Performance of a fast frequency-hopped noncoherent MFSK receiver with non-ideal noise normalization combining over Ricean fading channels with partial-band interference

An error probability analysis is performed for a noncoherent M-ary orthogonal frequency-shift keying (MFSK) communication system employing fast frequency-hopped (FFH) spread spectrum. The signal is assumed to be transmitted through a frequency-nonselective, slowly fading channel with partialband interference. The partial-band interference is modeled as a Gaussian process. The noise-normalized receiver is employed to minimize partial-band interference effects, and the effect of inaccurate noise measurement on the ability of the noisenormalized receiver to reject partial-band interference is examined. Each diversity reception is assumed to fade independently according to a Ricean process. Thermal noise is also included in the analysis. It is found that diversity dramatically reduces the degradation due to partial-band interference, and noise measurement error does not significantly degrade receiver performance. The robustness of the receiver with regard to noise measurement error is independent of the strength of channel fading.