Dynamic Parametric Equalizer Gain Adjustment via Lookup Table

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Solution Overview

Problem

Conventional parametric equalizers face challenges in dynamically adjusting their gain to prevent signal clipping, requiring complex real-time calculation of filter coefficients, which increases hardware complexity and manufacturing costs.

Innovation Solution

A method and system that dynamically adjust the gain of a parametric equalizer by using a first signal processing unit with a preset transfer function H1 and a second signal processing unit with a transfer function H2, where the gain is adjusted based on the level of the input signal without real-time coefficient calculation, using equations H1=[H(z)−1]/(G−1), H2=G−1 for 0<Gin<1/G, H2=1/Gin−1 for 1/G≤Gin≤1, and H2=0 for 1<Gin.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If real-time calculation of filter coefficients is performed to dynamically adjust gain, then signal clipping is prevented, but hardware complexity and manufacturing costs increase

Engineering Contradiction:
Improvesignal qualityVSAvoidhardware complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent pre-calculates and stores filter coefficients for multiple gain values in a lookup table before operation. During real-time processing, the system simply retrieves the appropriate pre-calculated coefficients based on the current signal level, avoiding complex real-time calculations while maintaining dynamic gain adjustment capability and preventing signal clipping.

Inventive Principle:
Principle #10Preliminary action

2Reliability

If real-time calculation of filter coefficients is performed to dynamically adjust gain, then signal clipping is prevented, but manufacturing costs rise

Engineering Contradiction:
Improvesignal qualityVSAvoidmanufacturing cost
Core Design Contradiction:
ReliabilityVSEase of manufacture

Solution Approach 1:

The patent pre-calculates and stores filter coefficients for multiple gain values in a lookup table before operation. During real-time processing, the system simply retrieves the appropriate pre-calculated coefficients based on the current signal level, avoiding complex real-time calculations while maintaining dynamic gain adjustment capability and preventing signal clipping.

Inventive Principle:
Principle #10Preliminary action

3Device complexity

If preset gain is used without dynamic adjustment, then hardware complexity is reduced, but signal clipping occurs when input level is high

Engineering Contradiction:
Improvehardware complexityVSAvoidsignal quality
Core Design Contradiction:
Device complexityVSReliability

Solution Approach 1:

The patent implements dynamic gain adjustment by detecting the input signal level and selectively applying different pre-calculated filter coefficients from a lookup table. The system transitions from a static preset gain approach to a dynamic approach where the filter characteristics automatically adapt to the input signal level, preventing clipping while maintaining signal quality without requiring complex real-time coefficient calculation hardware.

Inventive Principle:
Principle #15Dynamics

Data Source

PatentUS9288579B2Method for dynamically adjusting gain of parametric equalizer according to input signal, dynamic parametric equalizer and dynamic parametric equalizer system employing the same
Publication Date: 2016.03.15 WELLANG CO LTD
  • US9288579B2 patent drawing
  • US9288579B2 patent drawing
  • US9288579B2 patent drawing

AI summary

The present invention relates to a method for dynamically adjusting a gain of parametric equalizer according to an input signal, a dynamic parametric equalizer employing the same and a dynamic parametric equalizer system employing the same wherein a gain of parametric equalizer is dynamically adjusted according to a level of an input digital audio signal to prevent distortion of output signal.