Method and system for predicting a downlink channel

Abstract

Aspects of the subject disclosure may include, for example, receiving a plurality of orthogonal sounding reference signals (SRS) from a plurality of user equipment (UEs), wherein each SRS of the plurality of orthogonal SRS is provided by a respective UE of the plurality of UEs, determining a downlink (DL) channel, in frequency division duplex (FDD), using spatial correlations relating to the plurality of UEs, wherein the spatial correlations are based on the plurality of orthogonal SRS, calculating a plurality of DL precoding weights for a plurality of coherent modular antenna panels responsive to the determining the DL channel, and applying the plurality of DL precoding weights to the plurality of coherent modular antenna panels to enable multi-user (Mu)-multiple-input-multiple-output (MIMO) for the plurality of UEs. Other embodiments are disclosed.

What is claimed is: 
     
         1 . A method comprising:
 estimating, by a processing system including a processor, an uplink (UL) channel based on a plurality of pilot signals, wherein the plurality of pilot signals is provided by a plurality of user equipment (UEs), wherein each pilot signal of the plurality of pilot signals is provided by a respective UE of the plurality of UEs, and wherein the processing system is associated with an aggregation of modular antenna arrays;   calculating, by the processing system, a plurality of UL combining weights for the aggregation of modular antenna arrays responsive to the estimating the UL channel;   predicting, by the processing system, a downlink (DL) channel based on spatial correlations relating to the plurality of UEs, resulting in a predicted DL channel, wherein the spatial correlations are derived from channel vectors associated with the plurality of UEs;   calculating, by the processing system, a plurality of DL precoding weights for the aggregation of modular antenna arrays based on the predicted DL channel; and   utilizing, by the processing system, the plurality of UL combining weights and the plurality of DL precoding weights to operate the aggregation of modular antenna arrays for the plurality of UEs.   
     
     
         2 . The method of  claim 1 , wherein the UL channel and the DL channel are operated in frequency division duplex (FDD). 
     
     
         3 . The method of  claim 1 , wherein the utilizing enables multi-user (Mu)-multiple-input-multiple-output (MIMO) to be employed for one or more UEs of the plurality of UEs. 
     
     
         4 . The method of  claim 1 , wherein the predicting the DL channel based on the spatial correlations relating to the plurality of UEs comprises performing one or more averages of the spatial correlations. 
     
     
         5 . The method of  claim 1 , wherein the plurality of UL combining weights comprises a plurality of amplitudes for the UL, a plurality of phases for the UL, or a combination thereof. 
     
     
         6 . The method of  claim 1 , wherein the plurality of DL precoding weights comprises a plurality of amplitudes for the DL, a plurality of phases for the DL, or a combination thereof. 
     
     
         7 . The method of  claim 1 , wherein each pilot signal of the plurality of pilot signals comprises a sounding reference signal (SRS), and wherein, for input interference relating to a neighbor cell UE, a fixed UE, or an active external source, the calculating the plurality of UL combining weights and the calculating the plurality of DL precoding weights involves subtracting a summation of known UE channels from an autocovariance determined based on received signals in order to identify or isolate the input interference. 
     
     
         8 . The method of  claim 1 , wherein the aggregation of antenna arrays comprises a plurality of antenna panels, and wherein each antenna panel of the plurality of antenna panels comprises a plurality of antenna elements. 
     
     
         9 . The method of  claim 8 , wherein each UL combining weight of the plurality of UL combining weights corresponds to a respective antenna element of the plurality of antenna elements. 
     
     
         10 . The method of  claim 8 , wherein each DL precoding weight of the plurality of DL precoding weights corresponds to a respective antenna element of the plurality of antenna elements. 
     
     
         11 . A device comprising:
 a processing system including a processor, wherein the processing system is communicatively coupled with a plurality of coherent modular antenna panels; and   a memory that stores executable instructions that, when executed by the processing system, facilitate performance of operations, the operations comprising:
 determining a downlink (DL) channel, in frequency division duplex (FDD), using spatial correlations relating to a plurality of user equipment (UEs), wherein the spatial correlations are based on a plurality of orthogonal sounding reference signals (SRS) received from the plurality of UEs; 
 calculating a plurality of DL precoding weights for the plurality of coherent modular antenna panels responsive to the determining the DL channel; and 
 applying the plurality of DL precoding weights to the plurality of coherent modular antenna panels to enable multi-user (Mu)-multiple-input-multiple-output (MIMO) for the plurality of UEs. 
   
     
     
         12 . The device of  claim 11 , wherein the determining the DL channel using the spatial correlations relating to the plurality of UEs comprises determining one or more expectations of the spatial correlations. 
     
     
         13 . The device of  claim 11 , wherein each modular antenna panel of the plurality of coherent modular antenna panels comprises a plurality of antenna elements, resulting in multiple pluralities of antenna elements. 
     
     
         14 . The device of  claim 13 , wherein each DL precoding weight of the plurality of DL precoding weights corresponds to a respective antenna element of the multiple pluralities of antenna elements. 
     
     
         15 . The device of  claim 11 , wherein the plurality of UEs includes fixed wireless customer premises equipment (CPEs) located at or within a threshold distance from a cell edge associated with the processing system. 
     
     
         16 . A non-transitory machine-readable medium comprising executable instructions that, when executed by a processing system that is associated with a coherent combination of modular antenna arrays and that includes a processor, facilitate performance of operations, the operations comprising:
 responsive to an estimating of a frequency division duplex (FDD) uplink (UL) channel, determining a plurality of UL weights for the coherent combination of modular antenna arrays, wherein the estimating is based on pilot signals transmitted by a plurality of user equipment (UEs);   predicting an FDD downlink (DL) channel based on spatial correlations corresponding to the plurality of UEs, resulting in a predicted FDD DL channel, wherein the spatial correlations are based on channel vectors associated with the plurality of UEs;   determining a plurality of DL weights for the coherent combination of modular antenna arrays based on the predicted FDD DL channel; and   causing the plurality of UL weights and the plurality of DL weights to be applied to the coherent combination of modular antenna arrays for the plurality of UEs.   
     
     
         17 . The non-transitory machine-readable medium of  claim 16 , wherein the causing enables multi-user (Mu)-multiple-input-multiple-output (MIMO) to be employed for one or more UEs of the plurality of UEs. 
     
     
         18 . The non-transitory machine-readable medium of  claim 16 , wherein the predicting the FDD DL channel based on the spatial correlations corresponding to the plurality of UEs comprises performing one or more averages of the spatial correlations, and wherein the predicting the FDD DL channel further involves compensating for a difference between an UL frequency and a DL frequency by performing spatial-scaling of UL channel data such that a first phase difference between DL signals emitted by different antenna elements of the coherent combination of modular antenna arrays is the same as a second phase difference in an UL direction. 
     
     
         19 . The non-transitory machine-readable medium of  claim 16 , wherein the pilot signals comprise sounding reference signals (SRS). 
     
     
         20 . The non-transitory machine-readable medium of  claim 16 , wherein each modular antenna array of the coherent combination of modular antenna arrays comprises a group of antenna elements, resulting in multiple groups of antenna elements, and wherein each antenna element of the multiple groups of antenna elements is associated with a respective programmable device.