Low-Complexity Channel Selection and Iterative Detection for Overloaded Uplink Multiuser MIMO OFDM System

In this paper, anew iterative interference cancellation multiuser detection (MUD) method is proposed for overloaded multiple-input multiple-output (MIMO) coded orthogonal frequency division multiplexing (OFDM) systems. In the first iteration, a channel analyzer and selector are employed, which ensure that non-convergent channels are not used. Then low complexity RAKE reception is applied, and a successive interference cancellation (SIC)-based approach is used such that the strongest user is decoded first. In each iteration, the soft output of the convolutional decoder is fed back to cancel inter-user interference using parallel interference cancellation (PIC). The simulation results show that, this technique can achieve near-optimum bit error rate (BER) performance, and optimum frame error rate (FER) performance, with lower complexity than optimum maximum likelihood (ML) methods at the cost of 4% of channels rejected.