Adaptive Interference Suppression for Wireless Multiple-Access Communication Systems

Future wireless communication systems will involve significant adaptive signal processing capabilities to enhance the performance of high-rate transmission through limited-bandwidth, dynamic multiple-access channels. Structured interference is a dominant, performance-limiting characteristic of such channels, and this paper provides a brief overview of basic adaptive signal processing algorithms that are useful for combating this problem. We will focus primarily on adaptive linear methods for the suppression of multiple-access interference, although we will also discuss briefly the mitigation of such impairments as dispersion impulsive noise, and the exploitation of receiver diversity arising either from natural multipath or from the use of multiple antennas. Algorithms based on traditional techniques such as recursive-least-squares and on more recently developed methods involving subspace tracking will both be described.