Direct sequence spread spectrum acquisition with sample accumulation in fading channels

In this paper we consider direct sequence spread spectrum acquisition systems with a search mode employing a sliding correlator, followed by a verification mode employing parallel integrate-and-dump correlators. In this paper we focus on a technique to improve the performance of the search mode. Received PN code periods are correlated with a local section of the PN code. Delays corresponding to high correlation results are verified in the verification mode. If the verification process is not successful a new received PN code period is correlated. In conventional techniques, the correlation results from previous code periods are erased. In this paper we propose a method where these correlation results are retained and a moving average of correlation results is performed. A considerable improvement in the performance of the acquisition system is achieved