On estimating the RMS delay spread from the frequency-domain level crossing rate

Abstract

It is shown that the level crossing rate (LCR) of a Rayleigh distributed stochastic process is proportional to the second centralized moment of the normalized power spectrum of the underlying complex Gaussian process. This proportionality factor is independent of the power spectrum. The relation can be applied for estimating the RMS delay spread of time-dispersive (frequency-selective) radio channels from swept-frequency power measurements, where the RMS delay spread is proportional to the LCR in the frequency-domain, independent of the channel impulse response.