Spectrally encoded, multicarrier PSK communication in a multipath channel

This research examines the performance of a spectrally encoded, multicarrier, phase shift keying communications system in a frequency-selective, slowly-fading (FSSF) Rayleigh multipath channel. The literature discusses several frequency domain techniques including spectral encoding that have been used for interference avoidance and multiple access techniques. This research applies spectral encoding to mitigate the effects of multipath fading. Analysis and Matlab® simulations compare the performance of spectrally encoded and unencoded signals through a multipath fading channel using an L-diversity RAKE receiver. Encoded signals take on the spectral shape of the fading channel transfer function magnitude spectrum. Unencoded signals have a flat magnitude spectrum. Research results indicate for diversities (L) ranging between 2 and 50, spectrally encoded signals need 1.0 to 2.75dB less transmitted normalized bit energy to noise power spectral density ratios (E_b/N_o) to achieve the same probability of bit error (P_b) as unencoded signals.