DEMODULATION REFERENCE SIGNAL (DMRS) AND SOUNDING REFERENCE SIGNAL (SRS) BUNDLING UNDER UPLINK TIMING ADVANCE (TA)

Wireless communication devices, systems, and methods related to bundling of uplink communication signals under timing advance (TA) conditions are provided. For example, a method of wireless communication performed by a user equipment can include receiving, from a base station, a timing advance (TA), wherein the TA is scheduled to be implemented by the user equipment at a first time, the first time being after a start of a first uplink communication of a group of bundled uplink communications scheduled with phase coherence and before a start of a second uplink communication of the group of bundled uplink communications; determining whether to implement the TA at the first time or a second time, the second time being after transmission of the second uplink communication; and implementing the TA based on the determining

TECHNICAL FIELD

This application relates to wireless communication systems, and more particularly to bundling uplink communications (e.g., demodulation reference signals (DMRSs), sounding reference signals (SRSs), physical uplink control channel (PUCCH) communications, physical uplink shared channel (PUSCH) communications, etc.) under timing advance (TA) conditions, including associated methods, devices, and systems.

INTRODUCTION

To facilitate successful communications between a transmitter and a receiver, the transmitter may transmit one or more reference signals (alone or along with a data transmission). The reference signal(s) may include a predetermined sequence and may be transmitted at predetermined time and/or frequency locations. The receiver may estimate a channel response from the reference signal(s). Based on the channel estimation from processing the reference signal(s), either separately or bundled, the receiver can receive and decode communications from the transmitter.

In some instances, multiple reference signals may be bundled in the time domain across multiple time slots. When the reference signals are bundled, the receiver may perform joint channel estimation using the reference signals received across the multiple time slots, as opposed to performing a separate channel estimation for each individual slot based on the reference signal(s) received in the slot. When reference signals are bundled in the time domain, the transmitter can transmit the different reference signals with phase coherence to allow the receiver to perform the joint channel estimation. However, in some instances, the transmitter may be scheduled to implement a timing advance (TA) between the transmissions of the reference signals that are to be transmitted with phase coherence. In this regard, implementing the TA may cause the reference signals transmitted after implementation of the TA to be out of phase with the reference signals transmitted before the implementation of the TA. However, not implementing the TA may cause the transmitter and receiver to be out of synchronization. Accordingly, improved techniques for bundling uplink communication signals, including reference signals, under TA conditions are provided by the present disclosure.

BRIEF SUMMARY OF SOME EXAMPLES

Aspects of the present disclosure provide mechanisms for bundling uplink communications (e.g., demodulation reference signals (DMRSs), sounding reference signals (SRSs), physical uplink control channel (PUCCH) communications, physical uplink shared channel (PUSCH) communications, etc.) under timing advance (TA) conditions. In this regard, aspects of the present disclosure can enhance uplink cell coverage, especially towards the boundaries of the cell, by facilitating bundling of phase coherent uplink communications, while also maintaining synchronization between the user equipment (UE) and base station (BS) via timing advance (TA).

In an aspect of the disclosure, a method of wireless communication performed by a user equipment includes receiving, from a base station, a timing advance (TA), wherein the TA is scheduled to be implemented by the user equipment at a first time, the first time being after a start of a first uplink communication of a group of bundled uplink communications scheduled with phase coherence and before a start of a second uplink communication of the group of bundled uplink communications; determining whether to implement the TA at the first time or a second time, the second time being after transmission of the second uplink communication; and implementing the TA based on the determining.

In an additional aspect of the disclosure, a method of wireless communication performed by a base station includes transmitting, to a user equipment, a timing advance (TA), wherein the TA is scheduled to be implemented by the user equipment at a first time, the first time being after a start of a first uplink communication of a group of bundled uplink communications scheduled with phase coherence and before a start of a second uplink communication of the group of bundled uplink communications; receiving, from the user equipment, the first uplink communication; receiving, from the user equipment, the second uplink communication; and processing the first uplink communication and the second uplink communication based on when the TA was implemented by the user equipment.

In an additional aspect of the disclosure, a user equipment includes a transceiver configured to: receive, from a base station, a timing advance (TA), wherein the TA is scheduled to be implemented by the user equipment at a first time, the first time being after a start of a first uplink communication of a group of bundled uplink communications scheduled with phase coherence and before a start of a second uplink communication of the group of bundled uplink communications; and a processor in communication with the transceiver, the processor configured to: determine whether to implement the TA at the first time or a second time, the second time being after transmission of the second uplink communication; and implement the TA based on the determination.

In an additional aspect of the disclosure, a base station includes a transceiver configured to: transmit, to a user equipment, a timing advance (TA), wherein the TA is scheduled to be implemented by the user equipment at a first time, the first time being after a start of a first uplink communication of a group of bundled uplink communications scheduled with phase coherence and before a start of a second uplink communication of the group of bundled uplink communications; receive, from the user equipment, the first uplink communication; and receive, from the user equipment, the second uplink communication; and a processor in communication with the transceiver, the processor configured to: process the first uplink communication and the second uplink communication based on when the TA was implemented by the user equipment.

In an additional aspect of the disclosure, a user equipment includes means for receiving, from a base station, a timing advance (TA), wherein the TA is scheduled to be implemented by the user equipment at a first time, the first time being after a start of a first uplink communication of a group of bundled uplink communications scheduled with phase coherence and before a start of a second uplink communication of the group of bundled uplink communications; means for determining whether to implement the TA at the first time or a second time, the second time being after transmission of the second uplink communication; and means for implementing the TA based on the determining

In an additional aspect of the disclosure, a base station includes means for transmitting, to a user equipment, a timing advance (TA), wherein the TA is scheduled to be implemented by the user equipment at a first time, the first time being after a start of a first uplink communication of a group of bundled uplink communications scheduled with phase coherence and before a start of a second uplink communication of the group of bundled uplink communications; means for receiving, from the user equipment, the first uplink communication; means for receiving, from the user equipment, the second uplink communication; and means for processing the first uplink communication and the second uplink communication based on when the TA was implemented by the user equipment.

In an additional aspect of the disclosure, a non-transitory computer-readable medium has program code recorded thereon for wireless communication by a user equipment, the program code including code for causing the user equipment to receive, from a base station, a timing advance (TA), wherein the TA is scheduled to be implemented by the user equipment at a first time, the first time being after a start of a first uplink communication of a group of bundled uplink communications scheduled with phase coherence and before a start of a second uplink communication of the group of bundled uplink communications; code for causing the user equipment to determine whether to implement the TA at the first time or a second time, the second time being after transmission of the second uplink communication; and code for causing the user equipment to implement the TA based on the determining.

In an additional aspect of the disclosure, a non-transitory computer-readable medium has program code recorded thereon for wireless communication by a base station, the program code including code for causing the base station to transmit, to a user equipment, a timing advance (TA), wherein the TA is scheduled to be implemented by the user equipment at a first time, the first time being after a start of a first uplink communication of a group of bundled uplink communications scheduled with phase coherence and before a start of a second uplink communication of the group of bundled uplink communications; code for causing the base station to receive, from the user equipment, the first uplink communication; code for causing the base station to receive, from the user equipment, the second uplink communication; and code for causing the base station to process the first uplink communication and the second uplink communication based on when the TA was implemented by the user equipment.

DETAILED DESCRIPTION

Aspects of the present disclosure provide mechanisms for bundling uplink communications (e.g., demodulation reference signals (DMRSs), sounding reference signals (SRSs), physical uplink control channel (PUCCH) communications, physical uplink shared channel (PUSCH) communications, etc.) under timing advance (TA) conditions. In this regard, aspects of the present disclosure can enhance uplink cell coverage, especially towards the boundaries of the cell, by facilitating bundling of phase coherent uplink communications, while also maintaining synchronization between the user equipment (UE) and base station (BS) via timing advance (TA).

In this regard, to facilitate successful communications between a transmitter and a receiver, the transmitter may transmit one or more reference signals (alone or along with a data transmission). The reference signal(s) may include a predetermined sequence and may be transmitted at predetermined time and/or frequency locations. The receiver may estimate a channel response from the reference signal(s). Based on the channel estimation from processing the reference signal(s), either separately or bundled, the receiver can receive and decode communications from the transmitter.

In some instances, multiple reference signals may be bundled in the time domain across multiple time slots. When the reference signals are bundled, the receiver may perform joint channel estimation using the reference signals received across the multiple time slots, as opposed to performing a separate channel estimation for each individual slot based on the reference signal(s) received in the slot. When reference signals are bundled in the time domain, the transmitter can transmit the different reference signals with phase coherence to allow the receiver to perform the joint channel estimation. However, in some instances, the transmitter may be scheduled to implement a timing advance (TA) between the transmissions of the reference signals that are to be transmitted with phase coherence. In this regard, implementing the TA may cause the reference signals transmitted after implementation of the TA to be out of phase with the reference signals transmitted before the implementation of the TA. However, not implementing the TA may cause the transmitter and receiver to be out of synchronization. The present disclosure provides improved techniques for bundling uplink communication signals, including reference signals, under TA conditions.

In some instances, the TA is implemented when scheduled, while in other instances the TA implementation is delayed. When to implement the TA can be determined based on a configuration. The configuration may be a dynamic configuration and/or a predetermined/pre-programmed configuration stored in the memory of the UE and/or BS. The configuration may provide one or more rules for determining when to implement the TA. In this regard, the rules may be based on whether bundled uplink communications are scheduled with phase coherence, the number of bundled uplink communications, the length of time necessary for the bundled uplink communications, a magnitude of the TA, one or more other factors, and/or combinations thereof. In this regard, the configuration may provide rules for selecting the timing for a delayed TA implementation. In this regard, the delayed timing can be based on one or more of an uplink-to-downlink switch, a downlink-to-uplink switch, a time gap between the uplink communications, a power change between the uplink communications, and/or uplink communications not being scheduled with phase coherence. Additional features and benefits of the present disclosure are set forth in the following description.

In an embodiment, a UE115attempting to access the network100may perform an initial cell search by detecting a PSS from a BS105. The PSS may enable synchronization of period timing and may indicate a physical layer identity value. The UE115may then receive a SSS. The SSS may enable radio frame synchronization, and may provide a cell identity value, which may be combined with the physical layer identity value to identify the cell. The PSS and the SSS may be located in a central portion of a carrier or any suitable frequencies within the carrier.

After receiving the PSS and SSS, the UE115may receive a MIB. The MIB may include system information for initial network access and scheduling information for RMSI and/or OSI. After decoding the MIB, the UE115may receive RMSI and/or OSI. The RMSI and/or OSI may include radio resource control (RRC) information related to random access channel (RACH) procedures, paging, control resource set (CORESET) for physical downlink control channel (PDCCH) monitoring, physical uplink control channel (PUCCH), physical uplink shared channel (PUSCH), power control, and SRS.

