedback in a subsequent slot, or according to some other time interval.
[0111] Some wireless communication systems may provide for CJT. A network entity 105 may enable multiple TRPs that transmit signaling over a same time and frequency resources to a UE 115. To support CJT, the UE 115 may provide inter-TRP time misalignment and phase offset measurement and reporting. The UE 115 may transmit an uplink reference signal, such as an SRS, to each TRP. In response, the UE 115 may receive a downlink reference signal, such as a CSI-RS, from each TRP. The communications between the UE 115 and each TRP may have associated phase and / or time differences or offsets due to the inter-TRP phase and / or time misalignment and propagation delay between UE and each TRP. The UE 115 may calculate the offsets between each of the TRPs based on the received CSI-RSs and report the calculated offsets to one of the TRPs. For example, the UE 115 may calculate an inter-TRP phase offset and / or an inter-TRP timing offset between a first TRP and a second TRP, and the UE 115 may report the inter-TRP phase offset and / or an inter-TRP timing offset to the second TRP. The second TRP may use the inter-TRP phase offset and / or an inter-TRP timing offset from the UE 115 to synchronize with the first TRP. In some examples, the UE 115 may receive pre-coded CSI-RS from each TRP, and the CSI-RS precoding may ensure that channel propagation delay and channel phase are canceled out from the determination of inter-TRP phase offset and an inter-TRP timing offset.
[0112] In some examples, the UE 115 may transmit a SRS to a first TRP and a second TRP. The UE 115 may receive respective non-precoded CSI-RS from the first TRP and the second TRP. The UE 115 may calculate a UE-derived inter-TRP timing offset between the first TRP and the second TRP based on transmission of the SRS and reception of the non-precoded CSI-RS. The UE 115 may calculate a UE derived inter-TRP wideband phase offset between the first TRP and the second TRP based on transmission of the SRS and reception of the non-precoded CSI-RS. The UE 115 may transmit offset information to one of the TRPs, the offset information may be the UE-derived inter-TRP timing offset or the UE-derived inter-TRP wideband phase offset. In some examples, the UE 115 may receive a network-derived inter-TRP timing offset from one of the TRPs, and the UE 115 may calculate a TAE based on the network derived inter-TRP timing offset and the UE-derived inter-TRP timing offset. In some cases, the UE 115 may transmit the TAE to the TRP. The TRP may use the offset information to synchronize to the other TRP in case inter-TRP time alignment error is not negligible (e.g., greater than 30ns) .
[0113] The wireless communications system 100 may support techniques to align parameters for UE-assisted CJT with multiple TRPs. These techniques provide for a UE 115 to determine a frequency-domain reference point associated with the inter-TRP phase offset in a wideband radio frequency spectrum band. The reference point may be a first, middle, or configurable frequency domain unit (e.g., subband, resource block, or subcarrier) of the wideband radio frequency spectrum band. The techniques may provide definitions for the inter-TRP timing offset. For example, the inter-TRP timing offset may correspond to an average delay difference between the TRPs, a delay difference between peak powers of the TRPs, or be configurable. If the UE 115 is configured to report an inter-TRP phase offset and / or inter-TRP timing offset for one or more subbands of a wideband radio frequency spectrum band, the inter-TRP phase offset and the inter-TRP timing offset may be measured on frequency domain resources of either the subbands or across the entire wideband radio frequency spectrum band. The UE 115 may use multiple antenna ports to transmit the SRS or receive the CSI-RS, or both, and determine the inter-TRP timing offset and inter-TRP phase offset. A network entity 105, or a TRP of the multiple TRPs, may indicate which antenna ports the UE 115 is to use to determine the offset information, or the UE 115 may indicate which antenna ports the UE 115 has used to determine the offset information.
[0114] FIG. 2 shows an example of a wireless communications system 200 that supports alignment for UE-assisted coherent joint transmission with multiple transmission and reception points in accordance with one or more aspects of the present disclosure. The wireless communications system 200 may implement aspects of or may be implemented by aspects of the wireless communications system 100. For example, the wireless communications system 200 includes a UE 115-a, which may be an example of a UE 115 as described herein. The wireless communications system 200 may also include a TRP 205-a and a TRP 205-b, which may be examples of the network entity 105 as described here.
[0115] In some examples, the UE 115-a may communicate with the TRP 205-a using a communication link 125-a. The communication link 125-a may be an example of a 6th generation (6G) , a NR or LTE link between the UE 115-a and the TRP 205-a. The communication link 125-a may include bi-directional links that enable both uplink and downlink communications. For example, the TRP 205-a may transmit downlink signals 210-a, such as downlink control signaling and downlink data signals, to the UE 115-a using the communication link 125-a, and the UE 115-a may transmit uplink signals 215-a, including uplink control signaling and uplink data signals to the TRP 205-a using the communication link 125-a.
[0116] In some examples, the UE 115-a may communicate with the TRP 205-b using a communication link 125-b. The communication link 125-b may be an example of a 6th generation (6G) , a NR or LTE link between the UE 115-a and the TRP 205-b. The communication link 125-b may include bi-directional links that enable both uplink and downlink communications. For example, the TRP 205-b may transmit downlink signals 210-b, such as downlink control signaling and downlink data signals, to the UE 115-a using the communication link 125-b, and the UE 115-a may transmit uplink signals 215-b, including uplink control signaling and uplink data signals to the TRP 205-b using the communication link 125-b.
[0117] In some cases, the UE 115-a may communicate with the TRP 205-a and the TRP 205-b via CJT procedures and techniques, which may be applied to non-ideal synchronization and backhaul. In some applications, such as time division duplex (TDD) , channels between the UEs 115 and the TRPs (e.g., TRP 205-a and TRP 205-b) may exchange signaling, where the uplink and downlink may have transmission (Tx) reception (Rx) phase and timing misalignment. For example, there may be mismatch, or differences, between the uplink channel measured via SRSs and the downlink channel measured via the physical downlink shared channel (PDSCH) . Support of CJT communications may include inter-TRP time misalignment measurement and reporting and frequency or phase offset measurement and report. Phase and timing misalignment may be measured by the UE 115-a and reported to a selected TRP or to each TRP. One of the TRPs may calculate a timing alignment error and / or phase alignment error and synchronize to the other TRP using the inter-TRP timing and / or phase offsets. For example, the UE 115-a may transmit an SRS 220 to the TRP 205-a and TRP 205-b. The UE 115-a may receive a respective reference signal (e.g., CSI-RS 225-a and CSI-RS 225-b) from the TRP 205-a and TRP 205-b. Based on the SRS 220 and the reference signals, the UE 115-a may determine and transmit offset information 230 to the TRP 205-b.
[0118] In some cases, the UE 115-a, the TRP 205-a and the TRP 205-b may implement a phase and timing misalignment measurement and reporting procedure using CSI-RS precoded with the measured / estimated uplink channel (e.g., ) to cancel out channel impact in the downlink reference signal. The phase and timing misalignment measurement and reporting procedure using CSI-RS precoded with the measured / estimated uplink channel to cancel out channel impact in the downlink reference signal may be referred to as a first scheme. The UE 115-a may transmit an SRS 220 to the TRP 205-a (e.g., TRP1) and the TRP 205-b (e.g., TRP2) . The receiving of the SRS 220 by the TRP 205-a may be denotes as and receiving of the SRS 220 by the TRP 205-b may be denoted as where for receiver-side (either TRP or UE) ψRx (k) = exp (j2πkτRxΔf+jφRx) at subcarrier k and for transmitter-side (either TRP or UE) ψTx (k) =exp (-j2πkτTxΔf-jφTx) at subcarrier k. The representation z1 and z2 of the received SRS may indicate the received and measured values of the signals. The measured SRS (e.g., z1 and z2) are functions of a phase of the signal when received by the respective TRP ( and ) , a channel impulse response when received by the respective TRP ( and ) , and a phase of the signal when transmitted by the UE 115-a The combination of these variables yields a measurement / estimation of the uplink channel of the signal as received by the respective TRP ( and ) . The SRS may be transmitted with a single transceiver or antenna of the UE 115-a, if phase coherence is not guaranteed between the transceivers of the UE 115-a. In some cases, multiple UE antennas or transceivers may be use. The phase of the signal when received by the receiver at subcarrier k (ψRx (k) ) is a function of the subcarrier k, the timing offset of the receiver (τRx) , the subcarrier spacing (SCS) (Δf) , and the phase offset at the receiver (φRx) . The phase of the signal when transmitted by the transmitter at subcarrier k (ψTx (k) ) is a function of the subcarrier k, the timing offset of the transmitter (τTx) , the SCS (Δf) , and the phase offset at the transmitter (φTx) .
[0119] After reception of the SRS 220, each TRP (e.g., TRP 205-a, TRP 205-b) may transmit a corresponding CSI-RS (e.g., CSI-RS 225-a and CSI-RS 225-b) , such as a single-port CSI-RS. In some examples, each CSI-RS may be precoded based on the corresponding received SRS 220. For example, the TRP 205-a may precode the downlink reference signal based on the phase conjugate of received SRS (e.g., ) , and the TRP 205-b may precode the downlink reference signal based on the phase conjugate of received SRS (e.g., ) . The CSI-RS precoding may ensure that channel propagation delay and channel phase are canceled out, and have no impact to y1, y2 which are the received and measured values by the UE 115-a, from the TRP 205-a and the TRP 205-b, respectively of the precoded CSI-RS. The receiving of the CSI-RS from the TRP 205-a by the UE 115-a may be denotes as The receiving of the CSI-RS from the TRP 205-b by the UE 115-a may be denotes as The y1 and y2 describe how precoding the CSI-RS (e.g., CSI-RS 225-a and CSI-RS 225-b) may cancel out the channel propagation delay and channel phase. The first representation shows that the received CSI-RS (y1) is equal to the phase of the signal when received by the UE 115-a the downlink channel impulse response at the TRP 205-a the phase of the signal when transmitted by the TRP 205-a and the phase conjugate of the corresponding uplink reference signal The first representation of is also equal to the second representation which is a function of the measured / estimated downlink channel at the TRP 205-a and the conjugate of the measured / estimated uplink channel at the UE 115-a The first and second representations of y1 are equivalent to the third representation of which is represented by the channel amplitude of the TRP 205-a (|hTRP1|2) , the phase of the signal when received by the UE 115-a the phase of the signal when transmitted by the TRP 205-a the conjugate of the phase of the signal when received by the UE 115-a and the conjugate of the phase of the signal when transmitted by the UE 115-a Thus, the received precoded CSI-RS (y1) is represented by the downlink channel that is simplified to be the amplitude of the channel (|hTRP1|2) , and no longer includes the channel phase. Likewise, the received precoded CSI-RS (y2) , the downlink channel impulse response is simplified to be the amplitude of the channel (|hTRP2|2) , and no longer includes the channel phase. The UE 115-a may calculate which is a function of the conjugate of the received CSI-RS from the TRP 205-b and the received CSI-RS (y1) from the TRP 205-a. The UE Rx-Tx phase uncertainty is canceled out, and the remaining phase is the inter-TRP phase offset (φTRP2to1) and TAE (τTRP2to1) : The inter-TRP timing offset or TAE (τTRP2to1) and the phase offset between the TRP 205-a and the TRP 205-b may be estimated by the UE 115-a, and the UE 115-a may use ( (k) y1 (k) to derive or calculate the inter-TRP timing offset (τTRP2to1) and the inter-TRP phase offset (φTRP2to1) across subcarriers k=0, ..., K-1 over the entire bandwidth.
[0120] The estimated τTRP2to1, φTRP2to1 may be reported to the TRP 205-b in the first scheme to synchronize the TRP 205-b to the TRP 205-a. For example, the UE 115-a may transmit the offset information 230 including an offset information report to the TRP 205-b. The offset information report may indicate the estimated τTRP2to1, φTRP2to1.
[0121] In some cases, the UE 115-a and TRP 205-a and TRP 205-b may implement a phase and timing misalignment measurement and reporting procedure using normal non-precoded CSI-RS, such that the channel impact is not canceled out in the CSI-RS. The phase and timing misalignment measurement and reporting procedure using non-precoded CSI-RS may be referred to as a second scheme. In some cases, the TAE is negligible (e.g., less than 10 ns) , and the UE 115-a may determine and report the wideband phase offset (φTRP2to1) to the TRP 205-b. In some examples, the UE 115-a may transmit SRS 220 to the TRP 205-a (e.g., TRP1) and the TRP 205-b (e.g., TRP2) . The receiving of the SRS by the TRP 205-a may be denoted as and receiving of the SRS by the TRP 205-b may be denoted as where at subcarrier k are frequency-selective, and are wideband-common with negligible TAE. The SRS 220 may be transmitted with a single transceiver or antenna of the UE 115-a, if phase coherence is not guaranteed between the transceivers of the UE 115-a. Based on z1 (k) and z2 (k) across subcarriers k=0, . . ., K-1 over the entire bandwidth, the network-derived wideband phase offset between TRP 205-a and TRP 205-b may be measured by the network and UE Tx phase uncertainty is canceled out. The wideband-averaged phase offset may be denoted as
[0122] After receiving the SRS 220, each TRP may transmit a corresponding normal non-precoded downlink reference signal (e.g., CSI-RS 225-a and CSI-RS 225-b) , such as a single-port CSI-RS. The receiving of the CSI-RS from the TRP 205-a by the UE 115-a may be denotes as and the receiving of the CSI-RS from the TRP 205-b by the UE 115-a may be denotes as y2= where at subcarrier k are frequency-selective, and are wideband-common with negligible TAE. Based on y1 (k) and y2 (k) across subcarriers k=0, . . ., K-1 over the entire bandwidth, the phase offset between TRP 205-a and TRP 205-b may be measured by UE and reported to TRP 205-b, and the UE Rx phase uncertainty is canceled out. The UE-derived wideband-averaged phase offset may be denoted as The TRP 205-b may derive the inter-TRP phase offset as where channel phase is canceled out. The network-derived φTRP2to1 may be used by the TRP 205-b to synchronize the TRP 205-b to the TRP 205-a. I
[0123] In some examples, the UE 115-a may transmit the offset information 230 in the second scheme. The offset information 230 may include an offset information report to the TRP 205-b. The offset information report may indicate the estimated
[0124] In some cases, the TAE may not be negligible (e.g., greater than 30 ns) , when non-precoded CSI-RS is used, a procedure may be used to canceled out the impact of channel and TAE during the phase and timing misalignment measurement and reporting procedure. In order to make sure the channel phase and TAE may be canceled out, alignment between the UE-side estimated phase offset and TRP-side estimated phase offset may be used.
[0125] The wireless communications system 200 may support techniques to define parameters used in offset reporting for either scheme. For example, for either of the first scheme or the second scheme, the wireless communications system 200 may support techniques for the network and the UE 115-a to align on a phase definition, a delay or timing offset definition, and which antenna ports the UE 115-a uses for the measurements. In some examples, the definitions may be implemented for the wireless devices in the wireless communications system 200. Additionally, or alternatively, the network (e.g., via the TRP 205-a or the TRP 205-b, or both) , may configure the UE 115-a with parameters or the definitions. Additionally, or alternatively, the UE 115-a may report which parameters or definitions the UE 115-a has used to generate the offset information.
