BSS with Data Injection for Multi-User Detection in BPSK/QPSK Communications in Dynamic Channels

This paper presents a study on the detection of multiple co-channel transmissions employing block-based Blind Source Separation (BSS) in multi-antenna BPSK (Binary Phase Shift Keying) or QPSK (Quadrature Phase Shift Keying) wireless receivers operating in highly dynamic channels. Given the substantial variation in wireless channels' fading parameters within each data block, short block sizes are adopted to satisfy the quasi-stationarity requirement for BSS processing. To mitigate BSS performance degradation due to inaccurate statistical property estimation from short data blocks, injection of sign reversed data samples into received data blocks is performed. Efficient BSS algorithms previously developed for time-varying channel conditions are employed and compared to the popular Fast-ICA (Independent Component Analysis) algorithm. Simulation results confirm the effectiveness of the proposed technique, whose benefits also include avoidance of channel estimation and robustness against varied transmission powers.