Full diversity under multiple carrier frequency offsets of a family of space-frequency codes

A cooperative system may have both timing errors and multiple carrier frequency offsets (CFOs). To combat timing errors, space-frequency (SF) coded OFDM systems have been recently proposed for cooperative communications to achieve both full cooperative and full multipath diversities without time synchronization requirement. In this paper, we study the effect of multiple CFOs from relay nodes on a family of rotation based SF codes. We find that they can still achieve full diversities under the condition that the absolute values of normalized CFOs are less than 0.5. We further show that this full diversity property still holds for a complexity-reduced two-stage zero forcing (ZF) aided maximum likelihood (ML) decoding method, for which a ZF method is used to equalize multiple CFOs before ML decoding.

[1]  Huiming Wang,et al.  Computationally efficient MMSE and MMSE-DFE equalizations for asynchronous cooperative communications with multiple frequency offsets , 2008, 2008 IEEE International Symposium on Information Theory.

[2]  Sumit Roy,et al.  Rate-one space-frequency block codes with maximum diversity for MIMO-OFDM , 2005, IEEE Transactions on Wireless Communications.

[3]  Sumit Roy,et al.  Rate-one space frequency block codes with maximum diversity gain for MIMO-OFDM , 2003, GLOBECOM '03. IEEE Global Telecommunications Conference (IEEE Cat. No.03CH37489).

[4]  Xiang-Gen Xia,et al.  On the Full Diversity Property of A Space-Frequency Code Family with Multiple Carrier Frequency Offsets in Cooperative Communication Systems , 2010, J. Commun..

[5]  Xiang-Gen Xia,et al.  A Simple Alamouti Space–Time Transmission Scheme for Asynchronous Cooperative Systems , 2007, IEEE Signal Processing Letters.

[6]  Guangxi Zhu,et al.  An equalization technique for distributed stbc-ofdm system with multiple carrier frequency offsets , 2006, IEEE Wireless Communications and Networking Conference, 2006. WCNC 2006..

[7]  Ananthram Swami,et al.  Combating synchronization errors in cooperative relays , 2005, Proceedings. (ICASSP '05). IEEE International Conference on Acoustics, Speech, and Signal Processing, 2005..

[8]  Dennis Goeckel,et al.  CTH15-4: Multiple Frequency Offset Compensation in Cooperative Wireless Systems , 2006, IEEE Globecom 2006.

[9]  K. J. Ray Liu,et al.  Full-rate full-diversity space-frequency codes with optimum coding advantage , 2005, IEEE Transactions on Information Theory.

[10]  Xiang-Gen Xia,et al.  CTH13-6: Distributive High-Rate Space-Frequency Codes Achieving Full Cooperative and Multipath Diversities for Asynchronous Cooperative Communications , 2006, IEEE Globecom 2006.

[11]  Xiang-Gen Xia,et al.  Signal Detection in a Cooperative Communication System with Multiple CFOs by Exploiting the Properties of Space-Frequency Codes , 2008, 2008 IEEE International Conference on Communications.