User equipment (UE) assisted time and phase synchronization for coherent joint transmission

Abstract

Methods, systems, and devices for wireless communication that support user equipment (UE) assisted transmit and receive point (TRP) synchronization are described. The first TRP and the second TRP may transmit a first downlink reference signal (RS) and a second downlink RS to the secondary UE. The secondary UE may transmit a first uplink RS to the first TRP and a second uplink RS to the second TRP, wherein the first uplink RS and the second uplink RS are precoded based on the first downlink RS and the second downlink RS. The central node may calculate a relative timing offset, a relative phase offset, or both between the first TRP and the second TRP based on the first uplink RS and the second uplink RS. One of the first TRP or the second TRP may then be synchronized with the other TRP using a relative timing offset, a phase offset, or both.

Description

[0001] Cross-referencing

[0002] This patent application claims priority to U.S. Patent Application No. 18 / 458,897, filed August 30, 2023, entitled “USEREQUIPMENT (UE)-ASSISTED TIME AND PHASE SYNCHRONIZATION FOR COHERENT JOINTTRANSMISSION”, which is assigned to the assignee of this application and is expressly incorporated herein by reference. Technical Field

[0003] The following relates to wireless communications, including time and phase synchronization assisted by user equipment (UE) for coherent joint transmission (CJT).

[0004] background

[0005] Wireless communication systems are widely deployed to provide various types of communication content, such as voice, video, packet data, message sending and receiving, broadcasting, and so on. These systems can support communication with multiple users by sharing 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-A 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 Extended Orthogonal Frequency Division Multiplexing (DFT-S-OFDM). A wireless multiple access communication system may include one or more base stations, each supporting wireless communication of communication devices, which may be referred to as User Equipment (UE).

[0006] In some wireless communication systems, transmit-receive points (TRPs) can communicate with each other and with one or more UEs. Network entities, base stations, radio units (RUs), and other entities can be examples of TRPs capable of such communication. Summary of the Invention

[0007] The described techniques relate to improved methods, systems, devices, and apparatuses for user equipment (UE)-assisted time and phase synchronization for coherent joint transmission (CJT). For example, the described techniques provide UE-assisted transmit and receive point (TRP) synchronization, where the UE can assist in identifying two or more TRPs and mitigate potential transmit and receive mismatches between the two or more TRPs. For example, this disclosure describes techniques for accurately and efficiently estimating time offsets and / or phase offsets for synchronizing two or more TRPs. In some examples, a first TRP may transmit a first downlink reference signal (RS) to the auxiliary UE, and the auxiliary UE may transmit a first uplink RS to the first TRP, wherein the first uplink RS may be pre-decoded (e.g., by the auxiliary UE) based on the first downlink RS. The auxiliary UE may also receive a second downlink RS from a second TRP and transmit a second uplink RS to the second TRP, wherein the second uplink RS may be pre-decoded based on the second downlink RS. The uplink RS pre-decoding performed by the auxiliary UE can reduce or eliminate the effect of the phase of the channel used to transmit the first and second uplink RS. A central node (e.g., one of the first TRP or the second TRP, or a separate entity or another network device) can calculate the relative timing offset “ρ” and relative phase offset “φ” of the first TRP and the second TRP based on the first uplink RS and the second uplink RS. Then, one of the first TRP or the second TRP can use the relative timing offset, the relative phase offset, or both to synchronize with the other of the first TRP and the second TRP. The techniques described herein are also applicable to networks with multiple TRPs and one or more auxiliary UEs.

[0008] A method for wireless communication by a first TRP is described. The method may include: transmitting a first downlink RS to a first UE via a first resource set; and receiving a first pre-decoded uplink RS from the first UE via a second resource set associated with the first resource set, the first pre-decoded uplink RS being pre-decoded based on an estimate of the first downlink RS, wherein the first TRP synchronizes with the second TRP according to a phase offset, timing offset, or both between the first TRP and the second TRP, and wherein the phase offset, timing offset, or both are based on the first pre-decoded uplink RS and a second pre-decoded uplink RS associated with the second TRP.

[0009] A first TRP for wireless communication is described. The first TRP may include: one or more memories storing processor-executable code; and one or more processors coupled to the one or more memories. The one or more processors may be able to operate individually or collectively to execute code such that the first TRP: transmits a first downlink RS to a first UE via a first resource set; and receives a first pre-decoded uplink RS from the first UE via a second resource set associated with the first resource set, the first pre-decoded uplink RS being pre-decoded based on an estimate of the first downlink RS, wherein the first TRP is synchronized with the second TRP according to a phase offset, timing offset, or both between the first TRP and the second TRP, and wherein the phase offset, timing offset, or both are based on the first pre-decoded uplink RS and the second pre-decoded uplink RS associated with the second TRP.

[0010] Another first TRP for wireless communication is described. The first TRP may include: components for transmitting a first downlink RS to a first UE via a first resource set; and components for receiving a first pre-decoded uplink RS from the first UE via a second resource set associated with the first resource set, the first pre-decoded uplink RS being pre-decoded based on an estimate of the first downlink RS, wherein the first TRP is synchronized with the second TRP according to a phase offset, timing offset, or both between the first TRP and the second TRP, and wherein the phase offset, timing offset, or both are based on the first pre-decoded uplink RS and the second pre-decoded uplink RS associated with the second TRP.

[0011] A non-transitory computer-readable medium storing code for wireless communication is described. The code may include instructions executable by one or more processors to: transmit a first downlink RS to a first UE via a first resource set; and receive a first pre-decoded uplink RS from the first UE via a second resource set associated with the first resource set, the first pre-decoded uplink RS being pre-decoded based on an estimate of the first downlink RS, wherein a first TRP is synchronized with a second TRP based on a phase offset, timing offset, or both between the first TRP and a second TRP, and wherein the phase offset, timing offset, or both are based on the first pre-decoded uplink RS and a second pre-decoded uplink RS associated with the second TRP.

[0012] The methods described herein, and some examples of the first TRP and nontransitory computer-readable medium, may also include operations, features, components, or instructions for: receiving from the second TRP a message indicating a second pre-decoded uplink RS; and estimating a phase offset, timing offset, or both based on the conjugate product of the first pre-decoded uplink RS and the second pre-decoded uplink RS.

[0013] In the methods described herein, in some examples of the first TRP and non-transitory computer-readable media, the estimation of phase offset, timing offset, or both may be based on the calculation of the conjugate product of the uplink RS of the first pre-decoded and the uplink RS of the second pre-decoded for a set of multiple subcarriers.

[0014] In the methods described herein, in some examples of the first TRP and the nontransitory computer-readable medium, a first message indicating the first pre-decoded uplink RS is output to the central node, and in response to the first message, a second message indicating an estimate of phase offset, timing offset, or both is obtained from the central node, wherein the estimate of phase offset, timing offset, or both may be based on the product of the conjugate of the first pre-decoded uplink RS and the second pre-decoded uplink RS.

[0015] In the methods described herein, in some examples of the first TRP and non-transitory computer-readable media, the estimation of phase offset, timing offset, or both may be based on the calculation of the conjugate product of the uplink RS of the first pre-decoded and the uplink RS of the second pre-decoded for a set of multiple subcarriers.

[0016] In the methods described herein, in some examples of the first TRP and nontransitory computer-readable media, the central node includes either a second TRP or another network entity.

[0017] In some examples of the methods, first TRPs, and nontransitory computer-readable media described herein, a second pre-decoded uplink RS may be associated with a second downlink RS corresponding to a third resource set, and the methods, apparatus, and nontransitory computer-readable media may include additional operations, features, components, or instructions for obtaining a phase offset, timing offset, or both based on the conjugate product of the first pre-decoded uplink RS and the second pre-decoded uplink RS and further based on a subcarrier spacing index associated with the first resource set, second resource set, third resource set, fourth resource set, or any combination thereof.

[0018] In the methods described herein, in some examples of the first TRP and the nontransitory computer-readable medium, the frequency resources in the first resource set may have the same frequency as the corresponding frequency resources in the third resource set, or the frequency resources in the second resource set may have the same frequency as the corresponding frequency resources in the fourth resource set, or both.

[0019] In the methods described herein, in some examples of the first TRP and the nontransitory computer-readable medium, the time resources in the first resource set may be the same as the corresponding time resources in the third resource set, or the time resources in the second resource set may be the same as the corresponding time resources in the fourth resource set, or both.

[0020] In the methods described herein, in some examples of the first TRP and the nontransitory computer-readable medium, the time resources in the first resource set may be the same as the corresponding time resources in the third resource set, and the frequency resources in the second resource set may have the same frequency as the corresponding frequency resources in the fourth resource set.

[0021] The methods described herein, some examples of the first TRP and nontransitory computer-readable media may also include operations, features, components or instructions for: determining a threshold timing offset associated with synchronization based on the frequency interval between a first resource set, a second resource set, a third resource set, a fourth resource set or a combination thereof; and determining the threshold offset resolution based on the bandwidth of the uplink RS for the first pre-decoding, the uplink RS for the second pre-decoding, the first downlink RS, the second downlink RS or any combination thereof.

[0022] The methods described herein, some examples of the first TRP and nontransitory computer-readable media may also include operations, features, components or instructions for synchronizing timing or phase or both with the third TRP based on a second phase offset, a second timing offset or both between the second TRP and the third TRP, wherein the first TRP uses a combination of phase offset and second phase offset, a combination of timing offset and second timing offset or both to synchronize with the third TRP.

[0023] In the methods described herein, in some examples of the first TRP and the nontransient computer-readable medium, the second phase offset, the second timing offset, or both may be based on the uplink RS of the third pre-decoded data transmitted from the second UE to the second TRP and the uplink RS of the fourth pre-decoded data transmitted from the second UE to the third TRP.

[0024] The methods described herein, examples of the first TRP, and some examples of non-transitory computer-readable media may also include operations, features, components, or instructions for sending a control message to a first UE, the control message including an indication of a first resource set for a first downlink RS that may be associated with a second resource set for an uplink RS for a first pre-decoded.

[0025] The methods described herein, examples of the first TRP, and non-transitory computer-readable media may also include operations, features, components, or instructions for receiving capability signaling that instructs the first UE to provide the first TRP with a first pre-decoded uplink RS to assist in the synchronization of the first TRP and the second TRP.

[0026] In the methods described herein, in some examples of the first TRP and nontransitory computer-readable media, capability signaling indicates the first UE's ability to simultaneously receive downlink RS, the first UE's ability to simultaneously transmit uplink RS, one or more RS structures supported by the first UE, the range of time and frequency resources to which the first UE's transmit and receive characteristics can be consistent, the maximum number of TRPs to which the first UE can provide pre-decoded uplink RS, the first UE's ability to maintain receive phase continuity and transmit phase continuity in a certain number of symbols, or any combination thereof.

[0027] In some examples of the methods described herein, the first TRP, and the nontransitory computer-readable medium, the first downlink RS includes one of a tracking reference signal, a positioning reference signal, a synchronization signal block (SSB), or a demodulation reference signal (DMRS).

[0028] A method for wireless communication by a first UE is described. The method may include: receiving a first downlink RS from a first TRP via a first resource set; transmitting a first pre-decoded uplink RS to the first TRP via a second resource set associated with the first resource set, wherein the first pre-decoded uplink RS is pre-decoded based on an estimate of the first downlink RS; receiving a second downlink RS from a second TRP via a third resource set; and transmitting a second pre-decoded uplink RS to the second TRP via a fourth resource set associated with the third resource set, wherein the second pre-decoded uplink RS is pre-decoded based on an estimate of the second downlink RS, wherein the first, second, third, and fourth resource sets are configured for the first UE according to synchronization between the first and second TRPs.

[0029] A first UE for wireless communication is described. The first UE may include: one or more memories storing processor-executable code; and one or more processors coupled to the one or more memories. The one or more processors may be able to operate individually or jointly to execute code such that the first UE: receives a first downlink RS from a first TRP via a first resource set; transmits a first pre-decoded uplink RS to the first TRP via a second resource set associated with the first resource set, wherein the first pre-decoded uplink RS is pre-decoded based on an estimate of the first downlink RS; receives a second downlink RS from a second TRP via a third resource set; and transmits a second pre-decoded uplink RS to the second TRP via a fourth resource set associated with the third resource set, wherein the second pre-decoded uplink RS is pre-decoded based on an estimate of the second downlink RS, wherein the first resource set, second resource set, third resource set, and fourth resource set are configured for the first UE according to synchronization of the first TRP and the second TRP.

[0030] Another first UE for wireless communication is described. The first UE may include: components for receiving a first downlink RS from a first TRP via a first resource set; components for transmitting a first pre-decoded uplink RS to the first TRP via a second resource set associated with the first resource set, wherein the first pre-decoded uplink RS is pre-decoded based on an estimate of the first downlink RS; components for receiving a second downlink RS from a second TRP via a third resource set; and components for transmitting a second pre-decoded uplink RS to the second TRP via a fourth resource set associated with the third resource set, wherein the second pre-decoded uplink RS is pre-decoded based on an estimate of the second downlink RS, wherein the first resource set, second resource set, third resource set, and fourth resource set are configured for the first UE according to the synchronization of the first TRP and the second TRP.

[0031] A non-transitory computer-readable medium storing code for wireless communication is described. The code may include instructions executable by one or more processors to: receive a first downlink RS from a first TRP via a first resource set; transmit a first pre-decoded uplink RS to the first TRP via a second resource set associated with the first resource set, wherein the first pre-decoded uplink RS is pre-decoded based on an estimate of the first downlink RS; receive a second downlink RS from a second TRP via a third resource set; and transmit a second pre-decoded uplink RS to the second TRP via a fourth resource set associated with the third resource set, wherein the second pre-decoded uplink RS is pre-decoded based on an estimate of the second downlink RS, wherein the first, second, third, and fourth resource sets are configured for a first UE according to synchronization of the first and second TRPs.

[0032] In some examples of the methods described herein, the first user equipment (UE), and the nontransitory computer-readable medium, frequency resources in the first resource set may have the same frequency as corresponding frequency resources in the third resource set, frequency resources in the second resource set may have the same frequency as corresponding frequency resources in the fourth resource set, or both.

[0033] In some examples of the methods described herein, the first user equipment (UE), and the nontransitory computer-readable medium, the time resources in the first resource set may be the same as the corresponding time resources in the third resource set, the time resources in the second resource set may be the same as the corresponding time resources in the fourth resource set, or both.

[0034] In some examples of the methods described herein, the first user equipment (UE), and the nontransitory computer-readable medium, the time resources in the first resource set may be the same as the corresponding time resources in the third resource set, and the frequency resources in the second resource set may have the same frequency as the corresponding frequency resources in the fourth resource set.

[0035] The methods described herein, examples of the first user equipment (UE) and non-transitory computer-readable media may also include operations, features, components, or instructions for receiving a control message that includes an indication of a first resource set for a first downlink RS that may be associated with a second resource set for a first pre-decoded uplink RS.

[0036] The methods described herein, examples of the first user equipment (UE) and nontransitory computer-readable media may also include operations, features, components, or instructions for receiving control signaling, the control signaling including a first indication for a first resource set for a first downlink RS that may be associated with a second resource set for an uplink RS for a first pre-decoding, and a second indication for a third resource set for a second downlink RS that may be associated with a fourth resource set for an uplink RS for a second pre-decoding.

[0037] In some examples of the methods described herein, the first user equipment (UE), and nontransitory computer-readable media, control signaling includes one or more uplink RS configurations, one or more downlink reference configurations, one or more pointers associated with an uplink RS resource identifier or a downlink RS identifier, or any combination thereof.

[0038] In some examples of the methods, first user equipment (UE) and nontransitory computer-readable media described herein, the first downlink reference signal and the methods, apparatus and nontransitory computer-readable media may include additional operations, features, components or instructions for interpolating between corresponding frequency intervals of a plurality of instances of the first downlink RS and between corresponding frequency intervals of a plurality of instances of the second downlink RS, wherein the estimation of the first downlink RS and the estimation of the second downlink RS may be based on the interpolation.

[0039] The methods described herein, examples of the first user equipment (UE) and non-transitory computer-readable media may also include operations, features, components, or instructions for transmitting capability signaling that instructs the first UE to provide a first pre-decoded uplink RS to the first TRP to assist in the synchronization of the first TRP and the second TRP.

[0040] In the methods described herein, in some examples of the first user equipment (UE) and nontransitory computer-readable media, capability signaling indicates the first UE's ability to simultaneously receive downlink RS, the first UE's ability to simultaneously transmit uplink RS, one or more RS structures supported by the first UE, the range of time and frequency resources to which the first UE's transmit and receive characteristics can be consistent, the maximum number of TRPs to which the first UE can provide pre-decoded uplink RS, the first UE's ability to maintain receive phase continuity and transmit phase continuity in a certain number of symbols, or any combination thereof.

[0041] The methods described herein, examples of the first user equipment (UE) and nontransitory computer-readable media may also include operations, features, components, or instructions for: receiving a third downlink RS from a third TRP via a fifth resource set; and sending a third pre-decoded uplink RS to the third TRP via a sixth resource set that may be associated with the fifth resource set, wherein the third pre-decoded uplink RS may be pre-decoded based on an estimate of the third downlink RS. Attached Figure Description

[0042] Figure 1 An example of a wireless communication system that supports time and phase synchronization for user equipment (UE) for coherent joint transmission (CJT) is shown according to one or more aspects of this disclosure.

[0043] Figure 2 An example of a wireless communication system supporting UE-assisted time and phase synchronization for CJT is shown, according to one or more aspects of this disclosure.

[0044] Figure 3 An example of a wireless communication resource diagram supporting UE-assisted time and phase synchronization for CJT is shown, according to one or more aspects of this disclosure.

[0045] Figure 4 An example flowchart of a process supporting UE-assisted time and phase synchronization for CJT is shown, according to one or more aspects of this disclosure.

[0046] Figure 5 An example of a wireless communication system supporting UE-assisted time and phase synchronization for CJT is shown, according to one or more aspects of this disclosure.

[0047] Figure 6 and Figure 7 An example of a wireless communication resource diagram supporting UE-assisted time and phase synchronization for CJT is shown, according to one or more aspects of this disclosure.

[0048] Figure 8 and Figure 9 A block diagram of an apparatus for UE-assisted time and phase synchronization for CJT is shown, according to one or more aspects of this disclosure.

[0049] Figure 10 A block diagram of a communication manager supporting UE-assisted time and phase synchronization for CJT is shown, according to one or more aspects of this disclosure.

[0050] Figure 11 A diagram is shown of a system including a device for supporting UE-assisted time and phase synchronization for CJT, according to one or more aspects of this disclosure.

[0051] Figure 12 and Figure 13 A block diagram of an apparatus for UE-assisted time and phase synchronization for CJT is shown, according to one or more aspects of this disclosure.

[0052] Figure 14 A block diagram of a communication manager supporting UE-assisted time and phase synchronization for CJT is shown, according to one or more aspects of this disclosure.

[0053] Figure 15 A diagram is shown of a system including a device for supporting UE-assisted time and phase synchronization for CJT, according to one or more aspects of this disclosure.

[0054] Figures 16 to 19 A flowchart illustrating a method for UE-assisted time and phase synchronization for CJT according to one or more aspects of this disclosure is shown. Detailed Implementation

[0055] Some entities within a wireless communication system can perform synchronization processes to ensure accurate signaling for coordinated communication within the system. For example, some transmit and receive points (TRPs) within a wireless communication system can synchronize their time (e.g., clock timing, transmit timing, receive timing) and phase (e.g., signaling phase) with each other for transmitting and receiving. The use of such synchronization is likely to become increasingly influential due to the widespread use of Time Division Duplex (TDD) radio technology, Coherent Joint Transmission (CJT), and the expansion of new network architectures in next-generation and advanced wireless systems.

[0056] Some wireless communication systems, such as multi-user multiple-input multiple-output (MU-MIMO) systems, are particularly sensitive to time and / or phase mismatches between devices, such as time and phase mismatches between TRPs deployed within the system. In some cases, time and phase synchronization can be performed using air signaling between one or more TRPs in the wireless communication system. However, these synchronization techniques may be relatively inefficient when the channel between one or more TRPs is relatively weak, susceptible to interference, or affected by obstructions or other obstacles. In other cases, the network may rely on UE-assisted synchronization, where one or more auxiliary UEs provide synchronization information to one or more TRPs. However, such techniques may be inaccurate when transmit and receive mismatches exist at one or more auxiliary UEs, which can negatively impact the synchronization process.

[0057] According to various aspects of this disclosure, wireless communication systems may employ enhancement techniques for UE-assisted TRP synchronization that take into account possible transmit and receive mismatches at the UE (e.g., phase misalignment, timing misalignment), thereby providing more accurate time and phase offset estimates for synchronizing two or more TRPs. In some aspects, the first TRP may transmit a first downlink reference signal (RS) to the assisting UE, and the assisting UE may transmit a first uplink RS to the first TRP, wherein the first uplink RS may be pre-decoded based on the first downlink RS. The assisting UE may also receive a second downlink RS from a second TRP and may transmit a second uplink RS to the second TRP, wherein the second uplink RS may be pre-decoded based on the second downlink RS. The uplink RS pre-decoding performed by the UE can remove the effects of the channel used to transmit the first and second uplink RS (e.g., phase misalignment). A central node (e.g., one of the first and second TRPs, a separate entity) may then calculate the relative timing offset “ρ” and relative phase offset “φ” of the two TRPs based on the first and second uplink RS. Then, one of the first TRPs or the second TRP can use a relative timing offset, a phase offset, or both to synchronize with the other of the first TRP and the second TRP.

[0058] Additionally or alternatively, the techniques described herein can be applied to networks of TRPs and auxiliary UEs. For example, a set of TRPs can wirelessly communicate with a set of UEs. According to the techniques described herein, a first TRP in the TRP set can be synchronized with a second TRP in the TRP set based on one or more first offsets (e.g., time offsets, phase offsets) obtained via a first UE in the UE set. According to the techniques described herein, a second TRP can also be synchronized with a third TRP in the TRP set based on one or more second offsets obtained via a second UE in the UE set. The first TRP can then be synchronized with the third TRP based on a first offset and a second offset (e.g., a combination of a first offset and a second offset). Thus, a TRP set can have “N” TRPs, wherein a first TRP in the TRP set can be synchronized with an Nth TRP in the TRP set based on offsets obtained via at least N-1 UEs, which correspond to N-1 pairs (e.g., unique N-1 pairs) of TRPs in the TRP set.

