Interleaving of local code replicas-based rapid acquisition method for time division data multiplexing long pseudo-noise-code signals

In global navigation satellite system, to further improve acquisition and tracking performance and consequently improve anti-jamming capability of long pseudo-noise (PN)-code signals, time division data multiplexing technique is utilised. For the signals, how to avoid possible energy cancellation of odd and even chips and how to quickly test code phases as many as possible in parallel are two keys for rapid acquisition. In this study, an interleaving of local code replicas-based acquisition method is proposed. By interleaving odd-number and even-number chips of local code replicas, the proposed method breaks the intrinsic code phase relation of PN-codes, avoids the possible energy cancellation of odd and even chips, and accelerates the search process by testing more code phases through interleaved chips. The detection and mean acquisition time performance of the proposed method is analysed. It is shown that compared with the previous time-gate method, the proposed method greatly saves computation requirement by taking the advantage of frequency-domain correlation technique over time-domain one. Compared with the L2C-like method, the proposed method enhances the capability of testing code phases in parallel twice at the expense of degrading detection performance. Numerical results demonstrate that when the capability dominates over detection performance the proposed method is more desirable.