Ultra low-power sub-band acoustic echo cancellation for wireless headsets

Integrating voice-processing algorithms into headsets is a challenging task due to size and power constraints. As a result of the small size of these headsets, acoustic leakage between the closely located speaker and microphone is a common problem. To address this problem, an oversampled sub-band adaptive acoustic echo cancellation system is proposed and implemented on an ultra-low resource DSP system. The echo cancellation algorithm is integrated with two voice activity detectors and double-talk detection logic to provide a fully functional system. By using decimation, load balancing and other optimization techniques, the complete system consumes about 6 mW. Other signal-processing algorithms can be added with very little impact on power consumption and no impact on size. Tests on a Bluetooth headset show an echo return loss enhancement of about 15 dB for a typical headset signal level.