Performance of binary CPSK satellite communication system in the presence of noises and noisy carrier reference signal

The aim of this paper is the determination of error probability in detecting a binary coherent phase-shift-keying (CPSK) signal transmitted over a hard-limited channel in the presence of the uplink and the downlink noise and the noisy carrier reference signal. The phase-locked loop (PLL), as the constituent part of the receiver in the receiving ground station, is used in providing the synchronization reference signal extraction, which is assumed to be imperfect. The uplink noise influence is considered through the signal frequency offset remitted by the satellite station having the influence on the PLL parameters variations in the receiving ground station, consequently on the probability density function (p.d.f.) of the phase error, i.e. the total error probability (P_e). The downlink noise is taken into consideration, too. The obtained results are based on the PLL nonlinear model with the emphasis on the degradation in the system performance produced by the imperfect carrier signal extraction.