Echo detection, tracking, cancellation and noise fill in real time in a communication system
April 2, 2017. Estimated Expiration Date is calculated based on simple USPTO term provisions. It does not account for terminal disclaimers, term adjustments, failure to pay maintenance fees, or other factors which might affect the term of a patent.Patent ReferencesResidual echo elimination with proportionate noise injection Speech signal processing apparatus for extracting a speech signal from a noisy speech signal Network echo canceller Real-time digital audio reverberation system Devices and systems with parallel logic unit, and methods Devices and systems with parallel logic unit operable on data memory locations, and methods Method and apparatus for reducing residual far-end echo in voice communication networks Digital radio with vocoding encrypting codec Devices, systems and methods for conditional instructions Spectral noise compensation for telecommunication signal processing InventorsApplicationNo. 831874 filed on 04/02/1997US Classes:379/406.13, Fourier analysis370/289Having residual echo cancellation or suppressionExaminersPrimary: Vo, NguyenAssistant: Appiah, Charles N. Attorney, Agent or FirmInternational ClassesH04M 001/76H04B 003/20 AbstractA method for processing telecommunications signals to alleviate echo during a voice communication between a local talker and a remote talker comprises the application of circular buffers for near and far end signals to preserve processing time. Overlapping blocks of samples are processed and indexed by incrementing the index over time to generate an array for storing magnitude coherence versus time delay between outgoing and incoming samples. Echo is clipped based on power spectral matching. The clipped echo is replaced with noise fill of at least one of two types, white noise and tonal noise, at an appropriate level. Also, crackle which comprises high energy spikes and a residual echo effect which is low energy, bursty and non-linear may be identified and replaced with noise fill.Other References
Field of SearchHaving residual echo cancellation or suppressionInserted in gaps in main information Information superimposed on other information Echo suppression or cancellation LOW SPEED ASYNCHRONOUS DATA SYSTEM (E.G., TELETYPEWRITER SERVICE) Using a transversal filter Digital summation Including cancellation of certain signals Including cancellation of certain signals Voiced or unvoiced | |
