Linear Precoding Based Iterative Detection Algorithm in Asynchronous MIMO-OFDM Systems

In asynchronous Multiple-Input-Multiple-Output Orthogonal Frequency Division Multiplexing (MIMO-OFDM) over the selective Rayleigh fading channel, the performance of the existing linear detection algorithms improves slowly as the Signal Noise Ratio (SNR) increases. To improve the performance of asynchronous MIMO-OFDM, a low complexity iterative detection algorithm based on linear precoding is proposed in this paper. At the transmitter, the transmitted signals are spread by precoding matrix to achieve the space-frequency diversity gain, and low complexity iterative Interference Cancellation(IC) algorithm is used at the receiver, which relieves the error propagation by the precoding matrix The performance improvement is verified by simulations. Under the condition of 4 transmitting antennas and 4 receiving antennas at the BER of 10(-4), about 6 dB gain is obtained by using our proposed algorithm compared with traditional algorithm.