Research On Technologies Of Synchronization Base On The New Satellite Navigation Signals

With the in-depth application of satellite navigation systems in the military,national defense,and other areas of daily life,its vast market prospects will bring immeasurable economic value,many countries clearly recognize its importance,scrambling to develop their own satellite navigation systems,such that make the navigation band becoming more and more crowded.In order to improve the utilization of the navigation band,increasing the resistance to interference between the different navigation signals,all kind of navigation system make adjustment in signal structure,modulation scheme,received information etc.The BOC modulation as a new modulation scheme,widely used because of its unique characteristics to split the spectrum,But because the factors of signal itself,the correlation function with multimodal characteristics,prone to false lock in the synchronization process,so how to solve the wrong acquisition and tracking has become the primary problem.this paper studies BOC modulation signal synchronization algorithm.Firstly analyzed the current development situation of synchronization algorithms for BOC modulation signal at home and abroad,then focus on the generation mechanism of the advanced modulation schemes,and analyzed the characteristics of BOC modulation signal from the power spectral density and autocorrelation function,by compared the performance of the three signals indicating: spectral isolation coefficient,equivalent rectangular bandwidth and the RMS bandwidth show that the BOC modulation signal has a better advantage than the traditional modulation method.Detailed study the synchronization technology of BOC modulation signal,described acquisition and tracking the two important synchronization process from aspects of the basic methods for signal acquisition,tracking loop principle and the phase curves,and then focus on existing BPSK-like algorithm based on band,as well as synchronization algorithm based on peak detection,the main achievement of the two aspects of the analysis algorithms from algorithm principle and simulation algorithms.In order to solve the BOC modulation signal correlation peak easily lead to receiver wrong catch problem,this paper proposes a new acquisition algorithms based on the spurious correlation sequence.Inspired from FFT circular correlation acquisition algorithm,simple,suitable for software receiver,through simulation analysis showed that,compared with the FFT circular correlation acquisition algorithm,the new algorithm can effectively reduce the primary and secondary peak ratio,although the acquisition sensitivity decreased,butincreased the probability of acquisition,reducing the possibility of the wrong lock.Through the study of the correlation peak signal characteristics,we propose a new BOC modulation signal tracking algorithm,and design the tracking loop.The new algorithm can get completely unbiased correlation peak,can improve the tracking accuracy of the signal,and enhance the ability of anti-jamming and multipath,applies to both BOC and BOCcos sinusoidal signal,the principles of the new algorithm is analyzed and validated the feasibility eliminate secondary peaks get full unbiased correlation peak by simulation,at last analyzed the tracking performance of the new algorithm in the tracking accuracy and multipath suppression.The results show that,in the code within a certain range,the new algorithm has a better tracking performance.