High-sensitivity satellite navigation signal capturing method and system

Abstract

The invention discloses a high-sensitivity satellite navigation signal capturing method and a system. The system comprises a digital down-conversion module, an average sampling and block accumulation module, an FFT (fast Fourier transform) module, a circumference shifting module, a local PRN (pseudo random noise) code FFT conjugate memory, a complex multiplier module, an IFFT (inverse fast Fourier transform) module, a differential coherence integration module, a peak detection module and a sequential control module. The digital down-conversion module realizes digital down-conversion operation for satellite digital intermediate frequency signals; the average sampling and block accumulation module averagely samples satellite data and completes a block accumulation function; the FFT module searches code phase frequency domains; the circumference shifting module utilizes Doppler circumference shifting search to replace frequency compensation; the local PRN code FFT conjugate memory stores a local PRN code FFT conjugate result; the complex multiplier module realizes signal de-spreading; the IFFT module calculates different code phase coherence results; the differential coherence integration module accumulates differential coherence energy of de-spread satellite signals; the peak detection module realizes signal capturing output; and the sequential control module controls timing sequence of the various modules of the system. Weak signal capturing speed and sensitivity of a satellite navigation receiver are improved, and parameters can be configured flexibly.

Description

technical field [0001] The invention relates to the field of satellite navigation signal capture research, in particular to a high-sensitivity satellite navigation signal capture method and system. Background technique [0002] The Global Positioning System (GPS) is a global satellite navigation and positioning system jointly developed by the US Army, Navy and Air Force on the basis of the Navy Satellite Navigation System in the 1970s. It consists of three parts: the space segment, the ground control segment and the user segment. . The GPS system has also been widely used in the civilian field, and has developed into an international high-tech industry with multiple fields, multiple modes, multiple purposes, and multiple models. The GPS system of the United States is a satellite navigation and positioning system widely used in the world. At present, there are Russia's GLONASS system, Europe's "Galileo" system and China's Beidou (COMPASS) system that can enter the field of ...

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Problems solved by technology

However, the length of incoherent integration is limited by code Doppler, and as the number of incoherent accumulation increases, the effect of energy increase is not obvious

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