[0126] In some examples, the UE 115-a may be configured to report an inter-TRP wideband phase offset for a wideband radio frequency spectrum band. For example, for the first scheme, the UE 115-a may be configured to report an inter-TRP wideband phase offset and TAE. The inter-TRP wideband phase offset may be calculated at the UE 115-a based on the inter-TRP TAE (e.g., τTRP2to1) and a frequency domain location associated with the inter-TRP wideband phase offset. In some examples, the frequency domain location may be associated with the wideband phase offset. For example, the frequency domain location may be a first frequency domain resource or first frequency domain unit (e.g., first subcarrier, first resource block, or first subband) of the wideband radio frequency spectrum band. For example, the wideband radio frequency spectrum band may include K frequency units, from {0, 1, …, K-1} . The frequency domain location associated with the wideband phase offset may be k=0. For UE-received CSI-RSs from the TRP 205-a and the TRP 205-b (e.g., y1 (k) and y2 (k) , where (k) y1 (k) is across subcarriers k=0, …, K-1 over the entire bandwidth. The inter-TRP TAE may be calculated based on The inter-TRP wideband phase associated with k=0 may be determined based on which is conditioned on the calculated TAE τTRP2to1.
[0127] In some examples, the frequency domain location associated with the wideband phase offset may be a midway point of the wideband radio frequency spectrum band. For example, the frequency domain location may be a half-th frequency domain unit or The inter-TRP wideband phase (e.g., associated with may be obtained based on which is conditioned on the calculated TAE τTRP2to1.
[0128] In some examples, the frequency domain location associated with the wideband phase offset may be configurable. For example, k may be configured to be any value from k=0 to k=K-1. In some examples, the TRP 205-a or the TRP 205-b, or both, may transmit control signaling to indicate a value for the wideband phase offset.
[0129] For the second scheme, if the UE 115-a is configured to report the inter-TRP wideband phase offset and a delay offset or timing offset, the wideband phase offset may be calculated independently from the delay offset or timing offset. For example, the wideband phase offset may be calculated independently from In some other examples, the inter-TRP wideband phase offset may be calculated based on the delay offset or timing offset for the second scheme as described for the first scheme. For example, in the first scheme, the wideband phase offset may be based on τTRP2to1.
[0130] The wireless communications system 200 may provide a definition for a delay offset or a timing offset, or both. For example, for the second scheme, the inter-TRP delay offset may correspond to an average delay difference between the TRP 205-a and the TRP 205-b. In some examples, the inter-TRP delay offset may be defined as a delay difference between a highest power of delay paths of the TRP 205-a and the TRP 205-b, or a peak path delay difference. In some examples, the definition of the inter-TRP delay offset may be configurable. For example, the TRP 205-a or the TRP 205-b, or both, may transmit control signaling to the UE 115-a to define the inter-TRP delay offset as being based on the average delay difference or the peak path delay difference.
[0131] In some examples, a definition for the timing offset in the first scheme may be the same as the second scheme. For example, the timing offset may be defined based on an average delay difference, peak path delay difference, or configurable. In some other examples, the timing offset in the first scheme may not be explicitly defined. The reason is due to that, for the first scheme (CSI-RS precoded with the conjugate of estimated / measured UL channel) , an IFFT with (k) y1 (k) across subcarriers from k=0 to k=K-1 (e.g., over the entire bandwidth) may result in a single delay component associated with the TAE. The average delay difference and the peak path delay difference may be the same.
[0132] In some examples, the UE 115-a may be configured to report inter-TRP subband phase offsets. For the first scheme, the inter-TRP subband phase offsets may be correspond to, or be measured via, frequency domain resources on the corresponding subbands. For example, the UE 115-a may measure the CSI-RS 225 from the TRP 205-a and the TRP 205-b via a first subband to obtain a first inter-TRP subband phase offset for the first subband. In some examples, inter-TRP subband phase offset may be jointly measured on an entire wideband resource, such as a wideband radio frequency spectrum band that includes the subbands. Since the CSI-RS 225 are precoded with and (e.g., from the TRP 205-a and the TRP 205-b, respectively) in the frequency domain from k=0 to k=K-1, (k) y1 (k) may result in a linear phase shift in the frequency domain, based on which the UE 115-a may implement a linear interpolation or extrapolation algorithm in the frequency domain to obtain the inter-TRP subband offsets. In some examples, whether an inter-TRP subband phase offset is determined based on respective subband resources or across the entire wideband resource may be configurable. For example, the TRP 205-a or the TRP 205-b, or both, may transmit control signaling to the UE 115-a to configure the UE 115-a to determine an inter-TRP subband phase offset using respective subband resources or across an entire wideband resource.
[0133] In some examples, the inter-TRP subband phase offsets may be measured on the corresponding subbands for the second scheme. For UE-received CSI-RS from the TRP 205-a and the TRP 205-b (e.g., y1 (k) and y2 (k) ) , (k) y1 (k) across subcarriers from k=0 to k=K-1 may not result in linear phase shift in the frequency domain, as y1 (k) and y2 (k) may have multi-path channel propagation impact from a first channel between the TRP 205-a and the UE 115-a and a second channel between the TRP 205-b and the UE 115-a.
[0134] The first scheme and the second scheme may each be implemented using multiple UE antennas or more than one UE antenna port. For the first scheme, each TRP may transmit multiple precoded CSI-RSs 225. The second scheme may be implementable using a single CSI-RS 225 per TRP 205. For the second scheme, the network (e.g., via a network entity 105, the TRP 205-a, or the TRP 205-b) may indicate SRS ports, or UE antenna ports, the UE 115-a is to use to calculate the inter-TRP wideband phase offset, inter-TRP subband phase offset, delay offset, timing offset, or any combination thereof. The network may indicate the SRS ports via control signaling, such as RRC signaling, a MAC control element, or downlink control information. Additionally, or alternatively, the UE 115-a may report the SRS ports, or UE antenna ports, the UE 115-a has used to calculate the inter-TRP wideband phase offset, inter- TRP subband phase offset, delay offset, timing offset, or any combination thereof. The UE 115-a may indicate the SRS ports via control signaling, such as RRC signaling, a MAC control element, or uplink control information.
[0135] For the first scheme, the SRS ports, or UE antenna ports, may be aligned between the network and the UE 115-a implicitly based on the associated CSI-RS configuration. For example, each TRP may be associated with a quantity of CSI-RSs 225 which may be linked to a configured quantity of SRS ports. For example, the UE antenna ports for receiving the CSI-RS configured for phase offset measurement may be the same as the UE antenna ports for transmitting the selected or configured ports from the associated SRS resource.
[0136] In the second scheme, the UE 115-a may receive and process the CSI-RS 225. Denoting the ath UE antennas as [a] =1, …, A, CSI-RS received may be yUE [1] ←TRP1, …, yYE [A] ←TTP1 from the TRP 205-a and yUE [1] ←TRP2, …, yUE [A] ←TRP2 from the TRP 205-b. The UE 115-a may average over the frequency domain and across UE antennas, where The network, via the TRP 205-a and the TRP 205-b, may receive and process SRS. Using the same notation, the SRS received by the TRP 205-a may be zTRP1←UE [1] , …, zTRP1←UE [A] , and the SRS received by the TRP 205-b may be zTRP2←UE [1] , …, zTRP2←UE [A] . The network may average across the frequency domain and across UE antennas, where The network may derive the inter-TRP wideband phase offset as
[0137] FIG. 3 shows an example of a process flow 300 that supports alignment for UE-assisted coherent joint transmission with multiple transmission and reception points in accordance with one or more aspects of the present disclosure. The process flow 300 may implement aspects of a wireless communications system 100 or 200 as described herein. For example, the process flow 300 may be implemented by a UE 115-b, a TRP 205-c, or a TRP 205-d, or any combination thereof. The UE 115-b may be an example of a UE 115 described herein. The TRP 205-c and the TRP 205-d may each be an example of a TRP in a multi-TRP deployment or a network entity 105.
[0138] In some examples, the operations illustrated in process flow 300 may be performed by hardware (e.g., including circuitry, processing blocks, logic components, and other components) , code (e.g., software executed by a processor) , or any combination thereof. Alternative examples of the following may be implemented, where some steps are performed in a different order than described or are not performed at all. In some cases, steps may include additional features not mentioned below, or further steps may be added.
[0139] The process flow 300 may use some terms and formulations. For example, represents a Tx timing offset (e.g., Tx phase ramp over adjacent subcarriers separated by Δf) introduced by the clock jitter of TRP i. represents a phase uncertainty introduced by the Tx side clock jitter of TRP i, and is also referred to as the wideband Tx phase offset of TRP i. represents a Rx timing offset (e.g., Rx phase ramp over adjacent subcarriers separated by Δf) introduced by the clock jitter of TRP i. represents the phase uncertainty introduced by the Rx side clock jitter of TRP i, and may also be referred to as wideband Rx phase offset of TRP i. The phase and timing misalignment measurement and reporting procedure may have a goal to estimate the relative timing offset or TAE (τTRP2to1) and the relative phase uncertainty or phase alignment error (φTRP2to1) between a pair of TRPs (e.g., the TRP 205-a and the TRP 205-b) . The procedure may focus on TDD, and the relative timing offset &relative phase uncertainty is with respect to the combined Tx+Rx. In some cases, the timing offset &phase uncertainty at Tx and Rx of a given TRP is assumed to not be the same due to clock or phase lock loop (PLL) of Tx and Rx of a given TRP being different. For convenience, the notation at subcarrier k for TRP i and at subcarrier k for TRP i are used for formula simplification.
[0140] In some examples, the operations illustrated in the process flow 300 may be performed by hardware (e.g., including circuitry, processing blocks, logic components, and other components) , code (e.g., software executed by a processor) , or any combination thereof. Alternative examples of the following may be implemented, where some steps are performed in a different order than described or are not performed at all. In some cases, steps may include additional features not mentioned below, or further steps may be added.
[0141] At 305, the UE 115-b may receive control signaling indicating a configuration for an offset information report in a CJT scheme. For example, the UE 115-b may receive the offset information report configuration including an indication of a reference frequency domain resource for a UE-derived inter-TRP phase offset.
[0142] At 310, the UE 115-b may transmit SRS to the TRP 205-c (e.g., TRP1) and the TRP 205-d (e.g., TRP2) . For example, the UE 115-b may transmit a first reference signal to the TRP 205-c and the TRP 205-d. The transmitted may correspond to z1transmitted to the TRP 205-c and z2 transmitted to the TRP 205-d, where z_1= and At a receiver-side (e.g., either a TRP 205 or the UE 115-b) , ψRx (k) =exp (j2πkτRxΔf+jφRx) at subcarrier k. At a transmitter side (e.g., either a TRP 205 or the UE 115-b) , ψTx (k) = exp (-j2πkτTxΔf+jφTx) . In some examples, SRS ports may be transmitted with a single antenna / transceiver, if phase coherence is not guaranteed between the transceivers of the UE 115-b.
[0143] At 315, each TRP (e.g., TRP 205-c and TRP 205-d) may transmit a corresponding precoded CSI-RS. The pre-coded CSI-RS may be received by the UE 115-b as y1, y2. For example, the UE 115-b may receive, from the TRP 205-c and the TRP 205-d, respective second reference signals that are respectively precoded based on the first reference signal. For example, each CSI-RS may be precoded based on a phase of the first reference signals. For example, a first and second CSI-RS, y1 and y2, may be precoded based on phase conjugates of the first reference signal, and CSI-RS precoding may cancel out channel propagation delay and channel phase, therefore having no impact to y1 and y2. For example,
[0144] At 320, the UE 115-b may calculate the inter-TRP timing offset based on the received CSI-RSs (e.g., y1, y2) . The UE 115-b may calculate This may ensure that the UE receiver-to-transmitter phase uncertainty is canceled out, and the only remaining phase is the inter-TRP phase offset and the timing offset (e.g., the TAE) . For example, The inter-TRP timing offset (TAE) and phase offset between the two TRPs 205 may be estimated by (k) y1 (k) across subcarriers from k=0 to k=K-1 over an entire bandwidth spanning {0, …, K-1} frequency domain resources.
[0145] In some examples, the UE 115-b may average a phase measurement of the respective second reference signals using a subset of antenna ports of the UE 115-b to obtain the inter-TRP phase offset. In some examples, the UE 115-b may select the subset of antenna ports of the UE based at least in part on receiving the respective second reference signals. An offset information report may indicate the subset of antenna ports used for a determination of the UE-derived inter-TRP phase offset. In some examples, the UE 115-b may receive a control signal indicating the subset of antenna ports to use for a determination the UE-derived inter-TRP phase offset based on the first reference signal. The UE-derived inter-TRP phase offset may be based on the subset of antenna ports. In some examples, the configuration for the offset information report indicates the subset of antenna ports of the UE 115-b.
[0146] At 325, the UE 115-b may transmit, to the TRP 205-d, the estimated inter-TRP timing offset τTRP2to1 and phase offset φTRP2to1. For example, the UE 115-b may transmit the offset information report to the TRP 205-c or the TRP 205-d, or both. The offset information report may indicate a UE-derived inter-TRP phase offset between the TRP 205-c and the TRP 205-d or a UE-derived inter-TRP timing offset between the TRP 205-c and the TRP 205-d, or both, based on receiving the respective second reference signals and in accordance with the configuration for the offset information report. In some examples, the UE-derived inter-TRP phase offset is based on the UE-derived inter-TRP timing offset. At 330, the TRP 205-d may synchronize to the TRP 205-c based on the UE-derived inter-TRP timing offset and the UE-derived inter-TRP phase offset.
[0147] FIG. 4 shows an example of a process flow 400 that supports alignment for UE-assisted coherent joint transmission with multiple transmission and reception points in accordance with one or more aspects of the present disclosure. The process flow 400 illustrates a phase and timing misalignment measurement and reporting procedure using normal non-precoded CSI-RS with the TAE being non-negligible. The process flow 400 may implement or be implemented by aspects of the wireless communications systems 100 and 200 or the process flow 300 as described with reference to FIGs. 1, 2, and 3, respectively. For example, the process flow 400 may be implemented by a TRP 205-e and TRP 205-f, which may be examples of the TRPs as described with reference to FIG. 2 and FIG. 3. The process flow 400 may be implemented by a UE 115-c, which may be an example of the UEs as described with reference to FIGs. 1 and 2.
[0148] At 405, the UE 115-c may receive control signaling indicating a configuration for an offset information report in a CJT scheme.
[0149] At 410, the UE 115-c may transmit SRS to the TRP 205-e (e.g., TRP1) and the TRP 205-f (e.g., TRP2) . For example, the UE 115-c may transmit a first reference signal to both the TRP 205-e and the TRP 205-f. At 415, the TRP 205-f may calculate the network-derived inter-TRP delay or timing offset based on received SRS z1, z2.
[0150] At 420, each TRP (e.g., TRP 205-e and TRP 205-f) may transmit a corresponding FD-non-precoded CSI-RS that are received by the UE 115-c as y1, y2. For example, the UE 115-c may receive, from the TRP 205-e and the TRP 205-f, respective second FD-non-precoded reference signals that. In some examples, the UE 115-c may measure the respective second reference signals over respective frequency domain resources of one or more subbands to obtain a respective one or more UE-derived inter-TRP phase offsets for the one or more subbands. In some examples, the UE 115-c may measure the respective second reference signals over a wideband comprising one or more subbands to obtain a respective one or more UE-derived inter-TRP phase offsets for the one or more subbands. In some examples, the configuration for the offset information report indicates to calculate the UE-derived inter-TRP phase offset based on frequency domain resources of a wideband or one or more subbands.
