Introduction to Smart Antennas - Chapter 1

IntroductiontoSmartAntennas Copyright © 2007 by Morgan & Claypool All rights reserved. No part of this publication may be reproduced, stored in a retrieval system, or transmitted in any form or by any means—electronic, mechanical, photocopy, recording, or any other except for brief quotations in printed reviews, without the prior permission of the publisher. Introduction to Smart Antennas Constantine A. Balanis, Panayiotis I. Ioannides www.morganclaypool.com ISBN: 1598291769 ISBN: 9781598291766 ISBN: 1598291777 ISBN: 9781598291773 paperback paperback ebook ebook DOI: 10.2200/S00079ED1V01Y200612ANT005 A Publication in the Morgan & Claypool Publishers’ series SYNTHESIS LECTURES ON ANTENNAS #5 Lecture #5 Series Editor: Constantine A. Balanis, Arizona State University First Edition 10 9 8 7 6 5 4 3 2 1 IntroductiontoSmartAntennas ConstantineA.Balanis PanayiotisI.Ioannides Department of Electrical Engineering Arizona State University SYNTHESIS LECTURES ON ANTENNAS #5 &C M o r g a n &C l a y p o o l P u b l i s h e r s iv ABSTRACT Asthegrowingdemandformobilecommunicationsisconstantlyincreasing,theneedforbetter coverage, improved capacity and higher transmission quality rises. Thus, a more efficient use of the radio spectrum is required. Smart antenna systems are capable of efficiently utilizing the radio spectrum and, thus, is a promise for an effective solution to the present wireless systems’ problems while achieving reliable and robust high-speed high-data-rate transmission. The purposeofthisbookistoprovidethereaderabroadviewofthesystemaspectsofsmartantennas. In fact, smart antenna systems comprise several critical areas such as individual antenna array design, signal processing algorithms, space-time processing, wireless channel modeling and coding, and network performance. In this book we include an overview of smart antenna concepts, introduce some of the areas that impact smart antennas, and examine the influence of interaction and integration of these areas to Mobile Ad-Hoc Networks. In addition, the general principles and major benefits of using space–time processing are introduced, especially employing multiple-input multiple-output (MIMO) techniques. KEYWORDS Adaptive arrays, Switched-beam antennas, Phased array, SDMA, Mutual coupling, Direction of arrival, Adaptive beamforming, Channel coding, MANET, Network throughput, Space– time processing. v Contents 1. Introduction..................................................................1 2. MobileCommunicationsOverview.............................................5 2.1 General Description......................................................5 2.2 Cellular Communications Overview........................................6 2.3 The Evolution of Mobile Telephone Systems ............................... 6 2.4 The Framework..........................................................8 2.5 Cellular Radio Systems: Concepts and Evolution...........................10 2.5.1 Omnidirectional Systems and Channel Reuse.......................10 2.5.2 Cell Splitting....................................................12 2.5.3 Sectorized Systems...............................................12 2.6 Power Control..........................................................14 2.6.1 Spectral Efficiency...............................................15 2.7 Multiple Access Schemes ................................................ 16 2.7.1 FDMA.........................................................16 2.7.2 TDMA.........................................................17 2.7.3 CDMA.........................................................17 2.7.4 OFDM.........................................................19 3. AntennaArraysandDiversityTechniques ..................................... 21 3.1 Antenna Arrays.........................................................21 3.2 Antenna Classification...................................................22 3.2.1 Isotropic Radiators...............................................22 3.2.2 Omnidirectional Antennas........................................22 3.2.3 Directional Antennas ............................................ 23 3.2.4 Phased Array Antennas .......................................... 23 3.2.5 Adaptive Arrays ................................................. 23 3.3 Diversity Techniques .................................................... 26 4. SmartAntennas..............................................................33 4.1 Introduction............................................................33 4.2 Need for Smart Antennas................................................33 4.3 Overview...............................................................34 ... - tailieumienphi.vn