Two-way relaying with non-coherent differential MPSK modulation

This paper focuses on two-way relaying (TWR) system, where two source nodes exchange information with each other simultaneously via the relay node. We proposes a denoise-and-forward two-way relaying (DNF-TWR) scheme using non-coherent multiple differential phase-shift keying (M-DPSK) modulation when the channel state information (CSI) is unknown. Firstly, we design the denoising mapping function at the relay and the decoder at the source using maximum likelihood (ML) principle. Then we take DNF-TWR with differential binary phase-shift keying (2DPSK) modulation as an example to derive the closed-form end-to-end bit error rate (BER). The analytical results are verified through simulations. The simulation results show that DNF-TWR scheme with 2DPSK modulation works well, and the BER of DNF-TWR with M-DPSK modulation becomes larger as the modulation order M increases.