Echo Power Estimation With FIR Filtering for Robust Suppression
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing echo cancellation methods face challenges in accurately estimating echo power, leading to residual echo interference in audio signals during communication, especially in VoIP calls, due to clock-drift and nonlinearities in the echo path.
Innovation Solution
A method using a Finite Impulse Response (FIR) filter dynamically adapted in the time domain to estimate the echo power, which is then used for echo suppression, rather than estimating the actual echo signal, providing a more robust solution to echo interference.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-affected harmful factors
If echo cancellation methods are used to remove echo from audio signals, then echo suppression is achieved, but residual echo interference remains due to inaccurate echo power estimation
Solution Approach 1:
Instead of estimating the echo signal directly (which is difficult due to clock-drift and nonlinearities), the patent inverts the approach by estimating the echo power through the power response of an FIR filter. This indirect estimation method avoids the pitfalls of direct echo signal estimation and provides more accurate power measurements for effective echo suppression.
Solution Approach 2:
The patent introduces an FIR filter as an intermediary element between the echo path and the power estimation process. The FIR filter's power response serves as a mediator that translates the complex echo path characteristics into accurate echo power estimates, enabling effective echo suppression without directly measuring the echo signal itself.
2Reliability
If adaptive filtering is used to model echo path, then echo cancellation is improved, but clock-drift and nonlinearities reduce estimation accuracy
Solution Approach 1:
The patent extracts only the essential power response characteristics from the FIR filter rather than attempting to model the entire complex echo path. By taking out just the power response information, the system achieves reliable echo power estimation without being affected by clock-drift and nonlinearities that plague complete echo path modeling attempts.
Data Source
AI summary
Method, user device and computer program product for suppressing echo. An audio signal is output from a speaker. A microphone receives an audio signal, wherein the received audio signal includes an echo resulting from said outputted audio signal. A Finite Impulse Response filter estimate ĥ(t) is dynamically adapted in the time domain based on the outputted audio signal and the received audio signal to model an echo path h(t) of the echo in the received audio signal. At least one power response is determined from the filter estimate ĥ(t) and used to estimate the echo power of the echo in the received audio signal. The estimated echo power is used to apply echo suppression to the received audio signal, thereby suppressing the echo in the received audio signal.