A method and apparatus for reducing quantization noise

Abstract

This application discloses a method and device for reducing quantization noise. After dividing the original digital signal into frames, find the sampling point of the digital signal with the largest amplitude in two consecutive frames of signals, namely, the current frame and the next frame, and calculate the The largest target digital gain that does not cause the maximum amplitude to overflow. The target sampling point with the smallest energy and adjacent energy in the current frame is used as the gain switching point. According to the gain switching position and the number of gain switching steps, the original digital gain at the gain switching point The gain is gradually switched to the target digital gain and the analog gain is adjusted accordingly. Since the present application selects a plurality of target sampling points with the smallest energy as the gain switching point, compared with the prior art, the present application optimizes the selection of the gain switching point more effectively, so that the gain switching point near the The energy is minimized, the switching noise is reduced to the minimum, and then the quantization noise is reduced, and the auditory quality of the signal is improved.

Description

technical field [0001] The present invention relates to the technical field of quantization noise, and more specifically, to a method and device for reducing quantization noise. Background technique [0002] DAC (Digital to analog converter, digital to analog converter) is a device that converts digital signals into analog signals (in the form of current, voltage, or charge). In the process of digital signal conversion by DAC, certain quantization noise will be introduced, so that the final reconstructed analog signal has a certain signal-to-noise ratio, see figure 1 , a flow diagram of a DAC introducing quantization noise disclosed in the prior art. The original digital signal is transformed into an analog signal after being passed through the DAC. At this time, the quantization noise i is added in, and after passing through the PA (Power Amplifier, power amplifier), the reconstructed analog At this time, the reconstructed analog signal already contains certain quantizatio...

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Problems solved by technology

[0004] However, since it is impossible to adjust the digital gain D and the analog gain A synchronously in practice, the asynchronous switching of the digital gain D and the analog gain A will cause the signal to be discontinuous at the gain switching point, that is, there is a switching error. If the gain switching If the energy near the point is large, there will be very disturbing switching noise, which will affect the auditory quality of the signal

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