After obtaining the MIB, the RMSI and/or the OSI, the UE115can perform a random access procedure to establish a connection with the BS105. In some examples, the random access procedure may be a four-step random access procedure. For example, the UE115may transmit a random access preamble and the BS105may respond with a random access response. The random access response (RAR) may include a detected random access preamble identifier (ID) corresponding to the random access preamble, timing advance (TA) information, a UL grant, a temporary cell-radio network temporary identifier (C-RNTI), and/or a backoff indicator. Upon receiving the random access response, the UE115may transmit a connection request to the BS105and the BS105may respond with a connection response. The connection response may indicate a contention resolution. In some examples, the random access preamble, the RAR, the connection request, and the connection response can be referred to as a message 1 (MSG 1), a message 2 (MSG 2), a message 3 (MSG 3), and a message 4 (MSG 4), respectively. In some examples, the random access procedure may be a two-step random access procedure, where the UE115may transmit a random access preamble and a connection request in a single transmission and the BS105may respond by transmitting a random access response and a connection response in a single transmission. The combined random access preamble and connection request in the two-step random access procedure may be referred to as a message A (MSG A). The combined random access response and connection response in the two-step random access procedure may be referred to as a message B (MSG B).

After establishing a connection, the UE115may initiate an initial network attachment procedure with the network100. When the UE115has no active data communication with the BS105after the network attachment, the UE115may return to an idle state (e.g., RRC idle mode). Alternatively, the UE115and the BS105can enter an operational state or active state, where operational data may be exchanged (e.g., RRC connected mode). For example, the BS105may schedule the UE115for UL and/or DL communications. The BS105may transmit UL and/or DL scheduling grants to the UE115via a PDCCH. The BS105may transmit a DL communication signal to the UE115via a PDSCH according to a DL scheduling grant. The UE115may transmit a UL communication signal to the BS105via a PUSCH and/or PUCCH according to a UL scheduling grant. In some embodiments, the BS105and the UE115may employ hybrid automatic request (HARQ) techniques for communications to improve reliability. Additionally, the UE115and/or the BS105can utilize DRX (e.g., during RRC idle mode), including connected mode DRX (C-DRX) (e.g., during RRC connected mode), and/or DTX operating modes.

In an embodiment, the network100may operate over a system BW or a component carrier (CC) BW. The network100may partition the system BW into multiple BWPs (e.g., portions). A BS105may dynamically assign a UE115to operate over a certain BWP (e.g., a certain portion of the system BW). The assigned BWP may be referred to as the active BWP. The UE115may monitor the active BWP for signaling information from the BS105. The BS105may schedule the UE115for UL or DL communications in the active BWP. In some instances, a BS105may assign a pair of BWPs within the CC to a UE115for UL and DL communications. For example, the BWP pair may include one BWP for UL communications and one BWP for DL communications. In some instances, the BS105may dynamically switch the UE115from one BWP to another BWP, for example, from a wideband BWP to a narrowband BWP for power savings or from a narrowband BWP to a wideband BWP for communication.

The BS105may additionally configure the UE115with one or more CORESETs in a BWP. A CORESET may include a set of frequency resources spanning a number of symbols in time. The BS105may configure the UE115with one or more search spaces for PDCCH monitoring based on the CORESETS. The UE115may perform blind decoding in the search spaces to search for DL control information from the BS. The BS105may configure the UE115with various different CORSETs and/or search spaces for different types of PDCCH monitoring (e.g., DL/UL schedules and/or wake-up information). In an example, the BS105may configure the UE115with the BWPs, the CORESETS, and/or the PDCCH search spaces via RRC configurations.

In an embodiment, the BS105may establish a RRC connection with the UE115in a primary cell (PCell) (e.g., over a primary frequency carrier) and may subsequently configure the UE115to communicate over a secondary cell (SCell) (e.g., over a secondary frequency carrier). In an embodiment, the BS105may trigger the UE115to report channel information based on channel-state-information-reference signal (CSI-RS) transmitted by the BS105. In some instances, the triggering may be aperiodic, which may be referred to as aperiodic-CSI-RS (A-CSI-RS) triggering.

The network100may operate over a shared frequency band or an unlicensed frequency band, for example, at about 3.5 gigahertz (GHz), sub-6 GHz or higher frequencies in the mmWave band. The network100may partition a frequency band into multiple channels, for example, each occupying about 20 megahertz (MHz). The BSs105and the UEs115may be operated by multiple network operating entities sharing resources in the shared communication medium and may acquire channel occupancy time (COT) in the share medium for communications. A COT may be non-continuous in time and may refer to an amount of time a wireless node can send frames when it has won contention for the wireless medium. Each COT may include a plurality of transmission slots. A COT may also be referred to as a transmission opportunity (TXOP).

In some aspects, to facilitate successful communications between a transmitter and a receiver, such as a BS105and a UE115or vice versa, the transmitter may transmit one or more reference signals (alone or along with a data transmission), such as demodulation reference signals (DMRSs), sounding reference signals (SRSs), and/or the like. The reference signal(s) may include a predetermined sequence and may be transmitted at predetermined time and/or frequency locations. The receiver may then estimate a channel response from the reference signal(s). Based on the channel estimation from processing the reference signal(s), the receiver can receive and decode communications from the transmitter.

Further, in some aspects, multiple reference signals may be bundled in the time domain across multiple time slots. When the reference signals are bundled, the receiver (e.g., a BS105or a UE115) may perform joint channel estimation using the reference signals received across the multiple time slots, as opposed to performing a separate channel estimation for each individual slot based on the reference signal(s) received in the slot. When reference signals are bundled in the time domain, the transmitter (e.g., a BS105or a UE115) can transmit the different reference signals with phase coherence to allow the receiver to perform the joint channel estimation. However, as described below with reference toFIG. 2, in some instances, the transmitter may be scheduled to implement a timing advance (TA) between the transmissions of the reference signals that are to be transmitted with phase coherence. In this regard, implementing the TA may cause the reference signals transmitted after implementation of the TA to be out of phase with the reference signals transmitted before the implementation of the TA. However, not implementing the TA may cause the transmitter and receiver (e.g., the BS105and the UE115) to be out of synchronization.

Accordingly, the present disclosure provides improved techniques for bundling uplink communication signals, including reference signals, under TA conditions (e.g., while maintaining synchronization between a UE115and a BS105). In particular, the present disclosure provides mechanisms for a UE115and a BS105to determine whether to implement a TA as scheduled or with a delay such that synchronization between the UE115and the BS105is maintained and bundled uplink communications between the UE115and the BS105may be properly received and decoded (e.g., processed).

FIG. 2illustrates uplink bundling and timing advance scheduling200according to some aspects of the present disclosure. The uplink bundling and timing advance scheduling200ofFIG. 2illustrates aspects of one or more uplink channels210(e.g., physical uplink shared channel (PUSCH), physical uplink control channel (PUCCH), etc.), one or more downlink channels220(e.g., physical downlink shared channel (PDSCH), physical downlink control channel (PDCCH), etc.), a timing advance (TA)230, and uplink communications240(e.g., PUSCH communications, PUCCH communications, demodulation reference signals (DMRSs), sounding reference signals (SRSs), etc.). InFIG. 2, the x-axis represents time in some arbitrary units as shown.

In some instances, DMRS bundling can be an effective technique for enhancing cell coverage, including for uplink communications near the edge or boundary of a cell. At the UE, the DMRSs can be coherently transmitted over different time instants corresponding to different uplink transmissions (e.g., PUSCH transmissions and/or PUCCH transmissions). At the BS, the DMRSs received over different time instants can be coherently filtered and/or combined to enhance the accuracy of channel estimation. That is, the DMRSs received over the different time instants can be processed jointly instead of separately or individually. Similar types of bundling techniques can be applied to other types of uplink communications240, including without limitation bundling between SRSs, bundling between an SRS and a PUCCH, bundling between an SRS and PUSCH, bundling between PUCCHs, bundling between PUSCHs, bundling between PUSCH and PUCCH, etc.

Timing advance is a technique that can be utilized to achieve uplink and/or downlink synchronization in a cell. In this regard, due to propagation delay, the timing at which the downlink signal is transmitted by the BS and the timing at which the uplink signal is received at the BS may exhibit a large delay, potentially creating an uplink/downlink conflict. Moreover, since the propagation delay from different UEs is typically different, then the timing for uplink signals transmitted from different UEs can be different, which may create undesired inter-symbol interference at the BS. To address this issue, the TA230can be utilized. In this regard, the UE can advance (or delay) its uplink transmissions by a certain amount of time (which roughly corresponds to twice the propagation delay between the UE and BS). In some instances, the BS indicates a TA value (e.g., in the unit of multiples of transmission samples (based on the sampling rate, which can depend on the subcarrier spacing)) in the TA230transmitted over the downlink channel(s)220. In some instances, the TA230is transmitted in a media access control control element (MAC CE) over the PDSCH. After receiving the TA with the TA value, the UE can implement the TA value by adjusting (e.g., delaying or advancing) its transmission timing.

As shown inFIG. 2, in some instances a TA230-ais scheduled to be applied by the UE at a time260. In this regard, in some instances the TA-230ais scheduled to be implemented by the UE starting with an uplink transmission that is at least a time gap270(e.g., Tgap) after the UE receives the TA230-a. In some instances, the length of the time gap270is based on a TA processing time of the UE. Accordingly, the time260at which the TA is scheduled to implemented by the UE can be based upon when the UE receives the TA from the BS, the time gap270, a TA processing time of the UE, and/or a communication schedule of the UE. In the illustrated example ofFIG. 2, the time gap270ends during slot250-awhere uplink communication240-ais transmitted. Accordingly, in some instances the UE is scheduled to implement the TA230-aprior to the slot250-band the transmission of the associated uplink communication240-b.

Although the TA230-athat gets applied by the UE is provided by the BS, in some instances there can still be some slack or difference in the synchronization timing between the UE and the BS. For example, in some instances, this difference can be caused because the UE applies the TA230-abased on its estimated downlink receive timing, which is not always estimated accurately. As a consequence, upon the implementation of the TA230-aby the UE, the BS may need to re-estimate the uplink timing and adjust the phase of the received symbols accordingly. In other words, when the UE applies the TA230-aon an uplink transmission the BS may need to re-estimate the uplink timing. Because the timing and phase of uplink communications are highly correlated, the change in timing resulting from implementing the TA230-acan result in a corresponding phase change in the uplink communication. Accordingly, in the example ofFIG. 2, if the uplink communications240-aand240-bare bundled communications scheduled to be transmitted with phase coherence, implementing the TA230-aat the scheduled time260could cause the uplink communications240-aand240-bto not have phase coherence and, therefore, prevent the BS from coherently processing the consecutive slots250-aand250-band associated communications240-aand240-b. This can be the case even where the UE transmits the uplink communications240-aand240-bwith phase coherence/continuity. Accordingly, aspects of the present disclosure provide mechanisms for handling uplink bundling and TA scheduling when a TA (e.g., TA230-a) is scheduled to be implement by a UE between uplink communications that are scheduled to be transmitted with phase coherency (e.g., uplink communications240-a and240-b).

