Performance Loss Due to Atmospheric Noise and Noisy Carrier Reference Signal in Qpsk Communication Systems

Abstract

The purpose of this paper is to provide the theoretical approach for determining a coherent quatrenary phase-shift-keying performance by means of the system error probability. An expression for the bit error probability is determined when the signal, thermal Gaussian noise, atmospheric noise and imperfect carrier phase recovery are taken into consideration. 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 reference carrier is extracted by the non-linear first order PLL model with primary emphasis on the degradation in the system performance produced by imperfect carrier signal extraction. Ill. 4, bibl. 15 (in English; summaries in Lithuanian, English, Russian).