Impulse noise detection method in OFDM communication system

Abstract

The invention provides an impulse noise detection method in an OFDM communication system, comprising the following steps: setting a judgment threshold based on the average energy of the null subcarriers of at least one OFDM symbol in an OFDM communication system; estimating the average energy of the null subcarriers of subsequent OFDM symbols, comparing the average energy with the judgment threshold, and judging whether there is impulse noise; and updating the judgment threshold according to the comparison result, and giving an instruction on whether there is impulse noise detected. Impulse noise is detected based on the fact that data is not modulated on the null subcarriers in an OFDM communication system, energy mainly comes from leaked energy of Gaussian noise and adjacent subcarriers, and the energy of impulse noise is usually significantly higher than that of Gaussian noise.

Description

technical field [0001] The invention relates to an Orthogonal Frequency Division Multiplexing (OFDM) communication system, in particular to a pulse noise detection method in the OFDM communication system. Background technique [0002] Orthogonal Frequency Division Multiplexing (OFDM) technology is a multi-carrier modulation technology. Its modulation and demodulation are realized based on Inverse Fast Fourier Transform (IFFT) and Fast Fourier Transform (FFT) respectively, and it is the lowest complexity , The most widely used multi-carrier transmission scheme. OFDM data divides the channel into several orthogonal sub-channels, converts high-speed data signals into parallel low-speed sub-data streams, and modulates them on each sub-channel for transmission. At the receiving end, the orthogonal signals can be separated by correlation technology, which can reduce the mutual interference between sub-channels. [0003] For practical communication systems, in addition to additiv...

AI Technical Summary

Problems solved by technology

However, because the OFDM signal itself is Gaussian in the time domain, the peak-to-average ratio itself is relatively large, so the accuracy of the time-domain detection method is difficult to guarantee

For the frequency domain detection method, the FFT operation at the receiving end of the OFDM system expands the energy of the impulse noise to the entire frequency spectrum. Compared with the signal energy in the frequency domain, the energy of the diffused impulse noise becomes smaller. Only when the energy of the impulse noise is large can it More accurate detection, for impulse noise with lower energy, the effect is not ideal

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