Designing a high-performance echo-canceller for Voice-over-IP applications
Voice over IP (VolP) has become a primary focus of attention because it lies at the heart of the trend toward the convergence of data and voice communications. This new technology offers great promise in the more efficient use of scarce bandwidth for voice communications. However, there are still several technical problems that must be overcome before VolP will be widely accepted as an alternative to traditional connection-based voice communications. In this article Chang focuses on one of the most important problems -- that of echo cancellation. In doing so, he explains how echoes arise in voice communications, why they are a particular problem in VolP communication, and how programmable logic technology can be used to provide echo cancellation at a reasonable cost.