Signal Processing Apparatus High Frequency Harmonic Compensation
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing signal processing methods fail to adequately compensate high frequency harmonic components in sound signals, resulting in low sound quality during reproduction, particularly due to insufficient recording and compression techniques.
Innovation Solution
A signal processing apparatus that determines a reference frequency and bandwidth based on the sound signal, generates a coefficient stream with decreasing values for harmonics, and performs multiplication and folding processing to complement high frequency components, ensuring natural amplitude transitions and reduced distortion.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If conventional copying or folding methods are used to compensate high frequency components, then some high frequency harmonic components can be recovered, but the compensation is insufficient and high sound quality cannot be achieved
Solution Approach 1:
The patent applies local quality by using different processing methods for different frequency regions. Specifically, it performs folding processing on low frequency components to generate high frequency components, while separately processing middle frequency harmonic components through copying with amplitude adjustment. This region-specific processing ensures that each frequency band receives appropriate compensation tailored to its characteristics, thereby achieving high sound quality.
Solution Approach 2:
The patent combines multiple signal processing techniques to create a composite compensation method. It integrates folding processing (which mirrors low frequency components to high frequencies) with harmonic copying (which replicates middle frequency harmonics to higher frequencies with amplitude attenuation). This composite approach leverages the strengths of both methods to achieve comprehensive high frequency component compensation that neither method could achieve alone.
2Loss of information
If high frequency components are compensated by copying middle frequency harmonics, then some high frequency content is restored, but unnatural level differences and distortion occur
Solution Approach 1:
The patent applies parameter changes by dynamically adjusting the amplitude of copied harmonic components based on their frequency position. Specifically, it attenuates the amplitude of copied harmonics proportionally to their distance from the reference frequency, and applies smoothing processing to gradually transition amplitude values. This parameter adjustment prevents unnatural level differences and distortion that would otherwise occur with simple copying.
Solution Approach 2:
The patent introduces dynamics through smoothing processing that gradually transitions the amplitude values of copied harmonic components. Instead of abruptly copying harmonics with fixed amplitude, the system dynamically adjusts amplitude values to create smooth transitions between frequency regions. This dynamic processing eliminates discontinuities and unnatural level differences in the compensated signal.
Data Source
AI summary
A signal processing apparatus outputs a first coefficient stream that has values assigned to signal streams such that a maximum value of 1 or less is assigned to a signal stream closest to the first reference frequency among signal streams of harmonics appearing in frequency signal of sound, and for the other signal streams, the more distant from the first reference frequency the signal stream is, the smaller the value assigned to the signal stream becomes, generates a folding signal stream by multiplying the signal stream of the frequency signal having the bandwidth W on a lower frequency side than the first reference frequency by the first coefficient stream, and folding the signal stream of the frequency signal having a bandwidth W on the lower frequency side than the first reference frequency by using the first reference frequency as a symmetry axis, and outputs a complemented frequency signal.