[0059] The aspects of this disclosure are first described in the context of a wireless communication system. Additionally, the aspects of this disclosure are described in the context of wireless communication resource diagrams and process flowcharts. The aspects of this disclosure are further illustrated and described with reference to apparatus diagrams, system diagrams, and flowcharts relating to time and phase synchronization assisted by the UE for CJT.

[0060] Figure 1 An example of a wireless communication system 100 supporting UE-assisted time and phase synchronization for CJT is shown, according to one or more aspects of this disclosure. The wireless communication system 100 may include one or more network entities 105, one or more UEs 115, and a core network 130. In some examples, the wireless communication system 100 may be a Long Term Evolution (LTE) network, an Advanced LTE (LTE-A) network, an LTE-A Pro network, a New Radio (NR) network, or a network operating under other systems and radio technologies, including future systems and radio technologies not explicitly mentioned herein.

[0061] Network entity 105 may be distributed across a geographical area to form wireless communication system 100, and may include devices employing different forms or having different capabilities. In various examples, network entity 105 may be referred to as a network element, mobility element, radio access network (RAN) node, or network equipment, etc. In some examples, network entity 105 and UE 115 may wirelessly communicate via one or more communication links 125 (e.g., radio frequency (RF) access links). For example, network entity 105 may support coverage area 110 (e.g., a geographical coverage area) within which UE 115 and network entity 105 may establish one or more communication links 125. Coverage area 110 may be an example of a geographical area within which network entity 105 and UE 115 may support the transmission of signals according to one or more radio access technologies (RATs).

[0062] UE 115 can be distributed throughout the coverage area 110 of wireless communication system 100, and each UE 115 can be stationary or mobile, or stationary and mobile at different times. UE 115 can be devices in different forms or with different capabilities. Figure 1 Some example UE 115s are illustrated herein. The UE 115 described herein can be able to support various types of devices (such as, e.g., ...). Figure 1 It communicates with other UEs (115 or network entity 105) as shown.

[0063] As described herein, nodes of the wireless communication system 100 (which may be referred to as network nodes or wireless nodes) may be network entity 105 (e.g., any network entity described herein), UE 115 (e.g., any UE described herein), network controller, apparatus, device, 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 UE 115. Alternatively, a node may be network entity 105. Furthermore, a first node may be configured to communicate with a second or third node. In one aspect of this example, the first node may be UE 115, the second node may be network entity 105, and the third node may be UE 115. In another aspect of this example, the first node may be UE 115, the second node may be network entity 105, and the third node may be network entity 105. In other aspects of this example, the first node, the second node, and the third node may be different from these examples. Similarly, references to UE 115, network entity 105, device, equipment, computing system, etc., may include disclosures of UE 115, network entity 105, device, equipment, computing system, etc., as nodes. For example, a disclosure that UE 115 is configured to receive information from network entity 105 also discloses that a first node is configured to receive information from a second node.

[0064] In some examples, network entity 105 may communicate with core network 130, communicate with each other, or both. For example, network entity 105 may communicate with core network 130 via one or more backhaul communication links 120 (e.g., according to S1, N2, N3, or other interface protocols). In some examples, network entities 105 may communicate with each other directly (e.g., directly between network entities 105) or indirectly (e.g., via core network 130) via backhaul communication links 120 (e.g., according to X2, Xn, or other interface protocols). In some examples, network entities 105 may communicate with each other via midhaul communication link 162 (e.g., according to midhaul interface protocol) or fronthaul communication link 168 (e.g., according to fronthaul interface protocol) or any combination thereof. Backhaul communication link 120, midhaul communication link 162, or fronthaul communication link 168 may be or include one or more wired links (e.g., electrical links, fiber optic links), one or more wireless links (e.g., radio links, wireless optical links), etc., or various combinations thereof. UE 115 can communicate with core network 130 via communication link 155.

[0065] One or more network entities in network entity 105 described herein may include or be referred to as base station 140 (e.g., transceiver base station, radio base station, NR base station, access point, radio transceiver, node B, eNodeB (eNB), next-generation node B or gigabit node B (any of which may be referred to as gNB), 5G NB, next-generation eNB (ng-eNB), home node B, home evolution node B, or other suitable terms). In some examples, network entity 105 (e.g., base station 140) may be implemented in an aggregated (e.g., monolithic, standalone) base station architecture that may be configured to utilize a protocol stack that is physically or logically integrated within a single network entity 105 (e.g., a single RAN node, such as base station 140).

[0066] In some examples, network entity 105 may be implemented in a decomposed architecture (e.g., a decomposed base station architecture, a decomposed RAN architecture) that can be configured to utilize protocol stacks physically or logically distributed across two or more network entities 105, such as an integrated access 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, network entity 105 may include one or more of the following: a central unit (CU) 160, a distributed unit (DU) 165, a radio unit (RU) 170, a RAN intelligent controller (RIC) 175 (e.g., a near real-time RIC, a non-real-time RIC), a service management and orchestration (SMO) 180 system, or any combination thereof. 170 may also be referred to as a radio headend, intelligent radio headend, remote radio headend (RRH), remote radio unit (RRU), or TRP. One or more components of network entity 105 in a decomposed RAN architecture may be co-located, or one or more components of network entity 105 may be located in distributed locations (e.g., separate physical locations). In some examples, one or more network entities 105 in a decomposed RAN architecture may be implemented as virtual units (e.g., virtual CU (VCU), virtual DU (VDU), virtual RU (VRU)).

[0067] The functional splitting among CU 160, DU 165, and RU 170 is flexible and can support different functionalities depending on which functions (e.g., network layer functions, protocol layer functions, baseband functions, RF functions, and any combination thereof) are performed at CU 160, DU 165, or RU 170. For example, a protocol stack functional splitting can be used between CU 160 and DU 165, allowing CU 160 to support one or more layers of the protocol stack, and DU 165 to support one or more different layers of the protocol stack. In some examples, CU 160 can host higher protocol layer (e.g., Layer 3 (L3), Layer 2 (L2)) functionalities and signaling (e.g., Radio Resource Control (RRC), Serving Data Adaptation Protocol (SDAP), Packet Data Convergence Protocol (PDCP)). CU 160 can connect to one or more DU 165 or RU 170, and one or more DU 165 or RU 170 can 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 each can be at least partially controlled by CU 160. Additionally or alternatively, a protocol stack functional split can be employed between DU 165 and RU 170, such that DU 165 can support one or more layers of the protocol stack, and RU 170 can support one or more different layers of the protocol stack. DU 165 can support one or more different cells (e.g., via one or more RU 170). In some cases, functional decomposition between CU 160 and DU 165, or between DU 165 and RU 170, can be performed within the protocol layer (e.g., some functions of the protocol layer can be performed by one of CU 160, DU 165, or RU 170, while other functions of the protocol layer can be performed by different of CU 160, DU 165, or RU 170). CU 160 can be further functionally decomposed into CU control plane (CU-CP) functions and CU user plane (CU-UP) functions. CU 160 can be connected to one or more DU 165 via midhaul communication link 162 (e.g., F1, F1-c, F1-u), and DU 165 can be connected to one or more RU 170 via fronthaul communication link 168 (e.g., open fronthaul (FH) interface). In some examples, the midhaul communication link 162 or the fronthaul communication link 168 may be implemented based on the interfaces (e.g., channels) between the layers of the protocol stack, which are supported by the corresponding network entities 105 communicating via such communication links.

[0068] In a wireless communication system (e.g., wireless communication system 100), the infrastructure and spectrum resources for radio access can support wireless backhaul link capabilities to supplement wired backhaul connections, thereby providing an IAB network architecture (e.g., to core network 130). In some cases, in an IAB network, one or more network entities 105 (e.g., IAB node 104) may be partially controlled by each other. One or more IAB nodes 104 may be referred to as donor entities or IAB donors. One or more DU 165s or one or more RU 170s may be partially controlled by one or more CU 160s associated with donor network entity 105 (e.g., donor base station 140). One or more donor network entities 105 (e.g., IAB donors) may communicate with one or more additional network entities 105 (e.g., IAB node 104) via supported access and backhaul links (e.g., backhaul communication link 120). IAB node 104 may include an IAB mobile terminal (IAB-MT) controlled (e.g., scheduled) by a DU 165 of a coupled IAB donor. The IAB-MT may include a separate set of antennas for relaying communication with UE 115, or may share the same antennas (e.g., those of RU 170) for access to IAB node 104 via DU 165 of IAB node 104. (e.g., referred to as a virtual IAB-MT (vIAB-MT)). In some examples, IAB node 104 may include a DU 165 that supports communication links with additional entities (e.g., IAB node 104, UE 115) within a relay chain or configuration (e.g., downstream) of the access network. In such cases, one or more components of the decomposed RAN architecture (e.g., one or more IAB nodes 104 or components of IAB node 104) may be configured to operate according to the techniques described herein.

[0069] When the techniques described herein are applied in the context of a decomposed RAN architecture, one or more components of the decomposed RAN architecture can be configured to support UE-assisted time and phase synchronization for CJT as described herein. For example, some operations described as being performed by UE 115 or network entity 105 (e.g., base station 140) may additionally or alternatively be performed by one or more components of the decomposed RAN architecture (e.g., IAB node 104, DU 165, CU 160, RU 170, RIC 175, SMO 180).

[0070] UE 115 may include or be referred to as a mobile device, wireless device, remote device, handheld device, or subscriber device, or any other suitable term, wherein "device" may also be referred to as a cell, station, terminal, or client, etc. UE 115 may also include or be referred to as a personal electronic device, such as a cellular phone, personal digital assistant (PDA), tablet computer, laptop computer, or personal computer. In some examples, UE 115 may include or be referred to as a wireless local loop (WLL) station, Internet of Things (IoT) device, Internet of Everything (IoE) device, or machine-type communication (MTC) device, etc., which may be implemented in various objects such as appliances or vehicles, meters, etc.

[0071] The UE 115 described herein can communicate with various types of devices, such as other UEs 115 that sometimes act as relays, network entities 105, and network equipment including macro eNBs or gNBs, small cell eNBs or gNBs, or relay base stations, etc. Figure 1 As shown.

[0072] UE 115 and network entity 105 can wirelessly communicate with each other via one or more communication links 125 (e.g., access links) using resources associated with one or more carriers. The term "carrier" can refer to a set of RF spectrum resources having a defined physical layer structure for supporting communication link 125. For example, a carrier for communication link 125 may include a portion of the RF spectrum band (e.g., a bandwidth portion (BWP)) operating according to one or more physical layer channels for a given radio access technology (e.g., LTE, LTE-A, LTE-A Pro, NR). Each physical layer channel may carry acquisition signaling (e.g., synchronization signals, system information), control signaling coordinating carrier operation, user data, or other signaling. Wireless communication system 100 can support communication with UE 115 using carrier aggregation or multi-carrier operation. Depending on the carrier aggregation configuration, UE 115 can be configured to utilize multiple downlink component carriers and one or more uplink component carriers. Carrier aggregation can be used in conjunction with both frequency division duplex (FDD) component carriers and time division duplex (TDD) component carriers. Communication between network entity 105 and other devices can refer to communication between these devices and any part of network entity 105 (e.g., entity, sub-entity). For example, the terms “send,” “receive,” or “communicate” when referring to network entity 105 can refer to any part of the RAN’s network entity 105 (e.g., base station 140, CU160, DU 165, RU 170) communicating with another device (e.g., directly or via one or more other network entities 105).

[0073] In some examples, such as in carrier aggregation configurations, a carrier may also have acquisition signaling or control signaling to coordinate the operation of other carriers. A carrier may be associated with a frequency channel (e.g., an Evolved Universal Mobile Telecommunications System Terrestrial Radio Access (E-UTRA) Absolute RF Channel Number (EARFCN)) and may be identified according to a channel grating used for discovery by UE 115. A carrier may operate in standalone mode, in which case initial acquisition and connection can be made by UE 115 via that carrier, or the carrier may operate in non-standalone mode, in which case different carriers (e.g., the same or different radio access technologies) are used to anchor the connection.

[0074] The communication link 125 shown in the wireless communication system 100 may include downlink transmission (e.g., forward link transmission) from network entity 105 to UE 115, uplink transmission (e.g., return link transmission) from UE 115 to network entity 105, or both, as well as other transmission configurations. A carrier may carry downlink communication or uplink communication (e.g., in FDD mode), or may be configured to carry both downlink and uplink communication (e.g., in TDD mode).

[0075] A carrier may be associated with a specific bandwidth of the RF spectrum, and in some examples, the carrier bandwidth may be referred to as the carrier or the “system bandwidth” of the wireless communication system 100. For example, the carrier bandwidth may be one bandwidth in a set of bandwidths for a particular radio access technology (e.g., 1.4 MHz, 3 MHz, 5 MHz, 10 MHz, 15 MHz, 20 MHz, 40 MHz, or 80 MHz). Devices of the wireless communication system 100 (e.g., network entity 105, UE 115, or both) may have hardware configurations that support communication using a specific carrier bandwidth, or may be configured to support communication using one carrier bandwidth in a set of carrier bandwidths. In some examples, the wireless communication system 100 may include network entity 105 or UE 115 that supports concurrent communication using carriers associated with multiple carrier bandwidths. In some examples, each served UE 115 may be configured to operate using a portion (e.g., subband, BWP) or all of the carrier bandwidth.

[0076] The signal waveform transmitted via a carrier may include multiple subcarriers (e.g., using multi-carrier modulation (MCM) techniques, such as orthogonal frequency division multiplexing (OFDM) or discrete Fourier transform extended OFDM (DFT-S-OFDM)). In a system employing MCM, a resource element may refer to a resource of one symbol period (e.g., the duration of one modulation symbol) and one subcarrier, in which case the symbol period and subcarrier spacing may be inversely related. The number of bits carried by each resource element may depend on the modulation scheme (e.g., the order of the modulation scheme, the decoding rate of the modulation scheme, or both), such that a relatively high number of resource elements (e.g., in the transmission duration) and a relatively high modulation scheme order correspond to a relatively high communication rate. Wireless communication resources may refer to a combination of RF spectrum resources, temporal resources, and spatial resources (e.g., spatial layers or beams), and the use of multiple spatial resources may increase the data rate or data integrity used for communication with UE 115.

[0077] The time interval for network entity 105 or UE 115 can be expressed as a multiple of a basic time unit, such as the sampling period. seconds, of which It can represent the supported subcarrier spacing, and This can represent the supported Discrete Fourier Transform (DFT) size. The time interval of the communication resources can be organized according to radio frames, each with a specified duration (e.g., 10 milliseconds (ms)). Each radio frame can be identified by a System Frame Number (SFN) (e.g., ranging from 0 to 1023).

[0078] Each frame may include multiple consecutively numbered subframes or time slots, and each subframe or time slot may have the same duration. In some examples, a frame may (e.g., in the time domain) be divided into subframes, and each subframe may be further divided into a number of time slots. Alternatively, each frame may include a variable number of time slots, and the number of time slots may depend on the subcarrier spacing. Each time slot may include a number of symbol periods (e.g., depending on the length of the cyclic prefix appended to each symbol period). In some wireless communication systems 100, time slots may be further divided into multiple micro-time slots associated with one or more symbols. Excluding the cyclic prefix, each symbol period may be associated with one or more (e.g., The duration of a symbol period is associated with a (number) sampling period. The duration of a symbol period can depend on the subcarrier spacing or the operating frequency band.

[0079] A subframe, time slot, micro-time slot, or symbol can be the smallest scheduling unit of the wireless communication system 100 (e.g., in the time domain) and can be referred to as a transmission time interval (TTI). In some examples, the duration of the TTI (e.g., the number of symbol periods in the TTI) can be variable. Additionally or alternatively, the smallest scheduling unit of the wireless communication system 100 can be dynamically selected (e.g., in a burst of shortened TTIs (sTTIs)).

[0080] Depending on the technology, carriers can be used to multiplex physical channels for communication. One or more of Time Division Multiplexing (TDM), Frequency Division Multiplexing (FDM), or hybrid TDM-FDM techniques can be used, for example, to multiplex physical control channels and physical data channels for signaling via a downlink carrier. The control region (e.g., control resource set (CORESET)) of the physical control channel can be defined by a set of symbol periods and can extend across the system bandwidth of the carrier or a subset of that bandwidth. One or more control regions (e.g., CORESET) can be configured for a set of UEs 115. For example, one or more UEs in UE 115 can monitor or search for control regions to obtain control information based on one or more search space sets, and each search space set can include one or more control channel candidates in one or more aggregation levels arranged in a concatenated manner. The aggregation level of control channel candidates can refer to the amount of control channel resources (e.g., control channel elements (CCEs)) associated with coded information for a control information format having a given payload size. The search space set may include: a common search space set configured to transmit control information to multiple UEs 115, and a UE-specific search space set used to transmit control information to a specific UE 115.

[0081] Network entity 105 may provide communication coverage via one or more cells (e.g., macro cells, small cells, hotspots, or other types of cells, or any combination thereof). The term "cell" may refer to a logical communication entity used to communicate with network entity 105 (e.g., using a carrier) and may be associated with an identifier used to distinguish adjacent cells (e.g., Physical Cell Identifier (PCID), Virtual Cell Identifier (VCID), or other cell identifier). In some examples, a cell may also refer to a coverage area 110 or a portion of coverage area 110 (e.g., a sector) in which a logical communication entity operates. Depending on various factors such as the capabilities of network entity 105, the extent of such cells may range from smaller areas (e.g., structures, subsets of structures) to larger areas. For example, a cell may be or may include buildings, subsets of buildings, or external space between or overlapping coverage areas 110, etc.

[0082] Macro cells typically cover a relatively large geographical area (e.g., a radius of several kilometers) and allow unrestricted access to UE 115 that has a service subscription with a network provider supporting the macro cell. In contrast, small cells may be associated with a lower-power network entity 105 (e.g., a lower-power base station 140) and may operate using the same or different (e.g., licensed, unlicensed) frequency bands as macro cells. Small cells may provide unrestricted access to UE 115 that has a service subscription with a network provider, or restricted access to UE 115 associated with a small cell (e.g., UE 115 in a closed subscriber group (CSG), or UE 115 associated with a user in a home or office). Network entity 105 may support one or more cells and may also use one or more component carriers to support communication via one or more cells.

[0083] In some examples, a carrier can support multiple cells and can be configured with different cells based on different protocol types that can provide access for different types of devices (e.g., MTC, Narrowband IoT (NB-IoT), Enhanced Mobile Broadband (eMBB)).

[0084] In some examples, network entity 105 (e.g., base station 140, RU 170) may be mobile, and thus provide communication coverage to mobile coverage areas 110. In some examples, different coverage areas 110 associated with different technologies may overlap, but the different coverage areas 110 may be supported by the same network entity 105. In some other examples, overlapping coverage areas 110 associated with different technologies may be supported by different network entities 105. The wireless communication system 100 may include, for example, a heterogeneous network in which different types of network entities 105 use the same or different radio access technologies to provide coverage for various coverage areas 110.

[0085] The wireless communication system 100 can support synchronous or asynchronous operation. For synchronous operation, network entities 105 (e.g., base station 140) can have similar frame timings, and transmissions from different network entities 105 can be approximately time-aligned. For asynchronous operation, network entities 105 can have different frame timings, and in some examples, transmissions from different network entities 105 may not be time-aligned. The techniques described herein can be used for both synchronous and asynchronous operation.

[0086] Wireless communication system 100 may be configured to support ultra-reliable communication or low-latency communication, or various combinations thereof. For example, wireless communication system 100 may be configured to support ultra-reliable low-latency communication (URLLC). UE 115 may be designed to support ultra-reliable or low-latency or critical functions. Ultra-reliable communication may include private 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 business applications. The terms “ultra-reliable,” “low-latency,” and “ultra-reliable low-latency” are used interchangeably herein.

[0087] In some examples, UE 115 may be configured to support direct communication with other UE 115s via device-to-device (D2D) communication link 135 (e.g., according to peer-to-peer (P2P), D2D, or sidelink protocols). In some examples, one or more UE 115s performing D2D communication in a group may be within the coverage area 110 of network entity 105 (e.g., base station 140, RU 170), which may support aspects of such D2D communication configured (e.g., scheduled by network entity 105). In some examples, one or more UE 115s in such a group may be outside the coverage area 110 of network entity 105, or may otherwise be unable or not configured to receive transmissions from network entity 105. In some examples, the group of UE 115s communicating via D2D communication may support a one-to-many (1:M) system, where each UE 115 transmits to each of the other UE 115s in the group. In some examples, network entity 105 may facilitate the scheduling of resources used for D2D communication. In other examples, D2D communication may be performed between UEs 115 without involving network entity 105.

[0088] Core network 130 provides user authentication, access authorization, tracking, Internet Protocol (IP) connectivity, and other access, routing, or mobility functions. Core network 130 may be an evolved packet core (EPC) or a 5G core (5GC), which may include at least one control plane entity (e.g., a mobility management entity (MME), access and mobility management function (AMF)) for managing access and mobility, and at least one user plane entity (e.g., a serving gateway (S-GW), packet data network (PDN) gateway (P-GW), or user plane function (UPF)) for routing packets or interconnecting to external networks. The control plane entity manages non-access stratum (NAS) functions, such as mobility, authentication, and bearer management of UE 115 served by network entity 105 (e.g., base station 140) associated with core network 130. User IP packets can be delivered through the user plane entity, which provides IP address allocation and other functions. The user plane entity may connect to one or more network operator IP services 150. IP services 150 may include access to the Internet, intranets, IP Multimedia Subsystem (IMS), or packet-switched streaming services.

[0089] Wireless communication system 100 can operate using one or more frequency bands in the range of 300 MHz to 300 GHz. Generally, the area from 300 MHz to 3 GHz is referred to as the Ultra High Frequency (UHF) band or decimeter band because the wavelength range is 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 these waves are sufficient to penetrate structures so that macrocells can provide service to UE 115 located indoors. Compared to communication using smaller frequencies and longer wavelengths in the lower frequency (HF) or very high frequency (VHF) portions of the spectrum below 300 MHz, communication using UHF waves can be associated with smaller antennas and shorter ranges (e.g., less than 100 km).

