ВЛИЯНИЕ ЧАСТОТНОГО ШУМА В КАНАЛЕ СВЯЗИ НА ВЕРОЯТНОСТЬ БИТОВОЙ ОШИБКИ ПРИ ПЕРЕДАЧЕ КАМ СИГНАЛОВ

Abstract

The purpose of the article is to analyze the combined effect of amplitude white Gaussian noise(AWGN) present in the communication channel and frequency noise (FN) resulting from fluctuations inthe frequency of the signal in the communication channel on the probability of bit error when processingQAM signals. Research tasks to be solved: 1. Development of a mathematical model for processing theQAM signal, taking into account the combined effects of AWGN and FN in the communication channel.2. Numerical study of the combined effect of AWGN and FN on the probability of bit error when processingQAM signals. A mathematical model is proposed that establishes the relationship between thesignal-to-noise ratio in the channel and the mean square deviation of the signal frequency, on the onehand, and the probability of bit error during A mathematical model is proposed that establishes therelationship between the signal-to-noise ratio in the channel and the mean square deviation of the signalfrequency, on the one hand, and the probability of bit error during QAM signal demodulation, on theother. The visualization of the effects associated with the presence of AWGN and FN in the channel onthe signal constellation of the received QAM signal is given. The main patterns associated with jointaction AWGN and FN in the communication channel are: - the appearance of FN in the communicationchannel leads to a decrease in the signal level in the channel during the correlation processing of thereceived signal and a corresponding decrease in SNR; - In addition to the blurring of the signal constellationin the azimuthal direction, associated with the appearance of an integral phase fluctuation due tofrequency fluctuations during the pulse, an increase in the blurring of the signal constellation in theradial direction causes a decrease in the SNR. Based on the results obtained, it is concluded that it isnecessary to take into account more fully the deviations of the signal parameters in the channel due toboth the presence of AWGN and FN.