Research On Acquisition Methods And Performances Based On BOC Family Modulated Signals

With the development of satellite navigation technology,gobal satellite navigation system continues to mature and has become an important sign to measure a country's comprehensive national strength.With the use of satellite navigation systems,limited band resources become increasingly strained,traditional PSK-R navigation signal is meeting strait challenges.To alleviate the shortage pressure of spectrum band resources,BOC family modulated signal have been proposed.Existing satellite navigation systems have been widely using BOC family modulated signals,however,this modulated method causes multimodality on signal correlation function when using spectrum band split to alleviate the shortage of band resources.The characteristic of multimodality will cause error capture.The technology of capture is the heart of receiver,so it is important to study the acquisition methods of binary offset carrier modulated signals.Based on studying the generation mechanism of BOC family modulated signals,the characteristics about time domain and frequency domain of signals were summarized.According to modulation coefficient,based on the theory of code correlation waveform transform.The characteristics of BOC signal correlation function could be further summarized.The acquisition methods of BOC family modulated signals were mainly researched.By studying existing related reconstruction acquisition algorithms and non-related reconstruction acquisition algorithms,a cross-correlation function reconstruction and new cross-correlation function reconstruction acquisition algorithms were proposed based on the auxiliary signals of Pseudo Random Noise and Quadratic BOC.Wherein,CCRF introduced auxiliary signals and had a fixed phase shift to related functions.Based on the coincidence degree of reconstructed correlation peaks and auto-correlation peaks,this algorithm could not only eliminate the first sub-peak,but also achieved the purpose of main peak improvment and rest sub-peaks suppression.In order to adapt the acquisiton to higher-order coefficient BOC faminly signal,according to different coefficients,NCCRF had a non-fixed related functions phase shift to improve main peak.At the same time,this algorithm could also eliminate first sub-peak and restrain rest sub-peaks suppression.Aiming at the Multi-mode of BOC family modulation signals,the acquisitionperformance of new algorithms were verified in correlation value comparison and capture probability.The signal which was reconstructed had been simulated and analyzed from main peak mean contrast,frist sub-peak mean contrast,the contrast of main and frist sub-peak,the contrast of main and rest sub-peaks,correlation peaks detection probability in different SNR.The simulation was compared and analysed to vertify the algorithms' capabilities.Which could enhance the main peak,suppress the first sub-peak and detecte the correlation peaks in receiver.The simulation showed that the proposed algorithms could obtain the better performance of showing main peak and suppressing first sub-peak on BOC family modulation signals.