Performance of phase‐detector receivers for coded BPSK and QPSK communication

Abstract

The paper analyses the performance of phase‐detector receivers for soft decision demodulation of coded BPSK and QPSK communication. In these receivers the received signal is passed through a hard limiter and the information is extracted from the signal's phase only. The performance criteria are cutoff rates that are computed for both maximum likelihood receivers and practical receivers that use a finite set of integer metrics. For the latter type, the optimal partition parameters of the phase circle are computed. The performance of the analysed receivers is compared with the performance of the optimal coherent BPSK receiver. It is found that the reliance on the phase only for extraction of information induces a small performance degradation in BPSK and a considerable degradation in QPSK. It is also found that the performance of the phase‐detector QPSK receiver that demodulates the two quadrature branches independently is similar to the performance of the optimal phase‐detector QPSK receiv2r.