Research On Acquisition And Tracking Algorithms For BOC Based On SCCF

With the rapid development of the global satellite navigation system,Limited frequency band is not able to meet the needs of a variety of navigation systems coexist, Therefore,the method developed to solve the same frequency band different navigation signal interference problem is imminent, Binary Offset Carrier(BOC) is one of effective methods to solve this problem by changing the way of navigation signal modulation, Even though the BOC modulation settle band signal interference but it also produce fuzziness becauseof its self-correlation function is multimodality, This will give BOC signal acquisition and tracking potentially dangerous. The main purpose of this paper is to solve the multi-modal nature of certain types of BOC signal in acquisition and tracking process, the main work are as follows:First,There is a brief introduction of acquisition and tracking algorithm,and then focus on the modulation principle of the modulation scheme and the main features of themselves,through the analysis of comparative data of spectral isolation coefficient, equivalent rectangular bandwidth, and root bandwidth of BOC modulation and BPSK modulation, To summed that BOC signals in some aspects such as split spectral characteristics,anti-interference ability and tracking accuracy have better performance compared to conventional modulation method.Studying the BOC signal acquisition and tracking principle and tracking loop design method intensively, combined with the specific acquisition and tracking algorithm to deepen the understanding of the entire process. the specific algorithms and experience are as follows:By studying some non FFT serial acquisition and several FFT parallel acquisition algorithms,I get that FFT can accelerating capture progress, Except that, RZCC algorithm help me construct the idea of correlation function; In the tracking part, through learning ASPeCT algorithms and Side Lobes Cancellation algorithm,I learned that synthetic cross,correlation function can be used to form a thought to achieve the purpose of non blur.For the using signal of AltBOC(15,10) which has less capture technology, the first study is its modulation principle and basic characteristics, then give the abstract mathematical expression of this kind of signal and the correlation function expression, Finally, the acquisition algorithm for this signal is offered by a synthetic cross-correlation function idea,the algorithm is verified by simulation compared to the direct capture and finding that it can effectively increase the primary and secondary peak ratios, reducing the wrong lock possibility and improving the capture probabilities.For the cosine type BOC signals which have little research at home and abroad but have excellent performance, first given its generic model and related functions model, using the two models can be easily understood it and simplify the simulation process. Then a synthesis of cross-correlation function based on the idea to achieve the cosine type BOC (2n, n) signal tracking method and algorithm is given, By simulation, the algorithm can be fully achieved non blur purpose while maintaining the advantages of high tracking accuracy of BOC signal.