Denoise-and-Forward Two-Path Successive Relaying with DBPSK Modulation

To recover the spectral efficiency (SE) loss caused by the half-duplex mode, this letter proposes a denoise-and-forward two-path successive relaying (DNF-TPSR) scheme, in which channel state information is not required. With differential binary phase-shift keying (DBPSK) modulation, the mixed signals received at the relay are mapped into a denoised symbol, and the destination uses the denoised symbol received in the previous time slot to cancel the inter-relay interference in the current time slot. We derive the end-to-end bit error rate (BER) and the diversity gain, which are validated by the simulation results. Although DNF-TPSR could not achieve the BER of half-duplex relay selection scheme, the SE is significantly improved by our proposed DNF-TPSR. Moreover, the BER and the SE of DNF-TPSR outperform that of direct transmission and full-duplex relaying with residual self-interference exceeding a certain level.