Bandwidth and Spectra of Phase- and Frequency-modulated Waves

Download or read book Bandwidth and Spectra of Phase- and Frequency-modulated Waves written by Stanford University. Stanford Electronics Laboratories and published by . This book was released on 1962 with total page 56 pages. Available in PDF, EPUB and Kindle. Book excerpt: The spectrum of a cosine angle-modulated by a Gaussian random process (GRP) of (almost) arbitrary spectrum is investigated. Such a GRP provides a convenient model for voice signals, TV signals, and other types of complex communication signals. A simple closed form expression for the bandwidth of the modulated signal in terms of the bandwidth of the modulating signal is found. A general expansion for the shape of the spectrum of the modulated cosine is derived. In addition to reducing, in certain limiting situations, to known results, this expansion provides a practical means of obtaining the spectrum in intermediate cases. Examples are presented showing the spectrum of a cosine modulated by (1) a lowpass GRP with rectangular spectrum, and (2) a bandpass GRP of Gaussian spectrum. (Author).