Capturing method of satellite navigation signal in adjustable carrier wave doppler frequency searching range

Abstract

The invention relates to a capturing method of a satellite navigation signal in an adjustable carrier wave doppler frequency searching range. The method comprises the following steps that: an initial carrier wave doppler covering range and a corresponded carrier frequency is generated; code phase searching is completed under the carrier wave frequency to obtain a corresponded capturing result; because the covering of the initial carrier wave doppler is complete, search frequency point information of the carrier wave doppler that is frequency hopping information is written into a frequency hopping information memory to complete storage of the frequency hopping information that can be used for subsequent continuous capturing; and other unresearched satellites are switched for continuous execution. According to the invention, searching of an undetermined range of a carrier wave frequency can be completed at the expense of few hardware costs and a fast speed; satellites can be searched ina short time as much as possible; and first positioning time of a receiver is improved.

Description

Technical field [0001] The invention belongs to the technical field of satellite signal acquisition in the process of satellite navigation and positioning, and relates to a satellite navigation signal acquisition method with adjustable carrier Doppler uncertainty. Background technique [0002] The current satellite navigation signal acquisition technology mainly involves time domain and frequency domain acquisition, and is divided into matched filtering, FFT / IFFT, and time-domain serial correlation in terms of implementation methods. According to different applications, the acquisition strategy of baseband processing corresponds to different hardware scales. At present, time-domain serial acquisition or frequency-domain code phase parallel acquisition methods are usually used, that is, the way of traversing the frequency of carrier NCO is used to realize the correspondence to all carrier Doppler uncertain ranges. But according to the satellite orbital speed, take the maximum val...

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Problems solved by technology

However, according to the orbital velocity of the satellite, taking the maximum value in the horizontal direction, the maximum satellite velocity obtained is about 950m / s. Considering the stationary receiver, the Doppler frequency variation range caused by the satellite movement is -5-5kHz, so for any Satellites, the carrier NCO frequency of the static receiver needs to traverse -5-5kHz, resulting in a small number of satellites captured by the receiver within a certain period of time, which affects the performance of the receiver

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