FIG. 3illustrates uplink bundling and timing advance scheduling300according to some aspects of the present disclosure. The uplink bundling and timing advance scheduling300ofFIG. 3may be similar to and implement aspects of uplink bundling and timing advance scheduling200ofFIG. 2. The uplink bundling and timing advance scheduling300ofFIG. 3illustrates aspects of one or more uplink channels310(e.g., physical uplink shared channel (PUSCH), physical uplink control channel (PUCCH), etc.), one or more downlink channels320(e.g., physical downlink shared channel (PDSCH), physical downlink control channel (PDCCH), etc.), a timing advance (TA)330, and uplink communications340(e.g., PUSCH communications, PUCCH communications, demodulation reference signals (DMRSs), sounding reference signals (SRSs), etc.). InFIG. 3, the x-axis represents time in some arbitrary units as shown.

As shown, a TA330-ais transmitted over the downlink channel(s)320. In some instances, the TA330-ais transmitted in a MAC CE over the PDSCH. After receiving the TA330-a, the UE can implement the TA value by adjusting (e.g., delaying or advancing) its transmission timing.

As shown inFIG. 3, in some instances the TA330-ais scheduled to be applied by the UE at a time360. In some instances, the TA-330ais scheduled to be implemented by the UE starting with an uplink transmission that is at least a time gap370(e.g., Tgap) after the UE receives the TA330-a. In some instances, the length of the time gap370is based on a TA processing time of the UE. Accordingly, the time360at which the TA is scheduled to implemented by the UE can be based upon when the UE receives the TA330-afrom the BS, the time gap370, a TA processing time of the UE, and/or a communication schedule of the UE. In the illustrated example ofFIG. 3, the time gap370ends during slot350-awhere uplink communication340-ais transmitted. Accordingly, in some instances the UE is scheduled to implement the TA330-aprior to the slot350-band the transmission of the associated uplink communication340-b.

In some instances, the UE determines whether to implement the TA330-aat the time360or delay the implementation to a later time (e.g., after transmission of the uplink communication340-b). In some instances, the UE determines when to implement the TA330-abased on a configuration. The configuration may be a dynamic configuration received from a BS (e.g., via RRC signaling, MAC CE, DCI, or otherwise) or a predetermined/pre-programmed configuration stored in the memory of the UE. The configuration may provide one or more rules for the UE to utilize in determining when to implement the TA330-a. In this regard, the rules may be based on whether bundled uplink communications are scheduled with phase coherence, the number of bundled uplink communications, the length of time necessary for the bundled uplink communications, a magnitude of the TA, one or more other factors, and/or combinations thereof. The configuration may also provide rules for the UE to utilize in selecting the timing for implementing the TA330-awhen the implementation is to be delayed from time360. In this regard, the timing can be based on one or more of an uplink-to-downlink switch, a downlink-to-uplink switch, a time gap between uplink communications, a power change between uplink communications, and/or the uplink communications not being scheduled with phase coherence.

In the illustrated example ofFIG. 3, the UE implements the TA330-aat time360as indicated by adjustment380. Note that adjustment380shows an exaggerated delay period simply to illustrate the concept and is not necessarily to scale. It is understood that the adjustment380can be an advance or a delay in the uplink timing of the UE and will be based on the value included in the TA330-a. Implementing the TA330-aat the scheduled time360can cause the uplink communication340-bto not have phase coherency with uplink communication340-a. In other words, the UE is not expected to keep the phase coherence between uplink communications340-aand340-bif the UE applies the TA330-afor uplink communication340-b. Therefore, in some instances the BS processes the uplink communications340-aand340-bseparately, instead of coherently processing them together.

In some instances, the BS determines when the TA330-awas implemented by the UE based on the received uplink communications340-aand340-b, the TA processing capabilities of the UE, a configuration implemented by the UE, and/or other factors. In some instances, the timing of the implementation of the TA330-aby the UE is based on a configuration, as discussed above. In some instances, the BS utilizes aspects of the configuration to estimate and/or determine when the UE will implement the TA330-a. In this regard, as shown in the example ofFIG. 3, the BS may determine that the UE will implement the TA at time360and, therefore, determine to process the uplink communications340-aand340-bseparately.

FIG. 4illustrates uplink bundling and timing advance scheduling400according to some aspects of the present disclosure. The uplink bundling and timing advance scheduling400ofFIG. 4may be similar to and implement aspects of uplink bundling and timing advance schedulings200and300ofFIGS. 2 and 3. The uplink bundling and timing advance scheduling400ofFIG. 4illustrates aspects of one or more uplink channels410(e.g., physical uplink shared channel (PUSCH), physical uplink control channel (PUCCH), etc.), one or more downlink channels420(e.g., physical downlink shared channel (PDSCH), physical downlink control channel (PDCCH), etc.), a timing advance (TA)430, and uplink communications440(e.g., PUSCH communications, PUCCH communications, demodulation reference signals (DMRSs), sounding reference signals (SRSs), etc.). InFIG. 4, the x-axis represents time in some arbitrary units as shown.

As shown, a TA430-ais transmitted over the downlink channel(s)420. In some instances, the TA430-ais transmitted in a MAC CE over the PDSCH. After receiving the TA430-a, the UE can implement the TA value by adjusting (e.g., delaying or advancing) its transmission timing.

As shown inFIG. 4, in some instances the TA430-ais scheduled to be applied by the UE at a time460-a. In some instances, the TA-430ais scheduled to be implemented by the UE starting with an uplink transmission that is at least a time gap470(e.g., T_gap) after the UE receives the TA430-a. In some instances, the length of the time gap470is based on a TA processing time of the UE. Accordingly, the time460-aat which the TA is scheduled to implemented by the UE can be based upon when the UE receives the TA430-afrom the BS, the time gap470, a TA processing time of the UE, and/or a communication schedule of the UE. In the illustrated example ofFIG. 4, the time gap470ends during slot450-awhere uplink communication440-ais transmitted. Accordingly, in some instances the UE is scheduled to implement the TA430-aprior to the slot450-band the transmission of the associated uplink communication440-b.

In some instances, the UE determines whether to implement the TA430-aat the time460-aor delay the implementation to a later time, such as time460-b. In some instances, the UE determines when to implement the TA430-abased on a configuration. The configuration may be a dynamic configuration received from a BS (e.g., via RRC signaling, MAC CE, DCI, or otherwise) or a predetermined/pre-programmed configuration stored in the memory of the UE. The configuration may provide one or more rules for the UE to utilize in determining when to implement the TA430-a. In this regard, the rules may be based on whether bundled uplink communications are scheduled with phase coherence, the number of bundled uplink communications, the length of time necessary for the bundled uplink communications, a magnitude of the TA, one or more other factors, and/or combinations thereof. The configuration may also provide rules for the UE to utilize in selecting the timing for implementing the TA430-awhen the implementation is to be delayed from time460-a. In this regard, the time460-bcan be selected based on one or more of an uplink-to-downlink switch, a downlink-to-uplink switch, a time gap between uplink communications, a power change between uplink communications, and/or the uplink communications not being scheduled with phase coherence.

In some instances, the configuration may dictate that the UE should transmit a certain number (e.g., 2, 3, 4, etc.) of bundled uplink communications scheduled with phase coherency prior to implementing the TA430-a. The number of bundled uplink communications to transmit with phase coherency may be less than all the bundled uplink communications scheduled in some instances. As another example, the configuration may indicate that the UE should transmit any bundled uplink communications scheduled within a certain time period (e.g., number of slots, x ms, etc.) with phase coherency prior to implementing the TA430-a. Again, the number of bundled uplink communications in the time period may be less than all the bundled uplink communications scheduled in some instances. In some instances, delay in implementing the TA430-amay be partially based on the magnitude of the TA430-a. In this regard, a smaller magnitude TA430-amay be allowed a longer delay period for implementation than a larger magnitude TA430-a. In some instances, if a magnitude of the TA430-ais above a threshold, then the UE delays implementation of the TA; otherwise the UE applies the TA at460-aand keeps the phase coherence across the uplink communications440-aand440-b. In some instances, the UE is configured to implement the TA430-afollowing an uplink-to-downlink switch. In some instances, the UE is configured to implement the TA430-afollowing a downlink-to-uplink switch. In some instances, the UE is configured to implement the TA430-awhen a gap (e.g., time and/or number of slots/sub-slots) between uplink communications exceeds a threshold. That is, if the gap between two uplink communications is sufficiently large the UE can implement the TA430-a. In some instances, the UE is configured to implement the TA430-awhen there is a power change between uplink communications. In some instances, the UE is configured to implement the TA430-abetween uplink communications when the uplink communications are not scheduled with phase coherence.

As a result of delaying the implementation of the TA430-ain accordance with any of the techniques discussed above, there can be a time gap475between the initially scheduled implementation time460-aand the actual implementation time460-b. In some instances, the time gap475may be a fixed and/or predetermined amount of time and operate in a similar manner to time gap470. That is, the UE may implement the TA430-aafter the time gap475ends following the scheduled time460-a. In some instances, the time gap470and/or the time gap475is implemented by the UE using a timer.

In the illustrated example ofFIG. 4, the UE determines to delay the implementation of the TA430-afrom time460-ato time460-b. Accordingly, in some instances the uplink communication440-bis transmitted before implementing the TA430-a. In this regard, the uplink communication440-bmay be transmitted with phase coherence with the uplink communication440-aas a result of delaying implementation of the TA430-auntil after transmitting the uplink communication440-b. Therefore, the BS receiving the uplink communications440-aand440-bmay process the uplink communications440-aand440-bjointly, instead of separately, because of the phase continuity.

In some instances, the BS determines when the TA430-awas implemented by the UE based on the received uplink communications440-aand440-b, the TA processing capabilities of the UE, a configuration implemented by the UE, and/or other factors. In some instances, the timing of the implementation of the TA430-aby the UE is based on a configuration, as discussed above. In some instances, the BS utilizes aspects of the configuration to estimate and/or determine when the UE will implement the TA430-a. In this regard, as shown in the example ofFIG. 4, the BS may determine that the UE will implement the TA430-aat time460-band, therefore, determine to process the uplink communications440-aand440-bjointly.

