Positioning satellite signal capturing system with high sensitivity

Abstract

The invention discloses a positioning satellite signal capturing system with high sensitivity. The positioning satellite signal capturing system with the high sensitivity comprises a first digital-controlled oscillator, a half-band filter, a withdrawal device, a memorizer and a correlator, wherein the first digital-controlled oscillator is used for digital downconversion of input signals to enable in-phase orthogonal signals to be generated, the half-band filter is used for filtering high-frequency noise of the in-phase orthogonal signals, the withdrawal device is used for withdrawing filtered signals to reduce the rate of the signals, the memorizer is used for memorizing withdrawn signals, and the correlator is used for extracting signals from the memorizer for related searches. Due to the fact that the correlator is adopted for the related searches, flexible configuration of resources and searching speed is achieved in a searching process, and further the utilization rate of the resources is improved. Different capturing systems can be used only by replacing a gold code generating device and adjusting calculating speed, and therefore compatibility and transportability are good. Furthermore, balance between the resources and the searching speed can be achieved by increasing or decreasing the number of sub-correlators appropriately. The positioning satellite signal capturing system with the high sensitivity is widely used in the satellite communication field.

Description

technical field [0001] The invention relates to the field of satellite communication, in particular to a highly flexible positioning satellite signal acquisition system. Background technique [0002] The research and application of global navigation satellite system (GNSS) outdoor positioning technology has been very common. Acquisition systems are required for signal processing by GNSS receivers. The acquisition system is used to detect whether a valid GNSS signal is received from the antenna. The locally generated pseudo-random sequence (PRN) code needs to be synchronized with the received signal in order to despread the received signal. The acquisition system needs to estimate the PRN code phase difference and carrier Doppler frequency shift between the local signal and the received signal at the same time, so as to be used for subsequent tracking of the receiver. Therefore, the acquisition of GNSS signals is a two-dimensional search process, that is, the phase of the ...

AI Technical Summary

Problems solved by technology

The serial capture principle in the time domain is simple and easy to implement, but the capture time is very long; the FFT method in the frequency domain greatly reduces the capture time, but its FFT operation is usually limited by the computing power of the processor, and will consume more resources

In addition, the algorithms adopted by different capture systems are independent and incompatible, resulting in low portability between different capture systems

Once the capture system is finalized, it is difficult to expand

[0004] To sum up, the main disadvantages of the existing technology are that it occupies too many resources, the portability between different capture systems is low, and it is difficult to balance resources and search speed at the same time, so it is difficult to meet the needs of different application scenarios

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