Power line communication system impulse noise suppression method based on recursive compressed sensing

Abstract

The invention discloses a power line communication system impulse noise suppression method based on recursive compressed sensing. The method comprises: selecting a part of subcarriers from numerous subcarriers to serve as pilot frequency subcarriers to be used for block weakness channel estimation; combining the channel impulse response and the asynchronous impulse noise in the received signal onthe pilot frequency subcarrier and giving a combined probability density function; solving the hyper-parameter by using an expectation maximization method through two-step alternate iteration of E-step and M-step, and performing iterative estimation on the hyper-parameter in the E-step by using a Kalman filter and a smoother, so that estimated values of channel impulse response and asynchronous impulse noise can be further obtained; and finally, subtracting the estimated value of the asynchronous impulse noise from the received frequency domain signal; obtaining a frequency domain signal obtained after asynchronous pulse noise suppression. The method has the advantages that the block weak channel and the asynchronous pulse noise in the slow time-varying channel can be jointly estimated, and the estimation accuracy is high.

Description

technical field [0001] The invention relates to an impulse noise suppression technology, in particular to an impulse noise suppression method for a power line communication system based on recursive compressed sensing. Background technique [0002] With the rapid development of the smart grid, power line communication (PowerLine Communication, PLC) has been widely used. Power line communication is a communication method that uses power line medium for data signal transmission. The early research was based on substation switching as the research goal, and studied the problems of metering and load control. However, limited by the radio frequency spectrum, the research work at that time was not well developed. In the 1980s, the research work on power line communication became more important. However, since the power line design did not consider the transmission of data signals at the beginning, it basically does not have the electrical characteristics necessary for wired comm...

AI Technical Summary

Problems solved by technology

Some researchers proposed a method based on the least square method (LS) to jointly estimate the channel and impulse noise of the power line communication system. This method needs to accurately locate the position of the impulse noise in the received OFDM signal, but the general impulse Noise occurs randomly, it is difficult to locate the position of impulse noise in advance

Considering the joint estimation problem, some researchers use the sparse Bayesian learning method to jointly estimate the channel and impulse noise for each OFDM symbol. This method estimates the two jointly, but does not use the correlation of the time-varying channel in the OFDM frame. sex

The above methods can jointly estimate the general channel and asynchronous impulse noise in the slow time-varying channel, but they cannot effectively jointly estimate the special channel in the slow time-varying channel, that is, the block fading channel and the asynchronous impulse noise

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