# US 12,192,929 B2 · Method for reference signal time synchronization and calibration > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 12,192,929 B2 - Document ID: US12192929B2 - Status: Granted - Kind: B2 - Application number: 17/858,317 - Filed: 2022-07-06 - Published: 2022-11-03 - Granted: 2025-01-07 - Earliest claimed: 2020-08-07 - Assignees: Zte Corporation - Applicants: ZTE Corporation - Inventors: Huahua Xiao; Guozeng Zheng; Chuangxin Jiang; Zhaohua Lu; Shujuan Zhang - Web page: https://patentgrep.com/patent/US12192929B2 ## CPC - H04W 56/001: {Synchronization between nodes} - H04W 56/0015: {one node acting as a reference for the others} - H04L 5/0048: {Allocation of pilot signals, i.e. of signals known to the receiver (allocation of control signalling H04L5/0053; use of control signalling H04L5/0091)} - H04W 56/004: {compensating for timing error of reception due to propagation delay} - H04W 56/0065: {using measurement of signal travel time} - 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 This disclosure describes methods and systems for configuring, requesting, performing, and reporting timing measurements of reference signals in a wireless network for purposes of time synchronization between various reference signal transmission-reception points of the wireless network. The reference signal timing measurements may be used to derive time offsets for performing time synchronization and calibration of the transmission-reception points that help improve geographical positioning of wireless devices in the wireless network. ## Claims ### Claim 1 A method performed by a network node for reference signal synchronization in a wireless network, comprising: sending reference signal configuration information to a first transmission reception point (TRP 1) and a second transmission reception point (TRP 2) of the wireless network; sending measurement requests to trigger the TRP 1 and/or the TRP 2 to perform timing measurements of reference signals communicated between the TRP 1 and the TRP 2 according to the reference signal configuration information; receiving, from the TRP 1 and/or the TRP 2, measurement reports of the timing measurements; and generating time offset information for synchronizing between the TRP 1 and the TRP 2. ### Claim 2 (depends on 1) The method of claim 1, wherein the reference signal configuration information comprises at least one of transmission periodicity, transmission radio resource information, sequence information, transmission and/or reception scheduling information, initialization time information of system frame number (SFN), or transmission and/or reception beam information of the reference signals communicated between the TRP 1 and the TRP 2. ### Claim 3 (depends on 2) The method of claim 2, wherein the transmission and/or reception scheduling information of each of the reference signals comprises at least one of an SFN, a subframe number, a slot number, a mini slot number, or a symbol number. ### Claim 4 (depends on 2) The method of claim 2, wherein the transmission radio resource information comprises at least one of radio frequency, radio frequency bandwidth, or sub-carrier spacing for each of the reference signals. ### Claim 5 (depends on 2) The method of claim 2, wherein the transmission and/or reception beam information of each of the reference signals comprises a spatial filter. ### Claim 6 (depends on 1) The method of claim 1, wherein each of the measurement requests comprises at least one of a measurement periodicity, a measurement type, a measurement time resolution, or a reference signal identifier. ### Claim 7 (depends on 6) The method of claim 6, wherein the measurement type indicates which timing values of the reference signals need to be measured and reported by the TRP 1 and TRP 2. ### Claim 8 (depends on 1) The method of claim 1, wherein the each of the measurement reports comprises at least one of a reference signal measurement time value, corresponding reference signal identifier, a measurement time stamp, a measurement quality metrics, or a measurement time resolution. ### Claim 9 (depends on 8) The method of claim 8, wherein measurement time stamp comprises at least one of a system frame number, a subframe number, a slot number, a mini slot number, a symbol number, or a symbol index. ### Claim 10 (depends on 1) The method of claim 1, wherein the reference signals as scheduled by the reference signal configuration information comprise: a first reference signal (RS 1) transmitted from the TRP 1 at time Ttrp1,RS1,tx as measured by TRP 1 and received by