Research On Distortion Error Evaluation Indexes Of Moden Navigation Signals

With the development of Global Navigation Satellite System(GNSS),Binary Offset Carrier(BOC)signal is widely adopted.Evaluation of distortion errors of BOC signals is of great importance to GNSS signal integrity evaluation and monitoring.In former researches of BOC signal distortion,there were no analytical methods and indexes to describe the distortion errors of BOC signals,except the normal characteristics of the signals,including ranging and anti-multipath capacities.The paper mainly focused on the problem of evaluating the distortion error of BOC modulated signals.Firstly,it extended already accepted failure models to the new modulations.Then the analytical evaluation indexes for three signal distortion errors of BOC signals were first presented and the analytical evaluation theory for the 2nd-Order Step threat model errors of BOC signals was developed.The proposed evaluation indexes were used to evaluate the distortion errors of modern BeiDou global navigation signals,and several new conclusions were achieved.The paper mainly contains four parts:Firstly,the paper depicted the backgrounds of signal designs and signal quality monitoring of main global navigation satellite systems,including GPS,Galileo and BeiDou system.With the basis of the backgrounds,the topics of the paper were presented,then the research status of the topics were introduced.Secondly,the need of evaluating the distortion error of BOC modulated signals introduced the necessity to extend already accepted failure models to the new modulations.The 2nd-Order Step threat model was adopted in the paper.Starting from the 2nd-Order Step threat model,a similar threat model was here proposed for BOC signals,and then extended also to Multiplexed Binary Offset Carrier(MBOC),and to Alternate BOC(AltBOC)modulated signals.The characteristics of the distortion BOC modulated signals in time domain,frequency domain and correlation domain,including MBOC and AltBOC signals,are also presented.Thirdly,the analytical evaluation method for the 2nd-Order Step threat model errors of BOC signals was developed.For the three signal distortions,including digital distortion,analogue distortion,and digital-analogue distortion,several evaluated indexes are built.At last,the proposed evaluation indexes were used to evaluate the distortion errors of modern BeiDou global navigation signals,and several new conclusions were achieved,which were advisory to modern signal design and integrity monitoring.