[0090] The wireless communication system 100 can also operate in the Ultra High Frequency (SHF) band (also known as the centimeter band) in the range of 3 GHz to 30 GHz or in the Extremely High Frequency (EHF) band (e.g., 30 GHz to 300 GHz) (also known as the millimeter band) using the spectrum. In some examples, the wireless communication system 100 can support millimeter-wave (mmW) communication between the UE 115 and the network entity 105 (e.g., base station 140, RU170), and the EHF antennas of the corresponding devices can be smaller and more closely spaced than UHF antennas. In some examples, such techniques facilitate the use of antenna arrays within the device. However, compared to SHF or UHF transmission, EHF transmission may experience even greater attenuation and a shorter range. The techniques disclosed herein can be adopted for transmission across one or more different frequency bands, and the frequency band usage specified across these frequency bands may vary by country or regulatory authority.

[0091] Wireless communication system 100 may utilize both licensed and unlicensed RF spectrum bands. For example, wireless communication system 100 may use unlicensed bands (such as the 5 GHz Industrial, Scientific, and Medical (ISM) band) to employ Licensed Assisted Access (LAA), LTE Unlicensed (LTE-U) radio access technology, or NR technology. When operating with unlicensed RF spectrum, devices such as network entity 105 and UE 115 may employ carrier sensing for collision detection and avoidance. In some examples, operation using unlicensed bands may be combined with component carriers operating with licensed bands based on carrier aggregation configurations (e.g., LAA). Operation using unlicensed spectrum may include downlink transmission, uplink transmission, P2P transmission, or D2D transmission, etc.

[0092] Network entity 105 (e.g., base station 140, RU 170) or UE 115 may be equipped with multiple antennas that can be used to employ techniques such as transmit diversity, receive diversity, multiple-input multiple-output (MIMO) communication, or beamforming. The antennas of network entity 105 or UE 115 may be located within one or more antenna arrays or antenna panels, which can support MIMO operation 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, the antennas or antenna arrays associated with network entity 105 may be located at different geographical locations. Network entity 105 may include an antenna array having a collection of multiple rows and columns of antenna ports that network entity 105 can use to support beamforming for communication with UE 115. Similarly, UE 115 may include one or more antenna arrays that can support various MIMO or beamforming operations. Additionally or alternatively, the antenna panel may support RF beamforming for signals transmitted via the antenna ports.

[0093] Network entity 105 or UE 115 can use MIMO communication to leverage multipath signal propagation and improve spectral efficiency by transmitting or receiving multiple signals via different spatial layers. This technique is known as spatial multiplexing. The multiple signals can be transmitted, for example, by a transmitting device via different antennas or different combinations of antennas. Similarly, the multiple signals can be received by a receiving device via different antennas or different combinations of antennas. Each of the multiple signals can be referred to as a separate spatial stream and can carry information associated with the same data stream (e.g., the same codeword) or different data streams (e.g., different codewords). Different spatial layers can be associated with different antenna ports used for channel measurement and reporting. MIMO techniques include: single-user MIMO (SU-MIMO), where multiple spatial layers are transmitted to the same receiving device; and multi-user MIMO (MU-MIMO), where multiple spatial layers are transmitted to multiple devices.

[0094] Beamforming (also known as spatial filtering, directional transmission, or directional reception) is a signal processing technique that can be used at a transmitting or receiving device (e.g., network entity 105, UE 115) to shape or guide an antenna beam (e.g., a transmit beam, a receive beam) along a spatial path between the transmitting and receiving devices. Beamforming can be achieved by combining signals transmitted via antenna elements of an antenna array such that some signals propagating along a specific orientation relative to the antenna array experience constructive interference, while other signals experience destructive interference. Adjustments to the signals transmitted via the antenna elements may include applying amplitude shifts, phase shifts, or both to the signals carried via the antenna elements associated with the device. The adjustments associated with each of these antenna elements may be defined by a beamforming weight set associated with a specific orientation (e.g., relative to the antenna array of the transmitting or receiving device or relative to some other orientation).

[0095] UE 115 and network entity 105 can support data retransmission to increase the likelihood of successful data reception. Hybrid Automatic Repeat Request (HARQ) feedback is a technique used to increase the likelihood of correctly receiving data via communication links (e.g., communication link 125, D2D communication link 135). HARQ may include a combination of error detection (e.g., using Cyclic Redundancy Check (CRC)), forward error correction (FEC), and retransmission (e.g., Automatic Repeat Request (ARQ)). HARQ can improve throughput at the MAC layer under poor radio conditions (e.g., low signal-to-noise ratio conditions). In some examples, the device may support same-slot HARQ feedback, in which case the device can provide HARQ feedback in a specific time slot for data received via a previous symbol in that time slot. In some other examples, the device may provide HARQ feedback in subsequent time slots or according to a different time interval.

[0096] According to various aspects of this disclosure, the wireless communication system 100 may employ enhancement techniques for UE-assisted TRP synchronization that take into account possible transmit and / or receive mismatches (e.g., phase misalignment, timing misalignment), thereby providing more accurate time and phase offset estimates for synchronizing two or more TRPs (e.g., RU 170, which may be an example of a TRP). In some cases, the first TRP may transmit a first downlink RS to the auxiliary UE 115, and the auxiliary UE 115 may transmit a first uplink RS to the first TRP, wherein the auxiliary UE may pre-decode the first uplink RS based on the first downlink RS. The auxiliary UE 115 may also receive a second downlink RS from a second TRP and may transmit a second different uplink RS to the second TRP, wherein the auxiliary UE may pre-decode the second uplink RS based on the second downlink RS. The uplink RS pre-decoding performed by the UE may reduce or eliminate the effects of the channel (e.g., phase misalignment) on the transmission of the first and second uplink RS. Then, the central node (e.g., one of the first TRP or the second TRP, or a separate entity or network device) can calculate the relative timing offset ρ and phase offset φ of the two TRPs based on the first uplink RS and the second uplink RS. Then, one of the first TRP or the second TRP can use the relative timing offset, the relative phase offset, or both to synchronize with the other of the first TRP and the second TRP.

[0097] Additionally or alternatively, the techniques described herein can be applied to networks with multiple TRPs and auxiliary UEs 115. For example, a set of TRPs can wirelessly communicate with a set of UEs. According to the techniques described herein, a first TRP in the TRP set can be synchronized with a second TRP in the TRP set based on one or more first offsets (e.g., time offsets, phase offsets) obtained via a first UE 115 in the UE set. According to the techniques described herein, a second TRP can also be synchronized with a third TRP in the TRP set based on one or more second offsets obtained via a second UE 115 in the UE set. The first TRP can then be synchronized with the third TRP based on first and second offsets (e.g., a combination of first and second offsets). Therefore, the TRP set can have There are TRPs, where the first TRP in the TRP set can be based on at least Each UE 115 obtains an offset to synchronize with the Nth TRP in the TRP set, and these UEs correspond to the TRP set in the Nth TRP set. (e.g., unique) (Yes) TRP.

[0098] Figure 2 An example of a wireless communication system 200 supporting UE-assisted time and phase synchronization for CJT is shown, according to one or more aspects of this disclosure. The aspects of the wireless communication system 200 can be implemented... Figure 1 Various aspects, or implementation thereof. For example, wireless communication system 200 may include multiple TRPs 210 (e.g., a first TRP 210-a (e.g., TRP1) and a second TRP 210-a (e.g., TRP2)), which may be collectively referred to as TRP 210, and each may be a reference. Figure 1 Examples of network entities 105, RU 170, TRP, or other aspects described herein. Additionally, the wireless communication system 200 may include a UE 115-a (e.g., UE1), which may be a reference... Figure 1 An example of UE 115 is described. Although a specific number of TRPs, UEs and other aspects are shown in the wireless communication system 200, this disclosure is applicable to any number of TRPs, UEs, other aspects of the wireless communication system 200, or any combination thereof.

[0099] The wireless communication system 200 may include a TRP 210, a UE 115-a, and wireless communication links (e.g., wireless communication link 205-a, wireless communication link 205-b, and wireless communication link 205-c). In some cases, TRP 210-a and TRP 210-b may wirelessly communicate with each other via wireless communication link 205-a. Additionally or alternatively, the TRP may communicate with the UE 115-a via other wireless communication links. For example, TRP 210-a may communicate with the UE 115-a via wireless communication link 205-b, and TRP 210-b may wirelessly communicate with the UE 115-a via wireless communication link 205-c. In some example time periods, when communicating via wireless communication link 205-a, TRP 210-a and TRP 210-b may experience timing offsets. and phase shift .

[0100] In some cases, the first phase associated with TRP 210-a (e.g., phase alignment, phase synchronization, signaling phase) may become misaligned with the second phase associated with TRP 210-b (e.g., drift from the second phase) over a period of time, resulting in a phase shift. In some cases, the first phase, the second phase, or both may become misaligned due to relative timing drift between TRPs, where the relative timing drift may be caused by clock drift (e.g., if TRP 210 is not GPS connected). Additionally or alternatively, phase-locked loop (PLL) dynamics may cause phase drift (e.g., random phase drift) at TRP 210-a, TRP 210-b, or both (e.g., even if TRP 210 is GPS connected).

[0101] In some cases, the performance of CJT performed by TRP (e.g., in distributed MIMO systems) may be affected by the phase offset φ. 12 (For example, phase mismatch) has an effect (e.g., sensitivity to this phase shift). That is, with φ 12 Compared to the performance of CJT performed by TRP when φ is smaller, 12 The performance of CJT performed by TRPs can be poor when the size is relatively large. For example, wireless communication system 200 may be associated with MU-MIMO, where a set of UEs (e.g., UE 115-a and one or more other UEs) can be served by TRPs via the same wireless communication resources. In such examples, aspects of MU-MIMO communication, such as beam nulling and zeroing toward UEs that are not part of the UE set, can impose strict requirements on phase synchronization between TRPs.

[0102] In some specific implementations, time synchronization and phase synchronization between TRPs (e.g., by changing the phase and timing of one or more TRPs in the TRP) and Resetting to zero can be achieved via over-the-air (OTA) signaling between TRPs via wireless communication link 205-a. However, in some cases, OTA synchronization between TRPs may not be possible due to the relative weakness or degradation of wireless communication link 205-a (e.g., poor channel conditions in wireless communication link 205-a, the channel being weak). For example, wireless communication link 205-a may be relatively weak due to the downtilt angle in the macro deployment of the TRPs or because wireless communication link 205-a is a non-line-of-sight (NLOS) wireless communication link, etc.

[0103] In some cases, UE 115-a may be located near or between TRP 210 (e.g., within range of both TRP 210-a and TRP 210-b) and may assist in TRP synchronization (e.g., synchronization of timing and phase corresponding to the TRP). In some cases, since wireless communication links 205-b and 205-c are line-of-sight (LOS) connections, UE 115-a may assist in TRP synchronization. However, one challenge for UE 115-a in assisting TRP synchronization arises from the lack of transmit and receive calibration for UE 115-a. For example, the phase, timing, or both of the signal received by UE 115-a may differ from the signal transmitted by UE 115-a (e.g., out of sync, misaligned), and the transmit and receive channels may differ for UE 115-a. The lack of transmit and receive calibration at UE 115-a may cause UE 115-a to not properly synchronize TRP (e.g., if UE 115-a is used for synchronization assistance between TRP 210).

[0104] This disclosure describes techniques for estimating timing and phase offsets (e.g., phase uncertainty) between TRPs. Additionally or alternatively, the techniques described herein are applicable to wireless communication systems associated with TDD, and therefore the timing and phase offsets of the TRPs can be relative to a combination of transmit and receive offsets. The techniques described herein are additionally applicable when the transmit timing and transmit phase offsets of one TRP are not the same as the receive timing and receive phase offsets, respectively. In some cases, the transmit and receive offsets may be different because the receive clock of one TRP is different from the transmit clock of another TRP, the receive PLL dynamics of one TRP are different from the transmit PLL dynamics of another TRP, or both. Initially, this disclosure contemplates auxiliary synchronization for TRP 210-a, TRP 210-b, and UE 115-a. This disclosure also contemplates extending the techniques described herein to... The TRP network and the UE network are used to assist in synchronization.

[0105] To accommodate the timing offset ρ and phase offset φ of a pair of TRPs relative to the combined transmit and receive offsets, the following equations can be used:

[0106]

[0107]

[0108] Where ρ represents timing offset, φ represents phase offset, the superscript of the offset (e.g., T, R) indicates whether the offset is associated with transmission or reception, and the subscript of the offset indicates the TRP associated with the offset (e.g., TRP 210-a, TRP 210-b). For example, This can represent the receive timing offset associated with TRP 210-a, while This can represent the transmit phase offset associated with TRP 210-b.

[0109] In some cases, each timing offset may represent a phase ramp on a subcarrier (e.g., adjacent subcarriers), where the subcarriers can be separated by a frequency difference of ∆t (e.g., subcarrier spacing), where the transmit timing offset may represent a transmit phase ramp and the receive timing offset may represent a receive phase ramp. In some cases, the frequency difference may be introduced by clock jitter of the transmit or receive clock associated with the corresponding TRP.

[0110] In some cases, each phase offset may represent a phase uncertainty introduced by clock jitter of the corresponding TRP 210. For example, a transmit phase offset may represent a phase uncertainty introduced by jitter of the transmit clock of the corresponding TRP 210 (e.g., transmit-side clock jitter). As another example, a receive phase offset may represent a phase uncertainty introduced by jitter of the receive clock of the corresponding TRP 210 (e.g., receive-side clock jitter).

[0111] Figure 3 Examples of wireless communication resource diagrams 300 and 350 supporting time and phase synchronization for UE-assisted CJT according to one or more aspects of this disclosure are shown. Wireless communication resource diagram 300 may illustrate a first example of the technology described herein, and wireless communication resource diagram 350 may illustrate a second example of the technology described herein. Aspects of wireless communication resource diagrams 300 and 350 can be implemented Figure 1 and Figure 2 Various aspects, or implemented by them. For example, wireless communication resource diagrams 300 and 350 may illustrate resources for wireless communication between a first TRP (e.g., TRP1), a second TRP (e.g., TRP2) (collectively referred to as TRPs), and UE 115 (e.g., UE1), which may be referenced respectively. Figure 2 Examples of TRP 210-a, TRP 210-b, and UE 115-a described herein, or refer to Figure 1 Examples of the corresponding UE 115 and network devices described.

[0112] Wireless communication resource diagrams 300 and 350 may illustrate UE1 receiving first downlink RS from TRP1 and TRP2 respectively (e.g., Second downlink RS (e.g., (For example, as a result of a first downlink RS transmission from TRP1 and a second downlink RS transmission from TRP2). Additionally, TRP1 and TRP2 may each receive a first uplink RS from UE1 (e.g., ) and the second uplink RS (e.g., (e.g., first SRS and second SRS). Resource depictions 305 and 355 may show resources (e.g., time / frequency resources) for the first downlink RS and second downlink RS, as well as the first uplink RS and second uplink RS. Within resource depictions 305 and 355, each column may represent a time interval 315 (e.g., time slot, time resource), and each row may represent one or more frequency resources 320 (e.g., subcarrier, resource element (RE), one or more frequency resources). Additionally, resource depictions 305 and 355 respectively include resources 310 and 360 (e.g., OFDM symbols, resource elements, time and frequency resources) (e.g., resources 310-a, 310-b, 310-c, 310-d, 360-a, 360-b, 360-c, 360-d), wherein each resource 310 and 360 may correspond to a time resource and a frequency resource (e.g., time-frequency resource), and some of the resources 310 and 360 may be used to transmit (e.g., carry or deliver) an uplink RS or a downlink RS. Figure 3 The RS shown can be an example of a downlink RS, and Figure 3 The SRS shown may be an example of an uplink RS, however other examples of uplink RS and downlink RS may be considered (e.g., as described herein).

[0113] The first downlink RS and the first uplink RS may correspond to TRP1 and may be transmitted by TRP1, and the first uplink RS may be received by TRP1. Similarly, the second downlink RS and the second uplink RS may correspond to TRP2 and may be transmitted by TRP2, and the second uplink RS may be received by TRP2. To support UE-assisted time and phase synchronization for CJT according to one or more aspects of this disclosure, the downlink RS, uplink RS, or combinations thereof may follow one or more exemplary relationships.

[0114] A first example relationship can be that the frequency resources associated with an RS corresponding to the same TRP in a TRP are the same or close (e.g., adjacent frequency resources within a threshold frequency difference). For example, a first example relationship could be that both the first downlink RS and the first uplink RS are transmitted on the same frequency resource or on frequency resources close to each other. In one example, because the first uplink RS can be pre-decoded based on the first downlink RS, transmitting the first downlink RS and the first uplink RS on the same (e.g., nearly the same) frequency resources can cancel out the phase of the channel used to transmit the first downlink RS and the first uplink RS on the frequency resources (e.g., multiple frequency resources). In some cases, if the frequency resources of the first downlink RS and the first uplink RS are not the same, UE1 can interpolate between the different frequency resources to achieve an acceptable result.

[0115] A second example relationship could be that the time resources associated with RSs corresponding to the same TRP in the TRP are close to each other (e.g., within a threshold time difference, they are adjacent time resources, separated by 2–3 symbols for downlink-uplink handover within the same time slot). For example, a first example relationship could be that a first downlink RS and a first uplink RS are transmitted on time resources that are close to each other. In one example, because the first uplink RS can be pre-decoded based on the first downlink RS, transmitting the first downlink RS and the first uplink RS on time resources that are close to each other can cancel out the channel phase (e.g., assuming that the channel for these time resources is approximately constant if the time resources used to transmit the first downlink RS and the first uplink RS are relatively close to each other).

[0116] A third example relationship could be that the frequency resources associated with the first uplink RS and the second uplink RS are the same or close, the frequency resources associated with the first downlink RS and the second downlink RS are the same or close, or both. For example, a third example relationship could be that both the first downlink RS and the second downlink RS are transmitted on the same frequency resource or on frequency resources close to each other. In one example, transmitting the first downlink RS and the second downlink RS on the same (e.g., nearly the same) frequency resource can offset phase offsets that might be caused by a lack of transmit and receive calibration at UE1. In this example, because the phase offsets that might be caused by a lack of transmit and receive calibration at UE1 can offset, the remaining phase of the uplink RS can represent the timing offset and phase offset between TRPs.

[0117] In some cases, downlink RS and uplink RS can be transmitted (e.g., repeated) periodically throughout the frequency domain. For example, resources 310-d and 310-e can be used by UE1 to transmit a second uplink RS to TRP2. Resource 310-d can be transmitted via frequency resource k, and resource 310-e can be transmitted via frequency resource k+k0, where k0 represents the subcarrier spacing (e.g., in frequency) between repetitions of the second uplink RS.

[0118] In some cases, the resources used for uplink RS and downlink RS can affect the effectiveness of synchronization between TRPs. The subcarrier spacing k0 in the frequency domain between the resource elements of the downlink RS and uplink RS can determine the maximum timing offset that can be corrected by UE-assisted synchronization techniques, as described herein. In some cases, a larger k0 can indicate that UE-assisted synchronization can resolve (e.g., remove, synchronize) larger time offsets. For example, if k0 = 12 resource elements, UE-assisted synchronization can resolve ±1.39 μsec (e.g., assuming a 30 kHz subcarrier spacing (SCS)).

[0119] In some cases, the bandwidth associated with the uplink RS, downlink RS, or both can determine the minimum timing offset (e.g., timing offset resolution) that can be resolved (e.g., differentiated) via UE-assisted synchronization. For example, resource 310-a can be used by UE1 to receive the first downlink RS from TRP1. Resource 310-a can be associated with a frequency resource having bandwidth on which the first downlink RS is transmitted. In some cases, the larger the bandwidth of the frequency resource, the smaller the timing offset that can be resolved via UE-assisted synchronization.

[0120] Based on the example relationships, wireless communication resource diagram 300 may illustrate a first example of the technology described herein, while wireless communication resource diagram 350 may illustrate a second example of the technology described herein. For example, the first example of the technology described herein may follow a first example relationship and a third example relationship, and the second example of the technology described herein may follow a first example relationship and a second example relationship. In some cases, the first example may not require UE1 to perform simultaneous reception or simultaneous transmission and may be more accurate than the second example. In some cases, the second example may utilize less overhead (e.g., less time resources) and be less accurate than the first example compared to the first example, and may be associated with UE1 performing simultaneous transmission and reception.

[0121] As described above, wireless communication resource diagrams 300 and 350 respectively illustrate a first example and a second example of the technology described herein. In wireless communication resource diagrams 300 and 350, UE1 can receive a first downlink RS from TRP1. And receive the second downlink RS from TRP2 UE1 also sends the first uplink RS to TRP1. And send the second uplink RS to TRP2 In order to describe and The following equation can be used:

[0122]

[0123] in and These represent the first downlink channel and the second downlink channel used to transmit the first downlink RS and the second downlink RS, respectively. Additionally, and These can be represented by subcarrier-based spacing associated with the first channel and the second channel, respectively. The phase ramp (e.g., timing offset), and and These can represent the transmit phase offsets (e.g., random phase offsets) generated at TRP1 and TRP2, respectively. This can indicate an imbalance in the received phase and gain at UE1, and This can represent random noise that may affect the downlink RS.

[0124] As described in this article, the uplink RS and RS Each is based on the downlink RS and Perform pre-decoding. For example, and It can be described by the following equation:

[0125]

[0126] in and These represent the estimated first downlink RS and second downlink RS, respectively, as estimated by UE1 after receiving the first downlink RS and the second downlink RS. and This can represent the pre-decoder used by the UE to transmit the uplink RS, and can be obtained from the conjugate of the estimates of the first downlink RS and the second downlink RS, respectively, where if If the term is small enough, then the estimate is close to... Additionally, and These can be represented as the first uplink channel and the second uplink channel used to transmit the first uplink RS and the second uplink RS, respectively. and These can represent the receiving-side timing offsets of TRP1 and TRP2, respectively. and These can represent the received phase uncertainty at TRP1 and TRP2, respectively. This can indicate an imbalance in the transmission phase and gain at UE1, and This represents random noise in the first uplink RS and the second uplink RS. and These can represent the scaling of the first uplink RS and the second uplink RS, respectively.

