| Nowdasys, Global Navigation Satellite System (GNSS) has become one of the promising issues of information technology. It can provide positioning, navigation and timing services for users with characters of high precision, and real-time, which makes it become the new competition among powerful counties. In order to get rid of dependence on satellite navigation systems from the others, all the countries, regions or organizations are developing and building their own navigation satellite system actively. Obviously,thus will bring out interfere from different systems because most of the satellite systems possess the L frequency.At the same time, the sercive perfomacne will be imprvoed evidencely if all the GNSS are maken use of efficiently. Thus, issues of GNSS compatibility and interoperability are becoming hot. In this paper, aimed at improving the assessment theory of GNSS compatibility and interoperability, theoretical analysis and simulation research are combined. The main research in this paper includes:1) The demerits of traditional evaluation method of GNSS compatibility are analyzed,and the solution is provided. Firstly, the compatibility threshold is confirmed based on the four steps of signal processing in receiver,and the compatibility threshold of COMPASS is calculated. Then, the concept of Spectral Separation Coefficient is extended to the interference factor, and the concept of Code Tracking Spectral Sensitivity Coefficient is introduced to assess the impact of interference on performance of signal tracking. What's more, the impact of parameters from expectation signal and interference signal are analyzed.And the interference factors in B1/L1/E1 are calculated.2) Evaluation method of GNSS interoperability is proposed form the aspects of signal and service performance. The power efficiency of received signal, the detection probability of acquisition and the time of acquisition are chose to assess the signal performance. With the purpose of assess the service performance, assessment parameters, namely,Dilution Of Precision, Navigation Satellite System Precision and Navigation Satellite System Integrity are introduced. Then, availability and continuity of the assessment parameters are adopted to quantify the assessment parameters. Next,the weighted sum of availability and continuity is employed. At last, the single and multiple GNSS interoperability performance evaluation are achieved in condition of time and space.3) The software to analyze the GNSS compatibility and interoperability based on Matlab is developed. The researches and analysis are done with the software. From the simulation results of compatibility, it can be concluded: although the GPS and GALILEO system causing interference to the COMPASS system, but the carrier to noise ratio of the COMPASS system is still above the compatibility threshold. Therefore, the GPS and GALILEO system is compatible to the COMPASS system. In addition, it demonstrates that the interference from the GALILEO system COMPASS system is the least. From the evaluation results of GNSS interoperability, it can be seen: performance of BPSK-R (1) is the best in case of a limited bandwidth. What's more, GNSS system can be optimized using a combination of satellites,thereby improving the performance of satellite navigation systems in time and space significantly.Finally, the full-text is summarized and the compatibility and interoperability of GNSS is supposed perhaps to play an important role in signal and constellation design of COMPASS.In addition, according to the development of compatibility and interoperability of GNSS,the next investigation and the mainly aspect in the future are pointed out. |
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