A sinusoidal signal filtering system based on Fast Fourier Transform

Abstract

The invention relates to a sinusoidal signal filtering system based on fast Fourier transform, comprising a display interface, an RT system, a signal conditioning unit, a high-speed digital-to-analogconversion chip, an FPGA module, a high-speed analog-to-digital conversion chip and a signal output unit. Including fast Fourier transform algorithm, frequency compensation algorithm, phase locking and energy leakage suppression strategy. The filter system takes the FPGA chip as the core to ensure the real-time performance of the system. The filter system is based on a fast Fourier transform algorithm to capture the target AC signal, the characteristic frequency, the phase and the amplitude. After calculating two fast Fourier transform cycles, the AC signal of the next cycle is predicted and output in real time. Advantages: the filter algorithm of the fast Fourier transform proposed by the invention can extract the frequency, phase and amplitude of the sinusoidal signal from the sinusoidalsignal with very low signal-to-noise ratio, and the frequency, phase and amplitude of the sinusoidal signal can be reproduced and output in real time to realize the filtering function. It can be usedto extract sinusoidal signal in strong interference background.

Description

technical field [0001] The invention relates to a sinusoidal signal filtering system based on fast Fourier transform, which belongs to the technical field of signal processing. Background technique [0002] In practical applications, after being transmitted through various channels, the signal waveform will inevitably contain distortion. Therefore, in the research work of signal processing, filtering is a very important link. The detection of flames is very important in aero-engines. In order to realize the acquisition of high-frequency flame combustion state, it is very important to use optical sensors. However, the signal strength of optical sensors is extremely low, which is easily interfered, and the signal-to-noise ratio is extremely low. . [0003] Traditional filtering methods include spatial filtering and frequency domain filtering. Spatial filtering methods include neighborhood mean filtering method and median filtering method, etc. The disadvantage of these meth...

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Problems solved by technology

[0006] The present invention proposes a sinusoidal signal filtering system based on fast Fourier transform. Its purpose is to solve the shortcomings of the existing filtering technology, such as insufficient precision, phase delay, and inability to track the response in real time. It is a sinusoidal signal filtering system that can extract the frequency, phase and amplitude of the sinusoidal signal from the sinusoidal signal with a very low signal-to-noise ratio, and reproduce the output in real time.

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