DNF-AF Selection Two-Way Relaying
  Error propagation and noise propagation at the relay node would highly degrade system performance in two-way relay networks. In this paper, we introduce DNF-AF selection two-way relaying scheme which aims to avoid error propagation and mitigate noise propagation. If the relay successfully decodes the exclusive or (XOR) of the messages sent by the two transceivers, it applies denoise-and-forward (DNF). Otherwise, amplify-and-forward (AF) strategy will be utilized. In this way, decoding error propagation is avoided at the relay. Meanwhile, since the relay attempts to decode the XOR of the two messages instead of explicitly decoding the two messages, the larger usable range of XOR network coding can be obtained. As XOR network coding can avoid noise propagation, DNF-AF would mitigate noise propagation. In addition, bit error rate (BER) performance of DNF-AF selection scheme with BPSK modulation is theoretically analyzed in this paper. Numerical results verify that the proposed scheme has better BER performance than existing ones. 
Tian Zhang
cs.IT math.IT