A Practical Differential Receiver for Amplify-and-Forward Relaying
Peng Liu, Saeed Gazor, Il‐Min Kim · IEEE Wireless Communications Letters · 2014
A practical sequence detector of differential phase-shift keying (DPSK) is developed in closed-form for amplify-and-forward (AF) cooperative networks. This detector is applicable for general M-DPSK (M ≥ 2) with arbitrary sequence length N8≥ 1, which includes a single-by-symbol detector as a special case N8= 1. In contrast to the maximum likelihood detector (MLD) and the best-known diversity combiner (DC), the proposed detector does not require the knowledge of the channel statistics (which are unknown a priori in practice) and yet, still achieving significant performance improvement. Specifically, for N8= 1, the proposed detector outperforms DC by 1.7 dB and achieves near ML performance. For N8≥ 2, the proposed detector outperforms MLD and the performance gain compared with MLD increases as N8increases; this performance gain is approximately 1 dB for N8= 4.