Adaptive demodulation reference signals in wireless communication systems

Abstract

The described technology is generally directed towards adapting the demodulation reference signal sent in a wireless resource data block based on channel estimation performance. In general, if the demodulation reference signal received was not successfully able to be used to demodulate the resource data block, the demodulation reference signal density can be increased up to a maximum density, which costs resource elements but improves the channel estimation accuracy. If the demodulation reference signal received was able to be used to demodulate the resource data block, the demodulation reference signal density can be decreased down to minimum density, which saves resource elements for data. The network device can use HARQ ACK/NACK data (e.g., a current count or counted over a time period) to determine channel estimation performance, and/or the user equipment can recommend a demodulation reference signal density change.

What is claimed is: 
     
         1 . A method, comprising:
 determining, by network equipment comprising a processor, a change in channel estimation performance of a channel based on a first resource block comprising a first density of demodulation reference signals; and   in response to determining the change in the channel estimation performance and determining that the first density has not reached a limit of a density range, transmitting, by the network equipment, a second resource block comprising a second density of demodulation reference signals, wherein the second density is different than the first density.   
     
     
         2 . The method of  claim 1 , wherein the change is a decrease in the channel estimation performance. 
     
     
         3 . The method of  claim 2 , wherein the second density is higher than the first density. 
     
     
         4 . The method of  claim 2 , wherein the limit is an upper limit of the density range. 
     
     
         5 . The method of  claim 1 , wherein the change is an increase in the channel estimation performance. 
     
     
         6 . The method of  claim 5 , wherein the second density is lower than the first density. 
     
     
         7 . The method of  claim 5 , wherein the limit is a lower limit of the density range. 
     
     
         8 . Network equipment, comprising:
 a processor; and   a memory that stores executable instructions that, when executed by the processor, facilitate performance of operations, comprising:
 identifying a change in channel estimation performance of a communication channel based on a first resource block comprising a first density of demodulation reference signals; and 
 in response to identifying the change in the channel estimation performance and determining that the first density has not reached a boundary of a density range, sending a second resource block comprising a second density of demodulation reference signals, wherein the second density is different than the first density. 
   
     
     
         9 . The network equipment of  claim 8 , wherein the change is a decline in the channel estimation performance. 
     
     
         10 . The network equipment of  claim 9 , wherein the second density is higher than the first density. 
     
     
         11 . The network equipment of  claim 9 , wherein the boundary is an upper boundary of the density range. 
     
     
         12 . The network equipment of  claim 8 , wherein the change is a rise in the channel estimation performance. 
     
     
         13 . The network equipment of  claim 12 , wherein the second density is lower than the first density. 
     
     
         14 . The network equipment of  claim 12 , wherein the boundary is a lower boundary of the density range. 
     
     
         15 . A non-transitory machine-readable medium, comprising executable instructions that, when executed by a processor, facilitate performance of operations, comprising:
 detecting a change in channel estimation performance of a wireless channel based on a first resource block comprising a first density of demodulation reference signals; and   in response to detecting the change in the channel estimation performance and determining that the first density has not reached a limit of a density range, communicating a second resource block comprising a second density of demodulation reference signals, wherein the second density is different than the first density.   
     
     
         16 . The non-transitory machine-readable medium of  claim 15 , wherein the change is a reduction in the channel estimation performance. 
     
     
         17 . The non-transitory machine-readable medium of  claim 16 , wherein the second density is higher than the first density. 
     
     
         18 . The non-transitory machine-readable medium of  claim 16 , wherein the limit is maximum density. 
     
     
         19 . The non-transitory machine-readable medium of  claim 15 , wherein the change is an improvement in the channel estimation performance. 
     
     
         20 . The non-transitory machine-readable medium of  claim 19 , wherein the second density is lower than the first density, and the limit is a minimum density.