FIG. 5illustrates uplink bundling and timing advance scheduling500according to some aspects of the present disclosure. The uplink bundling and timing advance scheduling500ofFIG. 5may be similar to and implement aspects of uplink bundling and timing advance schedulings200,300, and400ofFIGS. 2-4. The uplink bundling and timing advance scheduling500ofFIG. 5illustrates aspects of one or more uplink channels510(e.g., physical uplink shared channel (PUSCH), physical uplink control channel (PUCCH), etc.), one or more downlink channels520(e.g., physical downlink shared channel (PDSCH), physical downlink control channel (PDCCH), etc.), a timing advance (TA)530, and uplink communications540(e.g., PUSCH communications, PUCCH communications, demodulation reference signals (DMRSs), sounding reference signals (SRSs), etc.). InFIG. 5, the x-axis represents time in some arbitrary units as shown.

As shown, a TA530-ais transmitted over the downlink channel(s)520. In some instances, the TA530-ais transmitted in a MAC CE over the PDSCH. After receiving the TA530-a, the UE can implement the TA value by adjusting (e.g., delaying or advancing) its transmission timing.

As shown inFIG. 5, in some instances the TA530-ais scheduled to be applied by the UE at a time560-a. In some instances, the TA-530ais scheduled to be implemented by the UE starting with an uplink transmission that is at least a time gap570(e.g., T_gap) after the UE receives the TA530-a. In some instances, the length of the time gap570is based on a TA processing time of the UE. Accordingly, the time560-aat which the TA is scheduled to implemented by the UE can be based upon when the UE receives the TA530-afrom the BS, the time gap570, a TA processing time of the UE, and/or a communication schedule of the UE. In the illustrated example ofFIG. 5, the time gap570ends during slot550-awhere uplink communication540-ais transmitted. Accordingly, in some instances the UE is scheduled to implement the TA530-aprior to the slot550-band the transmission of the associated uplink communication540-b.

In some instances, the UE determines whether to implement the TA530-aat the time560-aor delay the implementation to a later time, such as time560-b. In some instances, the UE determines when to implement the TA530-abased on a configuration as discussed above with respect toFIGS. 3 and 4. In this regard, the configuration may provide one or more rules for the UE to utilize in determining when to implement the TA530-a. In this regard, the rules may be based on whether bundled uplink communications are scheduled with phase coherence, the number of bundled uplink communications, the length of time necessary for the bundled uplink communications, a magnitude of the TA, one or more other factors, and/or combinations thereof. The configuration may also provide rules for the UE to utilize in selecting the timing for implementing the TA530-awhen the implementation is to be delayed from time560-a. In this regard, the time560-bcan be selected based on one or more of an uplink-to-downlink switch, a downlink-to-uplink switch, a time gap between uplink communications, a power change between uplink communications, and/or the uplink communications not being scheduled with phase coherence.

FIG. 5illustrates some examples of how the time560-bcan be selected in accordance with the present disclosure. For example, in some instances, the UE may be configured to transmit a certain number (e.g., 2, 3, 4, etc.) of bundled uplink communications scheduled with phase coherency prior to implementing the TA530-a. The number of bundled uplink communications to transmit with phase coherency may be all or less than all the bundled uplink communications scheduled. For example, inFIG. 5the UE may be configured to transmit both uplink communications540-aand540-bwith phase coherency prior to implementing the TA530-a.

As another example, the UE may be configured to transmit any bundled uplink communications scheduled within a certain time period (e.g., number of slots, x ms, etc.) with phase coherency prior to implementing the TA530-a. Again, the number of bundled uplink communications in the time period may be less than all the bundled uplink communications scheduled in some instances. InFIG. 5, for example, the UE may be configured to transmit both uplink communications540-aand540-bwith phase coherency during the allotted time period, then implement the TA530-a. In some instances, the UE may be configured to determine the amount of allowable delay for implementing the TA530-abased on the magnitude of the TA530-a. In this regard, a smaller magnitude TA530-amay be allowed a longer delay period for implementation than a larger magnitude TA530-a. In some instances, if a magnitude of the TA530-ais above a threshold, then the UE delays implementation of the TA530-a; otherwise the UE applies the TA530-aat560-aand keeps the phase coherence across the uplink communications540-aand540-b.

In some instances, the UE may be configured to implement the TA530-afollowing an uplink-to-downlink switch. InFIG. 5, for example, the UE may be configured to implement the TA530-afollowing a switch from uplink slot550-bto downlink slot550-c. Accordingly, prior to the next uplink communication (e.g., uplink communication540-d) and/or uplink slot (e.g., slot550-d) following the uplink-to-downlink switch the UE can implement the TA530-a.

In some instances, the UE may be configured to implement the TA530-afollowing a downlink-to-uplink switch. InFIG. 5, for example, the UE may be configured to implement the TA530-afollowing a switch from downlink slot550-cto uplink slot550-d. Accordingly, prior to the next uplink communication (e.g., uplink communication540-d) and/or the uplink slot (e.g., slot550-d) following the downlink-to-uplink switch the UE can implement the TA530-a.

In some instances, the UE may be configured to implement the TA530-awhen a gap (e.g., time and/or number of slots/sub-slots) between uplink communications exceeds a threshold. That is, if the gap between two uplink communications is sufficiently large the UE can implement the TA530-a. InFIG. 5, for example, the UE may be configured to implement the TA530-abetween uplink communications540-band540-dbecause the gap satisfies a threshold (e.g., 1 slot), whereas the gap between uplink communications540-aand540-bdoes not satisfy the threshold.

In some instances, the UE may be configured to implement the TA530-awhen there is a power change between uplink communications. InFIG. 5, for example, the UE may be configured to implement the TA530-abetween uplink communications540-band540-dbecause of power change or difference between the uplink communications540-band540-d, whereas uplink communications540-aand540-bmay be transmitted using the same power level.

In some instances, the UE may be configured to implement the TA530-abetween uplink communications when the uplink communications are not scheduled with phase coherence. InFIG. 5, for example, the UE may be configured to implement the TA530-abetween uplink communications540-band540-dbecause of the uplink communications540-band540-dare not scheduled with phase coherency, whereas uplink communications540-aand540-bmay be scheduled with phase coherency.

As a result of delaying the implementation of the TA530-ain accordance with any of the techniques discussed above, there can be a time gap575between the initially scheduled implementation time560-aand the actual implementation time560-b. In some instances, the time gap575may be a fixed and/or predetermined amount of time and operate in a similar manner to time gap570. That is, the UE may implement the TA530-aafter the time gap575ends following the scheduled time560-a. In some instances, the time gap570and/or the time gap575is implemented by the UE using a timer.

In the illustrated example ofFIG. 5, the UE determines to delay the implementation of the TA530-afrom time560-ato time560-b. Accordingly, in some instances the uplink communication540-bis transmitted before implementing the TA530-a. In this regard, the uplink communication540-bmay be transmitted with phase coherence with the uplink communication540-aas a result of delaying implementation of the TA530-auntil after transmitting the uplink communication540-b. Therefore, the BS receiving the uplink communications540-aand540-bmay process the uplink communications540-aand540-bjointly, instead of separately, because of the phase continuity.

In some instances, the BS determines when the TA530-awas implemented by the UE based on the received uplink communications540-aand540-b, the TA processing capabilities of the UE, a configuration implemented by the UE, and/or other factors. In some instances, the timing of the implementation of the TA530-aby the UE is based on a configuration, as discussed above. In some instances, the BS utilizes aspects of the configuration to estimate and/or determine when the UE will implement the TA530-a. In this regard, as shown in the example ofFIG. 5, the BS may determine that the UE will implement the TA530-aat time560-band, therefore, determine to process the uplink communications540-aand540-bjointly.

FIG. 6illustrates a signal diagram600illustrating uplink bundling and timing advance communications according to some aspects of the present disclosure. Aspects of the signal diagram600can be used for the uplink bundling and timing advance schedulings200,300,400, and500ofFIGS. 2-5.

At605, the BS105transmits a timing advance configuration to the UE115. In some instances, the timing advance configuration is a dynamic configuration determined by the BS. The timing advance configuration may be transmitted to the UE115via RRC signaling, MAC CE, DCI, or other suitable communication. In some instances, the BS105does not transmit the timing advance configuration to the UE115. For example, the configuration may be a predetermined/pre-programmed configuration stored in the memory of the UE in some instances. The timing advance configuration, at605, can indicate when to delay implementation of a TA in accordance with the present disclosure. In this regard, the timing advance configuration may provide one or more rules for determining when to implement the TA. In this regard, the configuration may be based on whether bundled uplink communications are scheduled with phase coherence, the number of bundled uplink communications, the length of time necessary for the bundled uplink communications, a magnitude of the TA, one or more other factors, and/or combinations thereof.

Further, the configuration, at605, may provide one or more rules for determining the timing for implementing the TA when the TA implementation will be delayed. In this regard, the timing of the delayed implementation can be based on one or more of an uplink-to-downlink switch, a downlink-to-uplink switch, a time gap between the second uplink communication and a third uplink communication, a power change between the second uplink communication and the third uplink communication, and/or the third uplink communication not being scheduled with phase coherence with the first uplink communication and/or the second uplink communication.

At610, the BS105can schedule uplink communications for the UE115. In this regard, the BS105may allocate resources to the UE115for use by the UE115in transmitting uplink communications. The allocated resources can include time and frequency resources that can be utilized by the UE115for any suitable communications, including without limitation DMRS, SRS, PUCCH, PUSCH, and other uplink communications. At615, the BS105can indicate the resources allocated to the UE115via an uplink grant.

At620, the BS105transmits a timing advance (TA) to the UE115. In some instances, the TA is transmitted, at620, via a media access control control element (MAC CE) communication (e.g., via PDSCH) or other suitable communication. As discussed above, in some instances the TA is scheduled to be implemented by the UE at a time that is after the start of a first uplink communication of a group of bundled uplink communications scheduled with phase coherence, but before the start of a second uplink communication of the group of bundled uplink communications (see, e.g.,FIGS. 2-5). In some instances, the time at which the TA is scheduled to be implemented by the UE is based on when the UE receives the TA from the BS, a TA processing time of the UE, and/or a communication schedule of the UE. In some instances, the UE may transmit a capability report indicating the BS the TA processing time of the UE and/or other information allowing the BS to determine when the UE will be scheduled to implement the TA based on when the BS transmits the TA to the UE.

