B1C signal unambiguous tracking method based on pseudo-exponential function

Abstract

Aiming at the tracking fuzziness problem of a Beidou B1C pilot channel QMBOC (6, 1, 4 / 33) signal, the invention provides and designs a B1C signal unambiguous tracking method based on a pseudo-exponential function, which comprises the following steps of: (1) carrying out carrier stripping and code correlation processing on the pilot channel QMBOC (6, 1, 4 / 33) signal; (2) the correlation value is sent to an exponential function module to be processed; (3) the discriminator processes an output value of the exponential function module; and (4) a discriminator result is processed by a loop filter to control a code loop NCO, and a local code phase is adjusted to form a closed loop. According to the invention, secondary peaks of correlation curves can be effectively eliminated, error locking points output by a discriminator are eliminated, correlation results of received signals and local signals are processed by using a pseudo-exponential function module, and unambiguous tracking of QMBOC (6, 1, 4 / 33) signals is realized. Meanwhile, compared with a traditional BPSK-like method, an SCPC method and an ASPeCT method, the B1C signal unambiguous tracking method based on the pseudo exponential function has better anti-multipath performance.

Description

technical field [0001] The invention relates to the technical field of signal unambiguous tracking methods, in particular to a B1C signal unambiguous tracking method based on a pseudo-exponential function. Background technique [0002] The B1C frequency of Beidou-3 navigation system is 1572.42MHz, and the pilot channel is modulated by quadrature multiplexed binary offset carrier (QMBOC), which is time-division multiplexed with the binary offset carrier of GPS ( Time Multiplexed Binary Offset Carrier (TMBOC) modulation and Galileo's composite binary offset carrier (Composite Binary Offset Carrier, CBOC) modulation are binary offset carrier (Binary Offset Carrier, BOC) derived modulation signals, called "new Institutional Navigation Signals". QMBOC signal has a certain degree of similarity with TMBOC and CBOC signals, but the realization of QMBOC signal in time domain is more complicated, which makes the research of QMBOC signal more difficult. Compared with the traditional ...

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Problems solved by technology

In addition, literature [13] Hodgart M, Blunt P, Unwin M. Double estimator a new receiver principle for tracing BOC signals. Inside GNSS, 2008: 26-36. A double-loop tracking method is proposed, which combines the spreading code and subcarrier Tracking separately, and combining the tracking results to achieve the effect of eliminating tracking ambiguity, but only combining the two tracking results can not improve the anti-multipath ability; literature [14] Yao Z, Lu MQ, Unambiguous sine-phased binaryoffset carrier modulated signal acquisition technique.IEEE Transactions on Wireless Communications,2010,9(2):577-580. A GRASS method is proposed, which is only applicable to sinusoidal BOC signals, and the implementation is complicated

The current ambiguity-free tracking technology cannot achieve both tracking ambiguity elimination effect and hardware implementation complexity at the same time, and the algorithm implementation with excellent tracking ambiguity elimination effect is often more complicated. Fuzzy tracking methods need further research

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