Two-way relaying with differential MPSK modulation in virtual full duplexing system

Two-way relaying (TWR) transmission achieves virtual full duplexing, which has attracted much attention in recent years for its high spectral efficiency. In a TWR system, two source nodes exchange information with each other simultaneously via a relay node. This paper proposes a decode-and-forward two-way relaying (DF-TWR) scheme and a denoise-and-forward two-way relaying (DNF-TWR) scheme using non-coherent multiple differential phase-shift keying (M-DPSK) modulation, in which channel state information (CSI) is not required. Firstly, we design the relay decoder in DF-TWR scheme, the relay denoising mapping function in DNF-TWR scheme, and the same source decoder in the two schemes using maximum likelihood (ML) principle. Then we analyse the end-to-end symbol error rate (SER) of DNF-TWR scheme with M-DPSK modulation. The simulation results show that the BER performance of DF-TWR scheme and DNF-TWR scheme are similar. The BER performance of the two schemes with 2DPSK modulation are good, and the BER performance with M-DPSK modulation are getting worse with the increase of modulation order M.