An Ordered Successive Interference Cancellation Detector With Soft Detection Feedback in IDMA Transmission

Abstract

In this paper, an ordered successive interference cancellation algorithm is proposed to realize efficient multi-user detection in interleave-division multiple access. In the proposed algorithm, the multiuser detection is implemented in the frequency domain and the bit detection results are obtained by de-spreading the chip detection results. Afterwards, the bit detection results are spread and interleaved to obtain regeneration soft chip results. The regeneration soft chip results are combined with the priori information provided by the channel decoder to obtain soft decision feedback symbols. In the proposed algorithm, the soft decision feedback symbols of detected users are exploited to cancel their interference to the subsequent un-detected users. In addition, the user detection order is optimized according to the signalto-interference-plus-noise-ratio. The simulation results show that the proposed algorithm can achieve better performance in both single-input-single-output and multiple-input-multiple-output scenario.

Keywords

• Frequency domain equalization
• soft decision feedback
• successive interference cancellation
• user detection order