INVESTIGATION OF CO-CHANNEL INTERFERENCE, CHANNEL DISPERSION, AND MULTI-USER DIVERSITY IN MIMO-BASED CELLULAR SYSTEMS

Abstract

OF THE DISSERTATION Investigation of Co-Channel Interference, Channel Dispersion, and Multi-User Diversity in MIMO-Based Cellular Systems by Rahul N. Pupala Dissertation Directors: Prof. David G. Daut and Prof. Larry J. Greenstein In recent years, Multiple-Input/Multiple-Output (MIMO) systems employing multiple antennas at both ends of the wireless link have been shown to deliver high spectral efficiencies with reasonable constellation sizes. A MIMO link is a special case of a Multi-Element Antenna (MEA) link, wherein one or both ends use a multi-element array. Recently proposed 4G cellular systems are being evaluated that combine MIMO with Orthogonal Frequency Division Multiplexing (MIMO-OFDM) for use at the radio layer, while WiMAX 802.16e is considering MIMO with Orthogonal Frequency Division Multiple Access (MIMO-OFDMA) for use on the downlink. Multi-User Diversity (MuD) has also been shown to have important consequences in the ever-increasing demand for higher spectral efficiency. A detailed study of MIMO, MIMOOFDM, and MuD is of utmost importance to understand how to maximize the performance gains that can be realized from these promising technologies. This thesis is broadly divisible into three parts. Part I investigates aspects of co-channel interference (CCI) as they relate to MIMO channels. First, the throughputs attainable by interference-limited cellular systems that employ MEA links are computed. The emphasis in this study is on the system-level perspective. That is, determining the distribution of performance over a coverage area, e.g., the cumulative distributive function (CDF) of throughput (TP) over the randomness of user location and shadow fading, as well as and taking into account the CCI produced by co-channel links in other cells. Using a general-purpose simulation platform developed in this work, throughput statistics are obtained over several channel conditions and