Iterative Equalization Algorithm Based on Precoding Matrix

摘要

Aiming to co-antenna interference and multipath interference in the LTE downlink Multiple Input Multiple Output Orthogonal Frequency Division Multiple (MIMO-OFDM) communication system, a low complexity iterative equalization algorithm based on precoding matrix is proposed. At the transmitter, the algorithm utilizes precoding matrix to reduce the antenna interference. At the receiver, the algorithm adopts soft interference elimination algorithm based on the Minimum Mean Square Error Sorted QR Decomposition (MMSE-SQRD) to avoid the complexity of solving inverse matrix, which is always involved in the traditional parallel soft interference elimination algorithm based on MMSE equalization. On the other hand, the algorithm has the priority for detection transmission symbol with maximum noise-signal ratio (SNR) to improve detection accuracy. Furthermore, the error of reconstructed signals is processed by the precoding matrix, which decreases the error propagation in iteration processing. Simulation results show that the performance of the proposed algorithm is improved compared with the existing iterative interference cancellation algorithm, that is, when the system is equipped with 2 transmitters and 2 receivers and the Bit Error Rate (BER) is 10~(-3), SNR is improved about 4.1 dB with five iterations.