Dual-frequency multi-code unambiguous combined acquisition algorithm based on channel fusion

Purpose To improve the acquisition performance while saving computation and hardware resources during the satellite signal acquisition phase, a dual-frequency multi-code unambiguous combined acquisition algorithm based on channel fusion is proposed in this paper. Design/methodology/approach Compared to traditional satellite signal combined acquisition algorithm, this algorithm combines the energy of L1 and L5 dual frequency points to improve acquisition performance. When the mixed signal is stripped by single channel, the different residual Doppler values in each residual carrier term and the mismatch of each sinc function generate spectrum fission problem, and the signal cannot be acquired correctly. To address the problem, a frequency difference correction factor weighting process is applied to the local carrier Doppler frequency in this paper to eliminate the abnormal effect of spectrum fission on acquisition. Findings The theoretical and simulation results shows that the proposed algorithm reduces the complexity of the algorithm structure and saves hardware resources while improving capture performance. Moreover, the proposed algorithm is suitable for multi-code combined acquisition. The more code signals are related, the further improvement of its acquisition performance will be achieved. Originality/value Compared with traditional combined acquisition methods, the algorithm proposed in this paper is to superimpose the energy of dual-frequency multi-code signal to improve the signal-to-noise ratio and eliminate the abnormal effect of spectrum fission on acquisition caused by single-channel carrier stripping of hybrid dual-frequency satellite signals. The proposed algorithm is suitable for multi-code combined acquisition. The more code signals are related, the further improvement of its acquisition performance will be achieved.