On the Impact of MIMO Implementations on Cellular Networks: An Analytical Approach from a Systems Perspective

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Date
2007-03-19
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Publisher
Virginia Tech
Abstract

Multiple-input/multiple-output (MIMO) systems with the adaptive array processing technique, also referred to as smart antennas, have received extensive attention in wireless communications due to their ability to combat multipath fading and co-channel interference, two major channel impairments that degrade system performance. However, when smart antennas are deployed in wireless networks, careful attention is required since any defective or imperfect operation of smart antennas can severely degrade the performance of the entire network. Therefore, the evaluation of network performance under ideal and imperfect conditions is critical in the process of system design and should precede deploying smart antennas on the wireless network.

This work focuses on the development of an analytical framework to evaluate the performance of wireless networks based on popular DS/CDMA cellular systems equipped with antenna arrays. Spatial diversity at both the base station (BS) and the mobile station (MS) is investigated through both analytical analysis and simulation. The main contribution of this research is to provide a comprehensive analytical framework for examining the system level performance with multiple antennas at both the BS and the MS. Using the framework developed in this research, system capacity and coverage of the uplink (or reverse link) are investigated when antenna arrays are implemented at both the BS and the MS. In addition, the system capacity and soft handoff capability of the downlink (or forward link) are examined taking into account MIMO. Furthermore, various physical and upper layer parameters that can affect the system level performance are taken into account in the analytical framework and their combined impact is evaluated. Finally, to validate the analytical analysis results, a system level simulator is developed and selective results are provided.

Description
Keywords
MIMO, System Coverage, DS/CDMA Cellular Network, Spatial Diversity, System Capacity
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