Research On The Key Technologies Of Baseband Signal Processing For The High Dynamic BD Receiver

BD/INS deeply integrated navigation is an effective method to improve the highdynamics adaptability and anti-jamming capability of the navigation system. GNSSreceiver is the core of BD/INS deeply integrated navigation system, its performancemainly depends on the baseband signal processing module of it. At present, the researchof baseband signal processing mostly focus on the GPS, although the BD system andGPS are similar, because of the difference between their signal systems, the researchresults of GPS cannot be used in the BD system directly. In this paper, base on the basictheory of the baseband signal processing module, aim at the characteristic of the BDsatellite signals, we make further study on the arithmetic of acquisition and tracking,designed and implemented a unipath BD receiver baseband signal processing module.Major features of this paper include：1. Analyze and summarize the GNSS receiver baseband signal processing moduleresearch status, briefly introduce the theory of the BD satellite signal system and theGNSS receiver.2. Analyze the key elements which affect the performance of the acquisition andadaptability of traditional acquisition methods in high dynamic, research the BDsatellite navigation message structure, propose a parity segmented acquisition methodbased on the FFT and multi-correlator. The acquisition time of this method is about500ms, the final acquisition frequency deviation is less than5Hz, and the code phasedeviation does not exceed0.165chips.3. Through the BD satellite signal analysis of the Doppler effect, point out that theDoppler shift causes navigation message data bit transition boundary slip in a1msintegration period and lead to a sudden lock-loss of tracking loop. According to BDsignal characteristics,2ms update tracking method and pseudo-navigation based methodare proposed, these two methods can be a good solution to the problem. The internalsignal source simulation and the outside signal generator experiments test these twomethods, the experimental results verify thefeasibility of these methods, the trackingloop can stably track more than50g of acceleration.4. Discuss the application of the tracking loop on the velocity and accelerationmeasurement, carrier Doppler measurement values obtained through the tracking loopto achieve a measurement of user’s movement speed, and analyze the generationprinciple of measurement error which caused by the local clock bias error; throughtheoretical derivation, a new method of memeasuring acceleration is proposed, and thefeasibility of the new method is verified by experiments.