An Adaptive Hybrid double-dwell PN Code Acquisition in Rayleigh Fading Channels Using OS-CFAR algorithm

Abstract

This paper proposes an adaptive non-coherent hybrid double dwell pseudo-noise (PN) acquisition scheme for code division multiple access (DS/CDMA) communication systems. Since existing acquisition systems have a fixed threshold value, they are unable to adapt to varying mobile communication environments resulting in a high false alarm rate or a low detection probability. Accordingly, an adaptively varying threshold scheme that uses an order statistic constant false alarm rate (OS−CFAR) algorithm is applied to a hybrid double-dwell system to improve the detection performance. Based on deriving formulas for the detection probability, miss detection probability, false alarm rate and mean acquisition time in Rayleigh fading channel, the performances of the proposed system are compared to the conventional hybrid system with fixed threshold and the adaptive serial system. This system is compared also to a hybrid system that using CA−CFAR algorithm.