Pre-processing Matrix Based Iterative Detection Algorithm in Asynchronous MIMO-OFDM

In asynchronous MIMO-OFDM over the selective Rayleigh fading channel, an iterative parallel multi- antenna interference cancellation algorithm based on pre-processing matrix is proposed. Before the signal is transmitted, the symbols are spread over all the subcarriers, which relieve the influence of deep fading in part of the subcarriers. In the receiver, the wrong decision value of last iteration is spread by the pre-processing matrix, which decrease the error propagation in iteration processing. The performance improvement is verified by simulation, when there are 4 transmitters 2 receivers and the Bit Error Rate (BER) is 10-5, SNR is improved about 4.5 dB compared with the traditional iterative parallel interference cancellation algorithm.