Research On Adaptive Multipath Mitigation Technology Of GPS Receiver

Global positioning system is a satellite navigation and positioning system based onwireless communication technology, satellite navigation technology. GPS is widely used inthe field of navigation and positioning of the vehicle, flight and ship.GPS is used more and more widely, has gradually penetrated into people’s daily lives.User put forward higher requirements for the positioning and navigation performance of thereceiver. As spread spectrum ranging system, tropospheric, ionospheric error, satellite orbiterrors and multipath error is still the main source of error of GPS. Among them, the first threeerrors are systematic errors, and will be able to eliminate it through modeling as well asdifferential, its positioning error would reduce to a satisfactory level. Multipath errors arerandom error related to the reflecting objects and the distance around the receiver antenna andchanges with the environment. It is difficult to mitigate by means of modeling and thus themultipath suppression technology has been a hot research in the field of satellite navigation.Since the early1970s, the start of the first multipath research, numerous satellitenavigation and wireless communication Scientists have done a lot of work to promote thedevelopment of the different multipath mitigate technology. Such as Narrow Correlator,double Δ discriminator, multipath estimate delay lock loop (MEDLL) technology and VisionCorrelator technology. These technologies have been applied to position receiver, andachieved gratifying results, but there are shortages, the effect of multipath mitigation is farfrom satisfactory, and large amounts of correlators are required. In practical applications, theshort delay multipath will have significant effect on the GPS receiver position. This paperbased on the positioning error in the practical application caused by the multipath signal to theGPS receiver, and further research is presented. By eliminating multipath interference in GPSreceiver, especially the short delay multipath interference to improve the positioning accuracyand stability of the GPS receiver.First, this paper introduces the research background and the research status of multipathmitigation technology. Through a detailed analysis of the generation of multipath signal andits propagation characteristics, research direct signal component and multipath signalsuperimposed effect. On the basis of detailed analysis of the working principle of thenavigation receiver code tracking Loop and carrier tracking Loop, study the impact of codemultipath error, and carrier multipath errors and comprehensive multipath error that multipathcaused. detailed theoretical analysis and simulation some typical multipath mitigation technology, narrow correlator technology, double Δ discriminator technology and MEDLLtechnology.Then, based on analysis of the basic principle of the adaptive filter, an adaptive multipathmitigation technical solution is proposed, which obtains the effects of multipath signal oncorrelation value of the received signals, by estimating the amplitude and delay parameters ofmultipath. Then eliminate the interference in the receiver signal tracking process. By the way,the validity of above programs is proved according simulations. A receiver code tracking loopdesign based on adaptive multipath mitigation techniques is proposed.At the end of this paper, a GPS software receiver is realized, which adopts simulatedGPS signal and real GPS signal separately to test adaptive multipath mitigation technique, andthe mitigation ability of the algorithm is proved.