[0151] At 425, the UE 115-c may calculate the inter-TRP timing offset and the inter-TRP wideband phase offset based on received FD-non-CSI-RSs (e.g., y1, y2) . The wideband averaged phase offset may be calculated as In some examples, the UE 115-c may calculate the inter-TRP wideband phase offset based on the reference frequency domain resource in accordance with the configuration for the offset information report.
[0152] At 430, the UE 115-c may transmit the offset information report to the TRP 205-e or the TRP 205-f, or both, that indicates the UE-derived inter-TRP phase offset between the TRP 205-e and the TRP 205-f based on receiving the respective FD-non-precoded second reference signals. In some examples, the offset information report may indicate a UE-derived inter-TRP delay offset between the TRP 205-e and the TRP 205-f based on receiving the respective FD-non-precoded second reference signals. For example, the UE 115-c may transmit the inter-TRP delay offset and the wideband phase offset to the network (e.g., TRP 205-f) . At 435, the network (e.g., TRP 205-f) may calculate the inter-TRP TAE as based on the reported inter-TRP delay offset from UE 115-c. The UE-derived inter-TRP phase offset may be based on the UE-derived inter-TRP delay offset and the reference frequency domain resource in accordance with the configuration for the offset information report.
[0153] In some examples, the reference frequency domain resource corresponds to a first subcarrier, resource block, or subband of a wideband configured for the UE 115-c, and the UE-derived inter-TRP phase offset is associated with the wideband. In some examples, the reference frequency domain resource corresponds to a middle subcarrier, resource block, or subband of a wideband configured for the UE 115-c, and the UE-derived inter-TRP phase offset is associated with the wideband.
[0154] In some examples, the UE-derived inter-TRP delay offset corresponds to an average delay difference between the TRP 205-e and the TRP 205-f based on the respective FD-non-precoded second reference signals. In some examples, the UE-derived inter-TRP timing offset corresponds to a delay difference between a first peak received power of the TRP 205-e and a second peak received power of the TRP 205-f based on the respective FD-non-precoded second reference signals. In some examples, the configuration for the offset information report indicates that the UE-derived inter- TRP delay offset corresponds to an average delay difference between the TRP 205-e and the TRP 205-f based on the respective FD-non-precoded second reference signals or the UE-derived inter-TRP delay offset corresponds to a delay difference between a first peak received power of the TRP 205-e and a second peak received power of the TRP 205-f based on the respective FD-non-precoded second reference signals.
[0155] At 440, the network (e.g., TRP 205-f) may calculate the inter-TRP wideband phase offset based on the inter-TRP TAE τTRP2to1 derived at the network. Based on the reported wideband phase offset from UE 115-c and the derived wideband phase offset at network, the network (TRP 205-f) may calculate the inter-TRP wideband phase offset without channel phase and TAE (e.g., phase alignment error) as At 445, the TRP 205-f may use the TAE τTRP2to1 and the phase alignment error φTRP2to1to synchronize to the TRP 205-e.
[0156] In some cases, in order to make sure the channel phase and inter-TRP TAE may be canceled out, the network (e.g., TRP 205-f) may first compensate the received SRS 2 (e.g., SRS received at TRP 205-f) based on the inter-TRP TAE τTRP2to1 derived at the network and then calculate the wideband-averaged phase offset based on TAE-compensated received SRS 2 and received SRS 1 (e.g., SRS received at TRP 205-f) . The FD-rotated (TAE-compensated) received SRS 2 may be calculated as The conjugate of the compensated receive SRS 2 may be calculated on multiple subcarriers. The inter-TRP wideband-averaged phase offset may be calculated as where the phase shift caused by may be canceled out by and the remaining part is the inter-TRP wideband phase. The phase error alignment may be calculated as
[0157] The phase and timing misalignment measurement and reporting procedure using normal FD-non-precoded CSI-RS with the TAE being non-negligible illustrated with the process flow 400 may be different from the procedure using precoded CSI-RSs. For example, the UE operation after receiving the CSI-RSs are different, and a mechanism to distinguish whether the CSI-RS is FD-precoded or FD-non-precoded may be implemented.
[0158] FIG. 5 shows a block diagram 500 of a device 505 that supports alignment for UE-assisted coherent joint transmission with multiple transmission and reception points in accordance with one or more aspects of the present disclosure. The device 505 may be an example of aspects of a UE 115 as described herein. The device 505 may include a receiver 510, a transmitter 515, and a communications manager 520. The device 505, or one or more components of the device 505 (e.g., the receiver 510, the transmitter 515, the communications manager 520) , may include at least one processor, which may be coupled with at least one memory, to, individually or collectively, support or enable the described techniques. Each of these components may be in communication with one another (e.g., via one or more buses) .
[0159] The receiver 510 may provide a means for receiving information such as packets, user data, control information, or any combination thereof associated with various information channels (e.g., control channels, data channels, information channels related to alignment for UE-assisted coherent joint transmission with multiple transmission and reception points) . Information may be passed on to other components of the device 505. The receiver 510 may utilize a single antenna or a set of multiple antennas.
[0160] The transmitter 515 may provide a means for transmitting signals generated by other components of the device 505. For example, the transmitter 515 may transmit information such as packets, user data, control information, or any combination thereof associated with various information channels (e.g., control channels, data channels, information channels related to alignment for UE-assisted coherent joint transmission with multiple transmission and reception points) . In some examples, the transmitter 515 may be co-located with a receiver 510 in a transceiver module. The transmitter 515 may utilize a single antenna or a set of multiple antennas.
[0161] The communications manager 520, the receiver 510, the transmitter 515, or various combinations or components thereof may be examples of means for performing various aspects of alignment for UE-assisted coherent joint transmission with multiple transmission and reception points as described herein. For example, the communications manager 520, the receiver 510, the transmitter 515, or various combinations or components thereof may be capable of performing one or more of the functions described herein.
[0162] In some examples, the communications manager 520, the receiver 510, the transmitter 515, or various combinations or components thereof may be implemented in hardware (e.g., in communications management circuitry) . The hardware may include at least one of a processor, a digital signal processor (DSP) , a central processing unit (CPU) , an application-specific integrated circuit (ASIC) , a field-programmable gate array (FPGA) or other programmable logic device, a microcontroller, discrete gate or transistor logic, discrete hardware components, or any combination thereof configured as or otherwise supporting, individually or collectively, a means for performing the functions described in the present disclosure. In some examples, at least one processor and at least one memory coupled with the at least one processor may be configured to perform one or more of the functions described herein (e.g., by one or more processors, individually or collectively, executing instructions stored in the at least one memory) .
[0163] Additionally, or alternatively, the communications manager 520, the receiver 510, the transmitter 515, or various combinations or components thereof may be implemented in code (e.g., as communications management software or firmware) executed by at least one processor (e.g., referred to as a processor-executable code) . If implemented in code executed by at least one processor, the functions of the communications manager 520, the receiver 510, the transmitter 515, or various combinations or components thereof may be performed by a general-purpose processor, a DSP, a CPU, an ASIC, an FPGA, a microcontroller, or any combination of these or other programmable logic devices (e.g., configured as or otherwise supporting, individually or collectively, a means for performing the functions described in the present disclosure) .
[0164] In some examples, the communications manager 520 may be configured to perform various operations (e.g., receiving, obtaining, monitoring, outputting, transmitting) using or otherwise in cooperation with the receiver 510, the transmitter 515, or both. For example, the communications manager 520 may receive information from the receiver 510, send information to the transmitter 515, or be integrated in combination with the receiver 510, the transmitter 515, or both to obtain information, output information, or perform various other operations as described herein.
[0165] The communications manager 520 may support wireless communications in accordance with examples as disclosed herein. For example, the communications manager 520 is capable of, configured to, or operable to support a means for receiving control signaling indicating a configuration for an offset information report in a coherent joint transmission scheme. The communications manager 520 is capable of, configured to, or operable to support a means for transmitting a first reference signal to both a first TRP and a second TRP. The communications manager 520 is capable of, configured to, or operable to support a means for receiving, from the first TRP and the second TRP, respective second reference signals that are respectively precoded based on the first reference signal. The communications manager 520 is capable of, configured to, or operable to support a means for transmitting the offset information report to the first TRP or the second TRP, or both, that indicates a UE-derived inter-TRP timing offset between the first TRP and the second TRP and a UE-derived inter-TRP phase offset between the first TRP and the second TRP based on receiving the respective second reference signals, where the UE-derived inter-TRP phase offset is based on the UE-derived inter-TRP timing offset and a reference frequency domain resource in accordance with the configuration for the offset information report.
[0166] Additionally, or alternatively, the communications manager 520 may support wireless communications in accordance with examples as disclosed herein. For example, the communications manager 520 is capable of, configured to, or operable to support a means for receiving control signaling indicating a configuration for an offset information report in a coherent joint transmission scheme. The communications manager 520 is capable of, configured to, or operable to support a means for transmitting a first reference signal to a first TRP and to a second TRP. The communications manager 520 is capable of, configured to, or operable to support a means for receiving, from the first TRP and the second TRP, respective second frequency-domain (FD) -non-precoded reference signals. The communications manager 520 is capable of, configured to, or operable to support a means for transmitting the offset information report to the first TRP or the second TRP, or both, where the offset information report indicates a UE-derived inter-TRP phase offset between the first TRP and the second TRP or a UE-derived inter-TRP delay offset between the first TRP and the second TRP, or both, based on receiving the respective second FD-non-precoded reference signals and in accordance with the configuration for the offset information report.
[0167] By including or configuring the communications manager 520 in accordance with examples as described herein, the device 505 (e.g., at least one processor controlling or otherwise coupled with the receiver 510, the transmitter 515, the communications manager 520, or a combination thereof) may support techniques for more efficient utilization of communication resources.
[0168] FIG. 6 shows a block diagram 600 of a device 605 that supports alignment for UE-assisted coherent joint transmission with multiple transmission and reception points in accordance with one or more aspects of the present disclosure. The device 605 may be an example of aspects of a device 505 or a UE 115 as described herein. The device 605 may include a receiver 610, a transmitter 615, and a communications manager 620. The device 605, or one of more components of the device 605 (e.g., the receiver 610, the transmitter 615, the communications manager 620) , may include at least one processor, which may be coupled with at least one memory, to support the described techniques. Each of these components may be in communication with one another (e.g., via one or more buses) .
[0169] The receiver 610 may provide a means for receiving information such as packets, user data, control information, or any combination thereof associated with various information channels (e.g., control channels, data channels, information channels related to alignment for UE-assisted coherent joint transmission with multiple transmission and reception points) . Information may be passed on to other components of the device 605. The receiver 610 may utilize a single antenna or a set of multiple antennas.
[0170] The transmitter 615 may provide a means for transmitting signals generated by other components of the device 605. For example, the transmitter 615 may transmit information such as packets, user data, control information, or any combination thereof associated with various information channels (e.g., control channels, data channels, information channels related to alignment for UE-assisted coherent joint transmission with multiple transmission and reception points) . In some examples, the transmitter 615 may be co-located with a receiver 610 in a transceiver module. The transmitter 615 may utilize a single antenna or a set of multiple antennas.
[0171] The device 605, or various components thereof, may be an example of means for performing various aspects of alignment for UE-assisted coherent joint transmission with multiple transmission and reception points as described herein. For example, the communications manager 620 may include a report configuration component 625, an SRS component 630, a precoded CSI-RS component 635, an offset report component 640, a non-precoded CSI-RS component 645, or any combination thereof. The communications manager 620 may be an example of aspects of a communications manager 520 as described herein. In some examples, the communications manager 620, or various components thereof, may be configured to perform various operations (e.g., receiving, obtaining, monitoring, outputting, transmitting) using or otherwise in cooperation with the receiver 610, the transmitter 615, or both. For example, the communications manager 620 may receive information from the receiver 610, send information to the transmitter 615, or be integrated in combination with the receiver 610, the transmitter 615, or both to obtain information, output information, or perform various other operations as described herein.
[0172] The communications manager 620 may support wireless communications in accordance with examples as disclosed herein. The report configuration component 625 is capable of, configured to, or operable to support a means for receiving control signaling indicating a configuration for an offset information report in a coherent joint transmission scheme. The SRS component 630 is capable of, configured to, or operable to support a means for transmitting a first reference signal to both a first TRP and a second TRP. The precoded CSI-RS component 635 is capable of, configured to, or operable to support a means for receiving, from the first TRP and the second TRP, respective second reference signals that are respectively precoded based on the first reference signal. The offset report component 640 is capable of, configured to, or operable to support a means for transmitting the offset information report to the first TRP or the second TRP, or both, that indicates a UE-derived inter-TRP timing offset between the first TRP and the second TRP and a UE-derived inter-TRP phase offset between the first TRP and the second TRP based on receiving the respective second reference signals, where the UE-derived inter-TRP phase offset is based on the UE-derived inter-TRP timing offset and a reference frequency domain resource in accordance with the configuration for the offset information report.
[0173] Additionally, or alternatively, the communications manager 620 may support wireless communications in accordance with examples as disclosed herein. The report configuration component 625 is capable of, configured to, or operable to support a means for receiving control signaling indicating a configuration for an offset information report in a coherent joint transmission scheme. The SRS component 630 is capable of, configured to, or operable to support a means for transmitting a first reference signal to a first TRP and to a second TRP. The non-precoded CSI-RS component 645 is capable of, configured to, or operable to support a means for receiving, from the first TRP and the second TRP, respective second frequency-domain (FD) -non-precoded reference signals. The offset report component 640 is capable of, configured to, or operable to support a means for transmitting the offset information report to the first TRP or the second TRP, or both, where the offset information report indicates a UE-derived inter-TRP phase offset between the first TRP and the second TRP or a UE-derived inter-TRP delay offset between the first TRP and the second TRP, or both, based on receiving the respective second FD-non-precoded reference signals and in accordance with the configuration for the offset information report.
[0174] FIG. 7 shows a block diagram 700 of a communications manager 720 that supports alignment for UE-assisted coherent joint transmission with multiple transmission and reception points in accordance with one or more aspects of the present disclosure. The communications manager 720 may be an example of aspects of a communications manager 520, a communications manager 620, or both, as described herein. The communications manager 720, or various components thereof, may be an example of means for performing various aspects of alignment for UE-assisted coherent joint transmission with multiple transmission and reception points as described herein. For example, the communications manager 720 may include a report configuration component 725, an SRS component 730, a precoded CSI-RS component 735, an offset report component 740, a non-precoded CSI-RS component 745, or any combination thereof. Each of these components, or components or subcomponents thereof (e.g., one or more processors, one or more memories) , may communicate, directly or indirectly, with one another (e.g., via one or more buses) .
