AUTHORS: Peter Olsovsky, Peter Podhoransky
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ABSTRACT: This paper investigates the problems of pseudorandom noise (PN) code acquisition techniques in direct-sequence code division multiple access (DS-CDMA) communication systems. PN code acquisition (or PN code synchronization) is the most essential first-stage processing in a DS-CDMA receiver. To speed up the multiple access process, initial synchronization should be performed in minimal time. PN code acquisition refers to the operation of synchronizing the locally generated PN code with the received PN code within one chip interval, beyond which the tracking process takes charge. This paper presents the interesting characteristics of effective PN code acquisition techniques for DS-CDMA systems. The techniques described in this paper are generally capable of determining the received PN code phase to within an accuracy of ±1 ⁄ 2 to ±1 ⁄ 4 of a chip. The aim of this paper is to propose the modified algorithm for parallel search realization of the maximum likelihood search technique for direct-sequence spread spectrum (DSSS) signals in MATLAB. In addition, the universal autonomous algorithm in MATLAB for PN code generation using a linear feedback shift register is proposed.
KEYWORDS: Direct-Sequence Code Division Multiple Access (DS-CDMA), Synchronization, PN Code Acquisition, Search Techniques, MATLAB
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