Rayleigh fading and pulse interference influence on the QPSK system performance

The purpose of this paper is to provide the theoretical approach for determining the bit error probability in detecting a coherent quaternary phase shift keyed signal in the presence of the Rayleigh fading, Gaussian noise and pulse interference, as well as the noisy carrier reference signal. Phase locked loop, as the constituent part of the receiver, is used in providing the synchronization reference signal extraction, which is assumed to be imperfect in this paper. The determined results are based on the nonlinear phase locked loop model with primary emphasis on the degradations in the system performance produced by the imperfect carrier signal extraction.