Method for improving performances of digital phase-locked loops

A digital phase-locked loop and phase-locked loop technology, applied in the field of communication, can solve problems such as poor effect and slow control speed, and achieve the effect of increasing the locking range, improving the locking accuracy, and reducing the steady-state phase jitter

Inactive Publication Date: 2009-11-18
SOUTHEAST UNIV
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

Traditional fixed bandwidth control cannot solve this contradiction, while fuzzy control does not need to establish an accurate system model,

Method used

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  • Method for improving performances of digital phase-locked loops
  • Method for improving performances of digital phase-locked loops
  • Method for improving performances of digital phase-locked loops

Examples

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Embodiment Construction

[0023] Firstly, the principle of the method of the present invention is described by taking the application background of carrier recovery as an example.

[0024] The phase-locked loop receiving form is u 1 (t)=cos(ω 0 t+θ e ) signal, where θ e In the process of carrier recovery, the function of the phase-locked loop is to obtain θ by calculation e , and using this θ e Get a carrier with the same frequency and phase.

[0025] The traditional phase-locked loop structure such as figure 1 , get the phase deviation θ through the phase detector e , through the loop filter to control the numerically controlled oscillator to obtain the carrier wave with the same frequency and phase. The loop filter often uses a fixed-bandwidth loop. Even if the phase-locked loop is divided into two processes of capture and tracking, and different bandwidths are used to improve the locking performance, the bandwidth is still fixed and cannot be updated in real time with the phase deviation, whi...

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Abstract

The invention provides a method for improving performances of digital phase-locked loops. The method adds a proportion differential control module, a fuzzy control module and a filter-parameter updating module one by one between a Hilbert phase detector and a loop filter of the conventional phase-locked loop circuit, automatically adjusts parameters of the loop filter according to the output of the phase detector, and then controls loop bandwidth and completes the self-adaptive control of a phase-locked loop so as to increase locking range, reduce locking time and reduce steady-state phase jitter.

Description

technical field [0001] The present invention relates to the field of communications, in particular to an improved digital lock for eliminating the carrier frequency offset and phase offset caused by the signal transmission process and improving the carrier recovery performance during the synchronization process of the FM receiver receiving the signal A method for phase loop performance. Background technique [0002] Compared with the analog phase-locked loop, the digital phase-locked loop has the advantages of stable performance, reliable operation and easy integration, so it has been widely used in frequency synthesis, tracking filtering, carrier recovery and other fields. With the development of digital technology and the improvement of the operation speed of integrated circuits, the application fields of digital phase-locked loops will be more extensive. [0003] The traditional carrier recovery phase-locked loop often uses a loop filter with a fixed bandwidth, which bri...

Claims

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Application Information

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IPC IPC(8): H03L7/085
Inventor 张萌汤佳健朱笛高星吴建辉戴志生方信昀王声扬武攀宗倩
Owner SOUTHEAST UNIV
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