the TRP 2 at time Ttrp2,RS1,rx as measured by TRP 2; and a second reference signal (RS 2) transmitted from the TRP 2 at time Ttrp2,RS2,tx as measured by the TRP 2 and received by the TRP 1 at time Ttrp1,RS2,rx as measured by TRP 1. ### Claim 11 (depends on 10) The method of claim 10, wherein: the measurement report from the TRP 1 comprises at least one of Ttrp1,RS1,tx, Ttrp1,RS2,rx, or Ttrp1,RS2,rx−Ttrp1,RS1,tx; and the measurement report from the TRP 2 comprises at least one of Ttrp2,RS2,tx, Ttrp2,RS1,rx, or Ttrp2,RS2,tx−Ttrp2,RS1,rx. ### Claim 12 (depends on 11) The method of claim 11, wherein generating the time offset comprises generating the time offset for synchronizing the TRP 1 and the TRP 2 based on at least one of Ttrp1,RS1,tx, Ttrp1,RS2,rx, Ttrp2,RS2,tx, and Ttrp2,RS1,rx. ### Claim 13 (depends on 12) The method of claim 12, wherein the time offset is derived by the network node as [(Ttrp2,RS1,rx−Ttrp1,RS1,tx)−(Ttrp1,RS2,rx−Ttrp2,RS2,tx)]/2. ### Claim 14 (depends on 12) The method of claim 12, wherein the time offset is derived by the network node as Esync_12=Ttrp1,RS2,rx−Ttrp2,RS2,tx−R12/c or Esync_21=Ttrp2,RS1,rx−Ttrp1,RS1,tx−R12/c, where R12 denotes a distance between the TRP 1 and TRP 2, and c represents signal propagation speed of the reference signals between the TRP 1 and the TRP 2. ### Claim 15 A method performed by a network node for reference signal synchronization in a wireless network, comprising: sending reference signal configuration information to a first transmission reception point (TRP 1), a second transmission reception point (TRP 2), and a third transmission reception point (TRP 3) of the wireless network; sending measurement requests to trigger the TRP 1, the TRP 2, and/or the TRP 3 to perform timing measurements of reference signals communicated between the TRP 1, and the TRP 2 and the TRP 3 according to the reference signal configuration information; receiving, from the TRP 1, TRP 2, and/or the TRP 3, measurement reports of the timing measurements; and generating time offset information for synchronizing the TRP 1, the TRP 2, and the TRP 3. ### Claim 16 (depends on 15) The method of claim 15, wherein the reference signals as scheduled by the reference signal configuration information comprise: a first reference signal (RS 1) transmitted from the TRP 1 at time Ttrp1,RS1,tx as measured by the TRP 1, and received by the TRP 2 at time Ttrp2,RS1,rx as measured by the TRP 2 and by the TRP 3 at time Ttrp3,RS1,rx as measured by the TRP 3; a second reference signal (RS 2) transmitted from the TRP 2 at time Ttrp2,RS2,tx as T measured by the TRP 2 and received by the TRP 1 at time Ttrp1,RS2,rx as measured by the TRP 1; and a third reference signal (RS 3) transmitted from the TRP 3 at time Ttrp3,RS3,tx as measured by the TRP 3 and received by the TRP 1 at time Ttrp1,RS3,rx as measured by the TRP 1. ### Claim 17 (depends on 16) The method of claim 16, wherein: the measurement report from the TRP 1 comprises at least one of Ttrp1,RS1,tx, Ttrp1,RS2,rx, or Ttrp1,RS2,rx−Ttrp1,RS1,tx; the measurement report from the TRP 2 comprises at least one of Ttrp2,RS2,tx, Ttrp2,RS1,rx, or Ttrp2,RS2,tx−Ttrp2,RS1,rx; and the measurement report from the TRP 3 comprises at least one of Ttrp3,RS1,rx, Ttrp3,RS3,tx, or Ttrp3,RS3,tx−Ttrp3,RS1,rx. ### Claim 18 (depends on 17) The method of claim 17, wherein generating the time offset comprises generating the time offset for synchronizing the TRP 2 and the TRP 3 based on at least one of Ttrp1,RS1,tx, Ttrp1,RS2,rx, Ttrp2,RS2,tx, Ttrp2,RS1,rx, Ttrp3,RS3,tx, Ttrp3,RS1,rx, and a reference signal time delay between RS 2 and RS 3 as measured by the TRP 1 and denoted by Ttrp2,trp3,RSTD. ### Claim 19 (depends on 18) The method of claim 18, wherein the time offset for synchronizing the TRP 2 and the TRP 3 is derived by the network node as: E sync ⁢ _ ⁢ 32 = ( T trp ⁢ 1 , RS ⁢ 3 , RS ⁢ 1 - T trp ⁢ 3 , RS ⁢ 3 , RS ⁢ 1 ) - ( T trp ⁢ 1 , RS ⁢ 2 , RS ⁢ 1 - T trp ⁢ 2 , RS ⁢ 2 , RS ⁢ 1 ) 2 - T trp ⁢ 2 , trp ⁢ 3 , RSTD , Where: Ttrp1,RS3,RS1=Ttrp1,RS3,rx−Ttrp1,RS1,tx; Ttrp3,RS3,RS1=Ttrp3,RS3,tx−Ttrp3,RS1,rx; Ttrp1,RS2,RS1=Ttrp1,RS2,rx−Ttrp1,RS1,tx; and Ttrp2,RS2,RS1=Ttrp2,RS2,tx−Ttrp2,RS1,rx. ### Claim 20 (depends on 18) The method of claim 18, the time offset for synchronizing the TRP 2 and the TRP 3 is derived by the network node as Esync_32=(R13−R12)/c−Ttrp2,trp3,RSTD, where: R12 denotes a distance between the TRP 1 and TRP 2; R13 denotes a distance between the TRP 1 and TRP 3; and c represents signal propagation speed of the reference signals between the TRP 1, the TRP 2, and the TRP 3.