Diversity exploiting MIMO-OFDMA ranging

This paper addresses initial ranging (uplink synchronization and power control) for TDD MIMO OFDMA systems. Exploiting the channel knowledge from the downlink control channel together with initial power control, we develop a novel initial ranging method which provides multiuser and multi-antenna diversity gains and significant power saving for the subscriber stations. By means of ranging signal design, we develop efficient low-complexity algorithms for OFDMA ranging. The advantages of the proposed approach over existing methods in terms of ranging performance, energy saving, and complexity saving are illustrated by analytical and simulation results.