Clipper Distortion of Two Narrow-Band Processes in Gaussian Noise

摘要

The envelopes of the output narrow-band components of a clipper, which is subjected to an input composed of two narrow-band processes and broad-band Gaussian noise, are evaluated for a variety of relative power levels. The collection of clipper output narrow-band components is composed of fundamentals, harmonics, and intermodulation products of the two input narrow-band components that may be either deterministic or random processes. The amplitudes and frequency locations of the components are evaluated quantitatively. When one of the input narrow-band components, denoted interference, is comparable in strength to the input noise, and the second input narrow-band component, denoted signal, is weaker, the harmonics of the interference and the low-order intermodulation products of the two components are significant in comparison with the fundamental output due to signal. Curves for all the significant output components for interference-to-noise ratios in the range -24 dB to +9 dB, in 3-dB increments, and signal-to-noise ratios in the range -43 dB to -3 dB are given. The effects of spectral foldover due to sampling the clipper output are easily evaluated from these results are discussed, as are the effects of amplitude-modulation of the input interference components on the clipper output components. Recommendations and methods of approach for future work are also presented. (Author)