The Spectral Analysis Of The Signal In Trophospheric Scatter Communication System

The simple theory of tropscatter communication is introduced in this thesis, with form of fadeing, diversity receiving and modulating。It is gived some methods analysing signal's sepctrum which is the FFT method, the time-frequency method 1, the time-frequency method 2 and the spectral correlation method。In this paper, the cyclic-spectral correlation funcation and cyclic-spectral correlation density of two generally modualted signals in tropscatter communiacations was gived。This thesis describes the implementation in MATLAB of four methods of computing the spectral density function estimate, the FFT method, the time-frequency method 1, the time-frequency method 2 and the spectral correlation method, to perform spectral analysis in two case which is noise free and SNR equals 0。The result is that cyclic-spectral anlysis method is one of the best arithmetic in tropscatter modulated signal analysing。...