At625, the UE115processes the TA. In some instances, the UE processes the TA to determine a TA value and/or when to implement the TA. In this regard, the UE can determine whether to implement the TA at the first time or a second time, the second time being after transmission of the second uplink communication. In some instances, the UE determines whether to implement the TA at an initially scheduled time or delay the implementation to a later time in accordance with the present disclosure (see, e.g.,FIGS. 2-5).

At630, the UE115implements the TA based on the processing of the TA at625. In this regard, the UE115may implement the TA at a suitable time relative to the uplink communications640-a,640-b, and/or640-c. In some instances, two or more of the uplink communications640-a,640-b, and/or640-care bundled and scheduled to be transmitted with phase coherence. The uplink communications640-a,640-b, and/or640-ccan include at least one of a demodulation reference signal (DMRS), a sounding reference signal (SRS), a physical uplink control channel (PUCCH) communication, a physical uplink shared channel (PUSCH) communication, and/or another uplink communication. In some instances, the uplink communications640-a,640-b, and/or640-care each the same type of uplink communication (e.g., DMRS, SRS, etc.). In some instances, at least one of the uplink communications640-a,640-b, and/or640-cincludes a different type of uplink communication than one of the other uplink communications640-a,640-b, and/or640-c.

In some instances, at step630, the UE115determines to implement the TA at an initially scheduled time between the uplink communication640-aand the uplink communication640-b(see, e.g.,FIG. 3). Accordingly, in some instances the uplink communication640-bis transmitted by the UE115after implementing the TA. In this regard, the uplink communication640-bmay be transmitted without phase coherence with the uplink communication640-a. Therefore, the BS105may process, at650, the uplink communications640-aand640-bseparately, instead of jointly, even if the uplink communications640-aand640-bwere initially scheduled to be transmitted with phase coherence.

In some instances, at step630, the UE115determines to delay implementation of the TA from an initially scheduled time between the uplink communication640-aand the uplink communication640-bto a later time (see, e.g.,FIGS. 4 and 5). Accordingly, in some instances the uplink communication640-bis transmitted by the UE115before implementing the TA. In this regard, the uplink communication640-bmay be transmitted with phase coherence with the uplink communication640-aas a result of delaying the implementation of the TA until after transmitting the uplink communication640-b. Therefore, the BS105, at650, may process the uplink communications640-aand640-bjointly, instead of separately.

FIG. 7is a block diagram of an exemplary UE700according to aspects of the present disclosure. The UE700may be a UE115as discussed above inFIG. 1. As shown, the UE700may include a processor702, a memory704, an uplink scheduling and control module708, a transceiver710including a modem subsystem712and a radio frequency (RF) unit714, and one or more antennas716. These elements may be in direct or indirect communication with each other, for example via one or more buses.

The uplink scheduling and control module708may be implemented via hardware, software, or combinations thereof. For example, uplink scheduling and control module708may be implemented as a processor, circuit, and/or instructions706stored in the memory704and executed by the processor702. In some examples, the uplink scheduling and control module708can be integrated within the modem subsystem712. For example, the uplink scheduling and control module708can be implemented by a combination of software components (e.g., executed by a DSP or a general processor) and hardware components (e.g., logic gates and circuitry) within the modem subsystem712.

The uplink scheduling and control module708may be used for various aspects of the present disclosure, for example, aspects ofFIGS. 3-6 and 9. The uplink scheduling and control module708is configured to communicate with other components of the UE700to receive a TA configuration, process the TA configuration, receive a TA, receive a MAC CE, determine when to implement the TA, implement the TA, transmit uplink communications (e.g., DMRS, SRS, PUCCH, PUSCH, etc.), perform PDCCH monitoring, perform PDSCH monitoring, determine whether a timer has expired, cancel a timer, determine whether a condition has occurred or is met, and/or perform other functionalities related to the uplink bundling and TA configurations and associated wireless communication techniques of a UE described in the present disclosure.

As shown, the transceiver710may include the modem subsystem712and the RF unit714. The transceiver710can be configured to communicate bi-directionally with other devices, such as the BSs105. The modem subsystem712may be configured to modulate and/or encode the data from the memory704, and/or the uplink scheduling and control module708according to a modulation and coding scheme (MCS) (e.g., a low-density parity check (LDPC) coding scheme, a turbo coding scheme, a convolutional coding scheme, a digital beamforming scheme, etc.). The RF unit714may be configured to process (e.g., perform analog to digital conversion or digital to analog conversion, etc.) modulated/encoded data (e.g., UL control information, UL data) from the modem subsystem712(on outbound transmissions) or of transmissions originating from another source such as a UE115or a BS105. The RF unit714may be further configured to perform analog beamforming in conjunction with the digital beamforming. Although shown as integrated together in transceiver710, the modem subsystem712and the RF unit714may be separate devices that are coupled together at the UE115to enable the UE115to communicate with other devices.

The RF unit714may provide the modulated and/or processed data (e.g., data packets or, more generally, data messages that may contain one or more data packets and other information) to the antennas716for transmission to one or more other devices. The antennas716may further receive data messages transmitted from other devices. The antennas716may provide the received data messages for processing and/or demodulation at the transceiver710. The transceiver710may provide the demodulated and decoded data (e.g., PDCCH signals, radio resource control (RRC) signals, media access control (MAC) control element (CE) signals, DCI, PDSCH signals, DL/UL scheduling grants, DL data, etc.) to the uplink scheduling and control module708for processing. The antennas716may include multiple antennas of similar or different designs in order to sustain multiple transmission links. The RF unit714may configure the antennas716. The RF unit714and/or the transceiver710may include components and/or circuitries that can be powers on and/or off dynamically for power savings. Additionally, or alternatively, the RF unit714and/or the transceiver710may include components and/or circuitries with multiple power states that can be configured to transition from one power state (e.g., a higher-power state) to another power state (e.g., a lower-power state) for power savings.

In an embodiment, the UE700can include multiple transceivers710implementing different RATs (e.g., NR and LTE). In an embodiment, the UE700can include a single transceiver710implementing multiple RATs (e.g., NR and LTE). In an embodiment, the transceiver710can include various components, where different combinations of components can implement different RATs.

FIG. 8is a block diagram of an exemplary BS800according to aspects of the present disclosure. The BS800may be a BS105as discussed above inFIG. 1. As shown, the BS800may include a processor802, a memory804, an uplink scheduling and control module808, a transceiver810including a modem subsystem812and a RF unit814, and one or more antennas816. These elements may be in direct or indirect communication with each other, for example via one or more buses.

The memory804may include a cache memory (e.g., a cache memory of the processor802), RAM, MRAM, ROM, PROM, EPROM, EEPROM, flash memory, a solid state memory device, one or more hard disk drives, memristor-based arrays, other forms of volatile and non-volatile memory, or a combination of different types of memory. In some instances, the memory804may include a non-transitory computer-readable medium. The memory804may store instructions806. The instructions806may include instructions that, when executed by the processor802, cause the processor802to perform operations described herein, for example, aspects ofFIGS. 3-6 and 10. Instructions806may also be referred to as code, which may be interpreted broadly to include any type of computer-readable statement(s) as discussed above.

The uplink scheduling and control module808may be implemented via hardware, software, or combinations thereof. For example, the uplink scheduling and control module808may be implemented as a processor, circuit, and/or instructions806stored in the memory804and executed by the processor802. In some examples, the uplink scheduling and control module808can be integrated within the modem subsystem812. For example, the uplink scheduling and control module808can be implemented by a combination of software components (e.g., executed by a DSP or a general processor) and hardware components (e.g., logic gates and circuitry) within the modem subsystem812.

The uplink scheduling and control module808may be used for various aspects of the present disclosure, for example, aspects ofFIGS. 3-6 and 10. The uplink scheduling and control module808can be configured to determine a TA configuration for one or more UEs, transmit the TA configuration to the one or more UEs, perform uplink scheduling for the one or more UEs, generate TAs for the one or more UEs, transmit the TAs to the one or more UEs, transmit MAC CE, transmit PDCCH communications, transmit PDSCH communications, determine when a UE has or will implement the TA, monitor for uplink communications (e.g., DMRS, SRS, PUCCH, PUSCH, etc.), process uplink communications (either separately or jointly), determine whether a timer has expired, cancel a timer, determine whether a condition has occurred or is met, and/or perform other functionalities related to the uplink bundling and TA configurations and associated wireless communication techniques of a base station described in the present disclosure.

As shown, the transceiver810may include the modem subsystem812and the RF unit814. The transceiver810can be configured to communicate bi-directionally with other devices, such as the UEs115and/or700and/or another core network element. The modem subsystem812may be configured to modulate and/or encode data according to a MCS (e.g., a LDPC coding scheme, a turbo coding scheme, a convolutional coding scheme, a digital beamforming scheme, etc.). The RF unit814may be configured to process (e.g., perform analog to digital conversion or digital to analog conversion, etc.) modulated/encoded data (e.g., PDCCH signals, RRC signals, MAC CE signals, DCI, PDSCH signals, etc.) from the modem subsystem812(on outbound transmissions) or of transmissions originating from another source, such as a UE115or700. The RF unit814may be further configured to perform analog beamforming in conjunction with the digital beamforming. Although shown as integrated together in transceiver810, the modem subsystem812and/or the RF unit814may be separate devices that are coupled together at the BS105to enable the BS105to communicate with other devices.

The RF unit814may provide the modulated and/or processed data, (e.g., data packets or, more generally, data messages that may contain one or more data packets and other information) to the antennas816for transmission to one or more other devices. This may include, for example, transmission of information to a UE115or700according to aspects of the present disclosure. The antennas816may further receive data messages transmitted from other devices and provide the received data messages for processing and/or demodulation at the transceiver810. The transceiver810may provide the demodulated and decoded data (e.g., RACH message(s), ACK/NACKs for PDCCH signals, UL data, ACK/NACKs for DL data, etc.) to the uplink scheduling and control module808for processing. The antennas816may include multiple antennas of similar or different designs in order to sustain multiple transmission links.

In an embodiment, the BS800can include multiple transceivers810implementing different RATs (e.g., NR and LTE). In an embodiment, the BS800can include a single transceiver810implementing multiple RATs (e.g., NR and LTE). In an embodiment, the transceiver810can include various components, where different combinations of components can implement different RATs.

FIG. 9is a flow diagram of a communication method900according to some aspects of the present disclosure. Aspects of the method900can be executed by a wireless communication device, such as the UEs115and/or700utilizing one or more components, such as the processor702, the memory704, the uplink scheduling and control module708, the transceiver710, the modem712, the one or more antennas716, and various combinations thereof. As illustrated, the method900includes a number of enumerated steps, but the method900may include additional steps before, after, and in between the enumerated steps. For example, in some instances one or more aspects of uplink bundling and timing advance schedulings200,300,400, and/or500and/or signaling diagram600may be implemented as part of method900. In some instances, one or more of the enumerated steps may be omitted or performed in a different order.

