《通信原理》中若干疑难问题的分析和推导

Analysis and Derivation of Several Puzzle Problems about ‘Principle of Communication'

根据多年的教学经验,以樊昌信编著的《通信原理(第六版)》为基础,将教材中证明不详,省略了推导过程,或令学生感到困惑而在其他教材中也很难找到满意答案的一些问题进行了分析.对单边带信号时域表达式,单双边带信号所具有的相同的抗噪性能,线性调制系统的相移法的实现的原理以及数字已调信号的功率谱密度与基带信号功率谱密度之间的关系等问题进行了详细的推导和证明.

In the recent ten years,the textbook ＂Principle of Communication（ sixth edition） ＂complied by Fan Changxin is used as our textbook,it is preferable to other textbooks both in the arrangement and in the content,but there are still some analysis or derivation about the some problems and conclusions are briefness or are omitted,which makes the learners puzzled,and it is exhausting to find the satisfied answers from other teaching materials.In this paper,we presented the details derivation of the time domain expression of the Single Side Band,the principle of linear modulation used the phase-shift and the relationship between the digital modulated single and the random digital base band single.In addition,the explanation that the SSB and the DSB have the same anti-noise performance is given in this paper.