# US 12,114,279 B2 · User equipment, base station, and method for time synchronization > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 12,114,279 B2 - Document ID: US12114279B2 - Status: Granted - Kind: B2 - Application number: 17/618,629 - Filed: 2021-05-14 - Published: 2022-07-28 - Granted: 2024-10-08 - Earliest claimed: 2020-05-15 - Assignees: Purplevine Innovation Company Limited - Applicants: Purplevine Innovation Company Limited - Inventors: Chun-Che Chien - Web page: https://patentgrep.com/patent/US12114279B2 ## CPC - H04W 56/0015: {one node acting as a reference for the others} - H04W 56/0045: {compensating for timing error by altering transmission time} - H04L 5/0051: {of dedicated pilots, i.e. pilots destined for a single user or terminal} - H04W 16/28: using beam steering - H04W 56/001: {Synchronization between nodes} - H04W 56/004: {compensating for timing error of reception due to propagation delay} - H04W 56/0055: {determining timing error of reception due to propagation delay} - H04W 74/0833: Random access procedures, e.g. with 4-step access - H04W 74/0838: using contention-free random access [CFRA] - H04W: WIRELESS COMMUNICATION NETWORKS (broadcast communication H04H; communication systems using wireless links for non-selective communication, e.g. wireless extensions H04M1/72) - H04L: TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION (arrangements common to telegraphic and telephonic communication H04M) ## Abstract A user equipment (UE) executes a time synchronization method. The UE transmits a synchronization-specific uplink signal and receives a synchronization-specific downlink signal in response to the synchronization-specific uplink signal. The synchronization-specific uplink signal may comprise a dedicated preamble for propagation-delay-related signaling associated with at least one of timing advance (TA), propagation delay (PD), and propagation delay compensation (PDC) between the UE and a serving base station of the UE. ## Claims ### Claim 1 A time synchronization method executable in a user equipment (UE), comprising: transmitting a synchronization-specific uplink signal, wherein the synchronization-specific uplink signal comprises a preamble for propagation-delay-related signaling, the propagation-delay-related signaling is associated with timing advance (TA) between the UE and a serving base station of the UE; receiving a synchronization-specific downlink signal in response to the synchronization-specific uplink signal; receiving a UE-side propagation delay compensation indication; and determining, based on the received UE-side propagation delay compensation indication, whether to perform UE-side TA-based propagation delay compensation for reference time information (RTI); wherein the UE-side propagation delay compensation indication indicates whether the UE-side TA-based propagation delay compensation is activated. ### Claim 2 (depends on 1) The time synchronization method of claim 1, wherein the preamble is transmitted based on a predetermined or previously acquired timing advance (TA). ### Claim 3 (depends on 1) The time synchronization method of claim 1, wherein the preamble is used for a non-contention based RACH procedure during an RRC_CONNECTED state of the UE. ### Claim 4 (depends on 1) The time synchronization method of claim 1, wherein the synchronization-specific downlink signal comprises a propagation-delay-related value of a specific value granularity, and the specific value granularity comprises one of a plurality of propagation-delay-related value granularities supported by the UE. ### Claim 5 (depends on 4) The time synchronization method of claim 4, wherein the synchronization-specific downlink signal is transmitted in a random access response (RAR) or a medium access control (MAC) control element (CE). ### Claim 6 (depends on 4) The time synchronization method of claim 4, wherein the propagation-delay-related value comprises a value of timing advance (TA), and the specific value granularity comprises a granularity of timing advance (TA). ### Claim 7 (depends on 6) The time synchronization method of claim 6, wherein the specific value granularity is selected from the plurality of propagation-delay-related value granularities based on TA content preference received from the UE or based on a synchronization requirement of a time sensitive communication (TSC) traffic. ### Claim 8 (depends on 1) The time synchronization method of claim 1, wherein the synchronization-specific downlink signal comprises a type of timing advance associated with a source of reference time information (RTI) or associated with a time sensitive communication (TSC) traffic type. ### Claim 9 (depends on 1) The time synchronization method of claim 1, further comprising: transmitting another synchronization-specific uplink signal synchronization-specific uplink signal comprises a request for provision or update of a propagation-delay-related value or reference time information (RTI), and the propagation-delay-related value comprises a value of at least one of timing advance (TA) or propagation delay (PD). ### Claim 10 (depends on 9) The time synchronization method of claim 9, further comprising: sending a request for a single shot RTI delivery in addition to periodic reporting of the RTI; sending a request to indicate or update granularity of the RTI; sending a request to indicate or update periodicity of periodic reporting of RTI; or sending a request to indicate or update