Expectation Propagation Aided Frequency Domain Turbo Equalizer for Single-Carrier Spatial Modulation Systems

Yun Chen, Wanbin Tang, Yue Xiao, Chen Zheng, Wei Xiang

Abstract: An efficient frequency-domain equalizer is developed for single-carrier (SC) aided spatial modulation (SM) systems over frequency-selective fading channels, by employing the idea of expectation propagation (EP) algorithms. Specifically, we design an EP-aided frequency domain turbo equalizer (EP-FDTE) for iterative information exchange between the equalizer and the soft decoder, leading to more reliable a posterior probability (APP) estimation for signal detection. Our simulation results demonstrate that the proposed equalizer outperforms conventional frequency-domain turbo equalizer (FDTE) and generalized approximate message passing (GAMP)-aided turbo equalizer for SC-SM transmission.