Gnss Receivers Quickly Locating Research And Analysis In The Complex Environment

With the rapid development of information technology as well as our own R&D Beidou navigation system, satellite navigation and positioning technology increasingly affect all aspects of people’s lives and the national economy. In addition to the open environment, the demand for satellite navigation applications in the complex environment also continue to strengthen. In the environment of city indoor-outdoor urban canyons and trees occlusion, navigation signal processing has become more complex, processing speed response becomes slow, seriously affecting the application effect of the navigation system. This article will do some research and analysis in the problems of quickly locating in the complex environment.For the problems of quickly locating in a complex environment, this paper analyzes the key issues of the complex environment quickly positioning technology, proposed practical signal processing algorithms, improved the capturing capacity and rapid positioning capability of the receiver under the environment. The main contents of this paper is divided into the following areas:First, this article analyzed the signal system of each satellite navigation system, including the carrier distribution, the spreading code generation and navigation message modulation. On this basis, this paper carried out a detailed analysis of the spreading code generation and cross-correlation and autocorrelation properties. Introduces a GNSS research platform architecture design.Secondly, this paper analyzes the characteristics of the satellite signal in the complex environment. Through the capture principle of navigation receiver analysis, introduced the signal capture range and several common capture algorithm. This paper analyzed both coherent and incoherent capture method and evaluation criteria of capture threshold.Thirdly, for the quick locating problem, this article introduced navigation receiver several start-up mode and workflow. After analysis of the cold start of the signal processing flow, this paper gives a new hot-start algorithm and analyzes the priori information, error analysis of the algorithm.Last, on the basis of the overall design verification system platform, analyzed the signal process and the key module of satellite signal navigation receiver in the perspective of software and hardware.After the entire system test, this complex environment quickly positioning technology research through the outdoor signal test. Verified the correctness of the conclusions presented in this paper.