A navigation signal source for signal occlusion area

Abstract

The invention relates to a navigation signal source for a signal sheltered area. The navigation signal source comprises a central processor, a positioning signal module, a communication module and an antenna. The positioning signal module is used to generate a civil code signal and an associated signal. The associated signal is added to enhance positioning in the signal sheltered area and improve the coverage range of satellite navigation. Due to the civil code signal and the associated signal are used simultaneously, transition between indoor and outdoor navigation can be realized in a smooth manner. The associated signal is a direct sequence spread spectrum signal or a frequency hopping spread spectrum signal or a frequency sweeping spread spectrum signal, so that the signal source has the anti-interference capabilities as resisting frequency offset and reducing the multipath effect. Air pressure and temperature sensors are arranged additionally, so that the elevation of the position of the navigation signal source is measured and used as reference of differential calculation of a user terminal, and the positioning precision of the user terminal is improved. A calibration test module composed of a light source and a receiver is provided to correct positioning deviation of the user terminal accurately.

Description

technical field [0001] The invention relates to the field of navigation and positioning, in particular to a signal source for enhancing satellite navigation signals in signal blocking areas (including outdoor signal blocking areas and indoor environments). Background technique [0002] In indoor positioning, it is very difficult to use navigation satellite signals to obtain more accurate pseudo-range values, because satellite signals are generally difficult to directly enter the room, and most of the navigation signals that can enter the room are reflected signals. The signal strength and signal-to-noise ratio change significantly and become very weak, making it impossible to receive weak signals and realize capture, tracking, demodulation and pseudo-range measurement of weak signals. Even if it can be measured, the obtained pseudorange length will have a large deviation, which is difficult to be used in indoor positioning. The invention patent with the application number 2...

AI Technical Summary

Problems solved by technology

[0002] In indoor positioning, it is very difficult to use navigation satellite signals to obtain more accurate pseudo-range values, because satellite signals are generally difficult to directly enter the room, and most of the navigation signals that can enter the room are reflected signals. The signal strength and signal-to-noise ratio change significantly and become very weak, unable to receive weak signals and realize capture, tracking, demodulation and pseudo-range measurement of weak signals

Even if it can be measured, the obtained pseudo-range length will have a large deviation, which is difficult to use in indoor positioning

The invention patent with the application number 201010143009.2 proposes a method of using ground base stations to broadcast ground navigation signals for positioning. This method has the advantage of wide coverage, but due to the many buildings in the city, the signal of the ground base station will be blocked by the buildings , produces a large non-line-of-sight error, so it is extremely difficult to become a necessary condition for indoor positioning

At present, indoor positioning uses a large number of signals from sensor network hotspots (APs) such as WiFi, Zigbee, and Bluetooth to achieve positioning. This can achieve indoor positioning, but the accuracy is poor, and because the original intention of these hotspots is to transmit communication information , its distribution is arranged based on communication flow requirements. To achieve positioning, more hotspots need to be added and arranged, which is cumbersome; another point is the signal system problem. These signals are designed according to the requirements of information transmission, and often cannot Meet the requirements of positioning measurement

Therefore, it is really not a good choice to simply use the original communication signal to realize indoor positioning and navigation.

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