Pulse noise suppression method for power line communication system

Abstract

The invention discloses a pulse noise suppression method for a power line communication system. The method comprises the following steps: transmitting a discrete time domain signal added with a cyclic prefix by a transmission end; acquiring a mixed signal only including asynchronous pulse noise and colored background noise by a receiving end according to a discrete time domain signal from which the cyclic prefix is removed and which carries asynchronous pulse noise interference; then, estimating a spectrum amplitude of the mixed signal by an iteratively adaptive algorithm; finding high amplitude points in the spectrum amplitude of the mixed signal through calculation of a mean value and a standard difference of the spectrum amplitude of the mixed signal and by use of a Chauvenet decision criterion; and setting a plurality of maximum amplitude values in the discrete time domain signal from which the cyclic prefix is removed and which carries the asynchronous pulse noise interference as 0 by counting the total quantity of the high amplitude points in the spectrum amplitude of the mixed signal in order to finish suppression of the asynchronous pulse noise and obtain a valid signal. The pulse noise suppression method has the advantages of high pulse noise suppression performance and relatively high robustness, and can be implemented well in the power line communication system.

Description

technical field [0001] The invention relates to an impulse noise estimation technique, in particular to a method for suppressing impulse noise in a power line communication system. Background technique [0002] In recent years, with the development of the smart grid and the advancement of communication technology, the power line communication (PowerLine Communication, PLC) using the smart grid has begun to develop towards high-speed, bi-directional and networked. As a well-established infrastructure, power lines have the characteristics of no need for repeated wiring and wide geographical distribution. Therefore, using them for data transmission can greatly reduce communication costs. 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 communication media, and there are problems such as poor system stability and serious noise interference, which ...

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Problems solved by technology

However, this type of method needs to estimate the statistical model of impulse noise, and a smaller or larger threshold value will lead to a serious decline in the performance of impulse noise suppression; at the same time, due to the relatively large peak-to-average value of the OFDM signal, it will cause some transmitted signals to have relatively large A high amplitude value will generate a false alarm when using the threshold value for judgment, and the transmitted signal that is not interfered by the impulse noise will be misjudged as the impulse noise signal, which will lead to the absence of the transmitted signal; in addition, the typical blanking method requires Set a fixed threshold value or use the signal-to-noise ratio and signal-to-interference-noise ratio at the input end to optimize the threshold value, but each has its own limitations. Use a fixed threshold value and change the signal-to-noise ratio or signal-to-interference-noise ratio at the input end , it will lead to a serious decline in the performance of impulse noise suppression; and the use of optimized thresholds requires prior knowledge of the signal-to-noise ratio and signal-to-interference-noise ratio at the input, which is difficult to achieve in actual power line communication systems

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