Power spectra and necessary bandwidth for simultaneous FDM and PSK signals
Abstract
This paper studies in detail the power spectra and necessary bandwidth for transmission of simultaneous FDM telephone channels and PSK data subcarrier. First, the spectra of the individual signals are derived in a simple form which avoids numerical convolutions. It is assumed that the modulated PSK carrier is a Gaussian process, and that the emphasis network has ideal characteristics. The FM power spectrum of simultaneous FDM and PSK is then obtained as the convolution of the individual spectra. The derived formulas are used to compute the out-of-band power as a function of bandwidth for a wide range of design parameters. Together with the analytical formulas, design curves are provided in which the out of band power is plotted versus bandwidth for different PSK and FDM parameters. The results are compared to Carson's rule bandwidth and a simple modification of Carson's rule is suggested. The modified formula can be accurately used to estimate bandwidth of high deviation and low deviation signals transmitted over the same RF channel. The obtained results are applicable to terrestrial microwave, satellite, and cable systems, transmitting analog telephone channels and/or wideband data signals.
- Publication:
-
Space Communication Broadcasting
- Pub Date:
- September 1985
- Bibcode:
- 1985SpCoB...3..207A
- Keywords:
-
- Bandwidth;
- Frequency Division Multiplexing;
- Phase Shift Keying;
- Power Spectra;
- Telephony;
- Voice Data Processing;
- Convolution Integrals;
- Frequency Modulation;
- Integral Equations;
- Spectrum Analysis;
- Communications and Radar