Low-Complexity Iterative Interference Cancellation Multiuser Detection for Overloaded MIMO OFDM IDMA System

In this paper, interleave-division multiple access (IDMA) is used for overloaded multiple-input multiple-output (MIMO) coded orthogonal frequency division multiplexing (OFDM) systems. An iterative interference cancellation multiuser detection (IIC-MUD) method is proposed, which has almost the same complexity but can achieve almost optimal (MAP) performance, much better than that of elementary signal estimation (ESE) method. The main idea of this IIC-MUD is the log-likelihood ratio (LLR) calculation, which is based on the channel impulse responses (CIRs). By the LLR convertor, we can obtain more reliable LLRs for the decoder, which can make full use of CIRs to obtain the channel gain. The performance of the proposed IIC-MUD is assessed through simulation results.