 dwell serial search system, the received PN signal plus noise was mul- tiplied by the local PN reference and subsequently (after square-law enve- lope detection to remove the unknown information modulation and unknown carrier phase) integrated for Td seconds, the result of which was used to make an acquisition decision by comparison with a threshold. Such a multiply-and-integrate type of correlation/detector structure is typified by Pseudonoise Code Acquisition in Direct-Sequence Receivers the fact that the local PN geneator is running continuously, and hence, a com- pletely new set of M = aT chips of the received signal is used for each suc- cessive threshold test. This poses a basic limitation on the search speed since the local PN reference phase can be updated (slewed) only at T -second intervals (assuming the threshold test fails). Thus, if the search is conducted in 1/N-chip increments, the search rate RID of the single dwell serial search technique is RID=1/Td 1/N-chip positions per second. (1.166) The search rate of a DS acquisition scheme can be significantly increased by replacing the multiply-and-integrate operation with a passive correlator device such as a matched filter (MF). This device can be implemented either as a continuous time or discrete time operation, and with such candidate state-of-the-art technologies as charge coupled devices (CCDs), surface acoustic wave (SAW) convolvers, and discrete time correlators [34], [36], [37]. In the continuous time case, the received PN waveform plus noise is con- volved with a fixed finite segment of the PN waveform corresponding to, say, M chips and the continuous time output is tested against a threshold to deter- mine when acquisition has occurred. In this configuration, the input contin- uously slides past the stationary (not running in time) stored PN waveform replica until the two are in synchronism, at which point the threshold ide- ally would be exceeded and the local PN generator enabled. Since, as dis- cussed in the introduction, in DS/SS systems