the RTI type of a corresponding traffic type. ### Claim 11 (depends on 9) The time synchronization method of claim 9, further comprising: sending a request to indicate or update periodicity or position of a downlink synchronization signal block (SSB), DMRS, or CSI-RS; or sending a request to indicate or update granularity of the TA or the propagation-delay-related value. ### Claim 12 (depends on 1) The time synchronization method of claim 1, further comprising: transmitting another synchronization-specific uplink signal in response to a TA validity event generated based on a TA validity condition. ### Claim 13 (depends on 12) The time synchronization method of claim 12, wherein the another synchronization-specific uplink signal comprises a preamble, a sounding reference signal (SRS) or an uplink DMRS signal for propagation-delay-related signaling, and is transmitted based on a predetermined or previously acquired timing advance (TA) or propagation delay (PD). ### Claim 14 (depends on 12) The time synchronization method of claim 12, wherein the TA validity condition is predefined or received from a system information block (SIB), a medium access control (MAC) control element (CE), or a radio resource control (RRC) signal. ### Claim 15 (depends on 12) The time synchronization method of claim 12, wherein the TA validity condition comprises at least one of a location of the UE, a beam direction, received signal strength, and a predetermined period of time. ### Claim 16 (depends on 15) The time synchronization method of claim 15, wherein the predetermined period of time comprises a time duration of a discontinuous reception (DRX) cycle. ### Claim 17 (depends on 1) The time synchronization method of claim 1, wherein the UE-side propagation delay compensation indication is transmitted in a radio resource control (RRC) signal. ### Claim 18 (depends on 17) The time synchronization method of claim 17, wherein the radio resource control (RRC) signal comprises a DLInformationTransfer message. ### Claim 19 (depends on 1) The time synchronization method of claim 1, wherein whether to perform the UE-side TA-based propagation delay compensation for RTI is determined based on whether propagation delay pre-compensation for RTI has been performed by serving base station. ### Claim 20 (depends on 19) The time synchronization method of claim 19, wherein whether the propagation delay pre-compensation for RTI has been performed is determined based on whether the UE-side TA-based propagation delay compensation is deactivated. ### Claim 21 (depends on 19) The time synchronization method of claim 19, further comprising: performing UE-side TA-based propagation delay compensation when the propagation delay pre-compensation has not been performed. ### Claim 22 (depends on 1) The time synchronization method of claim 1, further comprising: performing the UE-side TA-based propagation delay compensation based on a PD compensation triggering condition. ### Claim 23 (depends on 22) The time synchronization method of claim 22, wherein the PD compensation triggering condition comprises a range or a threshold of TA, a subcarrier spacing (SCS), a range or a threshold of received signal strength, a geographic location, or a beam direction. ### Claim 24 (depends on 22) The time synchronization method of claim 22, wherein the PD compensation triggering condition is received from a system information block (SIB), a medium access control (MAC) control element (CE), or a radio resource control (RRC) signal. ### Claim 25 (depends on 1) A user equipment (UE) comprising: a processor configured to call and run a computer program stored in a memory, to cause a device in which the processor is installed to execute the method of claim 1. ### Claim 26 (depends on 1) A chip, comprising: a processor, configured to call and run a computer program stored in a memory, to cause a device in which the chip is installed to execute the method of claim 1. ### Claim 27 (depends on 1) A non-transitory computer-readable storage medium, in which a computer program is stored, wherein the computer program causes a computer to execute the method of claim 1. ### Claim 28 A time synchronization method executable in a base station, comprising: receiving a synchronization-specific uplink signal, wherein the synchronization-specific uplink signal comprises a preamble for propagation-delay-related signaling, the propagation-delay-related signaling is associated with timing advance (TA) between a user equipment (UE) and the base station serving the UE; transmitting a synchronization-specific downlink signal in response to the synchronization-specific uplink signal; and transmitting a UE-side propagation delay compensation indication, wherein the UE-side propagation delay compensation indication indicates whether the UE-side TA-based propagation delay compensation for reference time information (RTI) is activated. ### Claim 29 (depends on 28) The time synchronization method of claim 28, wherein the preamble is transmitted based on a predetermined or previously acquired timing advance (TA). ### Claim 30 (depends on 28) The time synchronization method of claim 28, wherein the preamble is used for a non-contention based RACH procedure. ### Claim 31 (depends on 28) The time synchronization method of claim 28, wherein the synchronization-specific downlink signal comprises a propagation-delay-related value of a specific value granularity, and the specific value granularity comprises one