Introduction

Abstract

Many everyday problems encountered in communications and signal processing involve removing noise and distortion due to physical processes that are time varying or unknown or possibly both. These types of processes represent some of the most difficult problems in transmitting and receiving information. The area of adaptive signal processing techniques provides one approach for removing distortion in communications, as well as extracting information about unknown physical processes. A short consideration of some of these problems shows that distortion is often present regardless of whether the communication is conversation between people or data between physical devices.