A Diversity Transmission Technique with High Performance in Cooperative Communications Systems

The transmission scheme of STBC combined with frequency domain equalization (FDE) was discussed in the cooperative communications system in this paper, and the decision feedback as well as interference cancellation techniques were employed to improve the performance of the scheme. STBC carried out in the relay nodes to obtain the transmission signal, then, spatial and FDE were executed to the received signal after the fast Fourier transform (FFT) at the receiver, and finally, the estimation of the transmitted information was obtained by hard decisions after inverse FFT operations. The transmission scheme can obtain the cooperative diversities supplied by the relay nodes, and the complexity of FDE is low, so a practical use can be achieved. This paper introduces a new algorithm with high performance by mainly using decision feedback as well as interference cancellation techniques to reduce the signal-to-noise ratio (SNR) loss during the FDE. Computer simulations show that the new scheme can effectively work, when the SNR is 12 dB, the new one can reduce the bit error rate from 10<sup<-2</sup< to 10<sup<-3</sup< in the cooperative communications system.