摘要
首先引入了周期相关和周期功率谱(简称周期谱)的概念,并把它们用于振幅调制(AM)和正交振幅调制(QAM)信号的时间平均功率谱的推导。得到了精确的功率谱公式,适合于基带调制信号是非平稳的情况。假设基带信号平稳,则公式可以简化为一般通信教科书中的常见形式。
Cyclic correlation and cyclic power spectral density (cyclic spectrum) are discussed in this paper, followed by their application in the computation of timeaveraged power spectral density for both AM and QAM signals. Therefore, some precise formulas are deduced, which are suitable for nonstationary baseband modulating signals. When the baseband modulating signals are stationary, the formulas reduce to the familiar form in general textbooks.
出处
《南京邮电学院学报》
1997年第4期69-72,共4页
Journal of Nanjing University of Posts and Telecommunications(Natural Science)
关键词
随机信号
频谱分析
调幅
正交调制
Random signals, Spectrum analysis, Amplitude modulation, Quadrature modulation