Apparatus and method for intercepting input signal

Abstract

The invention discloses a method for cutting input signals, wherein the method comprises a modifying window function according to even bilateral index number signals, obtaining a modified window function, and multiplying the modified window function with the input signals to obtain output signals. The invention also discloses a device for cutting input signals, frequency spectrum leakage is betterinhibited through utilizing the invention when signals are cut, and minimum stopband rejection of a filter which utilizes design of the modified window function is reduced.

Description

technical field [0001] The invention relates to digital signal processing technology, in particular to a method and device for intercepting an input signal. Background technique [0002] Window functions are widely used in digital signal processing. For example, in actual digital signal processing, it is necessary to limit the observation time of the signal to a certain time interval, that is to say, only need to select the signal within a certain period of time for processing. analyze. In the process of using limited data, that is, intercepting a part of the signal data, the phenomenon that the spectrum components spread from the normal spectrum often occurs, which is the so-called "spectrum leakage". This is because, when truncating data, a discrete Fourier transform (DFT, Discrete Fourier Transform) needs to be performed. When performing DFT, truncation in the time domain is necessary, so the leakage effect is also inherent in DFT. In practical applications, this kind o...

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Problems solved by technology

However, the peak attenuation of the side lobe of the Hamming window function is -41dB, which is not as good as -57dB of the Blackman window; the attenuation speed of the side lobe is -6dB / oct, which is not as good as -18dB / oct of the Hanning window and Blackman window

Therefore, when using the Hamming window function to intercept the ideal unit impulse response, the "spectrum leakage" cannot be better suppressed, resulting in poor minimum attenuation performance of the stop band of the filter designed using the Hamming window

Finally, the peak signal-to-noise ratio (PSNR, Peak Signal to Noise Ratio) of the audio signal obtained by the AMR-WB+ audio encoder designed with this filter is small

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