【作者】 王晓春；

【导师】 张辉；

【作者基本信息】 西安电子科技大学 ， 通信与信息系统， 2005， 硕士

【摘要】 本文中简要阐述了对流层散射通信的原理，并给出对流层散射通信接收信号的衰落形式和抗衰落采取的调制信号方式和分集接收形式。提出了对流层散射通信通信信号谱分析的几种算法，包括：FFT算法、时—频分布算法1、时—频分布算法2、循环谱相关算法。给出了散射通信常用的两种调制信号(带内多频BPSK和QPSK)的循环谱相关函数和循环谱密度函数。通过使用MATLAB软件对上述四种算法对BPSK、QPSK、散射BPSK和散射QPSK信号在无噪声和信噪比为OdB时的计算结果。最后得出循环谱相关分析方法是进行对流层散射通信信号的最佳谱分析方法之一的结论。更多还原

【Abstract】 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。更多还原