Ghost cancellation equalizer

Abstract

The invention discloses a ghost cancellation equalizer, comprising a ghost filter which is used for canceling ghost and noise from a digital code element signal; an error generator which is used for generating the error output by the ghost filter; a channel estimator which is used for estimating and outputting channel pulse response of the digital code element signal which is input into the ghostfilter; a state generator which is used for determining and outputting the reliability of the output of the ghost filter; a coefficient updater which is used for receiving the error, determining a tap with a step size that needs to be changed based on the channel pulse response and changing a determined step size of the tap to update the tap coefficient of the ghost filter based on the reliability. The ghost cancellation equalizer can adjust the tap coefficient of the ghost filter according to the channel state information in time, thus improving the ghost cancellation effect greatly.

Description

Technical field The present invention relates to a ghost canceling device, in particular to a ghost canceling equalizer used in a digital television terrestrial broadcasting system. Background technique Digital television signals usually have different transmission paths (multipath transmission) during transmission, so that when the receiver receives the signal, ghost images are generated in the receiver. The basic idea of ​​ghost elimination is to estimate the characteristic parameters of the multipath path, generate an analog multipath path, obtain the analog multipath signal, and subtract the signal from the received signal to achieve ghost elimination. The structure of a ghost canceling equalizer commonly used in existing receivers is shown in Figure 1. The ghost canceling equalizer includes a feedforward filter 110, a feedback filter 120, a first operating unit 130, a second operating unit 140, and a decision unit 150. . The feedforward filter 110 receives the input sign...

AI Technical Summary

Problems solved by technology

Such conventional ghost canceling equalizers can equalize the input signal, but have no information about the state of the channel, therefore, cannot properly handle changes in the state of the static and dynamic channel

As a result, deghosting capability and system power consumption are limited

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