Dual-channel method for fast long PN-code acquisition

Long PN-code acquisition is a difficult and time-consuming task due to long code period. To accelerate acquisition, folding methods like XFAST are widely used. In high-dynamic environment however, the application of those methods are largely restricted due to nonnegligible residual frequency. This paper proposes a new dual-channel method for fast acquisition of long PN-code. In the proposed method, both non-overlapping local PN-code blocks are employed to correlate with input sample block; the detection process is eased through finding the maximum value among correlation results and verification is made with all the full and partial peaks taken into account. False alarm probabilities from analysis of the verification process are derived. Both theoretical and Monte Carlo simulations reveal that, with respect to acquisition probability and mean acquisition time under the same false alarm rate, dual-channel method has advantage over zero-padding and XFAST based folding methods under certain false alarm probabilities.