[0127] In response to and In the equation shown, The term indicates that the receive and transmit phase and gain imbalance of UE1 is transmitted along a portion of the uplink RS. To remove the effects of the phase and gain imbalance of UE1, the following equation can be used:

[0128]

[0129] in express The conjugate of, and It could be:

[0130]

[0131] This equation has no phase effect (e.g., only magnitude). Additionally, and This can represent the timing and phase offset between TRP1 and TRP2. Effectively, this can compensate for the phase and gain imbalance in the transmit and receive phases of UE1.

[0132] As described herein, Equations 1 and 2 describe the timing and phase offsets between TRP1 and TRP2. For multiple uplink RSs pre-decoded on corresponding downlink RSs over multiple frequency resources (e.g., subcarriers), Equation 7 can be used to estimate the parameters in Equations 1 and 2, which have intervals (e.g., regular intervals, periodicity) of k0 (e.g., k=0, k0, 2k0, 3k0, ...).

[0133] In wireless communication resource diagram 300, downlink RSs can be received via the same frequency resources and on time resources that are close to each other, and uplink RSs can be transmitted via the same frequency resources and on time resources that are close to each other. For example, resources 310-a and 310-b can be used by UE1 to receive (e.g., and for TRP transmission) the first downlink RS and the second downlink RS, respectively. The frequency resource associated with resource 310-a can be the same as the frequency resource associated with resource 310-b, and the time resource associated with resource 310-a can be close to (e.g., adjacent to) the time resource associated with resource 310-b.

[0134] In wireless communication resource diagram 300, resources 310-b and 310-c are used for UE1 to receive (e.g., for TRP2 transmission) a second downlink RS and for UE1 to transmit (e.g., for TRP2 reception) a second uplink RS, respectively. In some cases, the downlink RS and uplink RS may be associated with the same frequency resource and have separate durations of 325. For example, the frequency resource associated with resource 310-b may be the same as the frequency resource associated with resource 310-c.

[0135] As discussed above, uplink RS and downlink RS can be transmitted within one cycle of a frequency resource. In some cases, uplink RS and downlink RS can be repeated within one cycle of a frequency resource. For example, resources 310-c, 310-d, and 310-e can each be used by UE1 to transmit (e.g., for TRP2 reception) an instance of a second uplink RS. Resource 310-d can be associated with a frequency resource k (e.g., subcarrier spacing index k) counting upwards from the frequency resource associated with resource 310-c. Then, resource 310-e can be associated with a frequency resource k+k0 (e.g., subcarrier spacing index k+k0), where k0 can represent the frequency period (e.g., interval) within which the second uplink RS is transmitted.

[0136] In wireless communication resource diagram 350, downlink RSs can be received via relatively close (e.g., adjacent) frequency resources and on the same time resources, and uplink RSs can be transmitted via close frequency resources and on the same time resources. For example, resources 360-a and 360-b can be used by UE1 to receive (e.g., and for TRP transmission) a first downlink RS and a second downlink RS, respectively. The frequency resource associated with resource 360-a can be relatively close to the frequency resource associated with resource 360-b (e.g., within a threshold distance), and the time resource associated with resource 360-a can be the same as the time resource associated with resource 360-b.

[0137] In wireless communication resource diagram 350, resources 360-b and 360-c are used for UE1 reception (e.g., for TRP2 transmission) of a second downlink RS and for UE1 transmission (e.g., for TRP2 reception) of a second uplink RS, respectively. In some cases, each uplink RS may be associated with the same frequency resources as its associated downlink RS (e.g., the downlink RS on which the uplink RS is pre-decoded) and may be separated from the associated downlink RS by 375 seconds. For example, the frequency resources associated with resource 360-b may be the same as those associated with resource 360-c.

[0138] As discussed above, uplink RS and downlink RS can repeat within one cycle of frequency resources. For example, resources 360-d and 360-f can each be used for instances of a first uplink RS transmitted by UE1 (e.g., for TRP1 reception), and resources 360-e and 360-g can be used for instances of a second uplink RS transmitted by UE1 (e.g., for TRP2 reception). Resource 360-d can be associated with frequency resource k (e.g., subcarrier spacing index k) counting upwards from the frequency resource associated with resource 360-a, and resource 360-e can be associated with frequency resource k+1. Then, resource 360-f can be associated with frequency resource k+k0 (e.g., subcarrier spacing index k+k0), where k0 can represent a frequency cycle (e.g., interval) within which the second RS repeats, and resource 360-g can be associated with frequency resource k+k0+1.

[0139] For a second specific implementation of the technology described herein, as shown in wireless communication resource diagram 350, equations 1–8 can be adapted. For example, and The instance can be replaced with and .

[0140] Additionally, the second embodiment may assume that in frequency resources that are close to each other (e.g., adjacent frequency resources), the transmit and receive phase and gain imbalances of UE1 are the same (the frequency selectivity of the phase and gain imbalance is not very strong). For example, Equation 8 can be changed to look like the following:

[0141]

[0142] Where the assumption ,and .

[0143] A second specific implementation may also assume that in frequency resources that are close to each other (e.g., adjacent frequency resources), the transmit and receive phase ramps of TRP1 and TRP2 are small individually or jointly. For example, Equation 2 can be changed to look like the following:

[0144]

[0145] in The transmit and receive phase ramps of the TRP can be represented and are assumed to be insignificant (e.g., small enough that the resulting difference is negligible). It should also be noted that channels spanning adjacent frequency resources may differ (e.g., a second implementation may be suitable for channels with high frequency selectivity).

[0146] In some cases, the first embodiment may be more accurate than the second embodiment in estimating timing and phase offsets between TRPs. However, the first embodiment can use more resources (e.g., time resources, with greater overhead) to estimate the offsets between TRPs compared to the second embodiment.

[0147] Figure 4 An example of a process flowchart 400 supporting UE-assisted time and phase synchronization for CJT is shown, according to one or more aspects of this disclosure. The aspects of process flowchart 400 can be implemented... Figure 1 – Figure 3 Various aspects, or implementation thereof. For example, process flowchart 400 may include UE 115-b (e.g., UE1), first TRP 210-c (e.g., TRP1), and second TRP 210-d (e.g., TRP2), which may be collectively referred to as TRP 210, and may be a reference Figure 2 and Figure 3 The described UE (e.g., UE 115-a, UE1), first TRP 210-a (e.g., TRP1), and TRP 210-b (e.g., TRP2) are corresponding examples. UE 115-b may also be as referenced. Figure 1 The example of UE 115 described herein. Similarly, TRP 210-c and TRP 210-d may each be references. Figure 1 Examples of network entities 105, RU 170, TRPs, or other aspects described herein. Although a specific number of TRPs, UEs, and other aspects are shown in process flowchart 400, this disclosure is applicable to any number of TRPs, UEs, other aspects of process flowchart 400, or any combination thereof.

[0148] Process flowchart 400 may include a central node 450. In some cases, the central node 450 may be TRP 210-c, TRP 210-d, or both. Additionally or alternatively, the central node 450 may be a separate entity in the wireless communication system of the TRP and UE 115-b. For example, the central node 450 may be a network entity, an OEM entity, a network, or another entity. Process flowchart 400 initially considers two TRPs (e.g., TRP 210-c and TRP 210-d) and one UE 115-b to facilitate synchronization between the two TRPs. Process flowchart 400 may consider the case of the TRP's network and the UE's network, where TRP 210-c and TRP 210-d may be two TRPs in the TRP's network and may be synchronized with other TRPs in the TRP's network via a process similar to or the same as that described in process flowchart 400, but utilizing one or more other UEs in the UE's network.

[0149] In the following description of process flowchart 400, these operations may be performed in a different order than those shown, or other operations may be added to or removed from process flowchart 400. For example, some operations may be omitted from process flowchart 400, some operations may be performed in a different order or at different times, or other operations may be added to process flowchart 400. Although UE 115-b, TRP 210-c, TRP 210-d and central node 450 are shown as performing the operations of process flowchart 400, some aspects of some operations may also be performed by one or more other wireless or network devices.

[0150] At locations 405 and 410, UE 115-b may receive a first downlink RS and a second downlink RS from TRP 210-c and TRP 210-d, respectively. In some cases, the first downlink RS, the second downlink RS, or both may be a Channel State Information (CSI) RS, a Tracking Reference Signal (TRS), a Positioning Reference Signal (PRS), a Synchronization Signal Block (SSB), a Demodulation Reference Signal (DMRS), or any combination thereof. The first downlink RS received at UE 115-b may be referred to as y1, and the second downlink RS received at UE 115-b may be referred to as y2.

[0151] At positions 415 and 420, UE 115-b may transmit a first uplink RS and a second uplink RS to TRP 210-c and TRP2, respectively. As described herein, the first uplink RS and the second uplink RS may be pre-decoded based on the corresponding first downlink RS and second downlink RS. For example, UE 115-b may receive the first downlink RS from TRP 210-c at position 405 and may pre-decode the uplink RS based on the first downlink RS (e.g., generate a pre-decoded uplink RS). The pre-decoded uplink RS may be the first uplink RS, and UE 115-b may transmit a pre-decoded reference signal to TRP 210-c at position 415. In some cases, pre-decoding of the first uplink RS and the second uplink RS may reduce (e.g., eliminate) the effect of the phase of the channel used to transmit the first uplink RS and the second uplink RS when received by the TRP. The first uplink RS received at TRP 210-c can be referred to as The second uplink RS received at TRP 210-d can be referred to as .

[0152] In some cases, UE 115-b may receive control signaling (e.g., RRC signaling) for indicating link pairs (e.g., resource sets) for resources (e.g., resources for a downlink RS and a corresponding uplink RS). For example, UE 115-b may receive RRC signaling indicating link pairs of resources, where one resource in the link pair will be used for a first downlink RS, and the other resource in the link pair will be used for a first uplink RS. Similar link pairs of resources may be indicated for a second downlink RS and a second uplink RS. This may be to inform UE 115-b which downlink RS to use for pre-decoding which uplink RS (e.g., the first downlink RS is used for pre-decoding the first uplink RS, and the second downlink RS is used for pre-decoding the second uplink RS).

[0153] In some cases, link pairs of resources may be configured (e.g., indicated) as part of an uplink RS configuration. For example, configuration for a first uplink RS, a second uplink RS, or both may include an indication of one or more associated downlink RSs (e.g., resources for the corresponding one or more downlink RSs). Additionally or alternatively, path loss (PL)-RS may be used (e.g., reused) to indicate link pairs of resources, wherein PL-RS may be configured for information elements (e.g., new information elements) or configured by information elements. Additionally or alternatively, link pairs of resources may be configured for UE115-b as a downlink RS configuration. For example, configuration for a first downlink RS, a second downlink RS, or both may include an indication (e.g., a pointer) to the corresponding one or more uplink RSs (e.g., resources for the corresponding one or more uplink RSs).

[0154] In some cases, resource link pairs can be configured to UE 115-b via explicit configuration of the link pair's ID pointing to the corresponding resource. For example, an explicit configuration message may point to (e.g., indicate) a resource ID or resource set ID associated with the first downlink RS and a resource ID or resource set ID associated with the first uplink RS. Similar explicit configurations may be used for the second downlink RS and the second uplink RS in the same or different explicit configuration messages.

[0155] In some cases, the first number of ports of UE 115-b used for receiving downlink RS can be configured (e.g., limited) to be the same as the second number of ports of UE 115-b used for transmitting uplink RS. In some examples, the first and second numbers can be configured as a single port. In some cases, the first frequency bandwidth used by UE 115-b for receiving downlink RS can be configured to be the same as the second frequency bandwidth used by UE 115-b for transmitting uplink RS.

[0156] In some cases, the frequency interval k0 (e.g., tone interval, periodicity, frequency density) can be different between the downlink RS and the uplink RS. For example, UE 115-b can receive (e.g., estimate) instances of the first downlink RS on multiple first frequency resources (e.g., channels) spaced apart by a first interval, and can interpolate between these instances to estimate the frequency resources (e.g., channels, REs) between these instances. UE 115-b can then use the estimates made when receiving instances of the first downlink RS, the estimates made during interpolation, or both, to transmit instances of the first uplink RS at a second frequency interval that is the same as or different from the first frequency interval.

[0157] At points 425 and 430, central node 450 can obtain (e.g., TRP 210-c and TRP 210-d can send to central node 450) both a first uplink RS and a second uplink RS. As an example, if TRP 210-c is central node 450, then TRP 210-c can retain the first uplink RS, and TRP 210-d can send the second uplink RS to TRP 210-c. If TRP 210-d is central node 450, the opposite can occur. In another example, if the individual entity is central node 450, then at point 420, TRP 210-c can send the first uplink RS to central node 450, and at point 425, TRP 210-d can send the second uplink RS to central node 450.

[0158] At 435, the central node 450 can determine one or more of the timing offset and phase offset (e.g., relative timing offset and relative phase offset) between TRP 210-c and TRP 210-d. For example, as described herein, the central node 450 can calculate the product of the conjugates of the first uplink RS and the second uplink RS as part of determining one or more of the timing offset and phase offset. In some cases, calculating the product as described can ensure that the transmit and receive timing and gain imbalances (e.g., timing mismatch, phase mismatch) of UE 115-b are removed (e.g., canceled) from the determined timing offset, phase offset, or both.

[0159] By calculating the product as described herein, the remaining timing offset, phase offset, or both can be a timing offset (e.g., relative timing offset), a phase offset (e.g., relative phase offset), or both between TRP 210-c and TRP 210-d. Therefore, the lack of receive and transmit calibration for UE 115-b (e.g., transmit and receive mismatch) does not affect the determination (e.g., estimation) of the timing offset, phase offset, or both. In some cases, the product can be calculated multiple times using multiple instances of the first uplink RS and the second uplink RS transmitted via multiple frequency resources (e.g., subcarrier spacing). A more detailed description of calculating the product can be found in [link to document / document / etc.]. Figure 3 The description.

[0160] At 440, one or more of TRP 210-c and TRP 210-d (e.g., TRP 210-d in this example) may receive an indication of one or more determined offsets (e.g., timing offset and phase offset) between the TRPs. In some cases (e.g., if TRP 210-d is the central node 450), TRP 210-d may receive an indication of one or more determined offsets from itself. In other cases (e.g., if the central node 450 is TRP 210-c or another entity), the central node 450 may send one or more determined offsets to TRP 210-d.

[0161] At 445, one of TRP 210-c and TRP 210-d (e.g., TRP 210-d in this example) can be synchronized with the other of TRP 210-c and TRP 210-d (e.g., a synchronization process is performed with it). In some cases, one or more determined offsets can be used in the synchronization. For example, one or both TRPs can adjust the clock, timer, phase, or other aspects associated with the transmission or reception of the other one or both TRPs.

[0162] In addition to the steps described in process flowchart 400, at any time before, during, or after the described steps, the UE may send capability signaling to TRP 210-c, TRP 210-d, or both. Capability signaling may indicate the UE 115-b's ability to assist TRP synchronization. For example, capability signaling may instruct the UE 115-b to provide a first uplink RS to TRP 210-c, a second uplink RS to TRP 210-d, or both to assist the synchronization of TRP 210-c and TRP 210-d. Additionally or alternatively, capability signaling may indicate the UE 115-b's ability to support simultaneous downlink RS reception, the UE 115-b's ability to support simultaneous uplink RS transmission, one or more RS structures that the UE 115-b may support (e.g., a first example, a second example, a third example, or other examples), (e.g., within which, wherein) the UE 115-b's transmission and reception characteristics may be substantially consistent (e.g., within a certain threshold or range of values), the range of time and frequency resources (e.g., the number of REs, the number of tone intervals, the threshold (e.g., the maximum) range), the number of TRPs of uplink RSs that the UE 115-b may be able to provide to it based on the corresponding downlink RS for pre-decoding (e.g., the number of thresholds, the maximum number), the UE 115-b's ability to maintain receive phase continuity and transmit phase continuity in a certain number of symbols or resources (e.g., where the first example may be associated with 2 symbols for downlink RSs and 2 symbols for uplink RSs) (e.g., on a certain number of symbols or resources), or any combination thereof. In some cases (e.g., if UE 115-b is capable of simultaneous downlink RS reception but not simultaneous uplink RS transmission), UE 115-b may use the third example described herein. In some cases where the transmission and reception characteristics of UE 115-b are substantially consistent (e.g., within a range of values, based on thresholds, etc.), the range of time and frequency resources determines the accuracy of the techniques described herein (e.g., relative to the second example).

[0163] Figure 5 An example of a wireless communication system 500 supporting UE-assisted time and phase synchronization for CJT is shown, according to one or more aspects of this disclosure. The aspects of the wireless communication system 500 can be implemented... Figure 1 – Figure 4Various aspects, or implementation thereof. For example, the wireless communication system 500 may include a network of multiple TRPs, including a first TRP 210-e (e.g., TRP1), a second TRP 210-f (e.g., TRP2), a third TRP 210-g (e.g., TRP3), a fourth TRP 210-h (e.g., TRP4), a fifth TRP 210-i (e.g., TRP5), and a sixth TRP 210-j (e.g., TRP6), which may be collectively referred to as TRP 210, and may be a reference. Figure 1 Examples of network entities 105, RU 170, TRP, or other aspects described. In some examples, TRP 210 may be a reference. Figure 2 – Figure 4 Examples of TRPs (e.g., TRP1, TRP2, TRP 210-a, TRP210-b, TRP 210-c, TRP 210-d) are described. Additionally, the wireless communication system 500 may include multiple UEs, including a first UE 115-c (e.g., UE1), a second UE 115-d (e.g., UE2), a third UE (e.g., UE3), a fourth UE 115-f (e.g., UE4), and a fifth UE 115-g (e.g., UE5), which may be collectively referred to as UE 115 and may be a reference. Figure 1 An example of UE 115 as described. In some examples, each UE in UE 115 may be a reference. Figure 2 – Figure 4 Examples of UEs described (e.g., UE1, UE 115-a, UE 115-b). Although various numbers of TRPs, UEs, and other aspects are shown in the wireless communication system 200, this disclosure is applicable to any number of TRPs, UEs, other aspects of the wireless communication system 500, or any combination thereof.

[0164] Each TRP 210 in the network of TRP 210 can wirelessly communicate with another TRP 210 via wireless communication links 505 (e.g., wireless communication link 505-a, wireless communication link 505-b, and wireless communication link 505-c). In some examples, one or more wireless communication links in wireless communication links 505 may experience corresponding timing offsets. and corresponding phase offset The timing offset and phase offset of the corresponding wireless communication link 505 can correspond to the TRP using that wireless communication link. For example, wireless communication link 505-a can be used by TRP 210-e and TRP 210-i. Therefore, for example, the timing offset of wireless communication link 505-a can be expressed as: The subscript indicates that the timing offset is relative to TRP 210-e and TRP 210-h.

[0165] To assist synchronization, multiple pairs of TRPs in a TRP can communicate with one or more UEs via wireless communication links. For example, TRP 210-e and TRP 210-h can communicate with UE 115-e via wireless communication links 510-a and 510-b. According to the techniques described herein, TRP 210-e and TRP 210-h can synchronize timing and phase based on their communication with UE 115-e. Similarly, TRP 210-e can synchronize with TRP 210-f via communication with UE 115-c, TRP 210-e can synchronize with TRP 210-g via communication with UE 115-d, TRP 210-h can synchronize with TRP 210-i via communication with UE 115-f, and TRP 210-i can synchronize with TRP 210-j via communication with UE 115-g.

[0166] TRP networks may include There are several TRPs. In some cases, if there is a path of wireless communication link 505 between each TRP and every other TRP, joint synchronization can be achieved by obtaining the relative timing offset and relative phase offset of at least N-1 pairs (e.g., non-identical pairs) in the network of TRPs. There are two TRPs. If the UE participates in the synchronization between two TRPs, the two TRPs can be directly wirelessly connected, and if multiple wireless communication links 505 are between the two TRPs, the two TRPs can be indirectly wirelessly connected. For example, TRP 210-e and TRP 210-j can be indirectly wirelessly connected via a path including wireless communication links 505-a, 505-b, and 505-c. Therefore, TRP 210-e and TRP 210-j can be synchronized by obtaining the relative timing offset and relative phase offset between TRP 210-e and TRP 210-h, between TRP 210-h and TRP 210-i, and between TRP 210-i and TRP 210-j.

[0167] In some cases, TRP 210, the central node, or another entity may select UE 115 to participate in the synchronization of a pair of TRPs within a TRP. For example, TRP 210-e may select UE 115-e to participate in the synchronization between TRP 210-e and TRP 210-h. Selecting a UE to participate in synchronization ensures a path of wireless communication link 505 between each TRP in the TRP network.

[0168] In some cases, a pair of TRPs within a TRP may exchange RSs via OTA signaling (e.g., from TRP 210-h to TRP 210-i and from TRP 210-i to TRP 210-h), and the OTA signaling may not include communication with the UE. This pair of TRPs may also be jointly synchronized with the network of the TRPs. In other words, the network of the TRPs may include a combination of TRP pairs performing UE-assisted synchronization and TRP pairs performing OTA synchronization. In such cases, based on the transmit and receive calibration of the TRPs in the TRP pair, the TRP pair performing OTA synchronization may not pre-decode any RSs communicated for synchronization as described herein.

[0169] To jointly synchronize N TRPs in a network, at least N-1 UEs can be used. For calibration between any two TRPs, the first TRP of the two TRPs can obtain the relative timing offset and relative phase offset relative to the second TRP of the two TRPs by summing the relative offsets (e.g., paired relative offsets) across the wireless communication link 505 in the path from the first TRP to the second TRP. For example, the relative timing offset and relative phase offset between TRP 210-e and TRP 210-j can be obtained using the following equation:

[0170]

[0171] Figure 6 An example of a wireless communication resource diagram 600 supporting UE-assisted time and phase synchronization for CJT is shown, according to one or more aspects of this disclosure. The wireless communication resource diagram 600 can be illustrated for application to reference... Figure 5 The TRP210 described herein is a first example of the technology described herein, and the wireless communication resource diagram 650 can be illustrated for application to the reference. Figure 5 The TRP 210 described herein is a second example of the technology described herein.

