Improving Achievable Rates in MPSK Amplify-and-Forward Relay Networks via Clipping

Companding techniques, which are conventionally considered to reduce the peak-to-average power ratio (PAPR) for orthogonal frequency-division-multiplexing (OFDM) systems, decrease the achievable rate. However, we propose to employ clipping, one of the companding techniques, to improve the achievable rates for M-ary phase-shift-keying (MPSK) amplify-and-forward (AF) cooperative communications in this paper. The improved achievable rate of the system is shown through numerical results. It is also found that among the conventional companding techniques, the clipping technique may achieve the highest transmission rate.