tion time, what is needed is a detector that quickly dismisses a false sync position (which occurs in all but one cell per pass through the uncertainty region) but is allowed to integrate over a much longer time interval during the sin- gle cell which corresponds to the correct code alignment. The multiple dwell time system discussed previously was an attempt at accomplishing the above objective wherein the detector integration time was increased in discrete steps until the test failed (one output fell below t hresh- old). Thus, for a false sync position, very few steps would be needed (short integration time), whereas for the true sync position, all of the steps would be needed (long integration time). Another possibility is to allow the integration time to be continuous and replace the multiple threshold tests by a continuous test of a single dismissal threshold. Such a variable integration time detector is referred to as a sequential detector and the corresponding acquisition system is designed SO that the mean time to dismiss the false sync position is much smaller than the integration time of a single dwell system. Thus, since the search spends virtually all of its time dismissing false sync positions, the mean acquisition time of the sequential detection PN acquisition system will be much less than that of the single dwell time system. To further understand the mechanism by which the above reduction in acquisition time is achieved, we must consider a specific implementation. Consider the serial sequential detection PN acquisition system illustrated in Figure 1.43. Up until the output of the square-law envelope detector, the sys- tem operates identically to the single dwell acquisition system of Figure 1.1. Thus, in the absence of the bias voltage b, the output of the continuous time integrator would typically behave as in Figure 1.44a where we have illustrated both the signal plus noise and noise only cases. In particular, the integrator output would follow along the integrated mean of the square-law detect