Transmit Diversity Scheme

Abstract

The present invention relates to methods for implementing transmit diversity in a telecommunication network. In particular there is provided an algorithm for performing transmit diversity encoding in a transmitter ( 100 ) and transmit diversity decoding in a receiver ( 1700 ) respectively. In the method processed pairs of data blocks ( 314.1 A, 314.1 B) are transmitted on a first antenna ( 112.1 ) on N sub-carriers in a first temporal order; and a second antenna ( 112.2 ) in the reverse temporal order.

1 . A method of processing at least one sequence of data symbols to be transmitted over a wireless channel, comprising:
 (a) defining, in the at least one sequence of data symbols, a plurality of blocks of symbols;   (b) processing the least one sequence of data symbols on a block-by-block basis to provide frequency diversity in the subsequently transmitted signal;   (c) processing the blocks of data in groups of two or more blocks to provide time diversity in the subsequently transmitted signal; and   (d) processing the blocks of data for transmission over at least two antennas to provide for spatial diversity in the subsequently transmitted signal.   
     
     
         2 . A transmit diversity encoder configured to process at least one sequence of data symbols to be transmitted over a wireless channel including N sub-carriers having different frequencies, comprising:
 a block defining stage configured to define, in the at least one sequence of data symbols, a plurality of blocks of symbols;   a frequency encoder configured to process the blocks of symbols to provide frequency diversity within the blocks of symbols;   a space-time encoder configured to process the blocks of data in groups of two or more blocks to provide time diversity between blocks for transmission over different antennas.   
     
     
         3 . The transmit diversity encoder as claimed in  claim 2 , wherein the frequency encoder is configured to interleave the symbols of a block in the frequency domain, to provide frequency diversity in the block. 
     
     
         4 . A transmitter for a wireless communications network, comprising: at least two transmission antennas and the transmit diversity encoder as claimed in claim  12 . 
     
     
         5 . The transmitter according to  claim 4 , further comprises: at least one OFDM modulator for modulating data for transmission over a plurality of antennas. 
     
     
         6 . A base station for a wireless communications network, comprising: the transmitter as claimed in  claim 5 . 
     
     
         7 . A method of processing a received sequence of data symbols transmitted over a wireless channel, comprising:
 determining a space-time encoding scheme used it the transmission of sequence the data symbols;   defining at least one block of data symbols in the received sequence of data symbols on the basis of the determined space-time encoding scheme; and   processing the at least one block of data symbols, in accordance with the determined space-time encoding scheme.   
     
     
         8 . The method of processing a received sequence of data symbols transmitted over a wireless channel as claimed in  claim 7 , wherein the determining a space-time encoding scheme is made on the basis of received signaling data. 
     
     
         9 . The method of processing a received sequence of data symbols transmitted over a wireless channel as claimed in  claim 7 , wherein the defined block of symbols includes a plurality of consecutive data symbols transmitted on a plurality of sub-carriers. 
     
     
         10 . The method of processing a received sequence of data symbols transmitted over a wireless channel as claimed in  claim 7 , wherein the defined block of symbols includes a plurality of data symbols transmitted on a plurality of sub-carriers. 
     
     
         11 . The method of processing a received sequence of data symbols transmitted over a wireless channel as claimed  claim 7 , further comprising: generating a plurality of channel estimates corresponding to a plurality of transmission antennae used to transmit the wireless channel.