The Analysis And Research Of Multi-path Signal Estimation In GPS Receiver

Global Position System is more and more close with people's life from start run till now. Such as its features have global coverage, continuous / all-day work, high dynamic platform for services, and high-precision positioning. The GPS receiver as the interface of global positioning system,people are not only most closely related,but also a focus of study.The work order of GPS receivers is the signal search acquisition, signal tracking, sub-frame recognition, ephemeris and pseudo-range calculation, calculation of satellite position and location of the user to conduct accurate positioning. The concept of pseudo-range measurement accuracy of the main error comes from the following aspects, such as ephemeris error, satellite clock error and receiver clock error, ionospheric disturbances, tropospheric interference, multi-path errors, noise and so on. In some applications, the error introduced by multi-path to hold a dominant position, in which short-delay multi-path signals brought great error,with large amplitude and as difficult to be suppressed by improving the receiver. Current multi-path signals from the ground can be suppressed with the antenna designed. But multi-path signals from the antenna at the top by the antenna designed is difficult to suppress, it needs to improve the receiver or signal processing technologies to achieve. This paper mainly analyzed and studied multi-path signal suppression, by analyzing the cepstrum method, Teager-Kaiser algorithm and the estimated multi-path delay-locked loop technology, combined with TK and MEDLL two algorithms, improved the algorithm of MEDLL, at the same time estimated the parameters of multi-path signals, ultimately separate multi-path signals from the received signal, less affected by multi-path effects, and the signal processing algorithms implemented in the digital signal processor.Paper first analyzes the mathematical structures of multi-path signal and its classification, and then describes the composition of the receiver and under the multi-path signals interference in each module affected. On this basis, Detailed analysis the received signal of the receiver, and the use of improved algorithms is processing.First, the article design a GPS signal source used to generate the multi-path signals, and removal of the carrier, At the same time the local codes of alignment related to operations with it, obtained correlation function. Combined TK and MEDLL two algorithms, multi-path signals processing.Analysis and compared the results of two algorithms, also illustrates the two algorithms. Completed it in the MATLAB and based on it further analysis of two algorithms, fixed-point processing in the DSP.