Uplink timing adjustment with multiple numerologies

Abstract

Various communication systems may benefit from improved signaling. For example, it may be helpful to improve the management of the uplink timing alignment where multiple numerologies are used. A method may include receiving at a user equipment an indication from a network node. The timing adjustment granularity may be determined implicitly based on one or more multiple numerology assigned to a timing advance group. The method may also include applying at the user equipment the indicated timing adjustment granularity associated with one of the multiple numerologies.

1 . A method comprising:
 receiving, at a user equipment, from a network node, a timing advance command;   determining, based on the timing advance command and a timing adjustment granularity, a timing adjustment for a plurality of bandwidth parts,   wherein the plurality of bandwidth parts are configured with a plurality of subcarrier spacings,   wherein the plurality of subcarrier spacings comprise at least two different subcarrier spacings, and   wherein the timing adjustment granularity is determined based on a largest subcarrier spacing of the plurality of subcarrier spacings; and   transmitting an uplink transmission from the user equipment to the network node on at least one of the plurality of bandwidth parts based on the timing adjustment.   
     
     
         2 . The method of  claim 1 , wherein the timing adjustment granularity is associated with at least one of multiple numerologies associated with a timing advance group. 
     
     
         3 . The method of  claim 1 , further comprising:
 deriving a default timing adjustment granularity based on one of the multiple numerologies used in a received synchronization signal block; and   applying the default timing adjustment granularity before receiving the timing advance command.   
     
     
         4 . The method of  claim 1 , wherein the timing advance command is included as part of radio resource control signaling. 
     
     
         5 . The method of  claim 1 , wherein the user equipment uses a finer timing adjustment granularity for a larger subcarrier spacing and a coarser timing adjustment granularity for a smaller subcarrier spacing. 
     
     
         6 . A method comprising:
 transmitting, from a network node to a user equipment, a timing advance command,   wherein a timing adjustment for a plurality of bandwidth parts is determined based on the timing advance command and a timing adjustment granularity,   wherein the plurality of bandwidth parts are configured with a plurality of subcarrier spacings,   wherein the plurality of subcarrier spacings comprise at least two different subcarrier spacings, and   wherein the timing adjustment granularity is determined based on a largest subcarrier spacing of the plurality of subcarrier spacings; and   receiving an uplink transmission at the network node from the user equipment based on the timing adjustment.   
     
     
         7 . The method of  claim 6 , wherein the timing adjustment granularity is associated with at least one of multiple numerologies associated with a timing advance group. 
     
     
         8 . The method of  claim 6 , further comprising:
 transmitting the timing advance command from the network node to the user equipment as part of a radio resource control signaling.   
     
     
         9 . The method of  claim 6 , wherein a finer timing adjustment granularity is used for a larger subcarrier spacing and a coarser timing adjustment granularity is used for a smaller subcarrier spacing. 
     
     
         10 . An apparatus comprising:
 at least one processor; and   at least one memory storing program codes, wherein the at least one memory and the program codes are configured to, with the at least one processor, cause the apparatus at least to:
 receive, from a network node, a timing advance command; 
 determine, based on the timing advance command and a timing adjustment granularity, a timing adjustment for a plurality of bandwidth parts, 
 wherein the plurality of bandwidth parts are configured with a plurality of subcarrier spacings, 
 wherein the plurality of subcarrier spacings comprise at least two different subcarrier spacings, and 
 wherein the timing adjustment granularity is determined based on a largest subcarrier spacing of the plurality of subcarrier spacings; and 
 transmit an uplink transmission from the apparatus to the network node on at least one of the plurality of bandwidth parts based on the timing adjustment. 
   
     
     
         11 . The apparatus of  claim 10 , wherein the timing adjustment granularity is associated with at least one of multiple numerologies associated with a timing advance group. 
     
     
         12 . The apparatus of  claim 10 , wherein the at least one memory and the program codes are further configured to, with the at least one processor, cause the apparatus at least to:
 deriving a default timing adjustment granularity based on one of the multiple numerologies used in a received synchronization signal block; and   applying the default timing adjustment granularity before receiving the timing advance command.   
     
     
         13 . The apparatus of  claim 10 , wherein the timing advance command is included as part of radio resource control signaling. 
     
     
         14 . The apparatus of  claim 10 , wherein the apparatus is configured to use a finer timing adjustment granularity for a larger subcarrier spacing and a coarser timing adjustment granularity for a smaller subcarrier spacing. 
     
     
         15 . An apparatus comprising:
 at least one processor; and   at least one memory storing program codes, wherein the at least one memory and the program codes are configured to, with the at least one processor, cause the apparatus at least to:
 transmit, to a user equipment, a timing advance command, 
 wherein a timing adjustment for a plurality of bandwidth parts is determined based on the timing advance command and a timing adjustment granularity, 
 wherein the plurality of bandwidth parts are configured with a plurality of subcarrier spacings, 
 wherein the plurality of subcarrier spacings comprise at least two different subcarrier spacings, and 
 wherein the timing adjustment granularity is determined based on a largest subcarrier spacing of the plurality of subcarrier spacings; and 
 receive an uplink transmission from the user equipment based on the timing adjustment. 
   
     
     
         16 . The apparatus of  claim 15 , wherein the timing adjustment granularity is associated with at least one of multiple numerologies associated with a timing advance group. 
     
     
         17 . The apparatus of  claim 15 , wherein the at least one memory and the program codes are further configured to, with the at least one processor, cause the apparatus at least to:
 transmitting the timing advance command to the user equipment as part of a radio resource control signaling.   
     
     
         18 . The apparatus of  claim 15 , wherein a finer timing adjustment granularity is used for a larger subcarrier spacing and a coarser timing adjustment granularity is used for a smaller subcarrier spacing. 
     
     
         19 . A non-transitory computer-readable medium may encode instructions that, when executed in hardware, perform a process, the process comprising:
 receiving, at a user equipment, from a network node, a timing advance command;   determining, based on the timing advance command and a timing adjustment granularity, a timing adjustment for a plurality of bandwidth parts,   wherein the plurality of bandwidth parts are configured with a plurality of subcarrier spacings,   wherein the plurality of subcarrier spacings comprise at least two different subcarrier spacings, and   wherein the timing adjustment granularity is determined based on a largest subcarrier spacing of the plurality of subcarrier spacings; and   transmitting an uplink transmission, from the user equipment, to the network node, on at least one of the plurality of bandwidth parts based on the timing adjustment.   
     
     
         20 . A non-transitory computer-readable medium may encode instructions that, when executed in hardware, perform a process, the process comprising:
 transmitting, from a network node, to a user equipment, a timing advance command,   wherein a timing adjustment for a plurality of bandwidth parts is determined based on the timing advance command and a timing adjustment granularity,   wherein the plurality of bandwidth parts are configured with a plurality of subcarrier spacings,   wherein the plurality of subcarrier spacings comprise at least two different subcarrier spacings, and   wherein the timing adjustment granularity is determined based on a largest subcarrier spacing of the plurality of subcarrier spacings; and   receiving an uplink transmission, at the network node, from the user equipment, based on the timing adjustment.