Low-Complexity Linear Signal Detection on Two-Way Quantize-Forward Relay Channel

This letter considers a half-duplex two-way quantize-forward relay channel, where a relay quantizes the phases of the received signals and broadcasts the reconstructed signal to users to help them exchange messages. However, the existing maximum-likelihood (ML) detection method considers all possible signals from the transmitter and the relay, leading to extremely high detection complexity at the receiver. To address this issue, we propose a linear combining (LC) detection method and its simplified version, which significantly reduce the computational complexity while achieving reasonable symbol error rates compared to the ML detection.