Restraining device and restraining method for burst impulse noise of power line communication channel

Abstract

The invention discloses a restraining device and restraining method for burst impulse noise of a power line communication channel. The restraining device comprises a Fourier transformation module, a masking subcarrier selection module and a compressed sensing estimation module. The restraining method for the burst impulse noise of the power line communication channel is based on compressed sensing and comprises the steps of carrying out Fourier transformation on a received signal to obtain a frequency domain signal, carrying out masking subcarrier selection to obtain a subcarrier only comprising background noise and the burst impulse noise, estimating the burst impulse noise in the power line communication channel by using a signal recover method based on compressed sensing, and finally, removing the impulse noise from the received signal to obtain a signal with noise removed. Due to the facts that the burst impulse noise in the power line communication channel has the characteristic of sparsity, and the OFDM masking subcarrier selection and compressed sensing technologies are applied, the effect of restraining the noise can be remarkably improved, and signal information of positions interfered by burst impulse can be effectively kept.

Description

technical field [0001] The invention relates to a burst noise suppression technology, in particular to a suppression device and suppression method for burst noise of a power line communication channel. Background technique [0002] Power Line Communication (PLC) refers to the use of low-voltage power distribution lines as the transmission medium and the use of power networks for communication. It has the characteristics of no need for rewiring, wide coverage, and low cost. The low-voltage distribution network is mainly used to transmit alternating current. It was not considered for data transmission in the initial design, and its communication channel has strong noise, which has a great impact on the performance of power line communication. [0003] The low-voltage power line channel contains a variety of complex noises. These noises are mainly divided into five categories, and the specific classifications are as follows: [0004] 1. Colored background noise, which is a com...

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Problems solved by technology

[0005] 2. Narrowband noise, which is composed of several AM sine waves superimposed, mainly produced by medium and short wave radio stations, usually has a long duration of interference, but the power spectral density is very low

[0006] 3. The periodic pulse noise asynchronous to the power frequency of the power grid has a low power spectral density, which is mainly generated when the switching power supply is turned on and off, the TV receiver, and the computer monitor scan and display the image field

It is short in duration and its power spectral density decreases with increasing frequency

[0008] 5. Asynchronous burst pulse noise is mainly caused by the on-off of the switch connected to the power distribution network or the switching of the power grid. Its duration is very short, but the power spectrum intensity is very large, usually more than 50dB higher than the background noise. great influence

[0016] (1) This method performs nonlinear processing according to the set threshold, so the selection of the threshold has a great influence on the noise suppression performance. If the threshold is too small, the received signal will be destroyed; if the threshold is too large, it cannot effectively suppress the burst Impulse noise

[0017] (2) This method only reduces the magnitude of the burst noise, and the residual noise after processing still has a great impact on the performance of the communication system

[0022] (1) The threshold selection in this method has a great influence on the noise suppression performance

[0023] (2) This method sets the burst noise to zero, which can effectively suppress the burst noise, but causes damage to the original signal and affects the performance of subsequent processing

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