Research And Implementation Of Parallel Acquisition Technologies For Beidou B1C And B1I Signals

The global networking of BeiDou Navigation Satellite System(BDS)has officially kicked off.More and more signals are available for users with different demands in different fields.Multi-frequency joint processing has become a research hot spot in the field of satellite navigation.Due to the complexity of the surrounding environment,frequent alternating of strong and weak signals is likely to cause a receiver lose its lock on some satellite signals.How to achieve fast re-acquisition at this time will directly affect the accuracy and continuity of subsequent positioning results.In this paper,an adaptative method for Beidou B1C/B1 I dualfrequency joint acquisition based on signal-to-noise ratio(SNR)is proposed.According to SNR estimation,the receiver can determine whether current scene belongs to strong-signal environment or weak-signal environment.Then,the most suitable searching algorithm will be chosen to complete acquisition.This method can largely balance the contradiction between acquisition sensitivity and real-time performance.The proposed method is based on a heterogeneous computing platform built by a CPU and a GPU.The acquisition and bit synchronization modules are optimized in parallel.Finally,the receiver can realize real-time acquisition of 15 channel's B1 I signals,real-time joint acquisition of B1C/B1 I dual-frequency siganls with 300 channels,and real-time joint bit synchronization of dual-frequency siganls with 260 channels.