Automatic identification of impairments caused by intermodulation distortion in cable television pictures

The authors study the feasibility of automatically monitoring a television picture for the purpose of knowing whether or not impairments resulting from intermodulation beats are present. They develop a mathematical model for the intermodulation beats and show that the theoretical results confirm the experimental ones. These results show that by using the two-dimensional discrete Fourier transform of a picture the automatic detection and recognition of intermodulation distortion is feasible. The results demonstrate, contrary to common belief, that it is possible to monitor the signal in a nonintrusive fashion