At step910, the method900includes the UE receiving, from a BS, a timing advance (TA). In some instances, the TA is received via a media access control control element (MAC CE) communication (e.g., via PDSCH) or other suitable communication from the BS. In some instances, the TA is scheduled to be implemented by the UE at a time that is after the start of a first uplink communication of a group of bundled uplink communications scheduled with phase coherence, but before the start of a second uplink communication of the group of bundled uplink communications (see, e.g.,FIGS. 2-5). In some instances, the time at which the TA is scheduled to be implemented by the UE is based on when the UE receives the TA from the BS, a TA processing time of the UE, and/or a communication schedule of the UE. In some instances, the UE may transmit a capability report indicating the BS the TA processing time of the UE and/or other information allowing the BS to determine when the UE will be scheduled to implement the TA based on when the BS transmits the TA to the UE.

The first uplink communication can include at least one of a demodulation reference signal (DMRS), a sounding reference signal (SRS), a physical uplink control channel (PUCCH) communication, a physical uplink shared channel (PUSCH) communication, and/or another uplink communication. The second uplink communication can include at least one of a DMRS, an SRS, a PUCCH communication, a PUSCH communication, and/or another uplink communication. In some instances, the first and second uplink communications are the same type of uplink communication (e.g., DMRS and DMRS, SRS and SRS, etc.). In some instances, the first and second uplink communications are the different types of uplink communications (e.g., DMRS and SRS, DMRS and PUSCH communication, SRS and PUCCH communication, PUCCH communication and PUSCH communication, etc.). Accordingly, the bundled uplink communications scheduled with phase coherence may include the same and/or different types of uplink communications.

At step920, the method900includes the UE determining whether to implement the TA at the first time or a second time, the second time being after transmission of the second uplink communication. In some instances, the UE determines whether to implement the TA at the first time or the second time based on a configuration. The configuration may be a dynamic configuration received from the BS (e.g., via RRC signaling, MAC CE, DCI, or otherwise) or a predetermined/pre-programmed configuration stored in the memory of the UE. In this regard, the method900can include the UE receiving, from the BS, a configuration indicating when to delay implementation of the TA from the first time to the second time. The configuration may provide one or more rules for the UE to utilize in determining when to implement the TA at the first time and when to delay implementing the TA to a second time. In this regard, the rules may be based on whether bundled uplink communications are scheduled with phase coherence, the number of bundled uplink communications, the length of time necessary for the bundled uplink communications, a magnitude of the TA (e.g., if the TA has a magnitude greater than a threshold, then the TA is implemented at the first time), one or more other factors, and/or combinations thereof.

Further, the configuration may provide rules for the UE to utilize in selecting the timing of the second time when the TA implementation is to be delayed. In this regard, the timing of the second time can be based on one or more of an uplink-to-downlink switch, a downlink-to-uplink switch, a time gap between the second uplink communication and a third uplink communication, a power change between the second uplink communication and the third uplink communication, and/or the third uplink communication not being scheduled with phase coherence with the first uplink communication and/or the second uplink communication.

At step930, the method900includes the UE implementing the TA based on the determining. In this regard, the UE may implement the TA at the first time or delay implementation of the TA to a later time (e.g., the second time). When the UE implements the TA, the UE adjusts its transmission timing in accordance with the TA received from the BS. In this regard, implementing the TA helps to ensure that the UE and the BS are in synchronization and, as a result, that the UE's uplink communications are successfully received by the BS.

In some instances, the method900includes determining, at step920, to implement the TA at the first time and implementing, at step930, the TA at the first time. Accordingly, in some instances the second uplink communication is transmitted after implementing the TA. In this regard, the second uplink communication may be transmitted without phase coherence with the first uplink communication as a result of implementing the TA prior to transmitting the second uplink communication. Therefore, the BS receiving the first and second uplink communications may process the first and second uplink communications separately, instead of jointly.

In some instances, the method900includes the UE determining, at step920, to implement the TA at the second time and implementing, at step930, the TA at the second time. Accordingly, in some instances the second uplink communication is transmitted before implementing the TA. In this regard, the second uplink communication may be transmitted with phase coherence with the first uplink communication as a result of implementing the TA after transmitting the second uplink communication. Therefore, the BS receiving the first and second uplink communications may process the first and second uplink communications jointly, instead of separately.

In some instances, the method900includes the UE determining a timing for the second time. For example, the timing of the second time can be based on one or more of an uplink-to-downlink switch, a downlink-to-uplink switch, a time gap between the second uplink communication and a third uplink communication, a power change between the second uplink communication and the third uplink communication, and/or whether the third uplink communication is scheduled with phase coherence with the first uplink communication and/or the second uplink communication. In this regard, the UE may determine to implement the TA after an uplink-to-downlink switch occurs, after a downlink-to-uplink switch occurs, when a time gap between the second uplink communication and a third uplink communication satisfies a threshold amount, when there is a power change between the second uplink communication and the third uplink communication, and/or prior to the third uplink communication when the third uplink communication is not scheduled with phase coherence with the first uplink communication and/or the second uplink communication. In some instances, the UE implements the TA prior to an uplink transmission following the occurrence of one or more of these events. That is, upon occurrence of one or more of these events, the UE may delay implementing the TA until closer in time to when the UE is scheduled to transmit an uplink communication.

FIG. 10is a flow diagram of a communication method1000according to some aspects of the present disclosure. Aspects of the method1000can be executed by a wireless communication device, such as the BSs105and/or800utilizing one or more components, such as the processor802, the memory804, the uplink scheduling and control module808, the transceiver810, the modem812, the one or more antennas816, and various combinations thereof. As illustrated, the method1000includes a number of enumerated steps, but the method1000may include additional steps before, after, and in between the enumerated steps. For example, in some instances one or more aspects of uplink bundling and timing advance schedulings200,300,400, and/or500and/or signaling diagram600may be implemented as part of method1000. In some instances, one or more of the enumerated steps may be omitted or performed in a different order.

At step1010, the method1000includes the BS transmitting, to a UE, a timing advance (TA). In some instances, the TA is transmitted to the UE via a media access control control element (MAC CE) communication (e.g., via PDSCH) or other suitable communication. In some instances, the TA is scheduled to be implemented by the UE after the start of a first uplink communication of a group of bundled uplink communications scheduled with phase coherence and before the start of a second uplink communication of the group of bundled uplink communications (see, e.g.,FIGS. 2-5). In some instances, the time at which the TA is scheduled to be implemented by the UE is based on when the UE receives the TA from the BS, a TA processing time of the UE, and/or a communication schedule of the UE. In some instances, the BS may receive a capability report from the UE indicating the TA processing time of the UE and/or other information allowing the BS to determine when the UE will be scheduled to implement the TA based on when the BS transmits the TA to the UE.

At step1020, the method1000includes the BS receiving, from the UE, the first uplink communication. The first uplink communication can include at least one of a demodulation reference signal (DMRS), a sounding reference signal (SRS), a physical uplink control channel (PUCCH) communication, a physical uplink shared channel (PUSCH) communication, and/or another uplink communication.

At step1030, the method1000includes the BS receiving, from the UE, the second uplink communication. The second uplink communication can include at least one of a DMRS, an SRS, a PUCCH communication, a PUSCH communication, and/or another uplink communication.

In some instances, the first and second uplink communications are the same type of uplink communication (e.g., DMRS and DMRS, SRS and SRS, etc.). In some instances, the first and second uplink communications are the different types of uplink communications (e.g., DMRS and SRS, DMRS and PUSCH communication, SRS and PUCCH communication, PUCCH communication and PUSCH communication, etc.). Accordingly, the bundled uplink communications scheduled with phase coherence may include the same and/or different types of uplink communications.

At step1040, the method1000includes the BS processing the first uplink communication and the second uplink communication based on when the TA was implemented by the UE. In some instances, the BS determines when the TA was implemented by the UE based on the received first and second uplink communication signals, the TA processing capabilities of the UE, a configuration implemented by the UE, and/or other factors. In some instances, the timing of the implementation of the TA is based on a configuration. The configuration may be a dynamic configuration determined by the BS and transmitted to the UE (e.g., via RRC signaling, MAC CE, DCI, or otherwise) or a predetermined/pre-programmed configuration stored in the memory of the BS and/or UE. In this regard, the method1000can include the BS transmitting, to the UE, a configuration indicating when to delay implementation of the TA from the first time to the second time.

The configuration may provide one or more rules for determining when to implement the TA at the first time and when to delay implementing the TA to a second time. In this regard, the rules may be based on whether bundled uplink communications are scheduled with phase coherence, the number of bundled uplink communications, the length of time necessary for the bundled uplink communications, a magnitude of the TA (e.g., if the TA has a magnitude greater than a threshold, then the TA is implemented at the first time), one or more other factors, and/or combinations thereof. Further, the configuration may provide rules for selecting the timing for implementing the TA when the TA implementation is to be delayed. In this regard, the timing of the TA implementation can be based on one or more of an uplink-to-downlink switch, a downlink-to-uplink switch, a time gap between the second uplink communication and a third uplink communication, a power change between the second uplink communication and the third uplink communication, and/or the third uplink communication not being scheduled with phase coherence with the first uplink communication and/or the second uplink communication.

In some instances, the BS utilizes aspects of the configuration to estimate and/or determine when the UE will implement the TA. For example, the BS may determine that the UE will implement the TA after an uplink-to-downlink switch occurs, after a downlink-to-uplink switch occurs, when a time gap between the second uplink communication and a third uplink communication satisfies a threshold amount, when there is a power change between the second uplink communication and the third uplink communication, and/or prior to the third uplink communication when the third uplink communication is not scheduled with phase coherence with the first uplink communication and/or the second uplink communication. In some instances, the BS estimates and/or determines the UE will implement the TA prior to an uplink transmission following the occurrence of one or more of these events. That is, the BS estimates and/or determines that upon occurrence of one or more of these events, the UE may delay implementing the TA until closer in time to when the UE is scheduled to transmit an uplink communication.

In some instances, the UE implements the TA at the first time. Accordingly, in some instances the second uplink communication is transmitted after the UE has implemented the TA. In this regard, the second uplink communication may be received by the BS, at step1030, without phase coherence with the first uplink communication. Therefore, the BS, at step1040, may process the first and second uplink communications separately, instead of jointly.

