Method for the computation of interference and distortion levels in satellite FM-TV systems

A method for the prediction of interference and distortion levels in satellite FM-TV systems is proposed. The procedure, which is based on a statistical model of live video signals, makes it possible to predict the levels of both intersystem interference and intrasystem signal distortion. Statistical properties of video baseband spectra are investigated by evaluating the results of long-term measurements of live satellite TV channels. In particular the joint probability distribution for the random variables describing luminance and chrominance components of the video signal is derived from the measurements. The spectrum of the frequency-modulated signal is then analyzed, and the cumulative distribution of signal distortion due to bandlimiting is computed. Similarly, the distributions of adjacent and cochannel interference levels are calculated with examples illustrating the effects of subcarrier loading and energy dispersion. The procedure is particularly useful for the investigation of relative effects of system parameters on interference and distortion levels