Abstract: A new adaptive serial search pseudonoise(PN) code blind acquisition scheme is proposed, which does not need the help of the pilot signal. The ratio of the power estimation of the pre-correlation signal and post-correlation signal is used as the decision variable. The probability density function(pdf) of the decision statistics is derived. The decision threshold is shown to be independent of the signal power and noise power, so that the constant false alarm rate is achieved. The performance of the proposed scheme is theoretically analyzed an also simulated under the AWGN and Rayleigh fading environment. The results show that the CFAR is achieved in the proposed adaptive blind acquisition scheme.

Key words: DSSS, code acquisition, detection probability, constant false alarm rate