[0175] The communications manager 720 may support wireless communications in accordance with examples as disclosed herein. The report configuration component 725 is capable of, configured to, or operable to support a means for receiving control signaling indicating a configuration for an offset information report in a coherent joint transmission scheme. The SRS component 730 is capable of, configured to, or operable to support a means for transmitting a first reference signal to both a first TRP and a second TRP. The precoded CSI-RS component 735 is capable of, configured to, or operable to support a means for receiving, from the first TRP and the second TRP, respective second reference signals that are respectively precoded based on the first reference signal. The offset report component 740 is capable of, configured to, or operable to support a means for transmitting the offset information report to the first TRP or the second TRP, or both, that indicates a UE-derived inter-TRP timing offset between the first TRP and the second TRP and a UE-derived inter-TRP phase offset between the first TRP and the second TRP based on receiving the respective second reference signals, where the UE-derived inter-TRP phase offset is based on the UE-derived inter-TRP timing offset and a reference frequency domain resource in accordance with the configuration for the offset information report.
[0176] In some examples, to support receiving the control signaling indicating the configuration, the report configuration component 725 is capable of, configured to, or operable to support a means for receiving an indication of the reference frequency domain resource for the UE-derived inter-TRP phase offset.
[0177] In some examples, the reference frequency domain resource corresponds to a first subcarrier, resource block, or subband of a wideband configured for the UE. In some examples, the UE-derived inter-TRP phase offset is associated with the wideband.
[0178] In some examples, the reference frequency domain resource corresponds to a middle subcarrier, resource block, or subband of a wideband configured for the UE. In some examples, the UE-derived inter-TRP phase offset is associated with the wideband.
[0179] In some examples, the UE-derived inter-TRP timing offset corresponds to an average delay difference between the first TRP and the second TRP based on the respective second reference signals.
[0180] In some examples, the UE-derived inter-TRP timing offset corresponds to a delay difference between a first peak received power of the first TRP and a second peak received power of the second TRP based on the respective second reference signals.
[0181] In some examples, the configuration for the offset information report indicates that the UE-derived inter-TRP timing offset corresponds to an average delay difference between the first TRP and the second TRP based on the respective second reference signals or the UE-derived inter-TRP timing offset corresponds to a delay difference between a first peak received power of the first TRP and a second peak received power of the second TRP based on the respective second reference signals.
[0182] In some examples, the precoded CSI-RS component 735 is capable of, configured to, or operable to support a means for measuring the respective second reference signals over respective frequency domain resources of one or more subbands to obtain a respective one or more UE-derived inter-TRP phase offsets for the one or more subbands.
[0183] In some examples, the precoded CSI-RS component 735 is capable of, configured to, or operable to support a means for measuring the respective second reference signals over a wideband including one or more subbands to obtain a respective one or more UE-derived inter-TRP phase offsets for the one or more subbands.
[0184] In some examples, the configuration for the offset information report indicates to calculate the UE-derived inter-TRP phase offset based on frequency domain resources of a wideband or one or more subbands.
[0185] Additionally, or alternatively, the communications manager 720 may support wireless communications in accordance with examples as disclosed herein. In some examples, the report configuration component 725 is capable of, configured to, or operable to support a means for receiving control signaling indicating a configuration for an offset information report in a coherent joint transmission scheme. In some examples, the SRS component 730 is capable of, configured to, or operable to support a means for transmitting a first reference signal to a first TRP and to a second TRP. The non-precoded CSI-RS component 745 is capable of, configured to, or operable to support a means for receiving, from the first TRP and the second TRP, respective second frequency-domain (FD) -non-precoded reference signals. In some examples, the offset report component 740 is capable of, configured to, or operable to support a means for transmitting the offset information report to the first TRP or the second TRP, or both, where the offset information report indicates a UE-derived inter-TRP phase offset between the first TRP and the second TRP or a UE-derived inter-TRP delay offset between the first TRP and the second TRP, or both, based on receiving the respective second FD-non-precoded reference signals and in accordance with the configuration for the offset information report.
[0186] In some examples, the non-precoded CSI-RS component 745 is capable of, configured to, or operable to support a means for averaging a phase measurement of the respective second FD-non-precoded reference signals using a subset of antenna ports of the UE to obtain the inter-TRP phase offset.
[0187] In some examples, the non-precoded CSI-RS component 745 is capable of, configured to, or operable to support a means for selecting the subset of antenna ports of the UE based on receiving the respective second FD-non-precoded reference signals, where the offset information report indicates the subset of antenna ports used for a determination of the UE-derived inter-TRP phase offset.
[0188] In some examples, the non-precoded CSI-RS component 745 is capable of, configured to, or operable to support a means for receiving a control signal indicating the subset of antenna ports to use for a determination the UE-derived inter-TRP phase offset based on the first reference signal, where the UE-derived inter-TRP phase offset is based on the subset of antenna ports.
[0189] In some examples, the configuration for the offset information report indicates the subset of antenna ports of the UE.
[0190] In some examples, the UE-derived inter-TRP phase offset is based on the UE-derived inter-TRP delay offset.
[0191] In some examples, to support receiving the control signaling indicating the configuration, the report configuration component 725 is capable of, configured to, or operable to support a means for receiving an indication of a reference frequency domain resource, where the UE-derived inter-TRP phase offset is based on the reference frequency domain resource in accordance with the configuration for the offset information report.
[0192] In some examples, the offset information report indicates the UE-derived inter-TRP delay offset.
[0193] In some examples, the UE-derived inter-TRP delay offset corresponds to an average delay difference between the first TRP and the second TRP based on the respective second FD-non-precoded reference signals.
[0194] In some examples, the UE-derived inter-TRP delay offset corresponds to a delay difference between a first peak received power of the first TRP and a second peak received power of the second TRP based on the respective second FD-non-precoded reference signals.
[0195] In some examples, the configuration for the offset information report indicates that the UE-derived inter-TRP delay offset corresponds to an average delay difference between the first TRP and the second TRP based on the respective second FD-non-precoded reference signals or the UE-derived inter-TRP delay offset corresponds to a delay difference between a first peak received power of the first TRP and a second peak received power of the second TRP based on the respective second FD-non-precoded reference signals.
[0196] In some examples, the non-precoded CSI-RS component 745 is capable of, configured to, or operable to support a means for measuring the respective second FD-non-precoded reference signals over respective frequency domain resources of one or more subbands to obtain a respective one or more UE-derived inter-TRP phase offsets for the one or more subbands.
[0197] FIG. 8 shows a diagram of a system 800 including a device 805 that supports alignment for UE-assisted coherent joint transmission with multiple transmission and reception points in accordance with one or more aspects of the present disclosure. The device 805 may be an example of or include components of a device 505, a device 605, or a UE 115 as described herein. The device 805 may communicate (e.g., wirelessly) with one or more other devices (e.g., network entities 105, UEs 115, or a combination thereof) . The device 805 may include components for bi-directional voice and data communications including components for transmitting and receiving communications, such as a communications manager 820, an input / output (I / O) controller, such as an I / O controller 810, a transceiver 815, one or more antennas 825, at least one memory 830, code 835, and at least one processor 840. These components may be in electronic communication or otherwise coupled (e.g., operatively, communicatively, functionally, electronically, electrically) via one or more buses (e.g., a bus 845) .
[0198] The I / O controller 810 may manage input and output signals for the device 805. The I / O controller 810 may also manage peripherals not integrated into the device 805. In some cases, the I / O controller 810 may represent a physical connection or port to an external peripheral. In some cases, the I / O controller 810 may utilize an operating system such as or another known operating system. Additionally, or alternatively, the I / O controller 810 may represent or interact with a modem, a keyboard, a mouse, a touchscreen, or a similar device. In some cases, the I / O controller 810 may be implemented as part of one or more processors, such as the at least one processor 840. In some cases, a user may interact with the device 805 via the I / O controller 810 or via hardware components controlled by the I / O controller 810.
[0199] In some cases, the device 805 may include a single antenna. However, in some other cases, the device 805 may have more than one antenna, which may be capable of concurrently transmitting or receiving multiple wireless transmissions. The transceiver 815 may communicate bi-directionally via the one or more antennas 825 using wired or wireless links as described herein. For example, the transceiver 815 may represent a wireless transceiver and may communicate bi-directionally with another wireless transceiver. The transceiver 815 may also include a modem to modulate the packets, to provide the modulated packets to one or more antennas 825 for transmission, and to demodulate packets received from the one or more antennas 825. The transceiver 815, or the transceiver 815 and one or more antennas 825, may be an example of a transmitter 515, a transmitter 615, a receiver 510, a receiver 610, or any combination thereof or component thereof, as described herein.
[0200] The at least one memory 830 may include random access memory (RAM) and read-only memory (ROM) . The at least one memory 830 may store computer-readable, computer-executable, or processor-executable code, such as the code 835. The code 835 may include instructions that, when executed by the at least one processor 840, cause the device 805 to perform various functions described herein. The code 835 may be stored in a non-transitory computer-readable medium such as system memory or another type of memory. In some cases, the code 835 may not be directly executable by the at least one processor 840 but may cause a computer (e.g., when compiled and executed) to perform functions described herein. In some cases, the at least one memory 830 may include, among other things, a basic I / O system (BIOS) which may control basic hardware or software operation such as the interaction with peripheral components or devices.
[0201] The at least one processor 840 may include one or more intelligent hardware devices (e.g., one or more general-purpose processors, one or more DSPs, one or more CPUs, one or more graphics processing units (GPUs) , one or more neural processing units (NPUs) (also referred to as neural network processors or deep learning processors (DLPs) ) , one or more microcontrollers, one or more ASICs, one or more FPGAs, one or more programmable logic devices, discrete gate or transistor logic, one or more discrete hardware components, or any combination thereof) . In some cases, the at least one processor 840 may be configured to operate a memory array using a memory controller. In some other cases, a memory controller may be integrated into the at least one processor 840. The at least one processor 840 may be configured to execute computer-readable instructions stored in a memory (e.g., the at least one memory 830) to cause the device 805 to perform various functions (e.g., functions or tasks supporting alignment for UE-assisted coherent joint transmission with multiple transmission and reception points) . For example, the device 805 or a component of the device 805 may include at least one processor 840 and at least one memory 830 coupled with or to the at least one processor 840, the at least one processor 840 and the at least one memory 830 configured to perform various functions described herein.
[0202] In some examples, the at least one processor 840 may include multiple processors and the at least one memory 830 may include multiple memories. One or more of the multiple processors may be coupled with one or more of the multiple memories, which may, individually or collectively, be configured to perform various functions described herein. In some examples, the at least one processor 840 may be a component of a processing system, which may refer to a system (such as a series) of machines, circuitry (including, for example, one or both of processor circuitry (which may include the at least one processor 840) and memory circuitry (which may include the at least one memory 830) ) , or components, that receives or obtains inputs and processes the inputs to produce, generate, or obtain a set of outputs. The processing system may be configured to perform one or more of the functions described herein. For example, the at least one processor 840 or a processing system including the at least one processor 840 may be configured to, configurable to, or operable to cause the device 805 to perform one or more of the functions described herein. Further, as described herein, being “configured to, ” being “configurable to, ” and being “operable to” may be used interchangeably and may be associated with a capability, when executing code 835 (e.g., processor-executable code) stored in the at least one memory 830 or otherwise, to perform one or more of the functions described herein.
[0203] The communications manager 820 may support wireless communications in accordance with examples as disclosed herein. For example, the communications manager 820 is capable of, configured to, or operable to support a means for receiving control signaling indicating a configuration for an offset information report in a coherent joint transmission scheme. The communications manager 820 is capable of, configured to, or operable to support a means for transmitting a first reference signal to both a first TRP and a second TRP. The communications manager 820 is capable of, configured to, or operable to support a means for receiving, from the first TRP and the second TRP, respective second reference signals that are respectively precoded based on the first reference signal. The communications manager 820 is capable of, configured to, or operable to support a means for transmitting the offset information report to the first TRP or the second TRP, or both, that indicates a UE-derived inter-TRP timing offset between the first TRP and the second TRP and a UE-derived inter-TRP phase offset between the first TRP and the second TRP based on receiving the respective second reference signals, where the UE-derived inter-TRP phase offset is based on the UE-derived inter-TRP timing offset and a reference frequency domain resource in accordance with the configuration for the offset information report.
[0204] Additionally, or alternatively, the communications manager 820 may support wireless communications in accordance with examples as disclosed herein. For example, the communications manager 820 is capable of, configured to, or operable to support a means for receiving control signaling indicating a configuration for an offset information report in a coherent joint transmission scheme. The communications manager 820 is capable of, configured to, or operable to support a means for transmitting a first reference signal to a first TRP and to a second TRP. The communications manager 820 is capable of, configured to, or operable to support a means for receiving, from the first TRP and the second TRP, respective second frequency-domain (FD) -non-precoded reference signals. The communications manager 820 is capable of, configured to, or operable to support a means for transmitting the offset information report to the first TRP or the second TRP, or both, where the offset information report indicates a UE-derived inter-TRP phase offset between the first TRP and the second TRP or a UE-derived inter-TRP delay offset between the first TRP and the second TRP, or both, based on receiving the respective second FD-non-precoded reference signals and in accordance with the configuration for the offset information report.
[0205] By including or configuring the communications manager 820 in accordance with examples as described herein, the device 805 may support techniques for more efficient utilization of communication resources and improved coordination between devices, longer battery life, improved utilization of processing capability.
[0206] In some examples, the communications manager 820 may be configured to perform various operations (e.g., receiving, monitoring, transmitting) using or otherwise in cooperation with the transceiver 815, the one or more antennas 825, or any combination thereof. Although the communications manager 820 is illustrated as a separate component, in some examples, one or more functions described with reference to the communications manager 820 may be supported by or performed by the at least one processor 840, the at least one memory 830, the code 835, or any combination thereof. For example, the code 835 may include instructions executable by the at least one processor 840 to cause the device 805 to perform various aspects of alignment for UE-assisted coherent joint transmission with multiple transmission and reception points as described herein, or the at least one processor 840 and the at least one memory 830 may be otherwise configured to, individually or collectively, perform or support such operations.
[0207] FIG. 9 shows a block diagram 900 of a device 905 that supports alignment for UE-assisted coherent joint transmission with multiple transmission and reception points in accordance with one or more aspects of the present disclosure. The device 905 may be an example of aspects of a network entity 105 as described herein. The device 905 may include a receiver 910, a transmitter 915, and a communications manager 920. The device 905, or one or more components of the device 905 (e.g., the receiver 910, the transmitter 915, the communications manager 920) , may include at least one processor, which may be coupled with at least one memory, to, individually or collectively, support or enable the described techniques. Each of these components may be in communication with one another (e.g., via one or more buses) .
[0208] The receiver 910 may provide a means for obtaining (e.g., receiving, determining, identifying) information such as user data, control information, or any combination thereof (e.g., I / Q samples, symbols, packets, protocol data units, service data units) associated with various channels (e.g., control channels, data channels, information channels, channels associated with a protocol stack) . Information may be passed on to other components of the device 905. In some examples, the receiver 910 may support obtaining information by receiving signals via one or more antennas. Additionally, or alternatively, the receiver 910 may support obtaining information by receiving signals via one or more wired (e.g., electrical, fiber optic) interfaces, wireless interfaces, or any combination thereof.
