Acquisition of frequency-hopping spread spectrum signals by sequential detection

Binary quantized detectors for serial search acquisition of frequency-hopping waveforms are considered. Detector logic based on the optimal sequential-probability-ratio test is proposed and analyzed. A practical approximation of this detector is devised, on the basis of the simple generalized up-down counter logic. With respect to the fixed-size test, it is shown that the mean acquisition time can be reduced by a factor of 2 to at least 5, at the expense of very little additional complexity. The new detector is also compared with some heuristic sequential schemes previously analyzed in the literature.