In some instances, the UE implements the TA at the second time. Accordingly, in some instances the second uplink communication is transmitted by the UE before implementing the TA. In this regard, the second uplink communication may be received by the BS, at step1030, with phase coherence with the first uplink communication as a result of the UE implementing the TA after transmitting the second uplink communication. Therefore, the BS, at step1040, may process the first and second uplink communications jointly, instead of separately.

Further aspects of the present disclosure include the following:

1. A method of wireless communication performed by a user equipment, the method comprising:

receiving, from a base station, a timing advance (TA), wherein the TA is scheduled to be implemented by the user equipment at a first time, the first time being after a start of a first uplink communication of a group of bundled uplink communications scheduled with phase coherence and before a start of a second uplink communication of the group of bundled uplink communications;

determining whether to implement the TA at the first time or a second time, the second time being after transmission of the second uplink communication; and

implementing the TA based on the determining.

2. The method of clause 1, wherein:

the determining whether to implement the TA at the first time or at the second time includes determining to implement the TA at the first time; and

the implementing the TA includes implementing the TA at the first time.

3. The method of clause 2, further comprising:

transmitting the second uplink communication after implementing the TA.

4. The method of clause 3, wherein the transmitting the second uplink communication includes transmitting the second uplink communication without phase coherence with the first uplink communication.

5. The method of any of clauses 1-4, wherein:

the first uplink communication includes at least one of a first demodulation reference signal (DMRS) or a first sounding reference signal (SRS); and

the second uplink communication includes at least one of a second DMRS or a second SRS.

6. The method of any of clauses 1-5, wherein:

the first uplink communication includes at least one of a first physical uplink control channel (PUCCH) communication or a first physical uplink shared channel (PUSCH) communication; and

the second uplink communication includes at least one of a second PUCCH communication or a second PUSCH communication.

7. The method of any of clauses 1, 5, or 6, wherein:

the determining whether to implement the TA at the first time or at the second time includes determining to implement the TA at the second time; and

the implementing the TA includes implementing the TA at the second time.

8. The method of clause 7, further comprising:

transmitting the second uplink communication before implementing the TA.

9. The method of clause 8, wherein the transmitting the second uplink communication includes transmitting the second uplink communication with phase coherence with the first uplink communication.

10. The method of clause 7, further comprising:

determining a timing for the second time based on at least one of an uplink-to-downlink switch, a downlink-to-uplink switch, a time gap between the second uplink communication and a third uplink communication, or a power change between the second uplink communication and the third uplink communication.

11. The method of clause 7, wherein the determining to implement the TA at the second time is based on determining that the first uplink communication and the second uplink communication are scheduled with phase coherence.

12. The method of clause 11, wherein the determining to implement the TA at the second time is based on determining that a third uplink communication is not scheduled with phase coherence with the first uplink communication or the second uplink communication.

13. The method any of clauses 1-12, further comprising:

receiving, from the base station, a configuration indicating when to delay implementation of the TA from the first time to the second time,

wherein the determining whether to implement the TA at the first time or at the second time is based on the configuration.

14. A method of wireless communication performed by a base station, the method comprising:

transmitting, to a user equipment, a timing advance (TA), wherein the TA is scheduled to be implemented by the user equipment at a first time, the first time being after a start of a first uplink communication of a group of bundled uplink communications scheduled with phase coherence and before a start of a second uplink communication of the group of bundled uplink communications;

receiving, from the user equipment, the first uplink communication;

receiving, from the user equipment, the second uplink communication; and

processing the first uplink communication and the second uplink communication based on when the TA was implemented by the user equipment.

15. The method of clause 14, wherein the processing the first uplink communication and the second uplink communication includes:

processing the first uplink communication separately from the second uplink communication.

16. The method of clause 15, wherein the receiving the second uplink communication includes:

receiving the second uplink communication after the user equipment has implemented the TA.

17. The method of clause 16, wherein the receiving the second uplink communication includes:

receiving the second uplink communication without phase coherence with the first uplink communication.

18. The method any of clauses 14-17, wherein:

the receiving the first uplink communication includes receiving at least one of a first demodulation reference signal (DMRS) or a first sounding reference signal (SRS); and

the receiving the second uplink communication includes receiving at least one of a second DMRS or a second SRS.

19. The method of any of clauses 14-18, wherein:

the receiving the first uplink communication includes receiving at least one of a first physical uplink control channel (PUCCH) communication or a first physical uplink shared channel (PUSCH) communication; and

the receiving the second uplink communication includes receiving at least one of a second PUCCH communication or a second PUSCH communication.

20. The method of any of clauses 14, 18, or 19, wherein the processing the first uplink communication and the second uplink communication includes:

processing the first uplink communication together with the second uplink communication.

21. The method of clause 20, wherein the second uplink communication was transmitted by the user equipment before the user equipment implemented the TA.

22. The method of clause 21, wherein the receiving the second uplink communication includes:

receiving the second uplink communication with phase coherence with the first uplink communication.

23. The method of any of clauses 14-22, further comprising:

transmitting, to the user equipment, a configuration indicating when to delay implementation of the TA from the first time to a second time.

a transceiver configured to:receive, from a base station, a timing advance (TA), wherein the TA is scheduled to be implemented by the user equipment at a first time, the first time being after a start of a first uplink communication of a group of bundled uplink communications scheduled with phase coherence and before a start of a second uplink communication of the group of bundled uplink communications; and

a processor in communication with the transceiver, the processor configured to:determine whether to implement the TA at the first time or a second time, the second time being after transmission of the second uplink communication; andimplement the TA based on the determination.

25. The user equipment of clause 24, wherein the processor is further configured to:

determine to implement the TA at the first time; and

implement the TA at the first time.

26. The user equipment of clause 25, wherein the transceiver is further configured to:

transmit the second uplink communication after implementing the TA.

27. The user equipment of clause 26, wherein the transceiver is further configured to:

transmit the second uplink communication without phase coherence with the first uplink communication.

28. The user equipment of any of clauses 24-27, wherein the transceiver is further configured to:

transmit the first uplink communication including at least one of a first demodulation reference signal (DMRS) or a first sounding reference signal (SRS); and

transmit the second uplink communication including at least one of a second DMRS or a second SRS.

29. The user equipment of any of clauses 24-28, wherein the transceiver is further configured to:

transmit the first uplink communication including at least one of a first physical uplink control channel (PUCCH) communication or a first physical uplink shared channel (PUSCH) communication; and

transmit the second uplink communication including at least one of a second PUCCH communication or a second PUSCH communication.

30. The user equipment of any of clauses 24, 28, or 29, wherein the processor is further configured to:

determine to implement the TA at the second time; and

implement the TA at the second time.

31. The user equipment of clause 30, wherein the transceiver is further configured to:

transmit the second uplink communication before implementing the TA.

32. The user equipment of clause 31, wherein the transceiver is further configured to:

transmit the second uplink communication with phase coherence with the first uplink communication.

33. The user equipment of clause 30, wherein the processor is further configured to:

determine a timing for the second time based on at least one of an uplink-to-downlink switch, a downlink-to-uplink switch, a time gap between the second uplink communication and a third uplink communication, or a power change between the second uplink communication and the third uplink communication.

34. The user equipment of clause 30, wherein the processor is further configured to:

determine to implement the TA at the second time based on determining that the first uplink communication and the second uplink communication are scheduled with phase coherence.

35. The user equipment of clause 34, wherein the processor is further configured to:

determine to implement the TA at the second time based on determining that a third uplink communication is not scheduled with phase coherence with the first uplink communication or the second uplink communication.

36. The user equipment of any of clauses 24-35, wherein:

the transceiver is further configured to receive, from the base station, a configuration indicating when to delay implementation of the TA from the first time to the second time; and

the processor is further configured to determine whether to implement the TA at the first time or at the second time based on the configuration.

a transceiver configured to:transmit, to a user equipment, a timing advance (TA), wherein the TA is scheduled to be implemented by the user equipment at a first time, the first time being after a start of a first uplink communication of a group of bundled uplink communications scheduled with phase coherence and before a start of a second uplink communication of the group of bundled uplink communications;receive, from the user equipment, the first uplink communication; andreceive, from the user equipment, the second uplink communication; and a processor in communication with the transceiver, the processor configured to:process the first uplink communication and the second uplink communication based on when the TA was implemented by the user equipment.

38. The base station of clause 37, wherein the processor is further configured to:

process the first uplink communication separately from the second uplink communication.

39. The base station of clause 38, wherein the transceiver is further configured to:

receive the second uplink communication after the user equipment has implemented the TA.

40. The base station of clause 39, wherein the transceiver is further configured to:

receive the second uplink communication without phase coherence with the first uplink communication.

41. The base station of any of clauses 37-40, wherein the transceiver is further configured to:

receive the first uplink communication including at least one of a first demodulation reference signal (DMRS) or a first sounding reference signal (SRS); and

receive the second uplink communication including at least one of a second DMRS or a second SRS.

42. The base station of any of clauses 37-41, wherein the transceiver is further configured to:

receive the first uplink communication including at least one of a first physical uplink control channel (PUCCH) communication or a first physical uplink shared channel (PUSCH) communication; and

receive the second uplink communication including at least one of a second PUCCH communication or a second PUSCH communication.

43. The base station of any of clauses 37, 41, or 42, wherein the processor is further configured to:

process the first uplink communication together with the second uplink communication.

44. The base station of clause 43, wherein the transceiver is further configured to:

receive the second uplink communication, wherein the second uplink communication was transmitted by the user equipment before the user equipment implemented the TA.

45. The base station of clause 44, wherein the transceiver is further configured to:

receive the second uplink communication with phase coherence with the first uplink communication.

46. The base station of any of clauses 37-45, wherein the transceiver is further configured to:

transmit, to the user equipment, a configuration indicating when to delay implementation of the TA from the first time to a second time.

means for receiving, from a base station, a timing advance (TA), wherein the TA is scheduled to be implemented by the user equipment at a first time, the first time being after a start of a first uplink communication of a group of bundled uplink communications scheduled with phase coherence and before a start of a second uplink communication of the group of bundled uplink communications;

means for determining whether to implement the TA at the first time or a second time, the second time being after transmission of the second uplink communication; and

means for implementing the TA based on the determining

48. The user equipment of clause 47, wherein:

the means for determining whether to implement the TA at the first time or at the second time includes means for determining to implement the TA at the first time; and

the means for implementing the TA includes means for implementing the TA at the first time.

49. The user equipment of clause 48, further comprising:

means for transmitting the second uplink communication after implementing the TA.

50. The user equipment of clause 49, wherein the means for transmitting the second uplink communication includes means for transmitting the second uplink communication without phase coherence with the first uplink communication.

