Digital Signal Noise Removal via Frequency Domain Filtering
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Solution Overview
Problem
Active noise removal systems introduce quantization noise and result in loss of signal fidelity due to the use of analog-to-digital converters and existing noise cancellation techniques, which are inefficient and unreliable.
Innovation Solution
A noise removal system that transforms digital signals into frequency-domain signals, applies a threshold filter to remove noise bins, and uses a signal synthesizer to increase gain and reconstruct an output signal with improved dynamic range and precision, effectively eliminating background and quantization noise.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If an analog-to-digital converter (ADC) is used in active noise removal systems, then noise can be processed digitally, but quantization noise is introduced and signal fidelity is lost
Solution Approach 1:
The patent extracts and removes noise components from the frequency spectrum of the digital signal. By transforming the signal to frequency domain and identifying noise bins, the system selectively removes harmful frequency components while preserving the useful signal, thereby eliminating quantization noise without sacrificing signal fidelity.
Solution Approach 2:
The system changes the representation parameters of the signal by transforming from time domain to frequency domain. This parameter transformation enables selective manipulation of different frequency components, allowing noise removal while maintaining the integrity of the original signal through intelligent frequency bin selection and reconstruction.
2Object-affected harmful factors
If traditional noise cancellation techniques are used, then background noise can be reduced, but signal reliability decreases and dynamic range is limited
Solution Approach 1:
The patent moves the noise removal process from the time domain to the frequency domain, adding a dimensional perspective to signal processing. This frequency-domain approach enables selective noise bin removal while preserving signal bins, thereby maintaining signal reliability and expanding dynamic range beyond what traditional time-domain cancellation techniques can achieve.
Solution Approach 2:
The system applies different processing qualities to different parts of the frequency spectrum. Useful signal bins are preserved with high fidelity while noise bins are removed. This localized quality differentiation ensures that noise reduction does not compromise signal reliability, as each frequency bin receives treatment appropriate to its nature.
3Object-affected harmful factors
If anti-noise signal with opposite phase is used to cancel noise, then noise cancellation is achieved, but fidelity and overall signal energy are lost
Solution Approach 1:
Instead of using anti-phase cancellation that destroys both noise and signal energy, the patent converts the harmful noise components into removable frequency bins. By identifying and eliminating only the noise bins in the frequency domain, the system achieves noise cancellation while preserving the energy and fidelity of the useful signal bins, turning a destructive process into a selective purification process.
Data Source
AI summary
A system for noise removal is coupled to a signal unit that provides a digital signal. The noise removal system includes a transformation module to transform the digital signal into an f-digital signal, a threshold filter to generate a noiseless signal from the f-digital signal based on a threshold profile, and a signal synthesizer to provide a gain to the noiseless signal and to transform the noiseless signal into an output signal.