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Cellular networks are typically interference limited, with co-channel interference arising from cellular frequency reuse, ultimately limiting the quality and capacity of wireless networks [280,281]. However, Adaptive Antenna Arrays (AAAs) capable of exploiting the are spatial dimension in order to mitigate this co-channel interference and thus to increase the achievable network capacity [3,6,38,242,250,282]. | Third-Generation Systems and Intelligent Wireless Networking J.S. Blogh L. Hanzo Copyright 2002 John Wiley Sons Ltd ISBNs 0-470-84519-8 Hardback 0-470-84781-6 Electronic Chapter Adaptive Arrays in an FDMA TDMA Cellular Network 4.1 Introduction Cellular networks are typically interference limited with co-channel interference arising from cellular frequency reuse ultimately limiting the quality and capacity of wireless networks 280 281 However Adaptive Antenna Arrays AAAs are capable of exploiting the spatial dimension in order to mitigate this co-channel interference and thus to increase the achievable network capacity 3 6 38 242 250 282 Since an AAA may receive signals with a high gain from one direction whilst nulling signals arriving from other directions it is inherently suited to a CCI-limited cellular network. Thus a beam may be formed to communicate with the desired mobile whilst nulling interfering mobiles 6 Assuming that each mobile station is uniquely identifiable it is a relatively simple task to calculate the antenna array s receiver weights so as to maximise the received SINR. The use of adaptive antenna arrays in a cellular network is an area of intensive research and adaptive antenna array s have been studied widely in the context of both interference rejection and in single-cell situations 1 15 18 261 267 268 More recently work has been expanded to cover the analysis and performance benefits of using base stations equipped with adaptive antenna arrays across the whole of a cellular network 2 265 283 A further approach to improving the network performance is the employment of Dynamic Channel Allocation DCA techniques 284-292 which offer substantially improved callblocking packet dropping and grade-of-service performance in comparison to Fixed Channel Allocation FCA . A range of so-called distributed DCA algorithms were investigated by Cheng and Chuang 290 where a given physical channel could be invoked anywhere in the network provided that the .