of a plurality of propagation-delay-related value granularities supported by a UE. ### Claim 32 (depends on 31) The time synchronization method of claim 31, wherein the synchronization-specific downlink signal is transmitted in a random access response (RAR) or a medium access control (MAC) control element (CE). ### Claim 33 (depends on 31) The time synchronization method of claim 31, wherein the propagation-delay-related value comprises a value of timing advance (TA), and the specific value granularity comprises a granularity of timing advance (TA). ### Claim 34 (depends on 33) The time synchronization method of claim 33, wherein the specific value granularity is selected from the plurality of propagation-delay-related value granularities based on TA content preference received from the UE or based on a synchronization requirement of a time sensitive communication (TSC) traffic. ### Claim 35 (depends on 28) The time synchronization method of claim 28, wherein the synchronization-specific downlink signal comprises a type of timing advance associated with a source of reference time information (RTI) or associated with a time sensitive communication (TSC) traffic type. ### Claim 36 (depends on 28) The time synchronization method of claim 28, further comprising: receiving another synchronization-specific uplink signal synchronization-specific uplink signal comprises a request for provision or update of a propagation-delay-related value or reference time information (RTI), and the propagation-delay-related value comprises a value of at least one of timing advance (TA) or propagation delay (PD). ### Claim 37 (depends on 36) The time synchronization method of claim 36, further comprising: sending a message of RTI in response to a request for RTI; sending a message of RTI with granularity in response to a request indicating or updating the granularity of the RTI; periodically reporting RTI with periodicity in response to a request indicating or updating the periodicity of periodic reporting of RTI; or sending a message of RTI of the RTI type in response to a request indicating or updating the RTI type of a corresponding traffic type. ### Claim 38 (depends on 36) The time synchronization method of claim 36, further comprising: providing downlink synchronization signals with periodicity in response to a request for indicating or updating the periodicity or position of the downlink synchronization signals, wherein at least one of the downlink synchronization signals comprise downlink synchronization signal block (SSB), DMRS, or CSI-RS; or providing an update of the propagation-delay-related value with updated granularity in response to a request for indicating the updated granularity of the propagation-delay-related value. ### Claim 39 (depends on 28) The time synchronization method of claim 28, further comprising: providing a TA validity condition. ### Claim 40 (depends on 39) The time synchronization method of claim 39, wherein the TA validity condition is transmitted in a system information block (SIB), a medium access control (MAC) control element (CE), or a radio resource control (RRC) signal. ### Claim 41 (depends on 39) The time synchronization method of claim 39, wherein the TA validity condition comprises at least one of a UE location, a beam direction, received signal strength, and a predetermined period of time. ### Claim 42 (depends on 41) The time synchronization method of claim 41, wherein the predetermined period of time comprises a time duration of a discontinuous reception (DRX) cycle. ### Claim 43 (depends on 28) The time synchronization method of claim 28, wherein the UE-side propagation delay compensation indication is transmitted in a radio resource control (RRC) signal. ### Claim 44 (depends on 43) The time synchronization method of claim 43, wherein the radio resource control (RRC) signal comprises a DLInformationTransfer message. ### Claim 45 (depends on 28) The time synchronization method of claim 28, wherein the UE-side TA-based propagation delay compensation for RTI is deactivated if propagation delay pre-compensation for RTI has been performed by the base station. ### Claim 46 (depends on 28) The time synchronization method of claim 28, further comprising: transmitting a PD compensation triggering condition to a UE. ### Claim 47 (depends on 46) The time synchronization method of claim 46, wherein the PD compensation triggering condition comprises a range or a threshold of TA, a subcarrier spacing (SCS), a range or a threshold of received signal strength, a geographic location, or a beam direction. ### Claim 48 (depends on 46) The time synchronization method of claim 46, wherein the PD compensation triggering condition is transmitted in a system information block (SIB), a medium access control (MAC) control element (CE), or a radio resource control (RRC) signal. ### Claim 49 (depends on 28) A base station comprising: a processor configured to call and run a computer program stored in a memory, to cause a device in which the processor is installed to execute the method of claim 28. ### Claim 50 (depends on 28) A chip, comprising: a processor configured to call and run a computer program stored in a memory, to cause a device in which the chip is installed to execute the method of claim 28. ### Claim 51 (depends on 28) A non-transitory computer-readable storage medium, in which a computer program is stored, wherein the computer program causes a computer to execute the method of claim 28.