ClearOne announced today that it has been awarded a new patent on combining beamforming microphone arrays and echo cancellation.
On February 16, 2016, the U.S. Patent and Trademark Office (“USPTO”) issued United States Patent number 9,264,553 entitled “Methods and Apparatuses for Echo Cancellation with Beamforming Microphone Arrays.” The ‘553 patent covers the method of first generating a number of fixed beams through beamforming, followed by performing acoustic echo cancellation on each beam. The ‘553 patent also covers conferencing apparatuses that are configured to practice this method.
Previously, combining beamforming microphone arrays and acoustic echo cancellation involved performing acoustic echo cancellation first, followed by beamforming. ClearOne says this created a problem because the echo cancellation operation had to be performed separately on each individual microphone signal. When beam steering was performed first, the echo canceller constantly attempted to adapt to acoustic differences with every change in the beams, resulting in poor echo cancellation performance. Moreover, in order to achieve high directionality from a microphone array, a large number of microphones was required, requiring a large number of echo cancellers. Such a system would be more complex, cost more, have worse performance, or exhibit some combination of these drawbacks.
To solve these problems, engineers at ClearOne invented a method to generate a number of fixed beams, in which the number of beams is less than the number of microphones, for input into an echo canceller. The echo cancellation is then performed on the combined signals corresponding to a fixed beam rather than on each microphone signal. This enables superior directionality with excellent echo cancellation at a lower cost.