PLC signal filtering method and system utilizing Fermal theory

Abstract

The embodiment of the invention discloses a PLC signal filtering method and system using a hybrid theory. The method comprises the following steps: step 1, inputting an actually measured PLC signal sequence S; step 2, performing noise filtering processing on the PLC signal sequence S according to a Fermal signal theory, wherein the signal sequence after noise filtering is SNEW, wherein specifically, lambda OPT is an optimal approximation vector, D is a correction matrix, zOPT is an optimal noise approximation vector, alpha is a distance adjustment factor, and omega is an intermediate parameterfor solving the minimum value.

Description

technical field [0001] The invention relates to the field of electric power, in particular to a PLC signal filtering method and system. Background technique [0002] Compared with various wired communication technologies, power line communication has the advantages of no need for rewiring, easy networking, etc., and has broad application prospects. Power line communication technology is divided into narrowband power line communication (Narrowband over power line, NPL) and broadband power line communication (Broadband over power line, BPL); narrowband power line communication refers to the power line carrier communication technology with a bandwidth limited to 3k ~ 500kHz; power line communication technology includes The specified bandwidth of CENELEC in Europe (3 ~ 148.5kHz), the specified bandwidth of the US Federal Communications Commission (FCC) (9 ~ 490kHz), the specified bandwidth of the Japan Association of Radio Industries and Businesses (ARIB) (9 ~450kHz), and China...

AI Technical Summary

Problems solved by technology

[0003] Although the power line communication system has a wide range of applications and the technology is relatively mature, a large number of branches and electrical equipment in the power line communication system will generate a lot of noise in the power line channel; among them, random impulse noise has great randomness, and the noise intensity High, causing serious damage to the power line communication system, therefore, the suppression technology for random impulse noise has been the focus of research by domestic and foreign scholars; and the noise model does not conform to the Gaussian distribution

Therefore, the traditional communication system designed for Gaussian noise is no longer applicable to the power line carrier communication system, and the corresponding noise suppression technology must be studied to improve the signal-to-noise ratio of the power line communication system, reduce the bit error rate, and ensure the quality of the power line communication system

In practical applications, some simple nonlinear techniques are often used to eliminate power line channel noise, such as Clipping, Blanking and Clipping / Blanking techniques, but these research methods must work well under a certain signal-to-noise ratio. In order to eliminate the impact noise, in the power line communication system, some commercial power line transmitters are characterized by low transmission power. In some special cases, the transmission power may even be lower than 18w. Therefore, in some special cases, the signal will be Submerged in a large amount of noise, leading to low signal-to-noise ratio conditions in power line communication systems

[0004] With the application and popularization of nonlinear electrical appliances, the background noise in the medium and low voltage power transmission and distribution network presents more obvious non-stationary and non-Gaussian characteristics, and the commonly used low-pass filter is difficult to achieve ideal It is difficult to filter non-stationary non-Gaussian noise, which seriously affects the performance of PLC communication system

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