Control messaging of common phase error (cpe) compensation performance level for frequency division multiplex (fdm) symbols in wireless communication systems

Abstract

A wireless base station or user equipment (BS or UE) includes a receiver configured to receive a frequency division multiplexed (FDM) symbol transmitted by another wireless BS or UE, and a processor. The processor is configured to process the received FDM symbol to obtain its equalized FDM data subcarriers, generate a CPE estimate using the equalized FDM data subcarriers, and send to the other wireless BS or UE control messages that indicate a CPE compensation performance level using the CPE estimate. The other wireless BS or UE is enabled by the control messages to adapt a density in time and/or frequency of embedded pilot symbols within FDM symbols subsequently transmitted to the wireless BS or UE.

1 . A method, comprising:
 receiving, by a first wireless base station or user equipment (BS or UE), a frequency division multiplexed (FDM) symbol transmitted by a second wireless BS or UE;   processing, by the first BS or UE, the received FDM symbol to obtain its equalized FDM data subcarriers;   generating, by the first BS or UE, a CPE estimate using the equalized FDM data subcarriers;   sending, by the first wireless BS or UE to the second wireless BS or UE, control messages that indicate a CPE compensation performance level using the CPE estimate; and   wherein the second wireless BS or UE, in response to the control messages, is enabled to adapt a density in time and/or frequency of embedded pilot symbols within FDM symbols subsequently transmitted to the first wireless BS or UE.   
     
     
         2 . The method of  claim 1 ,
 wherein to adapt the density of embedded pilot symbols, the second wireless BS or UE reduces the density of embedded pilot symbols in the subsequently transmitted FDM symbols as long as the control messages continue to indicate an adequate CPE compensation performance level.   
     
     
         3 . The method of  claim 1 , further comprising:
 using, by the first wireless BS or UE, a blind CPE compensation method for subsequently received FDM symbols that are without embedded pilot symbols as long as the control messages continue to indicate an adequate CPE compensation performance level.   
     
     
         4 . The method of  claim 1 , further comprising:
 compensating, by the first BS or UE, each of the equalized FDM data subcarriers using the CPE estimate.   
     
     
         5 . The method of  claim 1 ,
 wherein the second wireless BS or UE adapts the density of embedded pilot symbols in a dynamic manner.   
     
     
         6 . The method of  claim 1 ,
 wherein the second wireless BS or UE adapts the density of embedded pilot symbols in a semi-static manner.   
     
     
         7 . The method of  claim 1 ,
 wherein said generating a CPE estimate comprises generating a CPE estimate based on a constellation diagram associated with a modulation scheme used by the second wireless BS or UE to generate the FDM data subcarriers of the transmitted FDM symbol.   
     
     
         8 . The method of  claim 1 ,
 wherein the control messages that indicate the CPE compensation performance level comprise RRC control messages.   
     
     
         9 . A wireless base station or user equipment (BS or UE), comprising:
 a receiver, configured to receive a frequency division multiplexed (FDM) symbol transmitted by another wireless BS or UE; and   a processor, configured to:
 process the received FDM symbol to obtain its equalized FDM data subcarriers; 
 generate a CPE estimate using the equalized FDM data subcarriers; and 
 send to the other wireless BS or UE control messages that indicate a CPE compensation performance level using the CPE estimate; and 
   wherein the other wireless BS or UE is enabled by the control messages to adapt a density in time and/or frequency of embedded pilot symbols within FDM symbols subsequently transmitted to the wireless BS or UE.   
     
     
         10 . The wireless BS or UE of  claim 9 ,
 wherein the other wireless BS or UE is enabled by the control messages to adapt the density of the embedded pilot symbols by reducing the density of embedded pilot symbols in the subsequently transmitted FDM symbols as long as the control messages continue to indicate an adequate CPE compensation performance level.   
     
     
         11 . The wireless BS or UE of  claim 9 ,
 wherein the processor is further configured to:
 use a blind CPE compensation method for subsequently received FDM symbols that are without embedded pilot symbols as long as the control messages continue to indicate an adequate CPE compensation performance level. 
   
     
     
         12 . The wireless BS or UE of  claim 9 ,
 wherein the processor is further configured to:
 compensate each of the equalized FDM data subcarriers using the CPE estimate. 
   
     
     
         13 . The wireless BS or UE of  claim 9 ,
 wherein the other wireless BS or UE is enabled by the control messages to adapt the density of the embedded pilot symbols in a dynamic manner.   
     
     
         14 . The wireless BS or UE of  claim 9 ,
 wherein the other wireless BS or UE is enabled by the control messages to adapt the density of the embedded pilot symbols in a semi-static manner.   
     
     
         15 . The wireless BS or UE of  claim 9 ,
 wherein the processor generates the CPE estimate based on a constellation diagram associated with a modulation scheme used by the other wireless BS or UE to generate the FDM data subcarriers of the transmitted FDM symbol.   
     
     
         16 . The wireless BS or UE of  claim 9 ,
 wherein the control messages that indicate the CPE compensation performance level comprise RRC control messages.   
     
     
         17 . A non-transitory computer-readable medium having instructions stored thereon that are capable of causing or configuring a wireless base station or user equipment (BS or UE) to perform operations comprising:
 receiving, by the wireless BS or UE, a frequency division multiplexed (FDM) symbol transmitted by another wireless BS or UE;   processing, by the BS or UE, the received FDM symbol to obtain its equalized FDM data subcarriers;   generating, by the BS or UE, a CPE estimate using the equalized FDM data subcarriers;   sending, by the wireless BS or UE to the other wireless BS or UE, control messages that indicate a CPE compensation performance level using the CPE estimate; and   wherein the other wireless BS or UE, in response to the control messages, is enabled to adapt a density in time and/or frequency of embedded pilot symbols within FDM symbols subsequently transmitted to the wireless BS or UE.   
     
     
         18 . The non-transitory computer-readable medium of  claim 17 , the operations further comprising:
 using, by the wireless BS or UE, a blind CPE compensation method for subsequently received FDM symbols that are without embedded pilot symbols as long as the control messages continue to indicate an adequate CPE compensation performance level.   
     
     
         19 . The non-transitory computer-readable medium of  claim 17 , the operations further comprising:
 compensating, by the BS or UE, each of the equalized FDM data subcarriers using the CPE estimate.   
     
     
         20 . The non-transitory computer-readable medium of  claim 17 ,
 wherein the control messages that indicate the CPE compensation performance level comprise RRC control messages.