51. The user equipment of any of clauses 47-50, further comprising:

means for transmitting the first uplink communication, wherein the means for transmitting the first uplink communication includes means for transmitting at least one of a first demodulation reference signal (DMRS) or a first sounding reference signal (SRS); and

means for transmitting the second uplink communication, wherein the means for transmitting the second uplink communication includes means for transmitting at least one of a second DMRS or a second SRS.

52. The user equipment of any of clauses 47-51, wherein:

means for transmitting the first uplink communication, wherein the means for transmitting the first uplink communication means for transmitting at least one of a first physical uplink control channel (PUCCH) communication or a first physical uplink shared channel (PUSCH) communication; and

means for transmitting the second uplink communication, wherein the means for transmitting the second uplink communication includes means for transmitting at least one of a second PUCCH communication or a second PUSCH communication.

53. The user equipment of any of clauses 47, 51, or 52, wherein:

the means for determining whether to implement the TA at the first time or at the second time includes means for determining to implement the TA at the second time; and

the means for implementing the TA includes means for implementing the TA at the second time.

54. The user equipment of clause 53, further comprising:

means for transmitting the second uplink communication before implementing the TA.

55. The user equipment of clause 54, wherein the means for transmitting the second uplink communication includes means for transmitting the second uplink communication with phase coherence with the first uplink communication.

56. The user equipment of clause 53, further comprising:

means for determining a timing for the second time based on at least one of an uplink-to-downlink switch, a downlink-to-uplink switch, a time gap between the second uplink communication and a third uplink communication, or a power change between the second uplink communication and the third uplink communication.

57. The user equipment of clause 53, wherein the means for determining to implement the TA at the second time includes means for determining that the first uplink communication and the second uplink communication are scheduled with phase coherence.

58. The user equipment of clause 57, wherein the means for determining to implement the TA at the second time includes means for determining that a third uplink communication is not scheduled with phase coherence with the first uplink communication or the second uplink communication.

59. The user equipment of any of clauses 47-58, further comprising:

means for receiving, from the base station, a configuration indicating when to delay implementation of the TA from the first time to the second time,

wherein the means for determining whether to implement the TA at the first time or at the second time is configured to determine whether to implement the TA at the first time or at the second time based on the configuration.

means for transmitting, to a user equipment, a timing advance (TA), wherein the TA is scheduled to be implemented by the user equipment at a first time, the first time being after a start of a first uplink communication of a group of bundled uplink communications scheduled with phase coherence and before a start of a second uplink communication of the group of bundled uplink communications;

means for receiving, from the user equipment, the first uplink communication;

means for receiving, from the user equipment, the second uplink communication; and

means for processing the first uplink communication and the second uplink communication based on when the TA was implemented by the user equipment.

61. The base station of clause 60, wherein the means for processing the first uplink communication and the second uplink communication includes:

means for processing the first uplink communication separately from the second uplink communication.

62. The base station of clause 61, wherein the means for receiving the second uplink communication includes:

means for receiving the second uplink communication after the user equipment has implemented the TA.

63. The base station of clause 62, wherein the means for receiving the second uplink communication includes:

means for receiving the second uplink communication without phase coherence with the first uplink communication.

64. The base station of any of clauses 60-63, wherein:

The means for receiving the first uplink communication includes means for receiving at least one of a first demodulation reference signal (DMRS) or a first sounding reference signal (SRS); and

the means for receiving the second uplink communication includes means for receiving at least one of a second DMRS or a second SRS.

65. The base station of any of clauses 60-64, wherein:

the means for receiving the first uplink communication includes means for receiving at least one of a first physical uplink control channel (PUCCH) communication or a first physical uplink shared channel (PUSCH) communication; and

the means for receiving the second uplink communication includes means for receiving at least one of a second PUCCH communication or a second PUSCH communication.

66. The base station of any of clauses 60, 64, or 65, wherein the means for processing the first uplink communication and the second uplink communication includes:

means for processing the first uplink communication together with the second uplink communication.

67. The base station of clause 66, wherein the means for receiving the second uplink communication includes means for receiving the second uplink communication, wherein the second uplink communication was transmitted by the user equipment before the user equipment implemented the TA.

68. The base station of clause 67, wherein the means for receiving the second uplink communication includes:

means for receiving the second uplink communication with phase coherence with the first uplink communication.

69. The base station of any of clauses 60-68, further comprising:

means for transmitting, to the user equipment, a configuration indicating when to delay implementation of the TA from the first time to a second time.

70. A non-transitory computer-readable medium having program code recorded thereon for wireless communication by a user equipment, the program code comprising:

code for causing the user equipment to receive, from a base station, a timing advance (TA), wherein the TA is scheduled to be implemented by the user equipment at a first time, the first time being after a start of a first uplink communication of a group of bundled uplink communications scheduled with phase coherence and before a start of a second uplink communication of the group of bundled uplink communications;

code for causing the user equipment to determine whether to implement the TA at the first time or a second time, the second time being after transmission of the second uplink communication; and

code for causing the user equipment to implement the TA based on the determining

the code for causing the user equipment to determine whether to implement the TA at the first time or at the second time includes code for causing the user equipment to determine to implement the TA at the first time; and

the code for causing the user equipment to implement the TA includes code for causing the user equipment to implement the TA at the first time.

code for causing the user equipment to transmit the second uplink communication after implementing the TA.

73. The non-transitory computer-readable medium of clause 72, wherein the code for causing the user equipment to transmit the second uplink communication includes code for causing the user equipment to transmit the second uplink communication without phase coherence with the first uplink communication.

74. The non-transitory computer-readable medium of any of clauses 70-73, wherein:

the code for causing the user equipment to the first uplink communication includes code for causing the user equipment to transmit at least one of a first demodulation reference signal (DMRS) or a first sounding reference signal (SRS); and

the code for causing the user equipment to transmit the second uplink communication includes code for causing the user equipment to transmit at least one of a second DMRS or a second SRS.

75. The non-transitory computer-readable medium of any of clauses 70-74, wherein:

the code for causing the user equipment to transmit the first uplink communication includes code for causing the user equipment to transmit at least one of a first physical uplink control channel (PUCCH) communication or a first physical uplink shared channel (PUSCH) communication; and

the code for causing the user equipment to transmit the second uplink communication includes code for causing the user equipment to transmit at least one of a second PUCCH communication or a second PUSCH communication.

76. The non-transitory computer-readable medium of any of clauses 70, 74, or 75, wherein:

the code for causing the user equipment to determine whether to implement the TA at the first time or at the second time includes code for causing the user equipment to determine to implement the TA at the second time; and

the code for causing the user equipment to implement the TA includes code for causing the user equipment to implement the TA at the second time.

code for causing the user equipment to transmit the second uplink communication before implementing the TA.

78. The non-transitory computer-readable medium of clause 77, wherein the code for causing the user equipment to transmit the second uplink communication includes code for causing the user equipment to transmit the second uplink communication with phase coherence with the first uplink communication.

code for causing the user equipment to determine a timing for the second time based on at least one of an uplink-to-downlink switch, a downlink-to-uplink switch, a time gap between the second uplink communication and a third uplink communication, or a power change between the second uplink communication and the third uplink communication.

80. The non-transitory computer-readable medium of clause 76, wherein the code for causing the user equipment to determine to implement the TA at the second time includes code for causing the user equipment to determine that the first uplink communication and the second uplink communication are scheduled with phase coherence.

81. The non-transitory computer-readable medium of clause 80, wherein the code for causing the user equipment to determine to implement the TA at the second time includes code for causing the user equipment to determine that a third uplink communication is not scheduled with phase coherence with the first uplink communication or the second uplink communication.

82. The non-transitory computer-readable medium of any of clauses 70-82, further comprising:

code for causing the user equipment to receive, from the base station, a configuration indicating when to delay implementation of the TA from the first time to the second time,

wherein the code for causing the user equipment to determine whether to implement the TA at the first time or at the second time includes code for causing the user equipment to determine whether to implement the TA at the first time or at the second time based on the configuration.

83. A non-transitory computer-readable medium having program code recorded thereon for wireless communication by a base station, the program code comprising:

code for causing the base station to transmit, to a user equipment, a timing advance (TA), wherein the TA is scheduled to be implemented by the user equipment at a first time, the first time being after a start of a first uplink communication of a group of bundled uplink communications scheduled with phase coherence and before a start of a second uplink communication of the group of bundled uplink communications;

code for causing the base station to receive, from the user equipment, the first uplink communication;

code for causing the base station to receive, from the user equipment, the second uplink communication; and

code for causing the base station to process the first uplink communication and the second uplink communication based on when the TA was implemented by the user equipment.

84. The non-transitory computer-readable medium of clause 83, wherein the code for causing the base station to process the first uplink communication and the second uplink communication includes:

code for causing the base station to process the first uplink communication separately from the second uplink communication.

85. The non-transitory computer-readable medium of clause 84, wherein the code for causing the base station to receive the second uplink communication includes:

code for causing the base station to receive the second uplink communication after the user equipment has implemented the TA.

86. The non-transitory computer-readable medium of clause 85, wherein the code for causing the base station to receive the second uplink communication includes:

code for causing the base station to receive the second uplink communication without phase coherence with the first uplink communication.

87. The non-transitory computer-readable medium of any of clauses 83-86, wherein:

the code for causing the base station to receive the first uplink communication includes code for causing the base station to receive at least one of a first demodulation reference signal (DMRS) or a first sounding reference signal (SRS); and

the code for causing the base station to receive the second uplink communication includes code for causing the base station to receive at least one of a second DMRS or a second SRS.

88. The non-transitory computer-readable medium of any of clauses 83-87, wherein:

the code for causing the base station to receive the first uplink communication includes code for causing the base station to receive at least one of a first physical uplink control channel (PUCCH) communication or a first physical uplink shared channel (PUSCH) communication; and

the code for causing the base station to receive the second uplink communication includes code for causing the base station to receive at least one of a second PUCCH communication or a second PUSCH communication.

89. The non-transitory computer-readable medium of any of clauses 83, 88, or 89, wherein the code for causing the base station to process the first uplink communication and the second uplink communication includes:

code for causing the base station to process the first uplink communication together with the second uplink communication.

90. The non-transitory computer-readable medium of clause 89, wherein the code for causing the base station to receive the second uplink communication includes code for causing the base station to receive the second uplink communication, wherein the second uplink communication was transmitted by the user equipment before the user equipment implemented the TA.

91. The non-transitory computer-readable medium of clause 90, wherein the code for causing the base station to receive the second uplink communication includes:

code for causing the base station to receive the second uplink communication with phase coherence with the first uplink communication.

92. The non-transitory computer-readable medium of any of clauses 83-91, further comprising:

code for causing the base station to transmit, to the user equipment, a configuration indicating when to delay implementation of the TA from the first time to a second time.