OFDM Based Distributed Space Time Coding for Asynchronous Relay Networks

— Recently Li and Xia have proposed a transmission scheme for wireless relay networks based on the Alamouti space time code and orthogonal frequency division multiplexing to combat the effect of timing errors at the relay nodes. This transmission scheme is amazingly simple and achieves a diversity order of two for any number of relays. Motivated by its simplicity, this scheme is extended to a more general transmission scheme that can achieve full cooperative diversity for any number of relays. The conditions on the distributed space time block code (DSTBC) structure that admit its application in the proposed transmission scheme are identified and it is pointed out that the recently proposed full diversity four group decodable DSTBCs from precoded co-ordinate interleaved orthogonal designs and extended Clifford algebras satisfy these conditions. It is then shown how differential encoding at the source can be combined with the proposed transmission scheme to arrive at a new transmissi...

• Type: Conference
• Year: 2008
• Where: ICC
• Authors: G. Susinder Rajan, B. Sundar Rajan
• Keywords: Communications, ICC 2008, Space Time Block Codes, Transmission Scheme, Wireless Relay Networks