System for rapidly acquiring GLONASS satellite signals in field programmable gate array (FPGA)

Abstract

The invention provides a system for rapidly acquiring GLONASS satellite signals in a field programmable gate array (FPGA), which filters and down-sampling data after down-conversion, stores the data and samples and stores local codes by utilizing a high-speed clock to drive the whole acquisition circuit. After the data is stored, a control unit controls data output in a data storage and a local code storage, and relevance and accumulation of the data is finished through a partial matching filtering unit. A fast fourier transform (FFT) unit takes charge of carrying out spectrum analysis on the data after partial matched filtering, a threshold is acquired by calculating operation results of FFT, a doppler frequency shift and a code phase corresponding to an output peak value after detection of the peak value are acquired, and then rapid acquisition of the GLONASS signals is finished. The system for rapidly acquiring the GLONASS satellite signals in the FPGA has the advantages of being fast in acquisition speed, few in occupied resource, and suitable for rapid acquisition of the satellite signals by means of a GLONASS receiver under a highly dynamic environment.

Description

technical field [0001] The invention relates to the field of satellite navigation, in particular to a fast acquisition system for realizing GLONASS satellite signals in FPGA. Background technique [0002] In countries such as Europe and the United States, the research and development of receivers have been relatively mature, but they are constantly improving in the pursuit of high-performance and diversified receivers, such as weak signal detection, fast signal search, and shortened start-up time. In recent years, research on GLONASS has continued to heat up. Since December 1996, the State Bureau of Surveying and Mapping has officially provided the precise ephemeris data of GLONASS to the public. In terms of receiver research, it mainly focuses on how GLONASS meets the requirements of vehicles, weapons, aviation, navigation, and personal handheld navigation devices. Acquisition of GLONASS signals is one of the core technologies of GLONASS receivers. For different applicat...

AI Technical Summary

Problems solved by technology

Usually, the sampling sliding correlation method takes up less resources, but it must correlate the phase of each frequency point, and the search time is too long, so it is not suitable for use in a high dynamic environment.

Matched filter capture method, the search speed is fast, but it takes up a lot of hardware resources, and it is difficult to implement in FPGA

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