PN code acquisition with adaptive antenna array and adaptive threshold for DS-CDMA wireless communications

In our paper, an efficient PN code acquisition scheme with adaptive antenna array and adaptive threshold is proposed. The basic structure is the combination of a conventional PN correlation searcher, an adaptive beamformer and an adaptive threshold setting circuit. The proposed scheme employs all array element outputs in the PN correlation searcher and also uses an adaptive threshold for each PN code phase hypothesis testing by estimating the instantaneous power prior to PN code despreading. Performance of the proposed scheme is theoretically analyzed and also simulated in terms of false alarm probability P-f, detection probability P-d and average acquisition time T-acq under Rayleigh mobile fading environment. Theoretical and simulation results show that the proposed scheme is robust against received signal power variations and can significantly improve PN code acquisition performance.