Receiver assistance-free capturing method for satellite weak signals

Abstract

The embodiment of the invention discloses a receiver assistance-free capturing method for satellite weak signals and relates to the technical field of satellite navigation. The operand can be reduced, operation time can be shortened, and positioning equipment can be relieved while the positioning performance and cost can be both considered. The method comprises the steps that a received baseband signal is divided into Nb blocks, and a ranging code with the length T1 is generated and divided into Nb blocks; every two adjacent divided blocks of the baseband signal are combined, and each combined block of the baseband signal is divided into an assigned number of sub-blocks with the equal length; the divided blocks of the ranging code are supplemented with zero of the equal length, and each zero-supplemented block of the ranging code is divided into an assigned number of sub-blocks of the equal length; Fourier transformation (FFT) and inverse Fourier transformation (IFFT) are carried out on the sub-blocks of the baseband signal and the sub-blocks of the ranging code, and a coherent integration matrix Mc in the time domain is obtained; energy of all points of Mc is obtained, and capture succeeds if the maximum value of the obtained energy is larger than a capture threshold value. The receiver assistance-free capturing method for satellite weak signals is suitable for capturing weak signals.

Description

technical field [0001] The invention relates to the technical field of satellite navigation, in particular to a receiver-free acquisition method for weak satellite signals. Background technique [0002] At present, various industries are more and more dependent on the application and dependence of global satellite navigation systems. Compared with positioning services in open areas in the wild, positioning in dense urban environments, mobile phone / vehicle navigation, and indoor and outdoor seamless positioning are more important to satellite navigation. The weak signal working ability of the receiver puts forward more stringent requirements. [0003] Double Block Zero Padding (DBZP, Double Block Zero Padding) is a widely recognized acquisition method in unassisted weak signal acquisition. It can simultaneously search for Doppler frequency shift and code phase in parallel. It is a dual-frequency Domain search method, very suitable for weak signal capture that needs to proces...

AI Technical Summary

Problems solved by technology

However, the double-block zero-padding algorithm requires a large amount of calculations and requires more computing resources of the positioning equipment. In order to ensure that the calculation time and the refresh frequency of the positioning signal are within an acceptable range, the positioning equipment needs to be equipped with sufficient computing functions. For example, higher-performance processors, receiving antennas, etc. At the same time, in order to ensure battery life, the battery capacity of the positioning device needs to be increased. This has caused the problem of high cost of the positioning device using the double-block zero-padding algorithm, and it is difficult to take care of it at the same time. Positioning performance and cost

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