I.V. Lipa, Y.N. Boldenkov

One of the most critical mode of navigation receiver is acquisition. Modern receiver should provide high-sensitive signal acquisition in a short time which opposes to another deal - to have low power consumption. Due to this fact it is very important to decrease signal acquisition time. There is a strict dependence between right detection probability and signal integration time during acquisition. But signal integration time is not the same as total acquisition time. Total acquisition time depends also on a way the acquisition process is provided. Delay and frequency of the signal are unknown. Common approach is to have consecutive or parallel search along the frequency and delay combination. For each combination signal must be integrated in correlator during some time. A two-stage acquisition approach is considered in this article. In the first stage we have short integration time and poor false alarm probability. But this stage allows us to limit a set of delay and frequency combinations to analyse. In the second stage only the limiter subset should be integrated on a sufficient time to provide good performance. Two-stage acquisition approach potential processing time gain and respective requirements are provided in the article.