Signal Processing Device Delay Compensation Noise Cancellation
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Solution Overview
Problem
Existing noise cancellation devices face challenges in effectively canceling noise when the reference signal cannot be captured in the vicinity of the noise source due to delays caused by additional noise paths, leading to insufficient noise cancellation.
Innovation Solution
A signal processing device and method that include a first input for obtaining a mixed signal, a second input for a differently mixed signal, a delay mechanism to generate a delayed mixed signal based on transmission distance, and an adaptive filtering mechanism to generate and update pseudo signals, ensuring effective noise cancellation even when the reference signal is not captured near the noise source.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the reference signal is captured in the vicinity of the noise source, then noise cancellation performance is improved, but the device complexity and difficulty of installation increase
Solution Approach 1:
The patent introduces a delay means as an intermediary component between the first mixed signal input and the subtracting means. This delay means compensates for the transmission time difference of the noise signal from the noise source to the second input means, allowing effective noise cancellation even when the reference signal cannot be captured in the vicinity of the noise source, thereby reducing installation complexity while maintaining cancellation performance
Solution Approach 2:
The patent applies preliminary action by pre-delaying the first mixed signal based on the estimated transmission distance of the noise source before it reaches the second input means. This preliminary delay alignment ensures that the noise components in both mixed signals are synchronized in time, enabling the adaptive filter to effectively generate pseudo-noise for cancellation without requiring proximity to the noise source
2Device complexity
If the reference signal is captured away from the noise source, then device complexity is reduced, but noise cancellation effectiveness deteriorates due to delay
Solution Approach 1:
The delay means serves as a time-aligning intermediary that compensates for the additional transmission path delay. By calculating the transmission distance from the noise source to the second input means and applying the corresponding delay to the first mixed signal, the system restores the temporal relationship between noise components in both signals, maintaining cancellation effectiveness despite distant reference signal capture
Solution Approach 2:
The patent dynamically adjusts the delay parameter of the first mixed signal based on the estimated transmission distance of the noise source. This parameter change (delay amount) compensates for the additional noise path, ensuring that the temporal characteristics of noise in both mixed signals are matched, thereby maintaining noise cancellation effectiveness without requiring the reference signal to be captured near the noise source
Data Source
AI summary
To achieve sufficient noise cancellation when a reference signal cannot be captured in the proximity of a noise source.The present invention is characterized by comprising: a first input means for obtaining a first mixed signal in which a first signal and a second signal are mixed; a second input means for obtaining a second mixed signal in which the first signal and the second signal are mixed in a different ratio from the first mixed signal; a delay means for generating a delayed first mixed signal by delaying the first mixed signal with a delay amount based on transmission distance from a generation source of the second signal to the second input means; a subtracting means for outputting an estimated first signal in which a pseudo second signal is subtracted from the delayed first mixed signal; and an adaptive filtering means for generating the pseudo second signal applying coefficients which are updated based on the estimated first signal to the second mixed signal.