Improved Decision-Feedback Detection Schemes for STTD over Time-Selective Fading Channels

Abstract

This paper proposes two efficient decision-feedback (DF) detection schemes for space time transmit diversity (STTD) over time-selective fading channels. The existing DF detection causes error propagation when the first symbol is not detected correctly. However, the proposed detection schemes provide two candidates for the first symbol and choose a better candidate according to a channel gain or an average log-likelihood ratio (LLR) based selection rule. Simulation results show that the proposed detection schemes reduce error propagation and yield significant signal-to-noise ratio (SNR) gain with slightly increased complexity, compared to existing DF detection scheme.