[0172] All aspects of wireless communication resource diagrams 600 and 650 are achievable. Figure 1 – Figure 5 Various aspects, or implementation thereof. For example, wireless communication resource diagrams 600 and 650 may illustrate resources for wireless communication between corresponding TRPs (e.g., TRP1, TRP2, TRP3, TRP4, TRP5, and TRP6) (which may be collectively referred to as TRPs) and one or more UEs (e.g., including UE1). A TRP may be a reference Figure 2 – Figure 5Examples of TRPs described (e.g., TRP1, TRP2, TRP3, TRP4, TRP5, TRP6, TRP 210-a, TRP210-b, TRP 210-c, TRP 210-d, TRP 210-e, TRP 210-f, TRP 210-g, and / or TRP 210-g). In some aspects, one or more TRPs in a TRP may be references. Figure 1 Examples of network entities 105, RU 170, TRP, or other aspects described. In some cases, the UE may be a reference. Figure 2 – Figure 5 Examples of UEs described (e.g., UE1, UE2, UE3, UE4, UE5, UE 115-a, UE 115-b, UE 115-c, UE 115-d, UE 115-f, UE 115-g). In some respects, the UE may be a reference. Figure 1 An example of UE 115 as described.

[0173] Wireless communication resource diagrams 600 and 650 may include resource depictions 605 and 655, where columns may represent time intervals 615 (e.g., time slots, symbols, time resources), and rows may represent frequency resources 620 (e.g., subcarriers, bandwidth, REs, one or more frequency resources). Resources 610 and 660 (e.g., REs, symbols) may each correspond to time resources and frequency resources (e.g., time-frequency resources), and some resources 610 and 660 may be used to transmit downlink RS, uplink RS, or both. In some cases, Figure 6 The RS shown can be an example of a downlink RS, and Figure 6 The SRS shown can be an example of an uplink RS. As described herein, uplink RS and downlink RS can include other types of signaling.

[0174] According to the technology disclosed herein and as described herein, downlink RS and uplink RS transmitted between TRP and UE may follow one or more example relationships. Based on the example relationships, wireless communication resource diagram 600 may illustrate a first example of the technology described herein applied to a network of TRP, while wireless communication resource diagram 650 may illustrate a second example of the technology described herein applied to a network of TRP. For example, the first example of the technology described herein may follow a first example relationship and a third example relationship, and the second example of the technology described herein may follow a first example relationship and a second example relationship. In some cases, the first example may not require UE1 to perform simultaneous reception or simultaneous transmission and may be more accurate than the second example. In some cases, the second example may utilize less overhead (e.g., less time resources) and is less accurate than the first example compared to the first example, and may be associated with or cause UE1 to perform simultaneous transmission and simultaneous reception.

[0175] In wireless communication resource diagrams 600 and 650, the resource allocation pattern for RS is as follows: Frequency resources are repeated. For N TRPs in a TRP network, the first example (e.g., the wireless communication resource illustrated in Figure 600) may have two time resources (e.g., symbols, time slots) on the downlink RS. The per-mode resource usage (e.g., overhead) of frequency resources (e.g., REs), and for uplink RSs, there may be two time resources ( The per-mode resource usage of N frequency resources in a network of TRPs. For example (e.g., illustrated in Wireless Communication Resources Figure 650), for a downlink RS, there may be a per-mode resource usage of N frequency resources over a time resource, and for an uplink RS, there may be a per-mode resource usage of N frequency resources over a time resource. Each mode of frequency resource usage.

[0176] Therefore, the first example may experience higher resource usage compared to the second example, but it may be more accurate than the second example due to following the first example relationship and the third example relationship. For the UEs participating in synchronization, the first example may also be less complex than the second example. For example, the first embodiment does not utilize simultaneous downlink RS reception or simultaneous uplink RS transmission. On the other hand, the second example may experience lower resource usage (e.g., almost half) compared to the first example, but it may be less accurate than the first example due to following the first example relationship and the second example relationship. Additionally, for the UEs participating in synchronization, the second example may be more complex than the first example. For example, the second example may utilize simultaneous downlink RS reception and simultaneous uplink RS transmission.

[0177] For reference Figure 3As described, the uplink RS (e.g., SRS) of wireless communication resource diagrams 600 and 650 can be pre-decoded based on the corresponding downlink RS (e.g., RS). For example, the uplink RS transmitted to TRP1 in resource 610-c can be pre-decoded based on the corresponding downlink RS received from TRP1 in resource 610-a, and the uplink RS transmitted to TRP2 in resources 610-d or 610-e can be pre-decoded based on the corresponding downlink RS received from TRP2 in resource 610-b. Similarly, the uplink RS transmitted to TRP3 in resource 660-d can be pre-decoded based on the corresponding downlink RS received from TRP3 in resource 660-c.

[0178] In wireless communication resource diagram 600, two Transmission Points (TRPs) receiving two uplink RSs in the same frequency resource can obtain the relative offset between the two TRPs based on the two uplink RSs. For example, since TRP5 receives the first downlink RS in resource 610-c via the same frequency resource as TRP6 receiving the second downlink RS in resource 610-f, TRP5 and TRP6 can obtain the relative timing offset and relative phase offset between TRP5 and TRP6 based on the first downlink RS and the second downlink RS.

[0179] In the wireless communication resource diagram 650, a curved arrow 665 can indicate two uplink RSs transmitted by the same UE. Therefore, two TRPs receiving the two uplink RSs indicated by the curved arrow 665 can obtain the relative offset between the two TRPs based on these two uplink RSs. For example, a first UE can transmit a first uplink RS associated with resource 660-b to TRP1 and a second uplink RS associated with resource 660-d to TRP4. Therefore, TRP1 and TRP4 can use the first and second uplink RSs to obtain the relative offset between TRP1 and TRP4.

[0180] As described herein, the relative offset between the first TRP and the second TRP can be obtained by multiplying the first uplink RS received at the first TRP by the conjugate of the second uplink RS received at the second TRP, wherein the first uplink RS and the second uplink RS are pre-decoded and transmitted by the same UE. The pre-decoding of the first uplink RS and the second uplink RS by the UE can be performed based on the first downlink RS and the second downlink RS received at the UE from the first TRP and the second TRP, respectively.

[0181] In wireless communication resource diagram 650, refer to Figure 5Multiple UEs in the UE's network can transmit uplink RS during resource 660. Additionally or alternatively, a TRP in the TRP's network can transmit more than one signal during resource 660. For example, in resource 660-a, TRP1 can transmit downlink RS to UE1, UE2, and UE3. This can be achieved through broadcasting, beamforming, or MU-MIMO techniques. Therefore, UE1, UE2, and UE3 can each transmit uplink RS to TRP1 in resource 660-b.

[0182] In some cases, multiple uplink RSs transmitted by multiple UEs in the same resources (e.g., time and frequency resources, symbols, time slots) can be distinguishable (e.g., orthogonalized) in the cyclic shift domain. For example, each UE transmitting an uplink RS during the same resource period can select (e.g., randomly select) a cyclic shift to associate with the corresponding uplink RS from multiple (e.g., 64) cyclic shifts, where the TRP can distinguish uplink RSs based on the associated cyclic shifts. The TRP can distinguish uplink RSs received during the same resource period as long as the number of UEs transmitting uplink RSs does not exceed a threshold number of cyclic shifts (e.g., a maximum number). Therefore, if the degree of a TRP corresponds to the number of UEs directly radio-connected to the TRP and assisted in synchronizing with another TRP, the degree of each TRP in the network of the TRP can be maintained below the threshold number of cyclic shifts.

[0183] Figure 7 An example of a wireless communication resource diagram 700 supporting UE-assisted time and phase synchronization for CJT is shown, according to one or more aspects of this disclosure. The wireless communication resource diagram 700 can be illustrated for applications such as reference... Figure 2 and Figure 3 The third possible example of the two TRPs described herein, and wireless communication resource diagram 750 can be illustrated for applications such as references. Figure 5 and Figure 6 This is the third example of the technology described in this paper for a TRP network.

[0184] The wireless communication resource diagrams 700 and 750 are achievable in various aspects. Figure 1 – Figure 6 Various aspects, or implementation thereof. For example, wireless communication resource diagrams 700 and 750 may illustrate resources for wireless communication between a TRP (e.g., TRP1, TRP2, TRP3, TRP4, TRP5, and TRP6) (which may be collectively referred to as TRP) and one or more UEs (e.g., including UE1). The TRP may be a reference Figure 2 – Figure 5Examples of TRPs described (e.g., TRP1, TRP2, TRP3, TRP4, TRP5, TRP6, TRP 210-a, TRP 210-b, TRP 210-c, TRP 210-d, TRP 210-e, TRP 210-f, TRP 210-g, and / or TRP 210-g). In some aspects, one or more TRPs in a TRP may be references. Figure 1 Examples of network entities 105, RU 170, TRP, or other aspects described. In some cases, the UE may be a reference. Figure 2 – Figure 5 Examples of UEs described (e.g., UE1, UE2, UE3, UE4, UE5, UE 115-a, UE 115-b, UE 115-c, UE 115-d, UE 115-f, UE 115-g). In some respects, the UE may be a reference. Figure 1 An example of UE 115 as described. Additionally, Figure 7 Downlink RSs y1 and y2 and uplink RSs z1 and z2 can be shown. These downlink RSs can be as follows: Figure 3 The examples described are the first downlink RS y1 and the second downlink RS y2, and these uplink RS can be as follows: Figure 3 Examples of the first uplink RS z1 and the second uplink RS z2 described.

[0185] Wireless communication resource diagrams 700 and 750 may include resource depictions 705 and 755, where columns may represent time intervals 715 (e.g., time slots, symbols, time resources), and rows may represent frequency resources 720 (e.g., subcarriers, bandwidth, REs, one or more frequency resources). Resources 710 (e.g., resource elements, symbols, resources 710-a, 710-b, 710-c, and 710-d) and resources 760 (e.g., resource elements, symbols, resources 760-a, 760-b, 760-c, 760-d, and 760-e) may each correspond to time resources and frequency resources (e.g., time-frequency resources), and some resources in 710 and 760 may be used to transmit downlink RS, uplink RS, or both. In some cases, Figure 7 The RS shown can be an example of a downlink RS, and Figure 7 The SRS shown can be an example of an uplink RS. As described herein, uplink and downlink RSs may also include other types of signaling.

[0186] The third example illustrated in wireless communication resource figures 700 and 750 may, at least in some respects, be a combination (e.g., a hybrid) of the first and second examples. In the third example, one or more UEs assisted by the TRP for synchronization may support simultaneous downlink RS reception but may not support simultaneous uplink RS transmission. For example, one or more UEs may not support simultaneous uplink transmission because simultaneous uplink transmission may affect the uplink link budget of one or more UEs.

[0187] For example, resource depictions 705 and 755 corresponding to the third example may include: a receive segment (e.g., receive segment 730, receive segment 780) including resources 710 and 760 for one or more UEs to receive downlink RS from the TRP; and a transmit segment (e.g., transmit segment 735, transmit segment 785) including resources 710 and 760 for one or more UEs to transmit uplink RS to the TRP.

[0188] In some respects, the receive segments 730 and 780 of the third embodiment can function similarly to how one or more UEs receive downlink RS in the second example, and the transmit segments 735 and 785 of the third example can function similarly to how one or more UEs transmit uplink RS in the first example. For example, in receive segments 730 and 780, one or more UEs can receive downlink RS from TRPs during the same time resource period and via frequency resources that are close to each other (e.g., adjacent, within a threshold frequency difference). However, in transmit segments 735 and 785, UEs can transmit uplink RS corresponding to two synchronous TRPs via the same frequency resource and during two time resources that are close to each other (e.g., adjacent, within a threshold time difference). A more detailed description of the different resource allocations for transmitting uplink RS and receiving downlink RS can be found in […]. Figure 3 and Figure 6 The description.

[0189] Resource descriptions 705 and 755 can illustrate different UEs transmitting uplink RSs via different time resources and frequency resources. However, it should be noted that, as described herein, by distinguishing multiple uplink RSs in a cyclic shift domain, these multiple uplink RSs can be transmitted by multiple UEs during the same time resource and via the same frequency resource (e.g., multiplexed).

[0190] Figure 8A block diagram 800 illustrates an apparatus 805 supporting UE-assisted time and phase synchronization for CJT according to one or more aspects of this disclosure. Apparatus 805 may be an example of various aspects of a TRP as described herein. Apparatus 805 may include a receiver 810, a transmitter 815, and a communication manager 820. Apparatus 805, or one or more components of apparatus 805 (e.g., receiver 810, transmitter 815, and communication manager 820), may include at least one processor that may be coupled to at least one memory to individually or jointly support or implement the described techniques. Each of these components may communicate with each other (e.g., via one or more buses).

[0191] Receiver 810 may provide components for acquiring (e.g., receiving, determining, identifying) information associated with various channels (e.g., control channels, data channels, information channels, channels associated with a protocol stack), such as user data, control information, or any combination thereof (e.g., I / Q samples, symbols, packets, protocol data units, service data units). The information may be passed to other components of device 805. In some examples, receiver 810 may support acquiring information by receiving signals via one or more antennas. Additionally or alternatively, receiver 810 may support acquiring information by receiving signals via one or more wired (e.g., electrical, fiber optic) interfaces, wireless interfaces, or any combination thereof.

[0192] Transmitter 815 may provide components for outputting (e.g., transmitting, providing, conveying, transmitting) information generated by other components of device 805. For example, transmitter 815 may output information associated with various channels (e.g., control channels, data channels, information channels, channels associated with a protocol stack), such as user data, control information, or any combination thereof (e.g., I / Q samples, symbols, packets, protocol data units, service data units). In some examples, transmitter 815 may support outputting information by transmitting signals via one or more antennas. Additionally or alternatively, transmitter 815 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, transmitter 815 and receiver 810 may be co-located in a transceiver, which may include or be coupled to a modem.

[0193] The communication manager 820, receiver 810, transmitter 815, or various combinations thereof, or various components thereof, may be examples of components used to perform various aspects of UE-assisted time and phase synchronization for CJT as described herein. For example, the communication manager 820, receiver 810, transmitter 815, or various combinations thereof, or components thereof, may be able to perform one or more of the functions described herein.

[0194] In some examples, the communication manager 820, receiver 810, transmitter 815, or various combinations or components thereof may be implemented in hardware (e.g., in communication management circuitry). The hardware may include at least one of a processor, DSP, CPU, ASIC, FPGA, or other programmable logic device, microcontroller, discrete gate or transistor logic device, discrete hardware component, or any combination thereof, configured as or otherwise individually or collectively to support components for performing the functions described herein. In some examples, at least one processor and at least one memory coupled to said at least one processor may be configured to perform one or more of the functions described herein (e.g., instructions stored in at least one memory are executed individually or collectively by one or more processors).

[0195] Additionally or alternatively, the communication manager 820, receiver 810, transmitter 815, or various combinations or components thereof may be implemented in code (e.g., as communication management software or firmware) executed by at least one processor. If implemented in code executed by at least one processor, the functionality of the communication manager 820, receiver 810, transmitter 815, or various combinations or components thereof may be performed by (e.g., a general-purpose processor, DSP, CPU, ASIC, FPGA, microcontroller, or any combination of these or other programmable logic devices configured, either individually or collectively, as a component for performing the functions described in this disclosure).

[0196] In some examples, the communication manager 820 may be configured to use or otherwise cooperate with the receiver 810, transmitter 815, or both to perform various operations (e.g., receiving, acquiring, monitoring, outputting, transmitting). For example, the communication manager 820 may receive information from the receiver 810, transmit information to the transmitter 815, or be integrated with the receiver 810, transmitter 815, or both to acquire information, output information, or perform various other operations as described herein.

[0197] The communication manager 820 may support wireless communications according to examples disclosed herein. For example, the communication manager 820 may be capable of, configured to, or operable to support components for transmitting a first downlink RS to a first UE via a first resource set. The communication manager 820 may be capable of, configured to, or operable to support components for receiving a first pre-decoded uplink RS from the first UE via a second resource set associated with the first resource set, the first pre-decoded uplink RS being pre-decoded based on an estimate of the first downlink RS, wherein the first TRP is synchronized with the second TRP based on a phase offset, timing offset, or both between the first TRP and the second TRP, and wherein the phase offset, timing offset, or both are based on the first pre-decoded uplink RS and the second pre-decoded uplink RS associated with the second TRP.

[0198] By including or configuring a communication manager 820 according to an example as described herein, device 805 (e.g., controlling receiver 810, transmitter 815, communication manager 820, or a combination thereof, or at least one processor otherwise coupled to them) can support techniques for more efficient utilization of communication resources. For example, the techniques described herein can allow for more reliable synchronization of TRPs, resulting in fewer errors in communication and fewer retransmissions of signaling. Therefore, more reliable communication via improved synchronization between TRPs, according to the techniques described herein, allows for more efficient utilization of communication resources.

[0199] Figure 9 A block diagram 900 illustrates an apparatus 905 supporting UE-assisted time and phase synchronization for CJT according to one or more aspects of this disclosure. Apparatus 905 may be an example of aspects of apparatus 805 or TRP 115 as described herein. Apparatus 905 may include a receiver 910, a transmitter 915, and a communication manager 920. Apparatus 905, or one or more components of apparatus 905 (e.g., receiver 910, transmitter 915, and communication manager 920), may include at least one processor that can be coupled to at least one memory to support the described techniques. Each of these components may communicate with each other (e.g., via one or more buses).

[0200] Receiver 910 may provide components for acquiring (e.g., receiving, determining, identifying) information associated with various channels (e.g., control channels, data channels, information channels, channels associated with a protocol stack), such as user data, control information, or any combination thereof (e.g., I / Q samples, symbols, packets, protocol data units, service data units). The information may be passed to other components of device 905. In some examples, receiver 910 may support acquiring information by receiving signals via one or more antennas. Additionally or alternatively, receiver 910 may support acquiring information by receiving signals via one or more wired (e.g., electrical, fiber optic) interfaces, wireless interfaces, or any combination thereof.

[0201] Transmitter 915 may provide components for outputting (e.g., transmitting, providing, conveying, transmitting) information generated by other components of device 905. For example, transmitter 915 may output information associated with various channels (e.g., control channels, data channels, information channels, channels associated with a protocol stack), such as user data, control information, or any combination thereof (e.g., I / Q samples, symbols, packets, protocol data units, service data units). In some examples, transmitter 915 may support outputting information by transmitting signals via one or more antennas. Additionally or alternatively, 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, transmitter 915 and receiver 910 may be co-located in a transceiver, which may include or be coupled to a modem.

[0202] Device 905 or its various components may be examples of parts used to perform various aspects of time and phase synchronization for UE assistance as described herein for CJT. For example, communication manager 920 may include transmitting component 925, receiving component 930, or any combination thereof. Communication manager 920 may be examples of aspects of communication manager 820 as described herein. In some examples, communication manager 920 or its various components may be configured to use or otherwise cooperate with receiver 910, transmitter 915, or both to perform various operations (e.g., receiving, acquiring, monitoring, outputting, transmitting). For example, communication manager 920 may receive information from receiver 910, transmit information to transmitter 915, or be integrated in combination with receiver 910, transmitter 915, or both to acquire information, output information, or perform various other operations as described herein.

[0203] Communication manager 920 may support wireless communication according to examples disclosed herein. Transmitting component 925 is capable of, configured to, or operable to support components for transmitting a first downlink RS to a first UE via a first resource set. Receiving component 930 is capable of, configured to, or operable to support components for receiving a first pre-decoded uplink RS from the first UE via a second resource set associated with the first resource set, the first pre-decoded uplink RS being pre-decoded based on an estimate of the first downlink RS, wherein the first TRP is synchronized with the second TRP based on a phase offset, timing offset, or both between the first TRP and the second TRP, and wherein the phase offset, timing offset, or both are based on the first pre-decoded uplink RS and the second pre-decoded uplink RS associated with the second TRP.

[0204] Figure 10 A block diagram 1000 is shown of a communication manager 1020 supporting time and phase synchronization for UE assistance in CJT according to one or more aspects of this disclosure. Communication manager 1020 may be an example of aspects of communication manager 820, communication manager 920, or both as described herein. Communication manager 1020 or its various components may be examples of parts for performing various aspects of time and phase synchronization for UE assistance in CJT as described herein. For example, communication manager 1020 may include a transmitting component 1025, a receiving component 1030, an offset estimation component 1035, a synchronization component 1040, or any combination thereof. Each of these components, or its components or sub-components (e.g., one or more processors, one or more memories), may communicate directly or indirectly with each other (e.g., via one or more buses).

[0205] Communication manager 1020 may support wireless communication according to examples disclosed herein. Transmitting component 1025 is capable of, configured to, or operable to support components for transmitting a first downlink RS to a first UE via a first resource set. Receiving component 1030 is capable of, configured to, or operable to support components for receiving a first pre-decoded uplink RS from the first UE via a second resource set associated with the first resource set, the first pre-decoded uplink RS being pre-decoded based on an estimate of the first downlink RS, wherein the first TRP is synchronized with the second TRP based on a phase offset, timing offset, or both between the first TRP and the second TRP, and wherein the phase offset, timing offset, or both are based on the first pre-decoded uplink RS and the second pre-decoded uplink RS associated with the second TRP.

[0206] In some examples, the receiving component 1030 is capable of, configured to, or operable to support components for receiving messages from the second TRP indicating the second pre-decoded uplink RS. In some examples, the offset estimation component 1035 is capable of, configured to, or operable to support components for estimating phase offset, timing offset, or both based on the conjugate product of the first pre-decoded uplink RS and the second pre-decoded uplink RS.

[0207] In some examples, the estimation of phase offset, timing offset, or both is based on the calculation of the conjugate product of the uplink RS of the first pre-decoded and the uplink RS of the second pre-decoded for a set of multiple subcarriers.

