Enhanced timing advance scheme to support mu-mimo in integrated access and backhaul

Abstract

Various embodiments disclosed herein provide for an enhanced timing advance scheme to support MU-MIMO in an integrated access and backhaul system. The timing advance scheme disclosed herein aligns the arrival time between backhaul links and access links to enable MU-MIMO gain at the receiver side. In the integrated access and backhaul system, which comprises distributed nodes, the timing advance offset for an access link transmission (a transmission to a node further away in hops from the core network, or to a user equipment device) can be modified by offsetting it with the timing advance of the backhaul link (e.g., from a parent node). This enables the arrival time for transmissions, both access link transmissions from the UE or child node, and backhaul link transmissions from a parent node to arrive at the same time.

What is claimed is: 
     
         1 . A relay network device, comprising:
 a processor; and   a memory that stores executable instructions that, when executed by the processor, facilitate performance of operations, comprising:
 determining a preliminary timing advance parameter associated with an access link based on a distance of a user equipment from the relay network device; and 
 determining a second timing advance parameter to apply to a first access link transmission based on a function of a difference between the preliminary timing advance parameter and a first timing advance parameter associated with a backhaul link. 
   
     
     
         2 . The relay network device of  claim 1 , wherein the operations further comprise:
 applying the second timing advance parameter to the first access link transmission to synchronize respective transmissions on the access link and the backhaul link.   
     
     
         3 . The relay network device of  claim 1 , wherein the backhaul link comprises a physical downlink shared channel. 
     
     
         4 . The relay network device of  claim 3 , wherein the operations further comprise:
 processing a backhaul link transmission of the backhaul link and a second access link transmission of the access link with a common physical layer stack and separate protocol stacks.   
     
     
         5 . The relay network device of  claim 4 , wherein the operations further comprise:
 mapping a first transport block associated with the backhaul link transmission and a second transport block associated with the second access link transmission to a first logical channel and a second logical channel, respectively.   
     
     
         6 . The relay network device of  claim 3 , wherein the operations further comprise:
 processing a backhaul link transmission of the backhaul link and a second access link transmission of the access link with a physical layer stack and a protocol stack.   
     
     
         7 . The relay network device of  claim 6 , wherein the operations further comprise:
 receiving the backhaul link transmission and the second access link transmission via separate antenna elements.   
     
     
         8 . A method, comprising:
 determining, by a network device comprising a processor, a preliminary timing advance parameter associated with an access link based on a distance of a user equipment associated with the access link from the network device; and   determining, by the network device, a second timing advance parameter to apply to a first access link transmission based on a function of a difference between the preliminary timing advance parameter and a first timing advance parameter associated with a backhaul link.   
     
     
         9 . The method of  claim 8 , further comprising applying, by the network device, the second timing advance parameter to the first access link transmission to synchronize transmissions on the access link and the backhaul link. 
     
     
         10 . The method of  claim 8 , wherein the backhaul link is a physical downlink shared channel. 
     
     
         11 . The method of  claim 10 , further comprising processing, by the network device, a backhaul link transmission of the backhaul link and a second access link transmission of the access link with a common physical layer stack and a protocol stack. 
     
     
         12 . The method of  claim 11 , further comprising mapping, by the network device, a first transport block associated with the backhaul link transmission and a second transport block associated with the second access link transmission to a first logical channel and a second logical channel, respectively. 
     
     
         13 . The method of  claim 10 , further comprising processing, by the network device, a backhaul link transmission of the backhaul link and a second access link transmission of the access link with different physical layer stacks and different protocol stacks. 
     
     
         14 . The method of  claim 13 , further comprising receiving, by the network device, the backhaul link transmission and the second access link transmission via different antenna elements. 
     
     
         15 . A non-transitory machine-readable medium, comprising executable instructions that, when executed by a processor of network equipment, facilitate performance of operations, comprising:
 determining a preliminary timing advance parameter associated with an access link based on a distance of a user equipment associated with the access link from the network equipment; and   determining a second timing advance parameter to apply to a first access link transmission based on a function of a difference between the preliminary timing advance parameter and a first timing advance parameter associated with a backhaul link.   
     
     
         16 . The non-transitory machine-readable medium of  claim 15 , wherein the operations further comprise:
 applying the second timing advance parameter to the first access link transmission to synchronize respective transmissions on the access link and the backhaul link.   
     
     
         17 . The non-transitory machine-readable medium of  claim 15 , wherein the backhaul link comprises a physical downlink shared channel. 
     
     
         18 . The non-transitory machine-readable medium of  claim 17 , wherein the operations further comprise:
 processing a backhaul link transmission of the backhaul link and a second access link transmission of the access link with a common physical layer stack and separate protocol stacks.   
     
     
         19 . The non-transitory machine-readable medium of  claim 18 , wherein the operations further comprise:
 mapping a first transport block associated with the backhaul link transmission and a second transport block associated with the second access link transmission to a first logical channel and a second logical channel, respectively.   
     
     
         20 . The non-transitory machine-readable medium of  claim 17 , wherein the operations further comprise:
 processing a backhaul link transmission of the backhaul link and a second access link transmission of the access link with separate physical layer stacks and separate protocol stacks.