A Low Complexity Non-linear Iterative Receiver for Overloaded MIMO-OFDM Systems

This paper proposes a low complexity receiver that outperforms the MLD in overloaded MIMO-OFDM systems. The proposed receiver applies iterative noise cancellation to improve the transmission performance. A low complexity LLR calculation technique is introduced in the proposed receiver. The proposed low complexity iterative non-linear receiver achieves better transmission performance than the MLD with smaller calculational complexity. The performance of the proposed techniques is verified by computer simulation in a 6×3 overloaded MIMO channel. When the reception process is only iterative 2times, the proposed iterative non-linear receiver attains a gain of 0.8dB at the BER of 10
⁻⁶
. The computational complexity is evaluated in terms of the number of additions. The proposed receiver achieves such superior performance with the complexity which is about half as much as conventional soft input decoding with the MLD.