System and Method for Pilot Design

Abstract

An apparatus for generating a pilot pattern for data to be transmitted in an orthogonal frequency-division multiplexing (OFDM) based communication system, having a for allocating pilot symbols for a plurality of data streams to form a plurality of pilot clusters in the pilot pattern, wherein each of the pilot clusters includes ones of the pilot symbols, the ones of the pilot symbols being for respectively different ones of the data streams. The apparatus also includes a mechanism for moving at least one of the pilot clusters from a first location in the resource block to a second location in the resource block to generate a second pilot pattern, the first and second locations being symmetrical in time, and a mechanism for generating a third pilot pattern based on the first and second pilot patterns.

What is claimed is: 
     
         1 . An apparatus for generating a pilot pattern for data to be transmitted in an orthogonal frequency-division multiplexing (OFDM) based communication system, comprising:
 means for allocating pilot symbols for a plurality of data streams to form a plurality of pilot clusters in the pilot pattern,   wherein each of the pilot clusters includes ones of the pilot symbols, the ones of the pilot symbols being for respectively different ones of the data streams;   wherein the pilot pattern is a first pilot pattern represented by a resource block;   means for moving at least one of the pilot clusters from a first location in the resource block to a second location in the resource block to generate a second pilot pattern, the first and second locations being symmetrical in time; and   means for generating a third pilot pattern based on the first and second pilot patterns.   
     
     
         2 . An apparatus for generating a pilot pattern for data to be transmitted in an orthogonal frequency-division multiplexing (OFDM) based communication system, comprising:
 means for allocating first and second pilot symbols for first and second ones of a plurality of data streams, respectively, to a same subcarrier of the communication system, the first and second pilot symbols corresponding to a same time,   wherein the pilot pattern is represented by first and second resource blocks;   means for allocating third and fourth pilot symbols to first and second boundary times in the first resource block, respectively, the third and fourth pilot symbols being for third and fourth ones of the plurality of data streams; and   means for symmetrically shifting the third and fourth pilot symbols from the boundary times to intermediate times in the first resource block.   
     
     
         3 . A method for generating a new pilot pattern for data to be transmitted in an orthogonal frequency-division multiplexing (OFDM) based communication system including a transmitter, the method comprising:
 generating, by the transmitter, the new pilot pattern based on a given pilot pattern including a plurality of pilot symbols.   
     
     
         4 . The method of  claim 3 , wherein the generating comprises:
 performing, by the transmitter, a symmetrical mapping on ones of the plurality of pilot symbols in the given pilot pattern to generate the new pilot pattern.   
     
     
         5 . The method of  claim 4 , wherein the ones of the plurality of pilot symbols are allocated to a first subcarrier frequency in the given pilot pattern, the performing comprising:
 allocating, by the transmitter, the ones of the plurality of pilot symbols to a second subcarrier frequency for the new pilot pattern, the first and second subcarrier frequencies being symmetrical with respect to a reference frequency.   
     
     
         6 . The method of  claim 4 , wherein the ones of the plurality of pilot symbols are allocated to a first time in the given pilot pattern, the performing comprising:
 allocating, by the transmitter, the ones of the plurality of pilot symbols to a second time for the new pilot pattern, the first and second times being symmetrical with respect to a reference time.   
     
     
         7 . The method of  claim 3 , wherein the generating comprises:
 performing, by the transmitter, a cyclic shift on the plurality of pilot symbols in the given pilot pattern to generate the new pilot pattern.   
     
     
         8 . The method of  claim 7 , wherein the performing comprises:
 performing, by the transmitter, the cyclic shift in time.   
     
     
         9 . The method of  claim 7 , wherein the performing comprises:
 performing, by the transmitter, the cyclic shift in frequency.   
     
     
         10 . The method of  claim 3 , wherein the generating comprises:
 performing, by the transmitter, a rotational shift on ones of the plurality of pilot symbols in the given pilot pattern to generate the new pilot pattern.   
     
     
         11 . The method of  claim 3 , wherein the given pilot pattern is represented by a resource block including a plurality of OFDM symbols, the generating comprising:
 superposing, by the transmitter, first and second ones of the plurality of OFDM symbols in the resource block to generate the new pilot pattern.