[0209] The transmitter 915 may provide a means for outputting (e.g., transmitting, providing, conveying, sending) information generated by other components of the device 905. For example, the transmitter 915 may output information such as user data, control information, or any combination thereof (e.g., I / Q samples, symbols, packets, protocol data units, service data units) associated with various channels (e.g., control channels, data channels, information channels, channels associated with a protocol stack) . In some examples, the transmitter 915 may support outputting information by transmitting signals via one or more antennas. Additionally, or alternatively, the transmitter 915 may support outputting information by transmitting signals via one or more wired (e.g., electrical, fiber optic) interfaces, wireless interfaces, or any combination thereof. In some examples, the transmitter 915 and the receiver 910 may be co-located in a transceiver, which may include or be coupled with a modem.
[0210] The communications manager 920, the receiver 910, the transmitter 915, or various combinations or components thereof may be examples of means for performing various aspects of alignment for UE-assisted coherent joint transmission with multiple transmission and reception points as described herein. For example, the communications manager 920, the receiver 910, the transmitter 915, or various combinations or components thereof may be capable of performing one or more of the functions described herein.
[0211] In some examples, the communications manager 920, the receiver 910, the transmitter 915, or various combinations or components thereof may be implemented in hardware (e.g., in communications management circuitry) . The hardware may include at least one of a processor, a DSP, a CPU, an ASIC, an FPGA or other programmable logic device, a microcontroller, discrete gate or transistor logic, discrete hardware components, or any combination thereof configured as or otherwise supporting, individually or collectively, a means for performing the functions described in the present disclosure. In some examples, at least one processor and at least one memory coupled with the at least one processor may be configured to perform one or more of the functions described herein (e.g., by one or more processors, individually or collectively, executing instructions stored in the at least one memory) .
[0212] Additionally, or alternatively, the communications manager 920, the receiver 910, the transmitter 915, or various combinations or components thereof may be implemented in code (e.g., as communications management software or firmware) executed by at least one processor (e.g., referred to as a processor-executable code) . If implemented in code executed by at least one processor, the functions of the communications manager 920, the receiver 910, the transmitter 915, or various combinations or components thereof may be performed by a general-purpose processor, a DSP, a CPU, an ASIC, an FPGA, a microcontroller, or any combination of these or other programmable logic devices (e.g., configured as or otherwise supporting, individually or collectively, a means for performing the functions described in the present disclosure) .
[0213] In some examples, the communications manager 920 may be configured to perform various operations (e.g., receiving, obtaining, monitoring, outputting, transmitting) using or otherwise in cooperation with the receiver 910, the transmitter 915, or both. For example, the communications manager 920 may receive information from the receiver 910, send information to the transmitter 915, or be integrated in combination with the receiver 910, the transmitter 915, or both to obtain information, output information, or perform various other operations as described herein.
[0214] The communications manager 920 may support wireless communications in accordance with examples as disclosed herein. For example, the communications manager 920 is capable of, configured to, or operable to support a means for transmitting control signaling indicating a configuration for an offset information report in a coherent joint transmission scheme with a second TRP. The communications manager 920 is capable of, configured to, or operable to support a means for receiving a first reference signal from a UE. The communications manager 920 is capable of, configured to, or operable to support a means for transmitting, to the UE, a second reference signal that is precoded based on the first reference signal. The communications manager 920 is capable of, configured to, or operable to support a means for receiving the offset information report from the UE, where the offset information report indicates a UE-derived inter-TRP timing offset between the first TRP and the second TRP and a UE-derived inter-TRP phase offset between the first TRP and the second TRP that is based on the UE-derived inter-TRP timing offset and a reference frequency domain resource in accordance with the configuration for the offset information report. The communications manager 920 is capable of, configured to, or operable to support a means for transmitting an indication of the UE-derived inter-TRP phase offset and the UE-derived inter-TRP timing offset to the second TRP.
[0215] Additionally, or alternatively, the communications manager 920 may support wireless communications in accordance with examples as disclosed herein. For example, the communications manager 920 is capable of, configured to, or operable to support a means for transmitting control signaling indicating a configuration for an offset information report in a coherent joint transmission scheme with a second TRP. The communications manager 920 is capable of, configured to, or operable to support a means for receiving a first reference signal from a UE. The communications manager 920 is capable of, configured to, or operable to support a means for transmitting, to the UE, a second frequency domain (FD) -non-precoded reference signal. The communications manager 920 is capable of, configured to, or operable to support a means for receiving the offset information report from the UE based on transmitting the second FD-non-precoded reference signal, where the offset information report indicates a UE-derived inter-TRP phase offset between the first TRP and the second TRP. The communications manager 920 is capable of, configured to, or operable to support a means for transmitting an indication of the UE-derived inter-TRP phase offset to the second TRP.
[0216] By including or configuring the communications manager 920 in accordance with examples as described herein, the device 905 (e.g., at least one processor controlling or otherwise coupled with the receiver 910, the transmitter 915, the communications manager 920, or a combination thereof) may support techniques for more efficient utilization of communication resources.
[0217] FIG. 10 shows a block diagram 1000 of a device 1005 that supports alignment for UE-assisted coherent joint transmission with multiple transmission and reception points in accordance with one or more aspects of the present disclosure. The device 1005 may be an example of aspects of a device 905 or a network entity 105 as described herein. The device 1005 may include a receiver 1010, a transmitter 1015, and a communications manager 1020. The device 1005, or one of more components of the device 1005 (e.g., the receiver 1010, the transmitter 1015, the communications manager 1020) , may include at least one processor, which may be coupled with at least one memory, to support the described techniques. Each of these components may be in communication with one another (e.g., via one or more buses) .
[0218] The receiver 1010 may provide a means for obtaining (e.g., receiving, determining, identifying) information such as user data, control information, or any combination thereof (e.g., I / Q samples, symbols, packets, protocol data units, service data units) associated with various channels (e.g., control channels, data channels, information channels, channels associated with a protocol stack) . Information may be passed on to other components of the device 1005. In some examples, the receiver 1010 may support obtaining information by receiving signals via one or more antennas. Additionally, or alternatively, the receiver 1010 may support obtaining information by receiving signals via one or more wired (e.g., electrical, fiber optic) interfaces, wireless interfaces, or any combination thereof.
[0219] The transmitter 1015 may provide a means for outputting (e.g., transmitting, providing, conveying, sending) information generated by other components of the device 1005. For example, the transmitter 1015 may output information such as user data, control information, or any combination thereof (e.g., I / Q samples, symbols, packets, protocol data units, service data units) associated with various channels (e.g., control channels, data channels, information channels, channels associated with a protocol stack) . In some examples, the transmitter 1015 may support outputting information by transmitting signals via one or more antennas. Additionally, or alternatively, the transmitter 1015 may support outputting information by transmitting signals via one or more wired (e.g., electrical, fiber optic) interfaces, wireless interfaces, or any combination thereof. In some examples, the transmitter 1015 and the receiver 1010 may be co-located in a transceiver, which may include or be coupled with a modem.
[0220] The device 1005, or various components thereof, may be an example of means for performing various aspects of alignment for UE-assisted coherent joint transmission with multiple transmission and reception points as described herein. For example, the communications manager 1020 may include a report configuring component 1025, an SRS reception component 1030, a precoded CSI-RS component 1035, an offset report reception component 1040, an TRP coordination component 1045, a non-precoded CSI-RS component 1050, or any combination thereof. The communications manager 1020 may be an example of aspects of a communications manager 920 as described herein. In some examples, the communications manager 1020, or various components thereof, may be configured to perform various operations (e.g., receiving, obtaining, monitoring, outputting, transmitting) using or otherwise in cooperation with the receiver 1010, the transmitter 1015, or both. For example, the communications manager 1020 may receive information from the receiver 1010, send information to the transmitter 1015, or be integrated in combination with the receiver 1010, the transmitter 1015, or both to obtain information, output information, or perform various other operations as described herein.
[0221] The communications manager 1020 may support wireless communications in accordance with examples as disclosed herein. The report configuring component 1025 is capable of, configured to, or operable to support a means for transmitting control signaling indicating a configuration for an offset information report in a coherent joint transmission scheme with a second TRP. The SRS reception component 1030 is capable of, configured to, or operable to support a means for receiving a first reference signal from a UE. The precoded CSI-RS component 1035 is capable of, configured to, or operable to support a means for transmitting, to the UE, a second reference signal that is precoded based on the first reference signal. The offset report reception component 1040 is capable of, configured to, or operable to support a means for receiving the offset information report from the UE, where the offset information report indicates a UE-derived inter-TRP timing offset between the first TRP and the second TRP and a UE-derived inter-TRP phase offset between the first TRP and the second TRP that is based on the UE-derived inter-TRP timing offset and a reference frequency domain resource in accordance with the configuration for the offset information report. The TRP coordination component 1045 is capable of, configured to, or operable to support a means for transmitting an indication of the UE-derived inter-TRP phase offset and the UE-derived inter-TRP timing offset to the second TRP.
[0222] Additionally, or alternatively, the communications manager 1020 may support wireless communications in accordance with examples as disclosed herein. The report configuring component 1025 is capable of, configured to, or operable to support a means for transmitting control signaling indicating a configuration for an offset information report in a coherent joint transmission scheme with a second TRP. The SRS reception component 1030 is capable of, configured to, or operable to support a means for receiving a first reference signal from a UE. The non-precoded CSI-RS component 1050 is capable of, configured to, or operable to support a means for transmitting, to the UE, a second frequency domain (FD) -non-precoded reference signal. The offset report reception component 1040 is capable of, configured to, or operable to support a means for receiving the offset information report from the UE based on transmitting the second FD-non-precoded reference signal, where the offset information report indicates a UE- derived inter-TRP phase offset between the first TRP and the second TRP. The TRP coordination component 1045 is capable of, configured to, or operable to support a means for transmitting an indication of the UE-derived inter-TRP phase offset to the second TRP.
[0223] FIG. 11 shows a block diagram 1100 of a communications manager 1120 that supports alignment for UE-assisted coherent joint transmission with multiple transmission and reception points in accordance with one or more aspects of the present disclosure. The communications manager 1120 may be an example of aspects of a communications manager 920, a communications manager 1020, or both, as described herein. The communications manager 1120, or various components thereof, may be an example of means for performing various aspects of alignment for UE-assisted coherent joint transmission with multiple transmission and reception points as described herein. For example, the communications manager 1120 may include a report configuring component 1125, an SRS reception component 1130, a precoded CSI-RS component 1135, an offset report reception component 1140, an TRP coordination component 1145, a non-precoded CSI-RS component 1150, or any combination thereof. Each of these components, or components or subcomponents thereof (e.g., one or more processors, one or more memories) , may communicate, directly or indirectly, with one another (e.g., via one or more buses) . The communications may include communications within a protocol layer of a protocol stack, communications associated with a logical channel of a protocol stack (e.g., between protocol layers of a protocol stack, within a device, component, or virtualized component associated with a network entity 105, between devices, components, or virtualized components associated with a network entity 105) , or any combination thereof.
[0224] The communications manager 1120 may support wireless communications in accordance with examples as disclosed herein. The report configuring component 1125 is capable of, configured to, or operable to support a means for transmitting control signaling indicating a configuration for an offset information report in a coherent joint transmission scheme with a second TRP. The SRS reception component 1130 is capable of, configured to, or operable to support a means for receiving a first reference signal from a UE. The precoded CSI-RS component 1135 is capable of, configured to, or operable to support a means for transmitting, to the UE, a second reference signal that is precoded based on the first reference signal. The offset report reception component 1140 is capable of, configured to, or operable to support a means for receiving the offset information report from the UE, where the offset information report indicates a UE-derived inter-TRP timing offset between the first TRP and the second TRP and a UE-derived inter-TRP phase offset between the first TRP and the second TRP that is based on the UE-derived inter-TRP timing offset and a reference frequency domain resource in accordance with the configuration for the offset information report. The TRP coordination component 1145 is capable of, configured to, or operable to support a means for transmitting an indication of the UE-derived inter-TRP phase offset and the UE-derived inter-TRP timing offset to the second TRP.
[0225] In some examples, to support transmitting the control signaling indicating the configuration, the report configuring component 1125 is capable of, configured to, or operable to support a means for transmitting an indication of the reference frequency domain resource for a determination of the UE-derived inter-TRP phase offset.
[0226] In some examples, the configuration for the offset information report indicates to calculate the UE-derived inter-TRP phase offset based on frequency domain resources of a wideband radio frequency spectrum band or one or more subbands.
[0227] Additionally, or alternatively, the communications manager 1120 may support wireless communications in accordance with examples as disclosed herein. In some examples, the report configuring component 1125 is capable of, configured to, or operable to support a means for transmitting control signaling indicating a configuration for an offset information report in a coherent joint transmission scheme with a second TRP. In some examples, the SRS reception component 1130 is capable of, configured to, or operable to support a means for receiving a first reference signal from a UE. The non-precoded CSI-RS component 1150 is capable of, configured to, or operable to support a means for transmitting, to the UE, a second frequency domain (FD) -non-precoded reference signal. In some examples, the offset report reception component 1140 is capable of, configured to, or operable to support a means for receiving the offset information report from the UE based on transmitting the second FD-non-precoded reference signal, where the offset information report indicates a UE-derived inter-TRP phase offset between the first TRP and the second TRP. In some examples, the TRP coordination component 1145 is capable of, configured to, or operable to support a means for transmitting an indication of the UE-derived inter-TRP phase offset to the second TRP.
[0228] In some examples, the report configuring component 1125 is capable of, configured to, or operable to support a means for transmitting a control signal indicating a subset of antenna ports to use for a determination of the UE-derived inter-TRP phase offset based on the first reference signal, where the UE-derived inter-TRP phase offset is based on the subset of antenna ports.
[0229] In some examples, the UE-derived inter-TRP phase offset is based on a UE-derived inter-TRP delay offset between the first TRP and the second TRP based on receiving the first reference signal and transmitting the second FD-non-precoded reference signal.
[0230] In some examples, the configuration for the offset information report indicates that the UE-derived inter-TRP delay offset corresponds to an average delay difference between the first TRP and the second TRP based on the second FD-non-precoded reference signal or the UE-derived inter-TRP delay offset corresponds to a delay difference between a first peak received power of the first TRP and a second peak received power of the second TRP based on the second FD-non-precoded reference signal.
[0231] In some examples, the offset information report indicates a subset of antenna ports of the UE used to calculate the UE-derived inter-TRP phase offset based on transmitting the second FD-non-precoded reference signal.
[0232] FIG. 12 shows a diagram of a system 1200 including a device 1205 that supports alignment for UE-assisted coherent joint transmission with multiple transmission and reception points in accordance with one or more aspects of the present disclosure. The device 1205 may be an example of or include components of a device 905, a device 1005, or a network entity 105 as described herein. The device 1205 may communicate with other network devices or network equipment such as one or more of the network entities 105, UEs 115, or any combination thereof. The communications may include communications over one or more wired interfaces, over one or more wireless interfaces, or any combination thereof. The device 1205 may include components that support outputting and obtaining communications, such as a communications manager 1220, a transceiver 1210, one or more antennas 1215, at least one memory 1225, code 1230, and at least one processor 1235. These components may be in electronic communication or otherwise coupled (e.g., operatively, communicatively, functionally, electronically, electrically) via one or more buses (e.g., a bus 1240) .
