Demodulation of binary PSK signals without explicit carrier synchronization

Demodulation of binary phase-shift-keying (BPSK) signals is modeled as a problem of maximum likelihood parameter estimation from incomplete data. The received signals are corrupted by additive white Gaussian noise with the carrier phase unknown and/or random. The expectation-maximization algorithm is applied in such a way that the demodulation is conducted directly on the received signal without any explicit carrier synchronization being established. Simulation shows that the bit error probability performance of the proposed algorithm is very close to that of the ideal coherent BPSK demodulation. The implementation of the proposed algorithm is simple and open-loop, meaning that no feedback tracking or voltage-controlled oscillator is needed, and hence can be applied to burst mode transmission such as time division multiple access (TDMA) in satellite communications