Repeater echo cancelling device and method based on shift of frequency spectrum

Abstract

The invention provides a repeater echo cancelling device and method based on the shift of a frequency spectrum. The repeater echo cancelling device comprises a receiving module, a digital down-conversion module, a digital signal processing module, a small signal generating module, an adding module, a digital up-conversion module, a power amplification module and a transmitter module. The method comprises the following steps: utilizing the shift of the frequency spectrum to generate small signals, adding the small signals to signal emitting frequency spectrum holes of a base station, utilizing the characteristic that the small signals and the emission signals only have different frequency point locations and amplitudes to realize echo cancellation, wherein the error after echo cancellation is 10<-14> in order of magnitude. The method can realize echo cancellation without estimation of channels, and realizes strong practicability under the fast time-varying channel condition. The algorithm is low in complexity, the real-time performance is high, hardware is simple to realize, and the error is small. Estimation to the channels is not required, and the error signals after cancellation are not gradually convergent.

Description

technical field [0001] The invention relates to an echo canceling method, in particular to a repeater echo canceling device and method based on frequency spectrum shifting. Background technique [0002] Most of the existing digital repeaters use the following technical principles to cancel the echo: by processing the transmitted signal and the received mixed signal containing echo noise, the characteristic parameters of the echo channel are estimated, and the An analog echo signal is generated internally in the repeater, which is subtracted from the received mixed signal to achieve echo cancellation. Since the echo channel is usually unknown and time-varying, an adaptive filter is generally used to estimate the echo channel. Among them, the adaptive filter based on the principle of minimum mean square error is the most widely used. [0003] The principle of echo cancellation technology based on adaptive filter is: the transmitted signal is fed back to the internal adaptive...

AI Technical Summary

Problems solved by technology

[0005] One of the purposes of the present invention is to provide a repeater echo canceling device based on frequency spectrum shifting, to solve the problem that the existing repeater echo canceling device needs to perform real-time self-correction of the echo channel under the fast time-varying channel condition. Adaptive estimation leads to the problem of large estimation error

[0006] The second purpose of the present invention is to provide a repeater echo cancellation method based on frequency spectrum shifting, to solve the problem that the existing echo cancellation method based on adaptive filter makes the approximation speed and accuracy impossible under fast time-varying channel conditions. balance problem

Images