[0208] In some examples, the transmitting component 1025 is capable of, configured to, or operable to support components for outputting a first message to the central node indicating the first pre-decoded uplink RS. In some examples, the offset estimation component 1035 is capable of, configured to, or operable to support components for obtaining from the central node an estimate of a phase offset, timing offset, or both in response to the first message, wherein the estimate of the phase offset, timing offset, or both is based on the product of the conjugate of the first pre-decoded uplink RS and the second pre-decoded uplink RS.

[0209] In some examples, the estimation of phase offset, timing offset, or both is based on the calculation of the conjugate product of the uplink RS of the first pre-decoded and the uplink RS of the second pre-decoded for a set of multiple subcarriers. In some examples, the central node includes a second TRP or one of other network entities.

[0210] In some examples, the second pre-decoded uplink RS is associated with a second downlink RS corresponding to a third resource set, and the offset estimation component 1035 is capable of, configured to, or operable to support components for obtaining phase offset, timing offset, or both based on the conjugate product of the first pre-decoded uplink RS and the second pre-decoded uplink RS and further based on the subcarrier spacing index associated with the first resource set, the second resource set, the third resource set, the fourth resource set, or any combination thereof.

[0211] In some examples, the frequency resources in the first resource set have the same frequency as the corresponding frequency resources in the third resource set, or the frequency resources in the second resource set have the same frequency as the corresponding frequency resources in the fourth resource set, or both.

[0212] In some examples, the time resource in the first resource set is the same as the corresponding time resource in the third resource set, or the time resource in the second resource set is the same as the corresponding time resource in the fourth resource set, or both. In some examples, the time resource in the first resource set is the same as the corresponding time resource in the third resource set, and the frequency resource in the second resource set has the same frequency as the corresponding frequency resource in the fourth resource set.

[0213] In some examples, the offset estimation component 1035 is capable of, configured to, or operable to support components for determining a threshold timing offset associated with synchronization based on the frequency spacing between a first resource set, a second resource set, a third resource set, a fourth resource set, or a combination thereof. In some examples, the offset estimation component 1035 is capable of, configured to, or operable to support components for determining the threshold offset resolution based on the bandwidth of the uplink RS for the first pre-decoding, the uplink RS for the second pre-decoding, the first downlink RS, the second downlink RS, or any combination thereof.

[0214] In some examples, the synchronization component 1040 is capable of, configured to, or operable to support components for synchronizing timing or phase or both with the third TRP based on a second phase offset, a second timing offset, or both between the second TRP and the third TRP, wherein the first TRP uses a combination of a phase offset and a second phase offset, a combination of a timing offset and a second timing offset, or both, to synchronize with the third TRP. In some examples, the second phase offset, the second timing offset, or both are based on a third pre-decoded uplink RS sent from the second UE to the second TRP and a fourth pre-decoded uplink RS sent from the second UE to the third TRP.

[0215] In some examples, the transmitting component 1025 is capable of, configured to, or operable to support components for transmitting control messages to a first UE, the control messages including indications of a first resource set for a first downlink RS and a second resource set for an uplink RS for a first pre-decoding.

[0216] In some examples, the receiving component 1030 is capable of, configured to, or operable to support components for receiving capability signaling that instructs the first UE to provide a first pre-decoded uplink RS to the first TRP to assist in the synchronization of the first TRP and the second TRP.

[0217] In some examples, capability signaling indicates the first UE's ability to simultaneously receive downlink RS, its ability to simultaneously transmit uplink RS, one or more reference signal structures supported by the first UE, the range of time and frequency resources in which the first UE's transmit and receive characteristics are substantially consistent (e.g., characteristics vary within a range of values ​​or parameters), the threshold (e.g., maximum) number of TRPs to which the first UE can provide pre-decoded uplink RS, the first UE's ability to maintain receive phase continuity and transmit phase continuity in a certain number of symbols, or any combination thereof. In some examples, the first downlink RS includes one of a tracking reference signal, a positioning reference signal, a synchronization block, or a demodulation reference signal.

[0218] Figure 11 A diagram of a system 1100 including a device 1105 supporting UE-assisted time and phase synchronization for CJT, according to one or more aspects of this disclosure, is shown. Device 1105 may be an example of device 805, device 905, or TRP as described herein, or a component including such devices. Device 1105 may include components for bidirectional voice and data communication, including components for transmitting and receiving communications, such as a communication manager 1120, a transceiver 1110, an antenna 1115, at least one memory 1125, code 1130, and at least one processor 1135. These components may communicate electronically via one or more buses (e.g., bus 1140) or be otherwise coupled (e.g., operatively, communicatively, functionally, electronically, electrically).

[0219] Transceiver 1110 may support bidirectional communication via a wired link, a wireless link, or both, as described herein. In some examples, transceiver 1110 may include a wired transceiver and may communicate bidirectionally with another wired transceiver. Additionally or alternatively, in some examples, transceiver 1110 may include a wireless transceiver and may communicate bidirectionally with another wireless transceiver. In some examples, device 1105 may include one or more antennas 1115 that may be capable of transmitting or receiving wireless transmissions (e.g., concurrently). Transceiver 1110 may also include a modem for: modulating a signal; providing the modulated signal for transmission (e.g., via one or more antennas 1115, via a wired transmitter); receiving the modulated signal (e.g., from one or more antennas 1115, from a wired receiver); and demodulating the signal. In some embodiments, transceiver 1110 may include one or more interfaces, such as one or more interfaces coupled to one or more antennas 1115 configured to support various receive or acquire operations, or one or more interfaces coupled to one or more antennas 1115 configured to support various transmit or output operations, or combinations thereof. In some embodiments, transceiver 1110 may include one or more processors or one or more memory components or be configured to couple to such processors or memory components, which are operable to perform or support operations based on received or acquired information or signals, or generate information or other signals for transmission or other output, or any combination thereof. In some embodiments, transceiver 1110, or transceiver 1110 and one or more antennas 1115, or transceiver 1110 and one or more antennas 1115 and one or more processors or one or more memory components (e.g., at least one processor 1135, at least one memory 1125, or both) may be included in a chip or chip assembly mounted in device 1105. In some examples, transceiver 1110 may be able to operate to support communication via one or more communication links (e.g., communication link 125, backhaul communication link 120, midhaul communication link 162, fronthaul communication link 168).

[0220] At least one memory 1125 may include RAM, ROM, or any combination thereof. At least one memory 1125 may store computer-readable, computer-executable code 1130 including instructions that, when executed by one or more of the at least one processor 1135, cause the device 1105 to perform the various functions described herein. The code 1130 may be stored in a non-transitory computer-readable medium such as system memory or another type of memory. In some cases, the code 1130 may not be directly executable by one of the at least one processor 1135, but may enable a computer (e.g., when compiled and executed) to perform the functions described herein. In some cases, at least one memory 1125 may contain a BIOS, etc., which controls basic hardware or software operations such as interaction with peripheral components or devices. In some examples, at least one processor 1135 may include multiple processors, and at least one memory 1125 may include multiple memories. One or more of the multiple processors may be coupled to one or more of the multiple memories, which may be configured individually or collectively to perform the various functions described herein (e.g., as part of a processing system).

[0221] At least one processor 1135 may include intelligent hardware devices (e.g., general-purpose processors, DSPs, ASICs, CPUs, FPGAs, microcontrollers, programmable logic devices, discrete gate or transistor logic devices, discrete hardware components, or any combination thereof). In some cases, at least one processor 1135 may be configured to operate a memory array using a memory controller. In some other cases, the memory controller may be integrated into one or more processors in at least one processor 1135. At least one processor 1135 may be configured to execute computer-readable instructions stored in memory (e.g., one or more memories in at least one memory 1125) to cause device 1105 to perform various functions (e.g., functions or tasks supporting UE-assisted time and phase synchronization for CJT). For example, device 1105 or components of device 1105 may include at least one processor 1135 and at least one memory 1125 coupled to one or more processors in at least one processor 1135, wherein at least one processor 1135 and at least one memory 1125 are configured to perform the various functions described herein. At least one processor 1135 may be an example of a cloud computing platform (e.g., one or more physical nodes and supporting software such as an operating system, virtual machine, or container instance) that can host functions (e.g., by executing code 1130) to perform the functions of device 1105. At least one processor 1135 may be any one or more suitable processors capable of executing scripts or instructions of one or more software programs stored in device 1105 (such as within one or more memories of at least one memory 1125). In some examples, at least one processor 1135 may include multiple processors, and at least one memory 1125 may include multiple memories. One or more of the multiple processors may be coupled to one or more of the multiple memories, which may be configured individually or collectively to perform the various functions described herein. In some examples, at least one processor 1135 may be a component of a processing system, which may refer to a system of machines (such as a series of machines), circuits (including, for example, one or both of processor circuitry (which may include at least one processor 1135) and memory circuitry (which may include at least one memory 1125)) or components that receive or acquire input and process the input to produce, generate, or acquire a set of outputs. The processing system may be configured to perform one or more of the functions described herein. Therefore, at least one processor 1135 or a processing system including at least one processor 1135 may be configured, configurable, or operable to cause the device 1105 to perform one or more of the functions described herein.Furthermore, as described herein, “configurable to,” “configurable to,” and “operable to” are used interchangeably and may be associated with the ability to perform one or more of the functions described herein when executing code stored in at least one memory 1125 or otherwise.

[0222] In some examples, bus 1140 may support communication at protocol layers (e.g., within a protocol layer) in a protocol stack. In some examples, bus 1140 may support communication associated with logical channels of a protocol stack (e.g., between protocol layers of the protocol stack), which may include communication performed within components of device 1105, or communication performed between different components of device 1105 that are co-addressable or may be located in different locations (e.g., where device 1105 may refer to a system in which one or more of communication manager 1120, transceiver 1110, at least one memory 1125, code 1130 and at least one processor 1135 may be located in one component of different components or partitioned between different components).

[0223] In some examples, the communication manager 1120 can manage (e.g., via one or more wired or wireless backhaul links) various aspects of communication with the core network 130. For example, the communication manager 1120 can manage the delivery of data communications by client devices such as one or more UEs 115. In some examples, the communication manager 1120 can manage communication with other network entities 105 and may include a controller or scheduler for cooperatively controlling communication with UE 115 with other network entities 105. In some examples, the communication manager 1120 may support an X2 interface within LTE / LTE-A wireless communication network technology to provide communication between network entities 105.

[0224] Communication manager 1120 may support wireless communication according to examples disclosed herein. For example, communication manager 1120 may be capable of, configured to, or operable to support components for transmitting a first downlink RS to a first UE via a first resource set. Communication manager 1120 may be capable of, configured to, or operable to support components for receiving a first pre-decoded uplink RS from the first UE via a second resource set associated with the first resource set, the first pre-decoded uplink RS being pre-decoded based on an estimate of the first downlink RS, wherein the first TRP is synchronized with the second TRP based on a phase offset, timing offset, or both between the first TRP and the second TRP, and wherein the phase offset, timing offset, or both are based on the first pre-decoded uplink RS and the second pre-decoded uplink RS associated with the second TRP.

[0225] By including or configuring a communication manager 1120 according to the example described herein, device 1105 can support techniques for improving communication reliability. For example, the techniques described herein can allow for more reliable synchronization of the TRP. More reliable synchronization can reduce the number of messages that are erroneously sent or received. Therefore, the techniques described herein can allow for improved communication reliability.

[0226] In some examples, the communication manager 1120 may be configured to use or otherwise cooperate with transceiver 1110, one or more antennas 1115 (e.g., where applicable) or any combination thereof to perform various operations (e.g., receiving, acquiring, monitoring, outputting, transmitting). Although the communication manager 1120 is illustrated as a separate component, in some examples, one or more functions described with reference to the communication manager 1120 may be supported or performed by transceiver 1110, one or more processors in at least one processor 1135, one or more memories in at least one memory 1125, code 1130 or any combination thereof (e.g., by a processing system including at least a portion of at least one processor 1135, at least one memory 1125, code 1130 or any combination thereof). For example, code 1130 may include instructions that can be executed by one or more of at least one processor 1135 to cause device 1105 to perform various aspects of UE-assisted time and phase synchronization for CJT as described herein, or at least one processor 1135 and at least one memory 1125 may otherwise be configured to perform or support such operations individually or jointly.

[0227] Figure 12 A block diagram 1200 is shown of an apparatus 1205 supporting UE-assisted time and phase synchronization for CJT according to one or more aspects of this disclosure. Apparatus 1205 may be an example of aspects of UE 115 as described herein. Apparatus 1205 may include a receiver 1210, a transmitter 1215, and a communication manager 1220. Apparatus 1205 or one or more components of apparatus 1205 (e.g., receiver 1210, transmitter 1215, and communication manager 1220) may include at least one processor that may be coupled to at least one memory to individually or jointly support or implement the described techniques. Each of these components may communicate with each other (e.g., via one or more buses).

[0228] Receiver 1210 may provide components 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 time and phase synchronization for UE assistance in CJT). The information may be transmitted to other components of device 1205. Receiver 1210 may utilize a single antenna or a collection of multiple antennas.

[0229] Transmitter 1215 may provide components for transmitting signals generated by other components of device 1205. For example, transmitter 1215 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 time and phase synchronization for UE assistance in CJT). In some examples, transmitter 1215 may be co-located with receiver 1210 in a transceiver module. Transmitter 1215 may utilize a single antenna or a collection of multiple antennas.

[0230] The communication manager 1220, receiver 1210, transmitter 1215, or various combinations thereof, or various components thereof, may be examples of components used to perform various aspects of UE-assisted time and phase synchronization for CJT as described herein. For example, the communication manager 1220, receiver 1210, transmitter 1215, or various combinations thereof, or components thereof, may be able to perform one or more of the functions described herein.

[0231] In some examples, the communication manager 1220, receiver 1210, transmitter 1215, or various combinations or components thereof may be implemented in hardware (e.g., in communication management circuitry). The hardware may include at least one of the following: a processor, digital signal processor (DSP), central processing unit (CPU), application-specific integrated circuit (ASIC), field-programmable gate array (FPGA) or other programmable logic device, microcontroller, discrete gate or transistor logic component, discrete hardware component, or any combination thereof, configured as or otherwise individually or collectively to support components for performing the functions described herein. In some examples, at least one processor and at least one memory coupled to said at least one processor may be configured to perform one or more of the functions described herein (e.g., instructions stored in at least one memory are executed individually or collectively by one or more processors).

[0232] Additionally or alternatively, the communication manager 1220, receiver 1210, transmitter 1215, or various combinations or components thereof may be implemented in code (e.g., as communication management software or firmware) executed by at least one processor. If implemented in code executed by at least one processor, the functionality of the communication manager 1220, receiver 1210, transmitter 1215, or various combinations or components thereof may be performed by (e.g., a general-purpose processor, DSP, CPU, ASIC, FPGA, microcontroller, or any combination of these or other programmable logic devices configured, either individually or collectively, as components for performing the functions described in this disclosure).

[0233] In some examples, the communication manager 1220 may be configured to use or otherwise coordinate with the receiver 1210, transmitter 1215, or both to perform various operations (e.g., receiving, acquiring, monitoring, outputting, transmitting). For example, the communication manager 1220 may receive information from the receiver 1210, transmit information to the transmitter 1215, or be integrated in combination with the receiver 1210, transmitter 1215, or both to acquire information, output information, or perform various other operations as described herein.

[0234] Communication manager 1220 may support wireless communications according to examples disclosed herein. For example, communication manager 1220 may be capable of, configured to, or operable to support components for receiving a first downlink RS from a first TRP via a first resource set. Communication manager 1220 may be capable of, configured to, or operable to support components for transmitting a first pre-decoded uplink RS to the first TRP via a second resource set associated with the first resource set, wherein the first pre-decoded uplink RS is pre-decoded based on an estimate of the first downlink RS. Communication manager 1220 may be capable of, configured to, or operable to support components for receiving a second downlink RS from a second TRP via a third resource set. The communication manager 1220 is capable of, configured to, or operable to support components for sending a second pre-decoded uplink RS to a second TRP via a fourth resource set associated with a third resource set, wherein the second pre-decoded uplink RS is pre-decoded based on an estimate of a second downlink RS, and wherein the first resource set, the second resource set, the third resource set, and the fourth resource set are configured for the first UE according to the synchronization of the first TRP and the second TRP.

[0235] By including or configuring a communication manager 1220 according to an example as described herein, device 1205 (e.g., controlling receiver 1210, transmitter 1215, communication manager 1220, or a combination thereof, or at least one processor otherwise coupled to them) can support techniques for more efficient utilization of communication resources. For example, the techniques described herein can allow for more reliable synchronization of TRPs, resulting in fewer errors in communication and fewer retransmissions of signaling. Therefore, more reliable communication via improved synchronization between TRPs, according to the techniques described herein, allows for more efficient utilization of communication resources.

[0236] Figure 13 A block diagram 1300 is shown of an apparatus 1305 supporting UE-assisted time and phase synchronization for CJT according to one or more aspects of this disclosure. Apparatus 1305 may be an example of aspects of apparatus 1205 or UE 115 as described herein. Apparatus 1305 may include receiver 1310, transmitter 1315, and communication manager 1320. Apparatus 1305 or one or more components of apparatus 1305 (e.g., receiver 1310, transmitter 1315, and communication manager 1320) may include at least one processor that may be coupled to at least one memory to support the described techniques. Each of these components may communicate with each other (e.g., via one or more buses).

[0237] Receiver 1310 may provide components 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 time and phase synchronization for UE assistance in CJT). The information may be transmitted to other components of device 1305. Receiver 1310 may utilize a single antenna or a collection of multiple antennas.

[0238] Transmitter 1315 may provide components for transmitting signals generated by other components of device 1305. For example, transmitter 1315 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 time and phase synchronization for UE assistance in CJT). In some examples, transmitter 1315 may be co-located with receiver 1310 in a transceiver module. Transmitter 1315 may utilize a single antenna or a collection of multiple antennas.

[0239] Device 1305 or its various components may be examples of parts used to perform various aspects of time and phase synchronization for UE assistance as described herein for CJT. For example, communication manager 1320 may include receiving component 1325, transmitting component 1330, or any combination thereof. Communication manager 1320 may be examples of aspects of communication manager 1220 as described herein. In some examples, communication manager 1320 or its various components may be configured to use or otherwise cooperate with receiver 1310, transmitter 1315, or both to perform various operations (e.g., receiving, acquiring, monitoring, outputting, transmitting). For example, communication manager 1320 may receive information from receiver 1310, transmit information to transmitter 1315, or be integrated in combination with receiver 1310, transmitter 1315, or both to acquire information, output information, or perform various other operations as described herein.

[0240] Communication manager 1320 can support wireless communication according to examples disclosed herein. Receiving component 1325 is capable of, configured to, or operable to support components for receiving a first downlink RS from a first TRP via a first resource set. Transmitting component 1330 is capable of, configured to, or operable to support components for transmitting a first pre-decoded uplink RS to the first TRP via a second resource set associated with the first resource set, wherein the first pre-decoded uplink RS is pre-decoded based on an estimate of the first downlink RS. Receiving component 1325 is capable of, configured to, or operable to support components for receiving a second downlink RS from a second TRP via a third resource set. Transmitting component 1330 is capable of, configured to, or operable to support components for transmitting a second pre-decoded uplink RS to a second TRP via a fourth resource set associated with a third resource set, wherein the second pre-decoded uplink RS is pre-decoded based on an estimate of a second downlink RS, wherein the first resource set, second resource set, third resource set, and fourth resource set are configured for the first UE according to the synchronization of the first TRP and the second TRP.

[0241] Figure 14A block diagram 1400 is shown of a communication manager 1420 supporting time and phase synchronization for UE assistance in CJT according to one or more aspects of this disclosure. Communication manager 1420 may be an example of communication manager 1220, communication manager 1320, or aspects thereof as described herein. Communication manager 1420 or its various components may be examples of parts for performing various aspects of time and phase synchronization for UE assistance in CJT as described herein. For example, communication manager 1420 may include receiving component 1425, transmitting component 1430, reference signal estimation component 1435, capability component 1440, or any combination thereof. Each of these components, or its components or sub-components (e.g., one or more processors, one or more memories), may communicate directly or indirectly with each other (e.g., via one or more buses).

[0242] Communication manager 1420 may support wireless communication according to examples disclosed herein. Receiving component 1425 is capable of, configured to, or operable to support components for receiving a first downlink RS from a first TRP via a first resource set. Transmitting component 1430 is capable of, configured to, or operable to support components for transmitting a first pre-decoded uplink RS to the first TRP via a second resource set associated with the first resource set, wherein the first pre-decoded uplink RS is pre-decoded based on an estimate of the first downlink RS. In some examples, receiving component 1425 is capable of, configured to, or operable to support components for receiving a second downlink RS from a second TRP via a third resource set. In some examples, the transmitting component 1430 is capable of, configured to, or operable to support components for transmitting a second pre-decoded uplink RS to a second TRP via a fourth resource set associated with a third resource set, wherein the second pre-decoded uplink RS is pre-decoded based on an estimate of a second downlink RS, and wherein the first resource set, the second resource set, the third resource set, and the fourth resource set are configured for the first UE according to the synchronization of the first TRP and the second TRP.

[0243] In some examples, the frequency resources in the first resource set have the same frequency as the corresponding frequency resources in the third resource set, the frequency resources in the second resource set have the same frequency as the corresponding frequency resources in the fourth resource set, or both.

[0244] In some examples, the time resource in the first resource set is the same as the corresponding time resource in the third resource set, the time resource in the second resource set is the same as the corresponding time resource in the fourth resource set, or both. In some examples, the time resource in the first resource set is the same as the corresponding time resource in the third resource set, and the frequency resource in the second resource set has the same frequency as the corresponding frequency resource in the fourth resource set.

[0245] In some examples, the receiving component 1425 is capable of, configured to, or operable to support components for receiving control messages, which include indications of a first resource set for a first downlink RS and a second resource set for an uplink RS for a first pre-decoding.

[0246] In some examples, the receiving component 1425 is capable of, configured to, or operable to support components for receiving control signaling, which includes a first indication associated with a first resource set for a first downlink RS and a second resource set for an uplink RS for a first pre-decoding, and a second indication associated with a third resource set for a second downlink RS and a fourth resource set for an uplink RS for a second pre-decoding. In some examples, the control signaling includes one or more uplink RS configurations, one or more downlink reference configurations, one or more pointers associated with an uplink RS resource identifier or a downlink RS identifier, or any combination thereof.

