Rate adaptive space-time modulation techniques for combating cochannel interference

Space-time coding is a highly effective approach for combating fading in wireless communications and improving the capacity of wireless networks. However, Catreux et al. (2000) showed that cochannel interference can degrade performance significantly in cellular systems. Here we design and demonstrate the interference suppression capability of low rate space-time codes. Optimal 1 b/s/Hz 2-space-time trellis codes with various numbers of states over Z/sub 4/ and GF(4) are obtained through search. We also propose rate adaptive space-time modulation which can increase the overall throughput. The effectiveness of this proposed method is demonstrated by using 2-space-time codes in an orthogonal frequency division multiplexing (OFDM) system with 2 transmit and 2 receive antennas.

[1]  Larry J. Greenstein,et al.  Simulation results for an interference-limited multiple-input multiple-output cellular system , 2000, IEEE Commun. Lett..

[2]  Geoffrey Ye Li,et al.  Transmitter diversity for OFDM systems and its impact on high-rate data wireless networks , 1999, IEEE J. Sel. Areas Commun..

[3]  Rick S. Blum,et al.  Optimum space-time convolutional codes , 2000, 2000 IEEE Wireless Communications and Networking Conference. Conference Record (Cat. No.00TH8540).

[4]  A. Robert Calderbank,et al.  Space-time codes for high data rate wireless communication: performance criteria , 1997, Proceedings of ICC'97 - International Conference on Communications.

[5]  Rick S. Blum,et al.  Improved techniques for 4 transmit and 4 receive antenna MIMO-OFDM for wireless communications , 2001, IEEE VTS 53rd Vehicular Technology Conference, Spring 2001. Proceedings (Cat. No.01CH37202).