Method and apparatus for pilot and data multiplexing in a wireless communication system

Abstract

Techniques for multiplexing pilots in a wireless transmission are described. In one aspect, a transmitter station generates multiple pilot sequences for multiple transmit antennas, with each pilot sequence comprising pilot symbols sent in the time domain on a different set of subcarriers. The transmitter station further generates multiple pilot transmissions for the transmit antennas based on the pilot sequences. In another aspect, a transmitter station generates multiple pilot sequences for multiple transmit antennas based on frequency-domain code division multiplexing (FD-CDM) of a Chu sequence defined by a transmitter-specific value. The transmitter station further generates multiple pilot transmissions for the transmit antennas based on the pilot sequences. In yet another aspect, a transmitter station generates multiple pilot transmissions for multiple transmit antennas based on a first multiplexing scheme and generates multiple data transmissions based on a second multiplexing scheme that is different from the first multiplexing scheme.

What is claimed is: 
     
         1 . An apparatus comprising:
 at least one processor configured to generate a plurality of pilot transmissions for a plurality of transmit antennas based on a first multiplexing scheme, and to generate a plurality of data transmissions for the plurality of transmit antennas based on a second multiplexing scheme different from the first multiplexing scheme; and   a memory coupled to the at least one processor.   
     
     
         2 . The apparatus of  claim 1 , wherein the first multiplexing scheme is orthogonal frequency division multiplexing (OFDM) and the second multiplexing scheme is single-carrier frequency division multiplexing (SC-FDM) or code division multiplexing (CDM). 
     
     
         3 . The apparatus of  claim 1 , wherein the first multiplexing scheme is single-carrier frequency division multiplexing (SC-FDM) and the second multiplexing scheme is orthogonal frequency division multiplexing (OFDM) or code division multiplexing (CDM). 
     
     
         4 . The apparatus of  claim 1 , wherein the first multiplexing scheme is frequency-domain code division multiplexing (FD-CDM) and the second multiplexing scheme is orthogonal frequency division multiplexing (OFDM) or single-carrier frequency division multiplexing (SC-FDM). 
     
     
         5 . The apparatus of  claim 1 , wherein the first multiplexing scheme is interleaved frequency division multiplexing (IFDM) and the second multiplexing scheme is localized frequency division multiplexing (LFDM). 
     
     
         6 . The apparatus of  claim 1 , wherein the at least one processor sends the plurality of pilot transmissions in a first time interval and sends the plurality of data transmissions in a second time interval with time division multiplexing (TDM). 
     
     
         7 . The apparatus of  claim 1 , wherein the at least one processor sends the plurality of pilot transmissions on a first set of subcarriers and sends the plurality of data transmissions on a second set of subcarriers with frequency division multiplexing (FDM). 
     
     
         8 . A method comprising:
 generating a plurality of pilot transmissions for a plurality of transmit antennas based on a first multiplexing scheme; and   generating a plurality of data transmissions for the plurality of transmit antennas based on a second multiplexing scheme different from the first multiplexing scheme.   
     
     
         9 . The method of  claim 8 , further comprising:
 sending the plurality of pilot transmissions in a first time interval; and   sending the plurality of data transmissions in a second time interval with time division multiplexing (TDM).   
     
     
         10 . An apparatus comprising:
 means for generating a plurality of pilot transmissions for a plurality of transmit antennas based on a first multiplexing scheme; and   means for generating a plurality of data transmissions for the plurality of transmit antennas based on a second multiplexing scheme different from the first multiplexing scheme.   
     
     
         11 . The apparatus of  claim 10 , further comprising:
 means for sending the plurality of pilot transmissions in a first time interval; and   sending the plurality of data transmissions in a second time interval with time division multiplexing (TDM).   
     
     
         12 . A computer program product comprising:
 a computer-readable medium storing instructions for performing a method comprising:
 generating a plurality of pilot transmissions for a plurality of transmit antennas based on a first multiplexing scheme; and 
 generating a plurality of data transmissions for the plurality of transmit antennas based on a second multiplexing scheme different from the first multiplexing scheme. 
   
     
     
         13 . The computer program product of  claim 12 , further comprising instructions for:
 sending the plurality of pilot transmissions in a first time interval; and   sending the plurality of data transmissions in a second time interval with time division multiplexing (TDM).   
     
     
         14 . An apparatus comprising:
 at least one processor configured to receive a plurality of pilot transmissions generated based on a first multiplexing scheme, and to receive a plurality of data transmissions generated based on a second multiplexing scheme different from the first multiplexing scheme, the plurality of pilot transmissions and the plurality of data transmissions being for a multiple-input multiple-output (MIMO) transmission sent from a plurality of transmit antennas to a plurality of receive antennas; and   a memory coupled to the at least one processor.   
     
     
         15 . The apparatus of  claim 14 , wherein the at least one processor derives channel estimates for the plurality of transmit antennas and the plurality of receive antennas based on the plurality of received pilot transmissions, and performs data detection for the plurality of received data transmissions based on the channel estimates. 
     
     
         16 . A method comprising:
 receiving a plurality of pilot transmissions generated based on a first multiplexing scheme; and   receiving a plurality of data transmissions generated based on a second multiplexing scheme different from the first multiplexing scheme, the plurality of pilot transmissions and the plurality of data transmissions being for a multiple-input multiple-output (MIMO) transmission sent from a plurality of transmit antennas to a plurality of receive antennas.   
     
     
         17 . The method of  claim 16 , further comprising:
 deriving channel estimates for the plurality of transmit antennas and the plurality of receive antennas based on the plurality of received pilot transmissions; and   performing data detection for the plurality of received data transmissions based on the channel estimates.   
     
     
         18 . An apparatus comprising:
 means for receiving a plurality of pilot transmissions generated based on a first multiplexing scheme; and   means for receiving a plurality of data transmissions generated based on a second multiplexing scheme different from the first multiplexing scheme, the plurality of pilot transmissions and the plurality of data transmissions being for a multiple-input multiple-output (MIMO) transmission sent from a plurality of transmit antennas to a plurality of receive antennas.   
     
     
         19 . The apparatus of  claim 18 , further comprising:
 means for deriving channel estimates for the plurality of transmit antennas and the plurality of receive antennas based on the plurality of received pilot transmissions; and   means for performing data detection for the plurality of received data transmissions based on the channel estimates.   
     
     
         20 . A computer program product comprising a computer-readable medium storing instructions for performing a method comprising:
 receiving a plurality of pilot transmissions generated based on a first multiplexing scheme; and   receiving a plurality of data transmissions generated based on a second multiplexing scheme different from the first multiplexing scheme, the plurality of pilot transmissions and the plurality of data transmissions being for a multiple-input multiple-output (MIMO) transmission sent from a plurality of transmit antennas to a plurality of receive antennas.   
     
     
         21 . The computer program product of  claim 20 , further comprising instructions for:
 deriving channel estimates for the plurality of transmit antennas and the plurality of receive antennas based on the plurality of received pilot transmissions; and   performing data detection for the plurality of received data transmissions based on the channel estimates.