Digital delay lock ring based on Kalman filtering and least square algorithm

Abstract

The invention relates to a digital delay lock ring based on Kalman filtering and the least square algorithm, which comprises a programmable gate array unit and a digital signal processing unit, wherein the programmable gate array unit comprises a correlator, a control signal generating module and a communication interface; and the digital signal processing unit comprises a Kalman filter, a multipath estimation module, a multipath reconstruction module, a multipath elimination module, a pseudo-code phase discriminator, a loop filter, a decision making module and a numerically controlled oscillator. The invention solves the problem of tracking errors caused by the delay lock ring simultaneously estimating direct signal and multipath signal time delays on multipath interference sensitive to noise signals and incapable of suppressing short time delay. With the digital delay lock ring, noise in relative outputs is filtered by using Kalman filtering, and parameter estimation is performed on the filtered relative outputs by using the least square algorithm.

Description

technical field [0001] The invention relates to a delay locked loop, in particular to a digital delay locked loop based on Kalman filter and least square algorithm. Background technique [0002] As a pseudo-code tracking loop in the communication system, the delay-locked loop is one of the main tracking loops of the receiver in the positioning system. The tracking accuracy of the received pseudo-code signal directly determines the positioning accuracy of the positioning and positioning system. Multipath interference is the main source of error in high-precision positioning systems. With the improvement of people's requirements for positioning accuracy, multipath error elimination technology has attracted extensive attention. With the digitalization of receivers, the multipath error elimination technology based on data processing has become a research hotspot. Currently existing DLLs based on data processing mainly include DLLs that only estimate the time delay of direct sig...

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Problems solved by technology

[0005] The purpose of the present invention is to solve the problem that the delay-locked loop that estimates the time delay of the direct signal and the multipath signal at the same time is sensitive to the noise signal and cannot suppress the tracking error caused by the multipath interference with a shorter time delay, and realizes a method using Kalman Filtering is a digital delay locked loop that filters the noise in the correlation output and uses the least squares algorithm to estimate the parameters of the filtered correlation output, namely: a digital delay locked loop based on Kalman filtering and the least squares algorithm

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