Noise Suppression Method Applied to Broadband OFDM Power Line Communication System

Abstract

The invention provides a noise suppression method applied to a broadband OFDM power line communication system. According to the noise suppression method, discrete Fourier transform is carried out on an OFDM signal at a receiving terminal; a protection frequency band signal is extracted from an output result and that is, a useless part distributed between two adjacent channels in the frequency spectrum is extracted; a correlated parameter of a pulse noise is estimated by combining time-domain and frequency-domain methods; and according to the estimated parameter of the pulse noise, a proper envelope window function is constructed to suppress the pulse noise in the time domain. Therefore, the pulse noise can be suppressed effectively; the frequency spectrum leakage can be reduced substantially; and performances of the broadband power line communication system can be improved.

Description

technical field [0001] The invention relates to the field of communication technology, in particular to a noise suppression method applied to a broadband OFDM power line communication system. Background technique [0002] Broadband power line communication technology uses the power line network to quickly spread information to every corner. In the broadband power line communication environment, there are a large number of unknown electrical devices with different power levels. The switching and working of these devices, as well as the radio waves generated by various radio devices, will bring various strong time-varying noise interference to the broadband power line communication channel. According to the different noise sources, it can be divided into: background noise and impulse noise. The amplitude of the latter is much higher than that of the background noise. According to the difference of the noise model, the impulse noise can be divided into: Bernoulli Gauss impulse...

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Problems solved by technology

However, for Bernoulli-Gaussian impulse noise, the effect of zero-suppression is remarkable, while for burst-type impulse noise, the commonly used zero-suppression technique is equivalent to processing within a simple rectangular window function envelope. Non-linear characteristics will bring a certain amount of spectrum leakage, leading to the problem of interference between subcarriers, and the performance of the system will be seriously degraded

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