Fast and accurate synchronization method and system for large frequency offset full-digital carrier signal

Abstract

The invention discloses a fast and accurate synchronization method and system for a large frequency offset full-digital carrier signal. The method comprises the following steps: firstly, ensuring thata receiver antenna sends a received analog signal to a digital-to-analog conversion module and converts the signal to a digital signal; performing first-stage open loop coarse estimation for a carrier frequency of the digital signal by adopting algorithms such as maximum likelihood frequency offset estimation, and controlling an output frequency of a local numerically-controlled oscillator basedon an estimation result to perform fast coarse synchronization with the carrier frequency of the received signal; and controlling the output frequency of the local numerically-controlled oscillator through a second-stage closed loop carrier synchronization module such as a Costas loop to facilitate the accurate synchronization tracking with the carrier frequency and phase of the received signal. According to the method and system disclosed by the invention, the problem of accuracy that a receiver performs frequency phase tracking for a carrier of the received signal under a large frequency offset can be solved.

Description

technical field [0001] The invention belongs to the field of digital carrier synchronization of communication systems, and in particular relates to a fast and accurate synchronization method and system for large frequency deviation full digital carrier signals. Background technique [0002] With the increasing demand for low-energy working environment in modern communication systems, the traditional modulation method containing carrier component in the received signal is gradually on the verge of being eliminated, while the modulation method of suppressing the carrier has been widely used. At this time, the ordinary phase-locked loop circuit can no longer complete the carrier synchronization processing of the received signal. Therefore, the carrier-suppressed tracking loop has been developed and popularized accordingly. As early as the 1980s, scholars from various countries began the "digital" research and design of carrier suppression tracking loops, and made certain impro...

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Problems solved by technology

[0003] In order to solve the technical problems raised by the above-mentioned background technology, the present invention aims to provide a fast and accurate synchronization method and system for all digital carrier signals with large frequency deviation. Move down, the accuracy of frequency and phase tracking of the received signal carrier at the receiving end

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