Method and arrangement in wireless communication networks using relaying

Abstract

A wireless communication system with relaying to enhance performance provides artificial frequency selectivity and spatial diversity by introducing delay diversity. A OFDM chunk is subjected to a 2D cyclic prefix by pre-appending to a representation of the chunk the last column of the representation. The last row of the pre-appended chunk is copied to the top of the augmented chunk forming an augmented chunk.

1 . A receiving radio node configured for communication in a communication system that uses relaying and Orthogonal Frequency Domain Multiplexing (OFDM), comprising means for removing a two-dimensional cyclic prefix from a received representation of an OFDM chunk. 
     
     
         2 . The receiving radio node according to  claim 1 , wherein a processing module for removing a two-dimensional cyclic prefix is provided for each antenna stream. 
     
     
         3 . The receiving radio node according to  claim 1 , further comprising a module for combining a plurality of signals to a common signal provided after the cyclic prefix removing modules. 
     
     
         4 . A receiving radio node configured for communication in a communication system that uses relaying and Orthogonal Frequency Domain Multiplexing (OFDM), comprising electronic circuitry configured to remove a two-dimensional cyclic prefix from a received representation of an OFDM chunk. 
     
     
         5 . The receiving radio node according to  claim 4  having multiple antenna systems, wherein a processing module for removing a two-dimensional cyclic prefix is provided for each antenna stream. 
     
     
         6 . The receiving radio node according to  claim 4 , further comprising a module for combining a plurality of signals to a common signal provided after the cyclic prefix is removed. 
     
     
         7 . A method in a radio receiver, comprising:
 receiving an orthogonal frequency domain multiplex (OFDM) radio signal;   extracting a received representation of an OFDM chunk from the received OFDM radio signal;   removing a two-dimensional cyclic prefix from the received representation of the OFDM chunk.   
     
     
         8 . The method in  claim 7 , wherein the received OFDM radio signal includes multiple receive antenna streams, the method further comprising removing a two-dimensional cyclic prefix for each antenna stream. 
     
     
         9 . The method in  claim 7 , wherein the received OFDM radio signal includes multiple receive antenna streams, the method further comprising combining plural signal corresponding to different antenna streams that have had a two dimensional prefix removed.