Positioning signal generating method and device

Abstract

The embodiments of the invention provide a positioning signal generating method and device. The method comprises the steps of: according to the acquired spread spectrum code rate and information rate, a sending end acquiring a ratio of the spread spectrum code rate to the information rate; obtaining a first spread spectrum code length according to the acquired first spread spectrum codes; then obtaining the number of the first spread spectrum codes and a second spread spectrum code length according to the ratio and the first spread spectrum code length, and generating second spread spectrum codes according to the second spread spectrum code length and the first spread spectrum codes; further, generating target spread spectrum codes according to the number of the first spread spectrum codes, the first spread spectrum codes and the second spread spectrum codes, wherein the length of the target spread spectrum codes is equal to the ratio; and performing spread spectrum modulation on a preset number of bits of navigation message by using the target spread spectrum codes to generate a positioning signal. By using the method and the device, the positioning signal generated by using the target spread spectrum modulation navigation message is easily captured, and the capturing sensitivity to GNSS (Global Navigation Satellite System) is improved.

Description

technical field [0001] The present invention relates to the field of communication technologies, in particular to a method and device for generating a positioning signal. Background technique [0002] In recent years, LBS (Location Based Service, location service) has been integrated into our daily life, and GNSS (Global Navigation Satellite System, global satellite navigation system) refers to the use of navigation satellites to locate ocean, ground, and space users. Navigation and positioning technology. The positioning signal sent by the global satellite navigation system is a spread spectrum modulated signal. The spread-spectrum modulated signal is generated by using a PN (Pseudo-Noise, pseudo-random) code as a spread-spectrum code to modulate the information code at the transmitting end. [0003] In the global satellite navigation system GNSS, the direct sequence spread spectrum technology is generally used, and the high-speed spreading code is used to spread the spec...

AI Technical Summary

Problems solved by technology

In engineering applications, when the ratio of the spreading code rate to the information rate is not an integer multiple of the code length of the pseudo-random code, the method of truncating the pseudo-random code is often used to obtain a new pseudo-random code, and the truncated pseudo-random code The code destroys the balance of the original pseudo-random code. Once the pseudo-random code is unbalanced, its spectral characteristics will deteriorate. The positioning signal generated by the truncated pseudo-random code spread spectrum modulation navigation message is not easy to be captured, and, in The receiving end uses the same truncated pseudo-random code for despreading. Since the autocorrelation and cross-correlation of the truncated pseudo-random code are reduced, the positioning signal is further difficult to be captured, which leads to the acquisition sensitivity of the GNSS positioning signal. reduce

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