Weak signal acquisition method based on overlapping multi-block zero padding algorithm

Abstract

The invention discloses a weak signal acquisition method based on an overlapping multi-block zero padding algorithm, and a defect of coherent accumulation length and block number invariability in an existing double-block zero padding algorithm is mainly solved. The solution is that a received RF signal is orderly subjected to filtering, down conversion and digital sampling at a receiving end, and an original baseband complex signal is obtained; navigation data used by a sending end is subjected to spread spectrum modulation and shaped offset quadrature phase shift keying modulation to obtain an original local signal; coherent accumulation extended data and a step factor are introduced, the original baseband complex signal and the local signal are subjected to block combination, and a new baseband complex signal data block and a new local signal data block are obtained; the new baseband complex signal data block and the new local signal data block are subjected to circular correlation, and related value data is obtained; according to a peak value which appears in the related value data, whether acquisition is successful is judged. According to the method, better acquisition performance can be obtained in a small frequency offset, and the method can be used for data transmission and satellite positioning navigation.

Description

technical field [0001] The invention belongs to the technical field of wireless communication, in particular to a method for capturing weak signals, which can be used for data transmission, satellite positioning and navigation and distance measurement. Background technique [0002] With the continuous development of satellite navigation technology, the application of global navigation and positioning system GNSS is becoming more and more extensive. The United States, Russia, China, and the European Union have all formulated policies and plans to accelerate the development of global satellite navigation technology. Positioning and navigation with no blind spots and high sensitivity has become the latest technology development direction, which requires the rapid capture of weak signals in high dynamic environments. [0003] In the traditional weak signal acquisition algorithm, the serial acquisition algorithm achieves signal acquisition by continuously adjusting the local carr...

AI Technical Summary

Problems solved by technology

However, in DBZP, the block length and the number of blocks are determined by the frequency resolution and the Doppler frequency offset search range and are fixed. In order to ensure a larger Doppler frequency offset search range, the block length used is shorter , but when the frequency offset is small, a short block length will lead to a decrease in detection performance and an increase in computation

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