[0233] The transceiver 1210 may support bi-directional communications via wired links, wireless links, or both as described herein. In some examples, the transceiver 1210 may include a wired transceiver and may communicate bi-directionally with another wired transceiver. Additionally, or alternatively, in some examples, the transceiver 1210 may include a wireless transceiver and may communicate bi-directionally with another wireless transceiver. In some examples, the device 1205 may include one or more antennas 1215, which may be capable of transmitting or receiving wireless transmissions (e.g., concurrently) . The transceiver 1210 may also include a modem to modulate signals, to provide the modulated signals for transmission (e.g., by one or more antennas 1215, by a wired transmitter) , to receive modulated signals (e.g., from one or more antennas 1215, from a wired receiver) , and to demodulate signals. In some implementations, the transceiver 1210 may include one or more interfaces, such as one or more interfaces coupled with the one or more antennas 1215 that are configured to support various receiving or obtaining operations, or one or more interfaces coupled with the one or more antennas 1215 that are configured to support various transmitting or outputting operations, or a combination thereof. In some implementations, the transceiver 1210 may include or be configured for coupling with one or more processors or one or more memory components that are operable to perform or support operations based on received or obtained information or signals, or to generate information or other signals for transmission or other outputting, or any combination thereof. In some implementations, the transceiver 1210, or the transceiver 1210 and the one or more antennas 1215, or the transceiver 1210 and the one or more antennas 1215 and one or more processors or one or more memory components (e.g., the at least one processor 1235, the at least one memory 1225, or both) , may be included in a chip or chip assembly that is installed in the device 1205. In some examples, the transceiver 1210 may be operable to support communications via one or more communications links (e.g., communication link (s) 125, backhaul communication link (s) 120, a midhaul communication link 162, a fronthaul communication link 168) .
[0234] The at least one memory 1225 may include RAM, ROM, or any combination thereof. The at least one memory 1225 may store computer-readable, computer-executable, or processor-executable code, such as the code 1230. The code 1230 may include instructions that, when executed by one or more of the at least one processor 1235, cause the device 1205 to perform various functions described herein. The code 1230 may be stored in a non-transitory computer-readable medium such as system memory or another type of memory. In some cases, the code 1230 may not be directly executable by a processor of the at least one processor 1235 but may cause a computer (e.g., when compiled and executed) to perform functions described herein. In some cases, the at least one memory 1225 may include, among other things, a BIOS which may control basic hardware or software operation such as the interaction with peripheral components or devices. In some examples, the at least one processor 1235 may include multiple processors and the at least one memory 1225 may include multiple memories. One or more of the multiple processors may be coupled with one or more of the multiple memories which may, individually or collectively, be configured to perform various functions herein (for example, as part of a processing system) .
[0235] The at least one processor 1235 may include one or more intelligent hardware devices (e.g., one or more general-purpose processors, one or more DSPs, one or more CPUs, one or more graphics processing units (GPUs) , one or more neural processing units (NPUs) (also referred to as neural network processors or deep learning processors (DLPs) ) , one or more microcontrollers, one or more ASICs, one or more FPGAs, one or more programmable logic devices, discrete gate or transistor logic, one or more discrete hardware components, or any combination thereof) . In some cases, the at least one processor 1235 may be configured to operate a memory array using a memory controller. In some other cases, a memory controller may be integrated into one or more of the at least one processor 1235. The at least one processor 1235 may be configured to execute computer-readable instructions stored in a memory (e.g., one or more of the at least one memory 1225) to cause the device 1205 to perform various functions (e.g., functions or tasks supporting alignment for UE-assisted coherent joint transmission with multiple transmission and reception points) . For example, the device 1205 or a component of the device 1205 may include at least one processor 1235 and at least one memory 1225 coupled with one or more of the at least one processor 1235, the at least one processor 1235 and the at least one memory 1225 configured to perform various functions described herein. The at least one processor 1235 may be an example of a cloud-computing platform (e.g., one or more physical nodes and supporting software such as operating systems, virtual machines, or container instances) that may host the functions (e.g., by executing code 1230) to perform the functions of the device 1205. The at least one processor 1235 may be any one or more suitable processors capable of executing scripts or instructions of one or more software programs stored in the device 1205 (such as within one or more of the at least one memory 1225) .
[0236] In some examples, the at least one processor 1235 may include multiple processors and the at least one memory 1225 may include multiple memories. One or more of the multiple processors may be coupled with one or more of the multiple memories, which may, individually or collectively, be configured to perform various functions herein. In some examples, the at least one processor 1235 may be a component of a processing system, which may refer to a system (such as a series) of machines, circuitry (including, for example, one or both of processor circuitry (which may include the at least one processor 1235) and memory circuitry (which may include the at least one memory 1225) ) , or components, that receives or obtains inputs and processes the inputs to produce, generate, or obtain a set of outputs. The processing system may be configured to perform one or more of the functions described herein. For example, the at least one processor 1235 or a processing system including the at least one processor 1235 may be configured to, configurable to, or operable to cause the device 1205 to perform one or more of the functions described herein. Further, as described herein, being “configured to, ” being “configurable to, ” and being “operable to”may be used interchangeably and may be associated with a capability, when executing code stored in the at least one memory 1225 or otherwise, to perform one or more of the functions described herein.
[0237] In some examples, a bus 1240 may support communications of (e.g., within) a protocol layer of a protocol stack. In some examples, a bus 1240 may support communications associated with a logical channel of a protocol stack (e.g., between protocol layers of a protocol stack) , which may include communications performed within a component of the device 1205, or between different components of the device 1205 that may be co-located or located in different locations (e.g., where the device 1205 may refer to a system in which one or more of the communications manager 1220, the transceiver 1210, the at least one memory 1225, the code 1230, and the at least one processor 1235 may be located in one of the different components or divided between different components) .
[0238] In some examples, the communications manager 1220 may manage aspects of communications with a core network 130 (e.g., via one or more wired or wireless backhaul links) . For example, the communications manager 1220 may manage the transfer of data communications for client devices, such as one or more UEs 115. In some examples, the communications manager 1220 may manage communications with one or more other network entities 105, and may include a controller or scheduler for controlling communications with UEs 115 (e.g., in cooperation with the one or more other network devices) . In some examples, the communications manager 1220 may support an X2 interface within an LTE / LTE-A wireless communications network technology to provide communication between network entities 105.
[0239] The communications manager 1220 may support wireless communications in accordance with examples as disclosed herein. For example, the communications manager 1220 is capable of, configured to, or operable to support a means for transmitting control signaling indicating a configuration for an offset information report in a coherent joint transmission scheme with a second TRP. The communications manager 1220 is capable of, configured to, or operable to support a means for receiving a first reference signal from a UE. The communications manager 1220 is capable of, configured to, or operable to support a means for transmitting, to the UE, a second reference signal that is precoded based on the first reference signal. The communications manager 1220 is capable of, configured to, or operable to support a means for receiving the offset information report from the UE, where the offset information report indicates a UE-derived inter-TRP timing offset between the first TRP and the second TRP and a UE-derived inter-TRP phase offset between the first TRP and the second TRP that is based on the UE-derived inter-TRP timing offset and a reference frequency domain resource in accordance with the configuration for the offset information report. The communications manager 1220 is capable of, configured to, or operable to support a means for transmitting an indication of the UE-derived inter-TRP phase offset and the UE-derived inter-TRP timing offset to the second TRP.
[0240] Additionally, or alternatively, the communications manager 1220 may support wireless communications in accordance with examples as disclosed herein. For example, the communications manager 1220 is capable of, configured to, or operable to support a means for transmitting control signaling indicating a configuration for an offset information report in a coherent joint transmission scheme with a second TRP. The communications manager 1220 is capable of, configured to, or operable to support a means for receiving a first reference signal from a UE. The communications manager 1220 is capable of, configured to, or operable to support a means for transmitting, to the UE, a second frequency domain (FD) -non-precoded reference signal. The communications manager 1220 is capable of, configured to, or operable to support a means for receiving the offset information report from the UE based on transmitting the second FD-non-precoded reference signal, where the offset information report indicates a UE-derived inter-TRP phase offset between the first TRP and the second TRP. The communications manager 1220 is capable of, configured to, or operable to support a means for transmitting an indication of the UE-derived inter-TRP phase offset to the second TRP.
[0241] By including or configuring the communications manager 1220 in accordance with examples as described herein, the device 1205 may support techniques for more efficient utilization of communication resources and improved coordination between devices.
[0242] In some examples, the communications manager 1220 may be configured to perform various operations (e.g., receiving, obtaining, monitoring, outputting, transmitting) using or otherwise in cooperation with the transceiver 1210, the one or more antennas 1215 (e.g., where applicable) , or any combination thereof. Although the communications manager 1220 is illustrated as a separate component, in some examples, one or more functions described with reference to the communications manager 1220 may be supported by or performed by the transceiver 1210, one or more of the at least one processor 1235, one or more of the at least one memory 1225, the code 1230, or any combination thereof (for example, by a processing system including at least a portion of the at least one processor 1235, the at least one memory 1225, the code 1230, or any combination thereof) . For example, the code 1230 may include instructions executable by one or more of the at least one processor 1235 to cause the device 1205 to perform various aspects of alignment for UE-assisted coherent joint transmission with multiple transmission and reception points as described herein, or the at least one processor 1235 and the at least one memory 1225 may be otherwise configured to, individually or collectively, perform or support such operations.
[0243] FIG. 13 shows a flowchart illustrating a method 1300 that supports alignment for UE-assisted coherent joint transmission with multiple transmission and reception points in accordance with one or more aspects of the present disclosure. The operations of the method 1300 may be implemented by a UE or its components as described herein. For example, the operations of the method 1300 may be performed by a UE 115 as described with reference to FIGs. 1 through 8. In some examples, a UE may execute a set of instructions to control the functional elements of the UE to perform the described functions. Additionally, or alternatively, the UE may perform aspects of the described functions using special-purpose hardware.
[0244] At 1305, the method may include receiving control signaling indicating a configuration for an offset information report in a coherent joint transmission scheme. The operations of 1305 may be performed in accordance with examples as disclosed herein. In some examples, aspects of the operations of 1305 may be performed by a report configuration component 725 as described with reference to FIG. 7.
[0245] At 1310, the method may include transmitting a first reference signal to both a first TRP and a second TRP. The operations of 1310 may be performed in accordance with examples as disclosed herein. In some examples, aspects of the operations of 1310 may be performed by an SRS component 730 as described with reference to FIG. 7.
[0246] At 1315, the method may include receiving, from the first TRP and the second TRP, respective second reference signals that are respectively precoded based on the first reference signal. The operations of 1315 may be performed in accordance with examples as disclosed herein. In some examples, aspects of the operations of 1315 may be performed by a precoded CSI-RS component 735 as described with reference to FIG. 7.
[0247] At 1320, the method may include transmitting the offset information report to the first TRP or the second TRP, or both, that indicates a UE-derived inter-TRP timing offset between the first TRP and the second TRP and a UE-derived inter-TRP phase offset between the first TRP and the second TRP based on receiving the respective second reference signals, where the UE-derived inter-TRP phase offset is based on the UE-derived inter-TRP timing offset and a reference frequency domain resource in accordance with the configuration for the offset information report. The operations of 1320 may be performed in accordance with examples as disclosed herein. In some examples, aspects of the operations of 1320 may be performed by an offset report component 740 as described with reference to FIG. 7.
[0248] FIG. 14 shows a flowchart illustrating a method 1400 that supports alignment for UE-assisted coherent joint transmission with multiple transmission and reception points in accordance with one or more aspects of the present disclosure. The operations of the method 1400 may be implemented by a network entity or its components as described herein. For example, the operations of the method 1400 may be performed by a network entity as described with reference to FIGs. 1 through 4 and 9 through 12. In some examples, a network entity may execute a set of instructions to control the functional elements of the network entity to perform the described functions. Additionally, or alternatively, the network entity may perform aspects of the described functions using special-purpose hardware.
[0249] At 1405, the method may include transmitting control signaling indicating a configuration for an offset information report in a coherent joint transmission scheme with a second TRP. The operations of 1405 may be performed in accordance with examples as disclosed herein. In some examples, aspects of the operations of 1405 may be performed by a report configuring component 1125 as described with reference to FIG. 11.
[0250] At 1410, the method may include receiving a first reference signal from a UE.The operations of 1410 may be performed in accordance with examples as disclosed herein. In some examples, aspects of the operations of 1410 may be performed by an SRS reception component 1130 as described with reference to FIG. 11.
[0251] At 1415, the method may include transmitting, to the UE, a second reference signal that is precoded based on the first reference signal. The operations of 1415 may be performed in accordance with examples as disclosed herein. In some examples, aspects of the operations of 1415 may be performed by a precoded CSI-RS component 1135 as described with reference to FIG. 11.
[0252] At 1420, the method may include receiving the offset information report from the UE, where the offset information report indicates a UE-derived inter-TRP timing offset between the first TRP and the second TRP and a UE-derived inter-TRP phase offset between the first TRP and the second TRP that is based on the UE-derived inter-TRP timing offset and a reference frequency domain resource in accordance with the configuration for the offset information report. The operations of 1420 may be performed in accordance with examples as disclosed herein. In some examples, aspects of the operations of 1420 may be performed by an offset report reception component 1140 as described with reference to FIG. 11.
[0253] At 1425, the method may include transmitting an indication of the UE-derived inter-TRP phase offset and the UE-derived inter-TRP timing offset to the second TRP. The operations of 1425 may be performed in accordance with examples as disclosed herein. In some examples, aspects of the operations of 1425 may be performed by an TRP coordination component 1145 as described with reference to FIG. 11.
[0254] FIG. 15 shows a flowchart illustrating a method 1500 that supports alignment for UE-assisted coherent joint transmission with multiple transmission and reception points in accordance with one or more aspects of the present disclosure. The operations of the method 1500 may be implemented by a UE or its components as described herein. For example, the operations of the method 1500 may be performed by a UE 115 as described with reference to FIGs. 1 through 8. In some examples, a UE may execute a set of instructions to control the functional elements of the UE to perform the described functions. Additionally, or alternatively, the UE may perform aspects of the described functions using special-purpose hardware.
[0255] At 1505, the method may include receiving control signaling indicating a configuration for an offset information report in a coherent joint transmission scheme. The operations of 1505 may be performed in accordance with examples as disclosed herein. In some examples, aspects of the operations of 1505 may be performed by a report configuration component 725 as described with reference to FIG. 7.
[0256] At 1510, the method may include transmitting a first reference signal to a first TRP and to a second TRP. The operations of 1510 may be performed in accordance with examples as disclosed herein. In some examples, aspects of the operations of 1510 may be performed by an SRS component 730 as described with reference to FIG. 7.
[0257] At 1515, the method may include receiving, from the first TRP and the second TRP, respective second frequency-domain (FD) -non-precoded reference signals. The operations of 1515 may be performed in accordance with examples as disclosed herein. In some examples, aspects of the operations of 1515 may be performed by a non-precoded CSI-RS component 745 as described with reference to FIG. 7.
[0258] At 1520, the method may include transmitting the offset information report to the first TRP or the second TRP, or both, where the offset information report indicates a UE-derived inter-TRP phase offset between the first TRP and the second TRP or a UE-derived inter-TRP delay offset between the first TRP and the second TRP, or both, based on receiving the respective second FD-non-precoded reference signals and in accordance with the configuration for the offset information report. The operations of 1520 may be performed in accordance with examples as disclosed herein. In some examples, aspects of the operations of 1520 may be performed by an offset report component 740 as described with reference to FIG. 7.
