Performance of a fast frequency-hopped noncoherent MFSK receiver with non-ideal noise-normalization combining

An error probability analysis is performed for a noncoherent, orthogonal M-ary 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 partial-band noise interference. The partial band interference is modeled as a Gaussian process. Noise-normalization combining is employed to minimize partial band interference effects, and the effect of inaccurate noise measurement on the ability of the noise-normalized receiver to reject partial-band interference is examined. The effects of thermal noise is included in the analysis. Each diversity reception is assumed to fade independently according to a Ricean process. It is found that 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