Beidou Navigation Long Code Random Signal Acquisition Method, Navigation Method and Receiver

Abstract

The invention discloses a method for capturing a random signal of a Beidou navigation long code, which includes searching for an idle channel to traverse all satellites and initiating a capture application; responding to the capture request, reading the local time and obtaining the starting point of the entire frame time; before capturing for the first time Set the parameters of the large time window and use the large time window for the first capture; set a small time window, and use the large time window or small time window to complete the subsequent signal capture according to the result of the first capture. The invention also discloses a navigation method including the acquisition method of the Beidou navigation long code random signal, and a receiver including the acquisition method of the Beidou navigation long code random signal and the navigation method. The invention improves the signal-to-noise ratio and improves the success rate of capture under weak signals; it is easy to understand and can be quickly implemented based on conventional capture design, and is applicable to any navigation equipment that uses Beidou navigation long code random signals, and has higher reliability , more practical and easier to implement.

Description

technical field [0001] The invention belongs to the field of digital signal processing, and in particular relates to a method for capturing random signals of a Beidou navigation long code, a navigation method and a receiver. Background technique [0002] With the development of economy and technology and the improvement of people's living standards, navigation technology has been widely used in people's production and life, bringing endless convenience to people's production and life. Therefore, ensuring the stable and reliable operation of the navigation system has become one of the most important tasks of the navigation system. [0003] At present, my country's Beidou-3 system has been officially put into operation. In the application, the power of the satellite navigation signal reaching the ground is relatively weak. Under normal circumstances, the signal power reaching the antenna is -160dBW, while the thermal noise of the receiver at normal temperature is -135dBW, and...

AI Technical Summary

Problems solved by technology

When the receiver is in a weak signal environment such as occlusion, the signal cannot be captured normally because it is weakened

The symbol rate of the navigation signal is high, the integration time is very short, the spread spectrum gain is relatively limited, and the user message is modulated, and there are frequent flips of the message symbol, which makes it impossible to use the conventional coherent integration method to improve the signal-to-noise ratio

Although the non-coherent integration method is not sensitive to symbol hopping, it will introduce square loss in the integration process, and the loss will increase with the decrease of signal-to-noise ratio, so this method is also limited

The long-code random signal is different from the periodic short-code signal, which has no periodicity or long periodicity. When the pseudo-random code used for acquisition search covers exactly the intermediate frequency data corresponding to the symbol hopping, neither coherent nor non-coherent methods can improve the signal. noise ratio

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