Research On Software Receiver Of BOC Signal

In this paper, softreceiver based on BOC signal is researched. Taking the relevant application background into consideration, the drawback, caused by the side-peak when acquition and tracking, is the key problem when designing a software receiver of BOC signal. The main research contents of this paper, which are aimed at solving the problem, are as follows:Firstly, the research condition of BOC signal technology is overviewed in this paper, as well as the development status of receivers on BOC singal. And the principle of modulation process of BOC signal is analyzed, where the autocorrelation function as well as the power spectral density of BOC signal is introduced. With the autocorrelation function and spectral density, the advantages of using BOC signal in GNSS system is analyzed.And then some other kinds of BOC singal are introduced.Then, disadvantages caused by the ambiguous of BOC modulation are analyzed. To solve the problem, on the base of traditional acquisition algorithms for traditional signals, ways to reduce the effects of the side-peak are proposed, among them are straight-correlation, BPSK-Like and ASPeCT algorithms, and after analyzing the performance of the three kinds of algorithms, ASPeCT is considered as the best way to solve the ambiguous problem for BOC(n,n) signal.Further more, to get a high synchronization result, tracking loop is reaserched,which contains a carrier lock loop and a pseudo-random code lock loop. A phase lock loop assisted by a frequency lock loop are chosen to be as the design proposal, after analyzing the performance of FLL and PLL separately. To avoid the effects of the ambiguous of the BOC signal in code lock loop, a improved discriminator based on ASPeCT algorithm is designed which can reduce the tracking steady-state error and remove the wrong tracking points.Finally, the Galileo E1 signal data is simulated with principle of Galileo ICD. With the input data, a confirmatory experiment are carried out to prove the design proposal are correct, during which the acquision and tracking process are done.