An Accurate Approximation of Frequency Selective Nakagami-m Fading for OFDM System Analysis

Abstract

We propose an approximation method for the channel impulse response of a specific OFDM subcarrier over frequency-selective Nakagami-m fading. Using fading figure matching as a basis, we show that a frequency domain channel can be approximated by Nakagami-m (Hoyt) and Nakagami-.. (Rice) models. The proposed approximation scheme is accurate in that the approximated envelope distribution is almost optimum in terms of Cramer-von-Mises criterion, simple in that the fading parameters are explicit functions of the fading parameters of the frequency-selective channel.