Estimation of Doppler spread and signal strength in mobile communications with applications to handoff and adaptive transmission

Abstract

Estimation of signal strength, a measure of channel quality, and Doppler spread which is proportional to the mobile speed, are important for handoff algorithms and optimal tuning of system parameters to changing channel conditions in adaptive transmission systems. This paper provides a survey of existing techniques for estimating the statistical parameters of the mobile channel. We discuss the current state of the art in estimation of the received signal strength, mobile velocity, and other related statistical channel parameters, illustrate their performance, and compare existing techniques. The sensitivity of these schemes to modeling error owing to the presence of line of sight, directional reception, and noise is characterized analytically and illustrated by simulations. Copyright © 2001 John Wiley & Sons, Ltd.