Crest factor minimization in the frequency domain

Abstract

This paper examines the minimization of the signal crest factor using a frequency-domain method. This method is based on the observation that low crest factor signals possess properties that reduce the effect of system nonlinearities. The main idea of this method is that instead of setting the signal crest factor as the cost function to be minimized, multisine signals are designed with their harmonic phases selected to minimize the distortion introduced by a cubic nonlinearity on the measurement of a frequency response function. The resulting signals are compared with other types of low crest factor signals. It is found that the method does not produce the lowest possible crest factors but that the signals do minimize the nonlinear distortion introduced by a cubic nonlinearity, while possessing a low crest factor. The signals are thus termed minimum distortion multisines.