Two-directional pseudo code parallel search system and realization method thereof

Abstract

The invention discloses a two-directional pseudo code parallel search system which comprises a signal receiving device, a local PN (pseudo-noise) code generator, a signal acquiring module and a single processor; the local PN code generator and the signal acquiring module are connected with the signal processor respectively; and the local PN code generator is connected with the signal acquiring module. The two-directional pseudo code parallel search system further comprises a signal input device connected with the signal acquiring module, and enables the searches in phase direction and Doppler direction to be finished simultaneously within the related integral time, thereby shortening the search time, and improving the search efficiency. As all digital signal processing is realized on hardware in an assembly line manner, and the concurrency of the hardware is fully utilized for completing the whole search process, the speed of data processing on the hardware is greatly improved compared with the data processing on software, and the chip realization is benefited.

Description

technical field [0001] The invention relates to a pseudo-code search system, in particular to a pseudo-code two-dimensional parallel search system for a satellite navigation system and an implementation method thereof. Background technique [0002] In the current satellite navigation system, the acquisition performance of satellite signals determines the sensitivity of the receiver and the first positioning time and other important performances, especially in the acquisition of P code, because the code word is very long, the amount of calculation required for the search is very large. As the key unit of the baseband signal processing of the Beidou-2 user machine, the pseudo code acquisition unit determines the important indicators of the user machine such as acquisition sensitivity and first positioning time. Usually, the search for the pseudocode is divided into two independent processes, namely, the search in the distance dimension and the search in the Doppler dimension. ...

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Problems solved by technology

The search process is like this, first estimate the Doppler value, and then search the entire code phase under the Doppler value, if no effective signal is found, then change a Doppler grid and continue searching until Search the entire possible range of Doppler. The code period of the P code of the satellite navigation signal is usually longer than 1 week, and the code rate is as high as 10.23MHz. Low, the capture time is long, it is difficult to meet the index requirements of P code capture

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