[0259] FIG. 16 shows a flowchart illustrating a method 1600 that supports alignment for UE-assisted coherent joint transmission with multiple transmission and reception points in accordance with one or more aspects of the present disclosure. The operations of the method 1600 may be implemented by a network entity or its components as described herein. For example, the operations of the method 1600 may be performed by a network entity as described with reference to FIGs. 1 through 4 and 9 through 12. In some examples, a network entity may execute a set of instructions to control the functional elements of the network entity to perform the described functions. Additionally, or alternatively, the network entity may perform aspects of the described functions using special-purpose hardware.
[0260] At 1605, the method may include transmitting control signaling indicating a configuration for an offset information report in a coherent joint transmission scheme with a second TRP. The operations of 1605 may be performed in accordance with examples as disclosed herein. In some examples, aspects of the operations of 1605 may be performed by a report configuring component 1125 as described with reference to FIG. 11.
[0261] At 1610, the method may include receiving a first reference signal from a UE.The operations of 1610 may be performed in accordance with examples as disclosed herein. In some examples, aspects of the operations of 1610 may be performed by an SRS reception component 1130 as described with reference to FIG. 11.
[0262] At 1615, the method may include transmitting, to the UE, a second frequency domain (FD) -non-precoded reference signal. The operations of 1615 may be performed in accordance with examples as disclosed herein. In some examples, aspects of the operations of 1615 may be performed by a non-precoded CSI-RS component 1150 as described with reference to FIG. 11.
[0263] At 1620, the method may include receiving the offset information report from the UE based on transmitting the second FD-non-precoded reference signal, where the offset information report indicates a UE-derived inter-TRP phase offset between the first TRP and the second TRP. The operations of 1620 may be performed in accordance with examples as disclosed herein. In some examples, aspects of the operations of 1620 may be performed by an offset report reception component 1140 as described with reference to FIG. 11.
[0264] At 1625, the method may include transmitting an indication of the UE-derived inter-TRP phase offset to the second TRP. The operations of 1625 may be performed in accordance with examples as disclosed herein. In some examples, aspects of the operations of 1625 may be performed by an TRP coordination component 1145 as described with reference to FIG. 11.
[0265] The following provides an overview of aspects of the present disclosure:
[0266] Aspect 1: A method for wireless communications at a UE, comprising: receiving control signaling indicating a configuration for an offset information report in a coherent joint transmission scheme; transmitting a first reference signal to both a first transmission and reception point (TRP) and a second TRP; receiving, from the first TRP and the second TRP, respective second reference signals that are respectively precoded based at least in part on the first reference signal; and transmitting the offset information report to the first TRP or the second TRP, or both, that indicates a UE-derived inter-TRP timing offset between the first TRP and the second TRP and a UE-derived inter-TRP phase offset between the first TRP and the second TRP based at least in part on receiving the respective second reference signals, wherein the UE-derived inter-TRP phase offset is based at least in part on the UE-derived inter-TRP timing offset and a reference frequency domain resource in accordance with the configuration for the offset information report.
[0267] Aspect 2: The method of aspect 1, wherein receiving the control signaling indicating the configuration comprises: receiving an indication of the reference frequency domain resource for the UE-derived inter-TRP phase offset.
[0268] Aspect 3: The method of any of aspects 1 through 2, wherein the reference frequency domain resource corresponds to a first subcarrier, resource block, or subband of a wideband configured for the UE, the UE-derived inter-TRP phase offset is associated with the wideband.
[0269] Aspect 4: The method of any of aspects 1 through 3, wherein the reference frequency domain resource corresponds to a middle subcarrier, resource block, or subband of a wideband configured for the UE, the UE-derived inter-TRP phase offset is associated with the wideband.
[0270] Aspect 5: The method of any of aspects 1 through 4, wherein the UE-derived inter-TRP timing offset corresponds to an average delay difference between the first TRP and the second TRP based at least in part on the respective second reference signals.
[0271] Aspect 6: The method of any of aspects 1 through 5, wherein the UE-derived inter-TRP timing offset corresponds to a delay difference between a first peak received power of the first TRP and a second peak received power of the second TRP based at least in part on the respective second reference signals.
[0272] Aspect 7: The method of any of aspects 1 through 6, wherein the configuration for the offset information report indicates that the UE-derived inter-TRP timing offset corresponds to an average delay difference between the first TRP and the second TRP based at least in part on the respective second reference signals or the UE-derived inter-TRP timing offset corresponds to a delay difference between a first peak received power of the first TRP and a second peak received power of the second TRP based at least in part on the respective second reference signals.
[0273] Aspect 8: The method of any of aspects 1 through 7, further comprising: measuring the respective second reference signals over respective frequency domain resources of one or more subbands to obtain a respective one or more UE-derived inter-TRP phase offsets for the one or more subbands.
[0274] Aspect 9: The method of any of aspects 1 through 8, further comprising: measuring the respective second reference signals over a wideband comprising one or more subbands to obtain a respective one or more UE-derived inter-TRP phase offsets for the one or more subbands.
[0275] Aspect 10: The method of any of aspects 1 through 9, wherein the configuration for the offset information report indicates to calculate the UE-derived inter-TRP phase offset based at least in part on frequency domain resources of a wideband or one or more subbands.
[0276] Aspect 11: A method for wireless communications at a first transmission and reception point (TRP) , comprising: transmitting control signaling indicating a configuration for an offset information report in a coherent joint transmission scheme with a second TRP; receiving a first reference signal from a UE; transmitting, to the UE, a second reference signal that is precoded based at least in part on the first reference signal; receiving the offset information report from the UE, wherein the offset information report indicates a UE-derived inter-TRP timing offset between the first TRP and the second TRP and a UE-derived inter-TRP phase offset between the first TRP and the second TRP that is based at least in part on the UE-derived inter-TRP timing offset and a reference frequency domain resource in accordance with the configuration for the offset information report; and transmitting an indication of the UE-derived inter-TRP phase offset and the UE-derived inter-TRP timing offset to the second TRP.
[0277] Aspect 12: The method of aspect 11, wherein transmitting the control signaling indicating the configuration comprises: transmitting an indication of the reference frequency domain resource for a determination of the UE-derived inter-TRP phase offset.
[0278] Aspect 13: The method of any of aspects 11 through 12, wherein the configuration for the offset information report indicates to calculate the UE-derived inter-TRP phase offset based at least in part on frequency domain resources of a wideband radio frequency spectrum band or one or more subbands.
[0279] Aspect 14: A method for wireless communications at a UE, comprising: receiving control signaling indicating a configuration for an offset information report in a coherent joint transmission scheme; transmitting a first reference signal to a first transmission and reception point (TRP) and to a second TRP; receiving, from the first TRP and the second TRP, respective second frequency-domain (FD) -non-precoded reference signals; and transmitting the offset information report to the first TRP or the second TRP, or both, wherein the offset information report indicates a UE-derived inter-TRP phase offset between the first TRP and the second TRP or a UE-derived inter-TRP delay offset between the first TRP and the second TRP, or both, based at least in part on receiving the respective second FD-non-precoded reference signals and in accordance with the configuration for the offset information report.
[0280] Aspect 15: The method of aspect 14, further comprising: averaging a phase measurement of the respective second FD-non-precoded reference signals using a subset of antenna ports of the UE to obtain the inter-TRP phase offset.
[0281] Aspect 16: The method of aspect 15, further comprising: selecting the subset of antenna ports of the UE based at least in part on receiving the respective second FD-non-precoded reference signals, wherein the offset information report indicates the subset of antenna ports used for a determination of the UE-derived inter-TRP phase offset.
[0282] Aspect 17: The method of any of aspects 15 through 16, further comprising: receiving a control signal indicating the subset of antenna ports to use for a determination the UE-derived inter-TRP phase offset based at least in part on the first reference signal, wherein the UE-derived inter-TRP phase offset is based at least in part on the subset of antenna ports.
[0283] Aspect 18: The method of any of aspects 15 through 17, wherein the configuration for the offset information report indicates the subset of antenna ports of the UE.
[0284] Aspect 19: The method of any of aspects 14 through 18, wherein the UE-derived inter-TRP phase offset is based at least in part on the UE-derived inter-TRP delay offset.
[0285] Aspect 20: The method of aspect 19, wherein receiving the control signaling indicating the configuration comprises: receiving an indication of a reference frequency domain resource, wherein the UE-derived inter-TRP phase offset is based at least in part on the reference frequency domain resource in accordance with the configuration for the offset information report.
[0286] Aspect 21: The method of any of aspects 14 through 20, wherein the offset information report indicates the UE-derived inter-TRP delay offset.
[0287] Aspect 22: The method of any of aspects 14 through 21, wherein the UE-derived inter-TRP delay offset corresponds to an average delay difference between the first TRP and the second TRP based at least in part on the respective second FD-non-precoded reference signals.
[0288] Aspect 23: The method of any of aspects 14 through 22, wherein the UE-derived inter-TRP delay offset corresponds to a delay difference between a first peak received power of the first TRP and a second peak received power of the second TRP based at least in part on the respective second FD-non-precoded reference signals.
[0289] Aspect 24: The method of any of aspects 14 through 23, wherein the configuration for the offset information report indicates that the UE-derived inter-TRP delay offset corresponds to an average delay difference between the first TRP and the second TRP based at least in part on the respective second FD-non-precoded reference signals or the UE-derived inter-TRP delay offset corresponds to a delay difference between a first peak received power of the first TRP and a second peak received power of the second TRP based at least in part on the respective second FD-non-precoded reference signals.
[0290] Aspect 25: The method of any of aspects 14 through 24, further comprising: measuring the respective second FD-non-precoded reference signals over respective frequency domain resources of one or more subbands to obtain a respective one or more UE-derived inter-TRP phase offsets for the one or more subbands.
[0291] Aspect 26: A method for wireless communications at a first transmission and reception point (TRP) , comprising: transmitting control signaling indicating a configuration for an offset information report in a coherent joint transmission scheme with a second TRP; receiving a first reference signal from a UE; transmitting, to the UE, a second frequency domain (FD) -non-precoded reference signal; receiving the offset information report from the UE based on transmitting the second FD-non-precoded reference signal, wherein the offset information report indicates a UE-derived inter-TRP phase offset between the first TRP and the second TRP; and transmitting an indication of the UE-derived inter-TRP phase offset to the second TRP.
[0292] Aspect 27: The method of aspect 26, further comprising: transmitting a control signal indicating a subset of antenna ports to use for a determination of the UE-derived inter-TRP phase offset based at least in part on the first reference signal, wherein the UE-derived inter-TRP phase offset is based at least in part on the subset of antenna ports.
[0293] Aspect 28: The method of any of aspects 26 through 27, wherein the UE-derived inter-TRP phase offset is based at least in part on a UE-derived inter-TRP delay offset between the first TRP and the second TRP based at least in part on receiving the first reference signal and transmitting the second FD-non-precoded reference signal.
[0294] Aspect 29: The method of aspect 28, wherein the configuration for the offset information report indicates that the UE-derived inter-TRP delay offset corresponds to an average delay difference between the first TRP and the second TRP based at least in part on the second FD-non-precoded reference signal or the UE-derived inter-TRP delay offset corresponds to a delay difference between a first peak received power of the first TRP and a second peak received power of the second TRP based at least in part on the second FD-non-precoded reference signal.
[0295] Aspect 30: The method of any of aspects 26 through 29, wherein the offset information report indicates a subset of antenna ports of the UE used to calculate the UE-derived inter-TRP phase offset based at least in part on transmitting the second FD-non-precoded reference signal.
[0296] Aspect 31: A UE for wireless communications, comprising one or more memories storing processor-executable code, and one or more processors coupled with the one or more memories and individually or collectively operable to execute the code to cause the UE to perform a method of any of aspects 1 through 10.
[0297] Aspect 32: A UE for wireless communications, comprising at least one means for performing a method of any of aspects 1 through 10.
[0298] Aspect 33: A non-transitory computer-readable medium storing code for wireless communications, the code comprising instructions executable by one or more processors to perform a method of any of aspects 1 through 10.
[0299] Aspect 34: A first transmission and reception point (TRP) for wireless communications, comprising one or more memories storing processor-executable code, and one or more processors coupled with the one or more memories and individually or collectively operable to execute the code to cause the first transmission and reception point (TRP) to perform a method of any of aspects 11 through 13.
[0300] Aspect 35: A first transmission and reception point (TRP) for wireless communications, comprising at least one means for performing a method of any of aspects 11 through 13.
[0301] Aspect 36: A non-transitory computer-readable medium storing code for wireless communications, the code comprising instructions executable by one or more processors to perform a method of any of aspects 11 through 13.
[0302] Aspect 37: A UE for wireless communications, comprising one or more memories storing processor-executable code, and one or more processors coupled with the one or more memories and individually or collectively operable to execute the code to cause the UE to perform a method of any of aspects 14 through 25.
[0303] Aspect 38: A UE for wireless communications, comprising at least one means for performing a method of any of aspects 14 through 25.
[0304] Aspect 39: A non-transitory computer-readable medium storing code for wireless communications, the code comprising instructions executable by one or more processors to perform a method of any of aspects 14 through 25.
[0305] Aspect 40: A first transmission and reception point (TRP) for wireless communications, comprising one or more memories storing processor-executable code, and one or more processors coupled with the one or more memories and individually or collectively operable to execute the code to cause the first transmission and reception point (TRP) to perform a method of any of aspects 26 through 30.
[0306] Aspect 41: A first transmission and reception point (TRP) for wireless communications, comprising at least one means for performing a method of any of aspects 26 through 30.
[0307] Aspect 42: A non-transitory computer-readable medium storing code for wireless communications, the code comprising instructions executable by one or more processors to perform a method of any of aspects 26 through 30.
[0308] It should be noted that the methods described herein describe possible implementations. The operations and the steps may be rearranged or otherwise modified and other implementations are possible. Further, aspects from two or more of the methods may be combined.
[0309] Although aspects of an LTE, LTE-A, LTE-A Pro, or NR system may be described for purposes of example, and LTE, LTE-A, LTE-A Pro, or NR terminology may be used in much of the description, the techniques described herein are applicable beyond LTE, LTE-A, LTE-A Pro, or NR networks. For example, the described techniques may be applicable to various other wireless communications systems such as Ultra Mobile Broadband (UMB) , Institute of Electrical and Electronics Engineers (IEEE) 802.11 (Wi-Fi) , IEEE 802.16 (WiMAX) , IEEE 802.20, Flash-OFDM, as well as other systems and radio technologies not explicitly mentioned herein.
[0310] Information and signals described herein may be represented using any of a variety of different technologies and techniques. For example, data, instructions, commands, information, signals, bits, symbols, and chips that may be referenced throughout the description may be represented by voltages, currents, electromagnetic waves, magnetic fields or particles, optical fields or particles, or any combination thereof.
