Performance analysis of the hybrid search code acquisition technique for cellular CDMA systems

The hybrid search algorithm, a combination of the maximum-likelihood search and serial search algorithms, is one of the most promising techniques that can be used for code acquisition in CDMA forward links. The hybrid search code acquisition system considered in this paper employs two operating modes, i.e., search and verification modes with M-parallel correlators used for maximum-likelihood detection in search mode. An analytical expression for the mean acquisition time is first obtained. The probabilities of detection, miss, and false alarm are also derived for both search and verification modes for frequency-selective Rayleigh fading environments with assumption that the fading envelope of the received signal is constant over the interval of post-detection integration (PDI). Numerical evaluation shall be performed to investigate the effects of sub-window size, number of post-detection integration in search and verification modes, and so on, in the forward link of cellular CDMA networks.