[0247] In some examples, the first downlink reference signal and reference signal estimation component 1435 are capable of, configured to, or operable to support components for interpolation between corresponding frequency intervals of multiple instances of the first downlink RS and between corresponding frequency intervals of multiple instances of the second downlink RS, wherein the estimation of the first downlink RS and the estimation of the second downlink RS are based on the interpolation.

[0248] In some examples, capability component 1440 is capable of, configured to, or operable to support components for transmitting capability signaling that instructs a first UE to provide a first pre-decoded uplink RS to a first TRP to assist in the synchronization of the first TRP and the second TRP.

[0249] In some examples, capability signaling indicates that the first UE supports the ability to simultaneously receive downlink RS, the first UE supports the ability to simultaneously transmit uplink RS, one or more reference signal structures supported by the first UE, the range of time and frequency resources in which the transmission and reception characteristics of the first UE are substantially consistent, the threshold (e.g., maximum) number of TRPs to which the first UE can provide pre-decoded uplink RS, the first UE's ability to maintain receive phase continuity and transmit phase continuity in a certain number of symbols, or any combination thereof.

[0250] In some examples, receiving component 1425 is capable of, configured to, or operable to support components for receiving a third downlink RS from a third TRP via a fifth resource set. In some examples, transmitting component 1430 is capable of, configured to, or operable to support components for transmitting a third pre-decoded uplink RS to a third TRP via a sixth resource set associated with the fifth resource set, wherein the third pre-decoded uplink RS is pre-decoded based on an estimate of the third downlink RS.

[0251] Figure 15 A diagram of a system 1500 including a device 1505 supporting UE-assisted time and phase synchronization for CJT is shown, according to one or more aspects of this disclosure. Device 1505 may be an example of device 1205, device 1305, or UE 115 as described herein, or a component including such devices. Device 1505 may communicate with one or more network entities 105, one or more UEs 115, or any combination thereof (e.g., wirelessly). Device 1505 may include components for bidirectional voice and data communication, including components for transmitting and receiving communications, such as a communication manager 1520, an input / output (I / O) controller 1510, a transceiver 1515, an antenna 1525, at least one memory 1530, code 1535, and at least one processor 1540. These components may communicate electronically or otherwise (e.g., operatively, communicatively, functionally, electronically, electrically) via one or more buses (e.g., bus 1545).

[0252] I / O controller 1510 manages the input and output signals of device 1505. I / O controller 1510 can also manage peripheral devices not integrated into device 1505. In some cases, I / O controller 1510 may represent a physical connection or port to an external peripheral device. In some cases, I / O controller 1510 may utilize an operating system such as iOS. ® ANDROID ® MS-DOS ® MS-WINDOWS ® OS / 2® UNIX ® LINUX ® Or another known operating system. Additionally or alternatively, the I / O controller 1510 may represent or interact with a modem, keyboard, mouse, touchscreen, or similar device. In some cases, the I / O controller 1510 may be implemented as part of one or more processors, such as at least one processor 1540. In some cases, a user may interact with the device 1505 via the I / O controller 1510 or via hardware components controlled by the I / O controller 1510.

[0253] In some cases, device 1505 may include a single antenna 1525. However, in other cases, device 1505 may have more than one antenna 1525, which may be capable of concurrently transmitting or receiving multiple wireless transmissions. Transceiver 1515 may communicate bidirectionally via one or more antennas 1525 as described herein, or via a wired or wireless link. For example, transceiver 1515 may represent a wireless transceiver and may communicate bidirectionally with another wireless transceiver. Transceiver 1515 may also include a modem for: modulating packets; providing the modulated packets to one or more antennas 1525 for transmission; and demodulating packets received from one or more antennas 1525. Transceiver 1515, or transceiver 1515 and one or more antennas 1525, may be an example of transmitter 1215, transmitter 1315, receiver 1210, receiver 1310, or any combination thereof or components thereof as described herein.

[0254] At least one memory 1530 may include random access memory (RAM) and read-only memory (ROM). At least one memory 1530 may store computer-readable, computer-executable code 1535, including instructions that, when executed by at least one processor 1540, cause device 1505 to perform the various functions described herein. Code 1535 may be stored in a non-transitory computer-readable medium such as system memory or another type of memory. In some cases, code 1535 may not be directly executable by at least one processor 1540, but may (e.g., when compiled and executed) cause the computer to perform the functions described herein. In some cases, at least one memory 1530 may include a basic I / O system (BIOS), etc., which controls basic hardware or software operations such as interaction with peripheral components or devices.

[0255] At least one processor 1540 may include intelligent hardware devices (e.g., general-purpose processors, DSPs, CPUs, microcontrollers, ASICs, FPGAs, programmable logic devices, discrete gate or transistor logic components, discrete hardware components, or any combination thereof). In some cases, at least one processor 1540 may be configured to operate a memory array using a memory controller. In some other cases, the memory controller may be integrated into at least one processor 1540. At least one processor 1540 may be configured to execute computer-readable instructions stored in memory (e.g., at least one memory 1530) to cause device 1505 to perform various functions (e.g., functions or tasks supporting UE-assisted time and phase synchronization for CJT). For example, device 1505 or components of device 1505 may include at least one processor 1540 and at least one memory 1530 coupled to or coupled to at least one processor 1540, wherein at least one processor 1540 and at least one memory 1530 are configured to perform the various functions described herein. In some examples, at least one processor 1540 may include multiple processors, and at least one memory 1530 may include multiple memories. One or more of a plurality of processors may be coupled to one or more of a plurality of memories, which may be configured individually or collectively to perform the various functions described herein. In some examples, at least one processor 1540 may be a component of a processing system, which may refer to a machine (such as a series of machines), circuitry (including, for example, one or both of processor circuitry (which may include at least one processor 1540) and memory circuitry (which may include at least one memory 1530)) or system of components that receive or receive input and process the input 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. Thus, at least one processor 1540 or a processing system including at least one processor 1540 may be configured, configurable, or operable to cause device 1505 to perform one or more of the functions described herein. Furthermore, as described herein, “configured to,” “configurable to,” and “operable to” are used interchangeably and may be associated with the ability to perform one or more of the functions described herein when executing code stored in at least one memory 1530 or otherwise.

[0256] Communication manager 1520 may support wireless communications according to examples disclosed herein. For example, communication manager 1520 may be capable of, configured to, or operable to support components for receiving a first downlink RS from a first TRP via a first resource set. Communication manager 1520 may be capable of, configured to, or operable to support components for transmitting a first pre-decoded uplink RS to the first TRP via a second resource set associated with the first resource set, wherein the first pre-decoded uplink RS is pre-decoded based on an estimate of the first downlink RS. Communication manager 1520 may be capable of, configured to, or operable to support components for receiving a second downlink RS from a second TRP via a third resource set. The communication manager 1520 is capable of, configured to, or operable to support components for sending a second pre-decoded uplink RS to a second TRP via a fourth resource set associated with a third resource set, wherein the second pre-decoded uplink RS is pre-decoded based on an estimate of a second downlink RS, and wherein the first resource set, the second resource set, the third resource set, and the fourth resource set are configured for the first UE according to the synchronization of the first TRP and the second TRP.

[0257] By including or configuring a communication manager 1520 according to an example as described herein, device 1505 can support techniques for improving communication reliability via communication with a TRP that is more reliably synchronized. For example, the techniques described herein can allow the TRP to synchronize under conditions that were previously unsuitable for synchronization (e.g., low-quality wireless communication links, NLOS channels). However, the techniques described herein can allow the TRP to synchronize via the UE, thereby providing more reliable communication to the UE.

[0258] In some examples, the communication manager 1520 may be configured to use or otherwise coordinate with the transceiver 1515, one or more antennas 1525, or any combination thereof to perform various operations (e.g., receiving, monitoring, transmitting). Although the communication manager 1520 is illustrated as a separate component, in some examples, one or more functions described with reference to the communication manager 1520 may be supported or executed by at least one processor 1540, at least one memory 1530, code 1535, or any combination thereof. For example, code 1535 may include instructions that can be executed by at least one processor 1540 to cause the device 1505 to perform various aspects of UE-assisted time and phase synchronization for CJT as described herein, or at least one processor 1540 and at least one memory 1530 may be otherwise configured to perform or support such operations individually or jointly.

[0259] Figure 16A flowchart illustrating a method 1600 for UE-assisted time and phase synchronization for CJT, according to various aspects of this disclosure, is shown. Operation of method 1600 may be implemented by a TRP or its components as described herein. For example, operation of method 1600 may be implemented by, as referenced... Figures 1 to 11 The TRP described is used for execution. In some examples, the TRP can execute a set of instructions to control the functional elements of the TRP to perform the described functions. Additionally or alternatively, the TRP may use dedicated hardware to perform aspects of the described functions.

[0260] At 1605, the method may include: transmitting a first downlink RS to a first UE via a first resource set. The operation of 1605 may be performed according to the examples disclosed herein. In some examples, aspects of the operation of 1605 may be provided by reference to [reference needed]. Figure 10 The described sending component 1025 is used to perform this.

[0261] At 1610, the method may include: receiving a first pre-decoded uplink RS from a first UE via a second resource set associated with a first resource set, the first pre-decoded uplink RS being pre-decoded based on an estimate of a first downlink RS, wherein a first TRP synchronizes with a second TRP based on a phase offset, timing offset, or both between the first TRP and a second TRP, and wherein the phase offset, timing offset, or both are based on the first pre-decoded uplink RS and a second pre-decoded uplink RS associated with the second TRP. Operation of 1610 may be performed according to examples as disclosed herein. In some examples, aspects of operation of 1610 may be provided by reference to [reference needed]. Figure 10 The described receiving component 1030 is used to perform this action.

[0262] Figure 17 A flowchart illustrating a method 1700 for UE-assisted time and phase synchronization for CJT, according to various aspects of this disclosure, is shown. Operation of method 1700 may be implemented by a TRP or its components as described herein. For example, operation of method 1700 may be implemented by, as referenced... Figures 1 to 11 The TRP described is used for execution. In some examples, the TRP can execute a set of instructions to control the functional elements of the TRP to perform the described functions. Additionally or alternatively, the TRP may use dedicated hardware to perform aspects of the described functions.

[0263] At 1705, the method may include: transmitting a first downlink RS to a first UE via a first resource set. The operation of 1705 may be performed according to examples as disclosed herein. In some examples, aspects of the operation of 1705 may be provided by reference to... Figure 10 The described sending component 1025 is used to perform this.

[0264] At 1710, the method may include: receiving a first pre-decoded uplink RS from a first UE via a second resource set associated with a first resource set, the first pre-decoded uplink RS being pre-decoded based on an estimate of a first downlink RS, wherein a first TRP synchronizes with a second TRP based on a phase offset, timing offset, or both between the first TRP and a second TRP, and wherein the phase offset, timing offset, or both are based on the first pre-decoded uplink RS and a second pre-decoded uplink RS associated with the second TRP. Operation of 1710 may be performed according to examples as disclosed herein. In some examples, aspects of operation of 1710 may be provided by reference to [reference needed]. Figure 10 The described receiving component 1030 is used to perform this action.

[0265] At 1715, the method may include: receiving from the second TRP a message indicating the second pre-decoding uplink RS. The operation of 1715 may be performed according to the examples disclosed herein. In some examples, aspects of the operation of 1715 may be provided by reference to [reference needed]. Figure 10 The described receiving component 1030 is used to perform this action.

[0266] At 1720, the method may include estimating a phase offset, timing offset, or both, based on the conjugate product of the first pre-decoded uplink RS and the second pre-decoded uplink RS. The operation of 1720 may be performed according to examples as disclosed herein. In some examples, aspects of the operation of 1720 may be derived from references... Figure 10 The offset estimation component 1035 described is used to perform this.

[0267] Figure 18 A flowchart illustrating a method 1800 for UE-assisted time and phase synchronization for CJT, according to various aspects of this disclosure, is shown. Operation of method 1800 may be implemented by a TRP or its components as described herein. For example, operation of method 1800 may be implemented by, as referenced... Figures 1 to 11 The TRP described is used for execution. In some examples, the TRP can execute a set of instructions to control the functional elements of the TRP to perform the described functions. Additionally or alternatively, the TRP may use dedicated hardware to perform aspects of the described functions.

[0268] At 1805, the method may include: transmitting a first downlink RS to a first UE via a first resource set. The operation at 1805 may be performed according to examples as disclosed herein. In some examples, aspects of the operation at 1805 may be provided by reference to [reference needed]. Figure 10 The described sending component 1025 is used to perform this.

[0269] At 1810, the method may include: receiving a first pre-decoded uplink RS from a first UE via a second resource set associated with a first resource set, the first pre-decoded uplink RS being pre-decoded based on an estimate of a first downlink RS, wherein a first TRP synchronizes with a second TRP based on a phase offset, timing offset, or both between the first TRP and a second TRP, and wherein the phase offset, timing offset, or both are based on the first pre-decoded uplink RS and a second pre-decoded uplink RS associated with the second TRP. Operation of 1810 may be performed according to examples as disclosed herein. In some examples, aspects of operation of 1810 may be provided by reference to [reference needed]. Figure 10 The described receiving component 1030 is used to perform this action.

[0270] In 1815, the method may include: outputting a first message to the central node indicating the first pre-decoded uplink RS. The operation of 1815 may be performed according to the examples disclosed herein. In some examples, aspects of the operation of 1815 may be derived from references... Figure 10 The described sending component 1025 is used to perform this.

[0271] At 1820, the method may include: in response to a first message, obtaining from a central node a second message indicating an estimate of a phase offset, a timing offset, or both, wherein the estimate of the phase offset, timing offset, or both is based on the conjugate product of the uplink RS of the first pre-decoded and the uplink RS of the second pre-decoded. The operation of 1820 may be performed according to examples as disclosed herein. In some examples, aspects of the operation of 1820 may be provided by reference to [reference needed]. Figure 10 The offset estimation component 1035 described is used to perform this.

[0272] Figure 19 A flowchart illustrating a method 1900 for UE-assisted time and phase synchronization for CJT, according to various aspects of this disclosure, is shown. Operation of method 1900 can be implemented by a UE or its components as described herein. For example, operation of method 1900 can be achieved by, as referenced... Figures 1 to 7 and Figures 12 to 15 The UE 115 described herein is used to perform this function. In some examples, the UE can execute a set of instructions to control the functional elements of the UE to perform the described function. Additionally or alternatively, the UE may use dedicated hardware to perform aspects of the described function.

[0273] At 1905, the method may include: receiving a first downlink RS from a first TRP via a first resource set. The operation at 1905 may be performed according to the examples disclosed herein. In some examples, aspects of the operation at 1905 may be provided by reference to [reference needed]. Figure 14 The described receiving component 1425 is used to perform this action.

[0274] At 1910, the method may include: sending a first pre-decoded uplink RS to a first TRP via a second resource set associated with a first resource set, wherein the first pre-decoded uplink RS is pre-decoded based on an estimate of a first downlink RS. The operation of 1910 may be performed according to examples as disclosed herein. In some examples, aspects of the operation of 1910 may be provided by reference to [reference needed]. Figure 14 The described sending component 1430 is used to perform this.

[0275] At point 1915, the method may include: receiving a second downlink RS from a second TRP via a third resource set. The operation at point 1915 may be performed according to examples as disclosed herein. In some examples, aspects of the operation at point 1915 may be provided by reference to [reference needed]. Figure 14 The described receiving component 1425 is used to perform this action.

[0276] At 1920, the method may include: sending a second pre-decoded uplink RS to a second TRP via a fourth resource set associated with a third resource set, wherein the second pre-decoded uplink RS is pre-decoded based on an estimate of a second downlink RS, and wherein the first resource set, second resource set, third resource set, and fourth resource set are configured for the first UE according to the synchronization of the first TRP and the second TRP. The operation at 1920 may be performed according to the examples disclosed herein. In some examples, aspects of the operation at 1920 may be provided by reference to [reference needed]. Figure 14 The described sending component 1430 is used to perform this.

[0277] The following provides an overview of the various aspects of this disclosure:

[0278] Aspect 1: A method for wireless communication at a first TRP, the method comprising: transmitting a first downlink RS to a first UE via a first resource set; and receiving a first pre-decoded uplink RS from the first UE via a second resource set associated with the first resource set, the first pre-decoded uplink RS being pre-decoded at least in part based on an estimate of the first downlink RS, wherein the first TRP is synchronized with the second TRP according to a phase offset, a timing offset, or both between the first TRP and the second TRP, and wherein the phase offset, the timing offset, or both are at least in part based on the first pre-decoded uplink RS and a second pre-decoded uplink RS associated with the second TRP.

[0279] Aspect 2: According to the method of aspect 1, the method further includes: receiving from the second TRP a message indicating the uplink RS of the second pre-decoded; and estimating the phase offset, the timing offset, or both based at least in part on the product of the conjugate of the uplink RS of the first pre-decoded and the uplink RS of the second pre-decoded.

[0280] Aspect 3: According to the method of aspect 2, wherein the estimation of the phase offset, the timing offset, or both is based at least in part on the calculation of the product of the conjugate of the uplink RS of the first pre-decoded and the uplink RS of the second pre-decoded for a plurality of subcarriers.

[0281] Aspect 4: The method according to any one of Aspects 1 to 3, the method further comprising: outputting a first message to a central node indicating the uplink RS of the first pre-decoded; and in response to the first message obtaining from the central node a second message indicating an estimate of the phase offset, the timing offset, or both, wherein the estimate of the phase offset, the timing offset, or both is at least partially based on the product of the conjugate of the uplink RS of the first pre-decoded and the uplink RS of the second pre-decoded.

[0282] Aspect 5: According to the method of aspect 4, wherein the estimation of the phase offset, the timing offset, or both is based at least in part on the calculation of the product of the conjugate of the first pre-decoded uplink RS and the second pre-decoded uplink RS for a plurality of subcarriers.

[0283] Aspect 6: The method according to any one of Aspects 4 to 5, wherein the central node includes the second TRP or another network entity.

[0284] Aspect 7: The method according to any one of Aspects 1 to 6, wherein the second pre-decoded uplink RS is associated with a second downlink RS corresponding to a third resource set, and wherein the second pre-decoded uplink RS is pre-decoded at least in part based on the second downlink RS and corresponds to a fourth resource set associated with the third resource set, the method further comprising: obtaining the phase offset, the timing offset, or both, at least in part based on the conjugate product of the first pre-decoded uplink RS and the second pre-decoded uplink RS and further at least in part based on a subcarrier spacing index associated with the first resource set, the second resource set, the third resource set, the fourth resource set, or any combination thereof.

[0285] Aspect 8: According to the method of aspect 7, wherein the frequency resources in the first resource set have the same frequency as the corresponding frequency resources in the third resource set, or the frequency resources in the second resource set have the same frequency as the corresponding frequency resources in the fourth resource set, or both.

[0286] Aspect 9: The method according to any one of Aspects 7 to 8, wherein the time resource in the first resource set is the same as the corresponding time resource in the third resource set, or the time resource in the second resource set is the same as the corresponding time resource in the fourth resource set, or both.

[0287] Aspect 10: The method according to any one of Aspects 7 to 9, wherein the time resource in the first resource set is the same as the corresponding time resource in the third resource set, and the frequency resource in the second resource set has the same frequency as the corresponding frequency resource in the fourth resource set.

[0288] Aspect 11: The method according to any one of Aspects 7 to 10, the method further comprising: determining a threshold timing offset associated with synchronization based at least in part on the frequency interval between the first resource set, the second resource set, the third resource set, the fourth resource set, or a combination thereof; and determining a threshold offset resolution based at least in part on the bandwidth of the uplink RS for the first pre-decoding, the uplink RS for the second pre-decoding, the first downlink RS, the second downlink RS, or any combination thereof.

[0289] Aspect 12: The method according to any one of Aspects 1 to 11, the method further comprising: synchronizing timing or phase or both with a third TRP based at least in part on a second phase offset, a second timing offset or both between the second TRP and the third TRP, wherein the first TRP uses a combination of the phase offset and the second phase offset, a combination of the timing offset and the second timing offset or both to synchronize with the third TRP.

[0290] Aspect 13: The method according to aspect 12, wherein the second phase offset, the second timing offset, or both are at least partially based on the uplink RS of the third pre-decoded data transmitted from the second UE to the second TRP and the uplink RS of the fourth pre-decoded data transmitted from the second UE to the third TRP.

[0291] Aspect 14: The method according to any one of Aspects 1 to 13, the method further comprising: sending a control message to the first UE, the control message including an indication of associating the first resource set for the first downlink RS with the second resource set for the first pre-decoding uplink RS.

[0292] Aspect 15: The method according to any one of Aspects 1 to 14, the method further comprising: receiving capability signaling, the capability signaling instructing the first UE to provide the first TRP with the capability of the first pre-decoded uplink RS to assist the synchronization of the first TRP and the second TRP.

[0293] Aspect 16: The method according to aspect 15, wherein the capability signaling indicates that the first UE supports the ability to simultaneously receive downlink RS, the first UE supports the ability to simultaneously transmit uplink RS, one or more RS structures supported by the first UE, the range of time and frequency resources for consistent transmission and reception characteristics of the first UE, the maximum number of TRPs of pre-decoded uplink RS that the first UE can provide to it, the ability of the first UE to maintain receive phase continuity and transmit phase continuity in a certain number of symbols, or any combination thereof.

[0294] Aspect 17: The method according to any one of Aspects 1 to 16, wherein the first downlink RS includes one of a tracking reference signal, a positioning reference signal, an SSB, or a DMRS.

[0295] Aspect 18: A method for performing wireless communication at a first UE, the method comprising: receiving a first downlink RS from a first TRP via a first resource set; transmitting a first pre-decoded uplink RS to the first TRP via a second resource set associated with the first resource set, wherein the first pre-decoded uplink RS is pre-decoded at least in part based on an estimate of the first downlink RS; receiving a second downlink RS from a second TRP via a third resource set; and transmitting a second pre-decoded uplink RS to the second TRP via a fourth resource set associated with the third resource set, wherein the second pre-decoded uplink RS is pre-decoded at least in part based on an estimate of the second downlink RS, wherein the first resource set, the second resource set, the third resource set, and the fourth resource set are configured for the first UE according to synchronization of the first TRP and the second TRP.

