Dynamic phase-locked loop bandwidth adjusting method for carrier extraction

Abstract

The invention discloses a dynamic phase-locked loop bandwidth adjusting method for carrier extraction. The bandwidth adjusting process can be divided into two stages, namely, the respond stage of switching from static bandwidth into dynamic bandwidth when the dynamic process is started and the recovery stage of switching the dynamic bandwidth back into the static bandwidth when the dynamic process is stopped. Compared with an FAB-PLL, the method has the advantages that no phase sliding locking failure happens in the adjusting process, the dynamic process response speed is high, the response speed is high, and the method has great application potential in the tasks where movement models such as rockets, missiles and low earth orbit satellites are complex and the environment time varying is obvious.

Description

technical field [0001] The invention relates to the field of wireless communication and measurement, in particular to a method for dynamically adjusting the bandwidth of a phase-locked loop for carrier extraction and tracking. Background technique [0002] Carrier extraction is one of the important technologies in the field of wireless communication and measurement. The tracking performance of the carrier is affected by various external factors that change with time, and there are optimal loop parameters under each external condition. In order to improve the tracking performance of the loop, various adaptive bandwidth adjustment methods have been proposed and widely used. Currently, commonly used adaptive bandwidth adjustment methods include FAB-PLL, PLB-PLL, and FL-PLL. [0003] Loop dynamic performance and loop tracking accuracy are the core issues in bandwidth adjustment. When a large bandwidth is used, the dynamic process can be better dealt with but the tracking accu...

AI Technical Summary

Problems solved by technology

(1) The focus of attention is only how to determine the optimal bandwidth in various environments, and there is no corresponding constraint in the switching process between different bandwidths, and there are risks such as phase loss or temporary loss of lock

(2) Due to the complex calculations, the update period of the loop bandwidth is long, usually every few milliseconds, which makes it unable to respond to some sudden dynamic processes in time, which will also cause phase slippage

But these invalid values ​​are still used in the subsequent smoothing process, resulting in loss of precision

Secondly, when the phase slip cycle loss is over, the received signal and the recovered signal have experienced different cycle numbers, so the phase deblurring process needs to be repeated, and this process will take a certain amount of time, so before the defuzzification is completed There will be some outliers different from the real pseudorange, resulting in discontinuity of the measured value

Images