Adaptive Hybrid PN Code Acquisition with Antenna Diversity in DS-CDMA Systems

Hae-Sock OH  Chae-Hyun LIM  Dong-Seog HAN  

IEICE TRANSACTIONS on Communications   Vol.E85-B   No.4   pp.716-722
Publication Date: 2002/04/01
Online ISSN: 
Print ISSN: 0916-8516
Type of Manuscript: PAPER
Category: Wireless Communication Technology
acquisition,  CFAR,  diversity,  

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An adaptive hybrid acquisition system is presented. The proposed system combines an antenna diversity technique and the cell-averaging constant false alarm rate (CA-CFAR) algorithm to acquire a pseudo-noise (PN) sequence for code-division multiple-access (CDMA) systems. Since conventional acquisition systems have a fixed threshold value, they are unable to adapt to varying mobile communications environments, resulting in a high false-alarm rate or low detection probability. Accordingly, an antenna diversity technique and adaptively varying threshold scheme using the CA-CFAR algorithm are applied to improve the detection performance. Based on deriving the detection probability, false alarm rate, miss detection probability, and mean acquisition time in Rayleigh fading channels, the performance of the proposed system is compared to that of a conventional system with a fixed threshold.