[0296] Aspect 19: According to the method of aspect 18, wherein the frequency resources in the first resource set have the same frequency as the corresponding frequency resources in the third resource set, and the frequency resources in the second resource set have the same frequency as the corresponding frequency resources in the fourth resource set, or both.

[0297] Aspect 20: The method according to any one of Aspects 18 to 19, wherein the time resource in the first resource set is the same as the corresponding time resource in the third resource set, the time resource in the second resource set is the same as the corresponding time resource in the fourth resource set, or both.

[0298] Aspect 21: The method according to any one of Aspects 18 to 20, wherein the time resource in the first resource set is the same as the corresponding time resource in the third resource set, and the frequency resource in the second resource set has the same frequency as the corresponding frequency resource in the fourth resource set.

[0299] Aspect 22: The method according to any one of aspects 18 to 21, the method further comprising: receiving a control message, the control message including an indication of associating the first resource set for the first downlink RS with the second resource set for the first pre-decoding uplink RS.

[0300] Aspect 23: The method according to any one of Aspects 18 to 22, the method further comprising: receiving control signaling, the control signaling including a first indication associated with a first resource set for the first downlink RS and a second resource set for the first pre-decoding uplink RS, and a second indication associated with a third resource set for the second downlink RS and a fourth resource set for the second pre-decoding uplink RS.

[0301] Aspect 24: The method according to aspect 23, wherein the control signaling includes one or more uplink RS configurations, one or more downlink reference configurations, one or more pointers associated with an uplink RS resource identifier or a downlink RS identifier, or any combination thereof.

[0302] Aspect 25: The method according to any one of Aspects 18 to 24, wherein the first downlink RS, the second downlink RS, the first pre-decoded uplink RS, and the second pre-decoded uplink RS each comprise a plurality of instances transmitted at corresponding frequency intervals, the method further comprising: interpolating between the corresponding frequency intervals of the plurality of instances of the first downlink RS and between the corresponding frequency intervals of the plurality of instances of the second downlink RS, wherein the estimation of the first downlink RS and the estimation of the second downlink RS are at least partially based on the interpolation.

[0303] Aspect 26: The method according to any one of Aspects 18 to 25, the method further comprising: sending capability signaling, the capability signaling instructing the first UE to provide the first TRP with the capability of the first pre-decoded uplink RS to assist the synchronization of the first TRP and the second TRP.

[0304] Aspect 27: The method according to aspect 26, wherein the capability signaling indicates that the first UE supports the ability to simultaneously receive downlink RS, the first UE supports the ability to simultaneously transmit uplink RS, one or more RS structures supported by the first UE, the range of time and frequency resources for consistent transmission and reception characteristics of the first UE, the maximum number of TRPs of pre-decoded uplink RS that the first UE can provide to it, the ability of the first UE to maintain receive phase continuity and transmit phase continuity in a certain number of symbols, or any combination thereof.

[0305] Aspect 28: The method according to any one of Aspects 18 to 27, the method further comprising: receiving a third downlink RS from a third TRP via a fifth resource set; and transmitting a third pre-decoded uplink RS to the third TRP via a sixth resource set associated with the fifth resource set, wherein the third pre-decoded uplink RS is pre-decoded at least in part based on an estimate of the third downlink RS.

[0306] Aspect 29: A first TRP for wireless communication, the first TRP comprising: one or more memories storing processor-executable code; and one or more processors coupled to the one or more memories and capable of operating individually or jointly to execute the code to cause the first transmitting and receiving point (TRP) to perform a method according to any one of aspects 1 to 17.

[0307] Aspect 30: A first TRP for wireless communication, the first TRP comprising: at least one component for performing the method according to any one of aspects 1 to 17.

[0308] Aspect 31: A non-transitory computer-readable medium storing code for wireless communication, said code including instructions executable by one or more processors to perform the method according to any one of aspects 1 to 17.

[0309] Aspect 32: A first UE for wireless communication, the first UE comprising: one or more memories storing processor-executable code; and one or more processors coupled to the one or more memories and individually or jointly operable to execute the code to cause the first UE to perform a method according to any one of aspects 18 to 28.

[0310] Aspect 33: A first UE for wireless communication, the first UE comprising: at least one component for performing the method according to any one of aspects 18 to 28.

[0311] Aspect 34: A non-transitory computer-readable medium storing code for wireless communication, said code including instructions executable by one or more processors to perform the method according to any one of aspects 18 to 28.

[0312] It should be noted that the methods described herein describe possible specific implementations, and the operations and steps can be rearranged or otherwise modified, and other specific implementations are also possible. Furthermore, aspects from two or more of these methods can be combined.

[0313] While aspects of LTE, LTE-A, LTE-A Pro, or NR systems may be described for illustrative purposes, and the terms LTE, LTE-A, LTE-A Pro, or NR may be used in most of the description, the techniques described herein are also applicable to networks outside of LTE, LTE-A, LTE-A Pro, or NR networks. For example, the techniques described are applicable to a variety of other wireless communication systems, such as Ultra Mobile Broadband (UMB), IEEE 802.11 (Wi-Fi), IEEE 802.16 (WiMAX), IEEE 802.20, Flash-OFDM, and other systems and radio technologies not explicitly mentioned herein.

[0314] The information and signals described herein can be represented using any of a variety of different techniques and methods. For example, data, instructions, commands, information, signals, bits, symbols, and chips mentioned throughout the description can be represented by voltage, current, electromagnetic waves, magnetic fields or magnetic particles, light fields or optical particles, or any combination thereof.

[0315] The various exemplary blocks and components described herein can be implemented or performed using a general-purpose processor, DSP, ASIC, CPU, FPGA or other programmable logic device, discrete gate or transistor logic unit, discrete hardware component, or any combination thereof, designed to perform the functions described herein. A general-purpose processor may be a microprocessor, but in alternative embodiments, a 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 cooperating with a DSP core, or any other such configuration). Any function or operation described herein that can be performed by a processor may be performed by multiple processors capable of performing the described functions or operations individually or jointly.

[0316] The functionality described herein can be implemented using hardware, software executed by a processor, firmware, or any combination thereof. When implemented using software executed by a processor, the functionality can be stored as one or more instructions or code on a computer-readable medium or transmitted using one or more instructions or code on a computer-readable medium. Other examples and specific implementations are within the scope of this disclosure and the appended claims. For example, due to the nature of software, the functionality described herein can be implemented using software executed by a processor, hardware, firmware, hardwiring, or any combination of these. Features implementing the functionality can also be physically located in various locations, including portions distributed such that the functionality is implemented at different physical locations.

[0317] Computer-readable media includes both non-transitory computer storage media and communication media, encompassing any medium that facilitates the transfer of a computer program from one location to another. Non-transitory storage media can be any available medium accessible 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, compressed optical disc (CD) ROM or other optical disc storage devices, magnetic disk storage devices or other magnetic storage devices, or any other non-transitory medium that can be used to carry or store desired program code components in the form of instructions or data structures, and accessible by a general-purpose or special-purpose computer or a general-purpose or special-purpose processor. Furthermore, any connection is appropriately referred to as computer-readable media. For example, if software is transmitted from a website, server, or other remote source using coaxial cable, fiber optic cable, twisted pair, digital subscriber line (DSL), or wireless technologies such as infrared, radio, and microwave, then coaxial cable, fiber optic cable, twisted pair, DSL, or wireless technologies such as infrared, radio, and microwave are included within the definition of computer-readable media. As used herein, disks and optical discs include CDs, laser discs, optical discs, digital multifunction discs (DVDs), floppy disks, and Blu-ray discs. Disks can magnetically reproduce data, and optical discs can optically reproduce data using lasers. Combinations of the above are also included within the scope of computer-readable media. Any function or operation described herein that can be performed by memory can be performed by multiple memories capable of performing the described function or operation individually or jointly.

[0318] As used herein, the word "or" in a list of items (e.g., a list of items accompanied by phrases such as "at least one of" or "one or more of") in the claims indicates an inclusive list, such that a list of at least one of, for example, 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). Furthermore, as used herein, the phrase "based on" should not be construed as a reference to a closed set of conditions. For example, an example step described as "based on condition A" could be based on both condition A and condition B without departing from the scope of this disclosure. In other words, as used herein, the phrase "based on" should be interpreted in the same manner as the phrase "at least partially based on".

[0319] As used herein, including in claims, the article “a” preceding a noun is open-ended and is understood to refer to “at least one” or “one or more” of those nouns. Therefore, the terms “a,” “at least one,” “one or more,” and “at least one of one or more” are interchangeable. For example, where a claim enumerates “components” performing 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 “component” having a characteristic or performing a function may refer to “at least one of one or more components” having a particular characteristic or performing a particular function. Subsequent references to a component introduced with the article “a” using the terms “the” or “the” can refer to any or all of the one or more components. For example, a component introduced with the article “a” can be understood to mean “one or more components,” and subsequent reference to “the component” in a claim can be understood as equivalent to referring to “at least one of the one or more components.” Similarly, subsequent references to a component introduced with the terms “the” or “the” as “one or more components” can refer to any or all of the one or more components. For example, reference to "the one or more components" in the subsequent claims can be understood as equivalent to reference to "at least one of the one or more components".

[0320] The term "determine" encompasses a variety of actions, and therefore, "determine" can include calculation, computation, processing, derivation, investigation, lookup (such as by searching in a table, database, or other data structure), identification, and similar actions. Furthermore, "determine" can include receiving (e.g., receiving information), accessing (e.g., accessing data stored in memory), etc. Moreover, "determine" can include parsing, acquiring, selecting, choosing, creating, and other similar actions.

[0321] In the accompanying drawings, similar components or features may have the same reference numerals. Furthermore, various components of the same type can be distinguished by adding a dash after the reference numeral and a second numeral for differentiation between similar components. If only the first reference numeral is used in the specification, the description applies to any of the similar components having the same first reference numeral, regardless of the second or other subsequent reference numerals.

[0322] The description herein, illustrated with reference to the accompanying drawings, describes an example configuration and does not represent all achievable examples or those within the scope of the claims. The term "example" as used herein means "serving as an example, instance, or illustration," not "preferred" or "advantageous over other examples." The detailed description includes specific details used to provide an understanding of the described techniques. However, these techniques can be practiced without these specific details. In some cases, known structures and devices are shown in block diagram form to avoid obscuring the concept of the described examples.

[0323] The description herein is provided to enable those skilled in the art to implement or use this disclosure. Various modifications to this disclosure will be apparent to those skilled in the art, and the general principles defined herein may be applied to other variations without departing from the scope of this disclosure. Therefore, this disclosure is not limited to the examples and designs described herein, but should be granted the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A first transmitting and receiving point (TRP), the first transmitting and receiving point (TRP) comprising: One or more memories, wherein the one or more memories store processor-executable code; and One or more processors, said one or more processors coupled to said one or more memories and capable of operating individually or jointly to execute said code to enable the first TRP: A first downlink reference signal is sent to a first user equipment (UE) via a first resource set; as well as The first pre-decoded uplink reference signal is received from the first UE via a second resource set associated with the first resource set. The first pre-decoded uplink reference signal is pre-decoded at least in part based on an estimate of the first downlink reference signal. The first TRP is synchronized with the second TRP based on a phase offset, a timing offset, or both between the first TRP and the second TRP. The phase offset, the timing offset, or both are at least in part based on the first pre-decoded uplink reference signal and a second pre-decoded uplink reference signal associated with the second TRP.

2. The first TRP of claim 1, wherein the one or more processors are individually or jointly further operable to execute the code to cause the first TRP to: Receive a message from the second TRP indicating the uplink reference signal for the second pre-decoding; and The phase offset, the timing offset, or both are estimated at least in part based on the product of the conjugate of the first pre-decoded uplink reference signal and the second pre-decoded uplink reference signal.

3. The first TRP of claim 2, wherein the estimation of the phase offset, the timing offset, or both is based at least in part on the calculation of the product of the conjugate of the first pre-decoded uplink reference signal and the second pre-decoded uplink reference signal for a plurality of subcarriers.

4. The first TRP of claim 1, wherein the one or more processors are individually or jointly further operable to execute the code to cause the first TRP to: Output a first message to the central node indicating the uplink reference signal of the first pre-decoded signal; and In response to the first message, a second message indicating an estimate of the phase offset, the timing offset, or both is obtained from the central node, wherein the estimate of the phase offset, the timing offset, or both is at least partially based on the product of the conjugate of the first pre-decoded uplink reference signal and the second pre-decoded uplink reference signal.

5. The first TRP of claim 4, wherein the estimation of the phase offset, the timing offset, or both is based at least in part on the calculation of the product of the conjugate of the first pre-decoded uplink reference signal and the second pre-decoded uplink reference signal for a plurality of subcarriers.

6. The first TRP of claim 4, wherein the central node comprises either the second TRP or another network entity.

7. The first TRP of claim 1, wherein the second pre-decoded uplink reference signal is associated with a second downlink reference signal corresponding to a third resource set, and wherein the second pre-decoded uplink reference signal is pre-decoded at least in part based on the second downlink reference signal and corresponds to a fourth resource set associated with the third resource set, and the one or more processors are individually or jointly further operable to execute the code to cause the first TRP to: The phase offset, the timing offset, or both are obtained at least in part based on the conjugate product of the first pre-decoded uplink reference signal and the second pre-decoded uplink reference signal, and further at least in part based on the subcarrier spacing index associated with the first resource set, the second resource set, the third resource set, the fourth resource set, or any combination thereof.

8. The first TRP according to claim 7, wherein the frequency resource in the first resource set has the same frequency as the corresponding frequency resource in the third resource set, or the frequency resource in the second resource set has the same frequency as the corresponding frequency resource in the fourth resource set, or both.

9. The first TRP according to claim 7, wherein the time resource in the first resource set is the same as the corresponding time resource in the third resource set, or the time resource in the second resource set is the same as the corresponding time resource in the fourth resource set, or both.

10. The first TRP according to claim 7, wherein the time resource in the first resource set is the same as the corresponding time resource in the third resource set, and the frequency resource in the second resource set has the same frequency as the corresponding frequency resource in the fourth resource set.

11. The first TRP of claim 7, wherein the one or more processors are individually or jointly further operable to execute the code to cause the first TRP to: The threshold timing offset associated with synchronization is determined at least in part based on the frequency intervals between the first resource set, the second resource set, the third resource set, the fourth resource set, or a combination thereof; and The threshold offset resolution is determined at least in part based on the bandwidth of the uplink reference signal used for the first pre-decoding, the uplink reference signal used for the second pre-decoding, the first downlink reference signal, the second downlink reference signal, or any combination thereof.

12. The first TRP of claim 1, wherein the one or more processors are individually or jointly further operable to execute the code to cause the first TRP to: The timing or phase or both of the first TRP are synchronized with the third TRP at least in part based on a second phase offset, a second timing offset or both between the second TRP and the third TRP, wherein the first TRP uses a combination of the phase offset and the second phase offset, a combination of the timing offset and the second timing offset or both of the first TRP to synchronize with the third TRP.

13. The first TRP of claim 12, wherein the second phase offset, the second timing offset, or both are at least partially based on a third pre-decoded uplink reference signal transmitted from the second UE to the second TRP and a fourth pre-decoded uplink reference signal transmitted from the second UE to the third TRP.

14. The first TRP of claim 1, wherein the one or more processors are individually or jointly further operable to execute the code to cause the first TRP to: A control message is sent to the first UE, the control message including an indication of the first resource set for the first downlink reference signal and the second resource set for the first pre-decoded uplink reference signal.

15. The first TRP of claim 1, wherein the one or more processors are individually or jointly further operable to execute the code to cause the first TRP to: The first UE receives capability signaling, which instructs the first UE to provide the first pre-decoded uplink reference signal to the first TRP to assist in the synchronization of the first TRP and the second TRP.

16. The first TRP of claim 15, wherein the capability signaling indicates the capability of the first UE to simultaneously receive downlink reference signals, the capability of the first UE to simultaneously transmit uplink reference signals, one or more reference signal structures supported by the first UE, the range of time and frequency resources for which the transmission and reception characteristics of the first UE are consistent, the number of thresholds of TRPs to which the first UE can provide pre-decoded uplink reference signals, the capability of the first UE to maintain receive phase continuity and transmit phase continuity in a certain number of symbols, or any combination thereof.

17. The first TRP of claim 1, wherein the first downlink reference signal includes one of a tracking reference signal, a positioning reference signal, a synchronization signal block, or a demodulation reference signal.

18. A first user equipment (UE), the first user equipment (UE) comprising: One or more memories, wherein the one or more memories store processor-executable code; and One or more processors, said one or more processors coupled to said one or more memories and capable of operating individually or jointly to execute said code to enable the first UE: Receive a first downlink reference signal from a first transmit-receive point (TRP) via a first resource set; A first pre-decoded uplink reference signal is sent to the first TRP via a second resource set associated with the first resource set, wherein the first pre-decoded uplink reference signal is pre-decoded at least in part based on an estimate of the first downlink reference signal; Receive the second downlink reference signal from the second TRP via the third resource set; as well as A second pre-decoded uplink reference signal is sent to the second TRP via a fourth resource set associated with the third resource set, wherein the second pre-decoded uplink reference signal is pre-decoded at least in part based on an estimate of the second downlink reference signal, and wherein the first resource set, the second resource set, the third resource set, and the fourth resource set are configured for the first UE according to the synchronization of the first TRP and the second TRP.

19. The first UE according to claim 18, wherein the frequency resources in the first resource set have the same frequency as the corresponding frequency resources in the third resource set, and the frequency resources in the second resource set have the same frequency as the corresponding frequency resources in the fourth resource set, or both.

20. The first UE according to claim 18, wherein the time resource in the first resource set is the same as the corresponding time resource in the third resource set, and the time resource in the second resource set is the same as the corresponding time resource in the fourth resource set, or both.

21. The first UE according to claim 18, wherein the time resource in the first resource set is the same as the corresponding time resource in the third resource set, and the frequency resource in the second resource set has the same frequency as the corresponding frequency resource in the fourth resource set.

22. The first UE of claim 18, wherein the one or more processors are individually or jointly further operable to execute the code to cause the first UE to: A control message is received, the control message including an indication of the association between the first resource set for the first downlink reference signal and the second resource set for the first pre-decoded uplink reference signal.

23. The first UE of claim 18, wherein the one or more processors are individually or jointly further operable to execute the code to cause the first UE to: Receive control signaling, the control signaling including a first indication for associating a first resource set for the first downlink reference signal with a second resource set for the first pre-decoding uplink reference signal, and a second indication for associating a third resource set for the second downlink reference signal with a fourth resource set for the second pre-decoding uplink reference signal.

24. The first UE of claim 23, wherein the control signaling includes one or more uplink reference signal configurations, one or more downlink reference configurations, one or more pointers associated with an uplink reference signal resource identifier or a downlink reference signal identifier, or any combination thereof.

25. The first UE of claim 18, wherein the first downlink reference signal, the second downlink reference signal, the first pre-decoded uplink reference signal, and the second pre-decoded uplink reference signal each comprise a plurality of instances transmitted at corresponding frequency intervals, and the one or more processors are individually or jointly further operable to execute the code to cause the first UE to: Interpolation is performed between the respective frequency intervals of the plurality of instances of the first downlink reference signal and between the respective frequency intervals of the plurality of instances of the second downlink reference signal, wherein the estimation of the first downlink reference signal and the estimation of the second downlink reference signal are at least partially based on the interpolation.

26. The first UE of claim 18, wherein the one or more processors are individually or jointly further operable to execute the code to cause the first UE to: Send capability signaling, the capability signaling instructing the first UE to provide the first TRP with the first pre-decoded uplink reference signal to assist the synchronization capability of the first TRP and the second TRP.

27. The first UE of claim 26, wherein the capability signaling indicates the first UE's ability to simultaneously receive downlink reference signals, the first UE's ability to simultaneously transmit uplink reference signals, one or more reference signal structures supported by the first UE, the range of time and frequency resources for which the first UE's transmit and receive characteristics are consistent, the number of thresholds of TRPs to which the first UE can provide pre-decoded uplink reference signals, the first UE's ability to maintain receive phase continuity and transmit phase continuity in a number of symbols, or any combination thereof.

28. The first UE of claim 18, wherein the one or more processors are individually or jointly further operable to execute the code to cause the first UE to: Receive the third downlink reference signal from the third TRP via the fifth resource set; and A third pre-decoded uplink reference signal is sent to the third TRP via a sixth resource set associated with the fifth resource set, wherein the third pre-decoded uplink reference signal is pre-decoded at least in part based on an estimate of the third downlink reference signal.

29. A method for wireless communication at a first TRP, the method comprising: A first downlink reference signal is sent to a first user equipment (UE) via a first resource set; as well as The first pre-decoded uplink reference signal is received from the first UE via a second resource set associated with the first resource set. The first pre-decoded uplink reference signal is pre-decoded at least in part based on an estimate of the first downlink reference signal. The first TRP is synchronized with the second TRP based on a phase offset, a timing offset, or both between the first TRP and the second TRP. The phase offset, the timing offset, or both are at least in part based on the first pre-decoded uplink reference signal and a second pre-decoded uplink reference signal associated with the second TRP.

30. A method for wireless communication at a first user equipment (UE), the method comprising: Receive a first downlink reference signal from a first transmit-receive point (TRP) via a first resource set; A first pre-decoded uplink reference signal is sent to the first TRP via a second resource set associated with the first resource set, wherein the first pre-decoded uplink reference signal is pre-decoded at least in part based on an estimate of the first downlink reference signal; Receive the second downlink reference signal from the second TRP via the third resource set; as well as A second pre-decoded uplink reference signal is sent to the second TRP via a fourth resource set associated with the third resource set, wherein the second pre-decoded uplink reference signal is pre-decoded at least in part based on an estimate of the second downlink reference signal, and wherein the first resource set, the second resource set, the third resource set, and the fourth resource set are configured for the first UE according to the synchronization of the first TRP and the second TRP.

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