A Hardware Optimised CMOS Adaptive Noise CancellerImplementation

Up until now, the main foci of development in mobile communication equipment have been to decrease its size and to extend its battery operation times. However, further reductions in the size of devices are physically limited by the user interface requirements and therefore, alternative aspects of these devices must be targeted for enhancement by designers. A feature of mobile communications equipment is the variety of environments within which they are used, so algorithms that can improve the quality of a transmission are highly desirable. In this paper, mobile telephony devices are being specifically considered and a CMOS implementation of the filter block of an adaptive noise canceller will be presented. Results will then be given to demonstrate how this circuit can significantly increase speech quality by suppressing interfering noise without requiring any prior assumptions on its properties.