[0311] The various illustrative blocks and components described in connection with the disclosure herein may be implemented or performed using a general-purpose processor, a DSP, an ASIC, a CPU, a graphics processing unit (GPU) , a neural processing unit (NPU) , an FPGA or other programmable logic device, discrete gate or transistor logic, discrete hardware components, or any combination thereof designed to perform the functions described herein. A general-purpose processor may be a microprocessor but, in the alternative, the processor may be any processor, controller, microcontroller, or state machine. A processor may also be implemented as a combination of computing devices (e.g., a combination of a DSP and a microprocessor, multiple microprocessors, one or more microprocessors in conjunction with a DSP core, or any other such configuration) . Any functions or operations described herein as being capable of being performed by a processor may be performed by multiple processors that, individually or collectively, are capable of performing the described functions or operations.
[0312] The functions described herein may be implemented using hardware, software executed by a processor, firmware, or any combination thereof. If implemented using software executed by a processor, the functions may be stored as or transmitted using one or more instructions or code of a computer-readable medium. Other examples and implementations are within the scope of the disclosure and appended claims. For example, due to the nature of software, functions described herein may be implemented using software executed by a processor, hardware, firmware, hardwiring, or combinations of any of these. Features implementing functions may also be physically located at various positions, including being distributed such that portions of functions are implemented at different physical locations.
[0313] Computer-readable media includes both non-transitory computer storage media and communication media including any medium that facilitates transfer of a computer program from one location to another. A non-transitory storage medium may be any available medium that may be accessed by a general-purpose or special-purpose computer. By way of example, and not limitation, non-transitory computer-readable media may include RAM, ROM, electrically erasable programmable ROM (EEPROM) , flash memory, compact disk (CD) ROM or other optical disk storage, magnetic disk storage or other magnetic storage devices, or any other non-transitory medium that may be used to carry or store desired program code means in the form of instructions or data structures and that may be accessed by a general-purpose or special-purpose computer or a general-purpose or special-purpose processor. Also, any connection is properly termed a computer-readable medium. For example, if the software is transmitted from a website, server, or other remote source using a coaxial cable, fiber optic cable, twisted pair, digital subscriber line (DSL) , or wireless technologies such as infrared, radio, and microwave, then the coaxial cable, fiber optic cable, twisted pair, DSL, or wireless technologies such as infrared, radio, and microwave are included in the definition of computer-readable medium. Disk and disc, as used herein, include CD, laser disc, optical disc, digital versatile disc (DVD) , floppy disk, and Blu-ray disc. Disks may reproduce data magnetically, and discs may reproduce data optically using lasers. Combinations of the above are also included within the scope of computer-readable media. Any functions or operations described herein as being capable of being performed by a memory may be performed by multiple memories that, individually or collectively, are capable of performing the described functions or operations.
[0314] As used herein, including in the claims, “or” as used in a list of items (e.g., a list of items prefaced by a phrase such as “at least one of” or “one or more of” ) indicates an inclusive list such that, for example, a list of at least one of A, B, or C means A or B or C or AB or AC or BC or ABC (i.e., A and B and C) . Also, as used herein, the phrase “based on” shall not be construed as a reference to a closed set of conditions. For example, an example step that is described as “based on condition A” may be based on both a condition A and a condition B without departing from the scope of the present disclosure. In other words, as used herein, the phrase “based on” shall be construed in the same manner as the phrase “based at least in part on. ”
[0315] As used herein, including in the claims, the article “a” before a noun is open-ended and understood to refer to “at least one” of those nouns or “one or more” of those nouns. Thus, the terms “a, ” “at least one, ” “one or more, ” and “at least one of one or more” may be interchangeable. For example, if a claim recites “acomponent” that performs one or more functions, each of the individual functions may be performed by a single component or by any combination of multiple components. Thus, the term “a component” having characteristics or performing functions may refer to “at least one of one or more components” having a particular characteristic or performing a particular function. Subsequent reference to a component introduced with the article “a” using the terms “the” or “said” may refer to any or all of the one or more components. For example, a component introduced with the article “a” may be understood to mean “one or more components, ” and referring to “the component” subsequently in the claims may be understood to be equivalent to referring to “at least one of the one or more components. ” Similarly, subsequent reference to a component introduced as “one or more components” using the terms “the” or “said” may refer to any or all of the one or more components. For example, referring to “the one or more components” subsequently in the claims may be understood to be equivalent to referring to “at least one of the one or more components. ”
[0316] The term “determine” or “determining” encompasses a variety of actions and, therefore, “determining” can include calculating, computing, processing, deriving, investigating, looking up (such as via looking up in a table, a database, or another data structure) , ascertaining, and the like. Also, “determining” can include receiving (e.g., receiving information) , accessing (e.g., accessing data stored in memory) , and the like. Also, “determining” can include resolving, obtaining, selecting, choosing, establishing, and other such similar actions.
[0317] In the appended figures, similar components or features may have the same reference label. Further, various components of the same type may be distinguished by following the reference label by a dash and a second label that distinguishes among the similar components. If just the first reference label is used in the specification, the description is applicable to any one of the similar components having the same first reference label irrespective of the second reference label or other subsequent reference label.
[0318] The description set forth herein, in connection with the appended drawings, describes example configurations and does not represent all the examples that may be implemented or that are within the scope of the claims. The term “example” used herein means “serving as an example, instance, or illustration” and not “preferred” or “advantageous over other examples. ” The detailed description includes specific details for the purpose of providing an understanding of the described techniques. These techniques, however, may be practiced without these specific details. In some figures, known structures and devices are shown in block diagram form in order to avoid obscuring the concepts of the described examples.
[0319] The description herein is provided to enable a person having ordinary skill in the art to make or use the disclosure. Various modifications to the disclosure will be apparent to a person having ordinary skill in the art, and the generic principles defined herein may be applied to other variations without departing from the scope of the disclosure. Thus, the disclosure is not limited to the examples and designs described herein but is to be accorded the broadest scope consistent with the principles and novel features disclosed herein.
Claims
A user equipment (UE) , comprising:one or more memories storing processor-executable code; andone or more processors coupled with the one or more memories and individually or collectively operable to execute the code to cause the UE to:receive control signaling indicating a configuration for an offset information report in a coherent joint transmission scheme;transmit a first reference signal to both a first transmission and reception point (TRP) and a second TRP;receive, from the first TRP and the second TRP, respective second reference signals that are respectively precoded based at least in part on the first reference signal; andtransmit the offset information report to the first TRP or the second TRP, or both, that indicates a UE-derived inter-TRP timing offset between the first TRP and the second TRP and a UE-derived inter-TRP phase offset between the first TRP and the second TRP based at least in part on receiving the respective second reference signals, wherein the UE-derived inter-TRP phase offset is based at least in part on the UE-derived inter-TRP timing offset and a reference frequency domain resource in accordance with the configuration for the offset information report.The UE of claim 1, wherein, to receive the control signaling indicating the configuration, the one or more processors are individually or collectively operable to execute the code to cause the UE to:receive an indication of the reference frequency domain resource for the UE-derived inter-TRP phase offset.The UE of claim 1, wherein the reference frequency domain resource corresponds to a first subcarrier, resource block, or subband of a wideband configured for the UE, and the UE-derived inter-TRP phase offset is associated with the wideband.The UE of claim 1, wherein the reference frequency domain resource corresponds to a middle subcarrier, resource block, or subband of a wideband configured for the UE, and the UE-derived inter-TRP phase offset is associated with the wideband.The UE of claim 1, wherein the UE-derived inter-TRP timing offset corresponds to an average delay difference between the first TRP and the second TRP based at least in part on the respective second reference signals.The UE of claim 1, wherein the UE-derived inter-TRP timing offset corresponds to a delay difference between a first peak received power of the first TRP and a second peak received power of the second TRP based at least in part on the respective second reference signals.The UE of claim 1, wherein the configuration for the offset information report indicates that the UE-derived inter-TRP timing offset corresponds to an average delay difference between the first TRP and the second TRP based at least in part on the respective second reference signals or the UE-derived inter-TRP timing offset corresponds to a delay difference between a first peak received power of the first TRP and a second peak received power of the second TRP based at least in part on the respective second reference signals.The UE of claim 1, wherein the one or more processors are individually or collectively further operable to execute the code to cause the UE to:measure the respective second reference signals over respective frequency domain resources of one or more subbands to obtain a respective one or more UE-derived inter-TRP phase offsets for the one or more subbands.The UE of claim 1, wherein the one or more processors are individually or collectively further operable to execute the code to cause the UE to:measure the respective second reference signals over a wideband comprising one or more subbands to obtain a respective one or more UE-derived inter-TRP phase offsets for the one or more subbands.The UE of claim 1, wherein the configuration for the offset information report indicates to calculate the UE-derived inter-TRP phase offset based at least in part on frequency domain resources of a wideband or one or more subbands.A first transmission and reception point (TRP) , comprising:one or more memories storing processor-executable code; andone or more processors coupled with the one or more memories and individually or collectively operable to execute the code to cause the first transmission and reception point (TRP) to:transmit control signaling indicating a configuration for an offset information report in a coherent joint transmission scheme with a second TRP;receive a first reference signal from a user equipment (UE) ;transmit, to the UE, a second reference signal that is precoded based at least in part on the first reference signal;receive the offset information report from the UE, wherein the offset information report indicates a UE-derived inter-TRP timing offset between the first TRP and the second TRP and a UE-derived inter-TRP phase offset between the first TRP and the second TRP that is based at least in part on the UE-derived inter-TRP timing offset and a reference frequency domain resource in accordance with the configuration for the offset information report; andtransmit an indication of the UE-derived inter-TRP phase offset and the UE-derived inter-TRP timing offset to the second TRP.The first transmission and reception point (TRP) of claim 11, wherein, to transmit the control signaling indicating the configuration, the one or more processors are individually or collectively operable to execute the code to cause the first transmission and reception point (TRP) to:transmit an indication of the reference frequency domain resource for a determination of the UE-derived inter-TRP phase offset.The first transmission and reception point (TRP) of claim 11, wherein the configuration for the offset information report indicates to calculate the UE-derived inter-TRP phase offset based at least in part on frequency domain resources of a wideband radio frequency spectrum band or one or more subbands.A user equipment (UE) , comprising:one or more memories storing processor-executable code; andone or more processors coupled with the one or more memories and individually or collectively operable to execute the code to cause the UE to:receive control signaling indicating a configuration for an offset information report in a coherent joint transmission scheme;transmit a first reference signal to a first transmission and reception point (TRP) and to a second TRP;receive, from the first TRP and the second TRP, respective second frequency-domain (FD) -non-precoded reference signals; andtransmit the offset information report to the first TRP or the second TRP, or both, wherein the offset information report indicates a UE-derived inter-TRP phase offset between the first TRP and the second TRP or a UE-derived inter-TRP delay offset between the first TRP and the second TRP, or both, based at least in part on receiving the respective second FD-non-precoded reference signals and in accordance with the configuration for the offset information report.The UE of claim 14, wherein the one or more processors are individually or collectively further operable to execute the code to cause the UE to:average a phase measurement of the respective second FD-non-precoded reference signals using a subset of antenna ports of the UE to obtain the inter-TRP phase offset.The UE of claim 15, wherein the one or more processors are individually or collectively further operable to execute the code to cause the UE to:select the subset of antenna ports of the UE based at least in part on receiving the respective second FD-non-precoded reference signals, wherein the offset information report indicates the subset of antenna ports used for a determination of the UE-derived inter-TRP phase offset.The UE of claim 15, wherein the one or more processors are individually or collectively further operable to execute the code to cause the UE to:receive a control signal indicating the subset of antenna ports to use for a determination the UE-derived inter-TRP phase offset based at least in part on the first reference signal, wherein the UE-derived inter-TRP phase offset is based at least in part on the subset of antenna ports.The UE of claim 15, wherein the configuration for the offset information report indicates the subset of antenna ports of the UE.The UE of claim 14, wherein the UE-derived inter-TRP phase offset is based at least in part on the UE-derived inter-TRP delay offset.The UE of claim 19, wherein, to receive the control signaling indicating the configuration, the one or more processors are individually or collectively operable to execute the code to cause the UE to:receive an indication of a reference frequency domain resource, wherein the UE-derived inter-TRP phase offset is based at least in part on the reference frequency domain resource in accordance with the configuration for the offset information report.The UE of claim 14, wherein the offset information report indicates the UE-derived inter-TRP delay offset.The UE of claim 14, wherein the UE-derived inter-TRP delay offset corresponds to an average delay difference between the first TRP and the second TRP based at least in part on the respective second FD-non-precoded reference signals.The UE of claim 14, wherein the UE-derived inter-TRP delay offset corresponds to a delay difference between a first peak received power of the first TRP and a second peak received power of the second TRP based at least in part on the respective second FD-non-precoded reference signals.The UE of claim 14, wherein the configuration for the offset information report indicates that the UE-derived inter-TRP delay offset corresponds to an average delay difference between the first TRP and the second TRP based at least in part on the respective second FD-non-precoded reference signals or the UE-derived inter-TRP delay offset corresponds to a delay difference between a first peak received power of the first TRP and a second peak received power of the second TRP based at least in part on the respective second FD-non-precoded reference signals.The UE of claim 14, wherein the one or more processors are individually or collectively further operable to execute the code to cause the UE to:measure the respective second FD-non-precoded reference signals over respective frequency domain resources of one or more subbands to obtain a respective one or more UE-derived inter-TRP phase offsets for the one or more subbands.A first transmission and reception point (TRP) , comprising:one or more memories storing processor-executable code; andone or more processors coupled with the one or more memories and individually or collectively operable to execute the code to cause the first transmission and reception point (TRP) to:transmit control signaling indicating a configuration for an offset information report in a coherent joint transmission scheme with a second TRP;receive a first reference signal from a user equipment (UE) ;transmit, to the UE, a second frequency domain (FD) -non-precoded reference signal;receive the offset information report from the UE based on transmitting the second FD-non-precoded reference signal, wherein the offset information report indicates a UE-derived inter-TRP phase offset between the first TRP and the second TRP; andtransmit an indication of the UE-derived inter-TRP phase offset to the second TRP.The first transmission and reception point (TRP) of claim 26, wherein the one or more processors are individually or collectively further operable to execute the code to cause the first transmission and reception point (TRP) to:transmit a control signal indicating a subset of antenna ports to use for a determination of the UE-derived inter-TRP phase offset based at least in part on the first reference signal, wherein the UE-derived inter-TRP phase offset is based at least in part on the subset of antenna ports.The first transmission and reception point (TRP) of claim 26, wherein the UE-derived inter-TRP phase offset is based at least in part on a UE-derived inter-TRP delay offset between the first TRP and the second TRP based at least in part on receiving the first reference signal and transmitting the second FD-non-precoded reference signal.The first transmission and reception point (TRP) of claim 28, wherein the configuration for the offset information report indicates that the UE-derived inter-TRP delay offset corresponds to an average delay difference between the first TRP and the second TRP based at least in part on the second FD-non-precoded reference signal or the UE-derived inter-TRP delay offset corresponds to a delay difference between a first peak received power of the first TRP and a second peak received power of the second TRP based at least in part on the second FD-non-precoded reference signal.The first transmission and reception point (TRP) of claim 26, wherein the offset information report indicates a subset of antenna ports of the UE used to calculate the UE-derived inter-TRP phase offset based at least in part on transmitting the second FD-non-precoded reference signal.
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