Error probabilities for FFH/BFSK with ratio-statistic combining and soft decoding in a fading channel with partial-band jamming

An error probability analysis is performed for a communications link with convolutional coding and soft-decision Viterbi decoding implemented on a fast frequency-hopped binary frequency-shift (FFH/BFSK) spread spectrum system. The generated signal is transmitted through a frequency nonselective, slowly fading channel with partial-band jamming and additive white Gaussian noise. To reduce the effects of partial-band jamming, ratio-statistic combining is introduced at the receiver before the soft decision Viterbi decoding. With the use of convolutional coding and soft decision Viterbi decoding, the performance of the receiver is improved dramatically when the E_b/N_j is greater than about 12 dB, and multiple hops per bit are not required in order to force the jammer to move from a partial-band to a full-band jamming strategy