A post-detection-combining matched-filter scheme for coarse acquisition of slow frequency hopping/multiple frequency shift keying signals, based on a convergent infinite series approach, is analysed. An analytical formula is developed which characterises acquisition performance both in a benign broadband Gaussian noise channel and in an adverse environment containing random partial-band noise jamming. Detection and false alarm probabilities are evaluated for various jamming conditions. It is shown that the scheme is relatively insensitive in miss detection performance, while vulnerable in false alarm performance, to jamming. By increasing the number of largest squared envelopes combined or by widening the spread-spectrum band, a significant improvement in performance of the worst case can be achieved.
