Performance of a fast frequency-hopped DFT-based MFSK receiver with noise-normalization combining in a fading channel with partial-band interference

An error probability analysis is performed for a discrete-Fourier-transform-based (DFT-based) frequency-shift keying communications system using fast frequency-hopped spread spectrum (FFHSS) signals. A linear combination procedure referred to as noise normalization is used at the receiver to minimize the effects of partial-band interference. The use of FFHSS is found to improve the performance of the DFT-based receiver in all but the most severe cases of Doppler shift. The amount of Doppler shift necessary to warrant the use of a nonuniform window is relatively insensitive to the frequency-hop rate used. In general, in the absence of any information concerning the nature of the received signal, a nonuniform window should be used because the performance degradation experienced at small Doppler shifts is insignificant compared to the performance enhancement gained at large Doppler shifts