Smart Antennas for Code Division Multiple Access Systems

Smart Antennas for Code Division Multiple Access Systems

Salman Durrani (The Australian National University, Australia) and Marek E. Bialkowski (The University of Queensland, Australia)
DOI: 10.4018/978-1-59904-988-5.ch017
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Abstract

This chapter discusses the use of smart antennas in Code Division Multiple Access (CDMA) systems. First, we give a brief overview of smart antenna classification and techniques and describe the issues that are important to consider when applying these techniques in CDMA systems. These include system architecture, array antennas, channel models, transmitter and receiver strategies, beamforming algorithms, and hybrid (beamforming and diversity) approach. Next, we discuss modeling of smart antennas systems. We present an analytical model providing rapid and accurate assessment of the performance of CDMA systems employing a smart antenna. Next, we discuss a simulation strategy for an adaptive beamforming system. A comparison between the analytical results and the simulation results is performed followed by a suitable discussion.
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Introduction

Over the last two decades smart antenna technologies, referred to as Multiple Input Single Output (MISO) or Single Input Multiple Output (SIMO), have received much attention (Alexiou, 2004). Conventional cellular systems make use of omnidirectional or sectorized antenna systems. “The major drawback of such antenna systems is that electromagnetic energy is radiated unnecessarily in too many directions within the entire cell thus causing interference to other users in the system. One way to limit this interference and direct the energy to the desired user is to use smart antennas” (Osseiran, 2006). Smart antenna systems consist of an array of antenna elements whose signals are intelligently combined to exploit the spatial domain and improve the performance of a wireless system. For narrowband variety of these systems, the “basic principle is to multiply the signals at different antenna elements with complex weights before the signals are transmitted or when the received signals are summed up” (Pedersen, 2003). This allows a narrow beam (with gain) to be created towards the desired user and low side-lobes towards other users. Smart antennas offer a broad range of ways to improve the performance of wireless systems. For example, in the initial development of the system they offer enhanced range and in a longer term increased capacity of wireless systems. Due to the capability of spatial separation of signals, they allow different subscribers to share the same spectral resources (Space Division Multiple Access). The same capability of spatial separation of signals allows for mitigating adverse multi-path effects.

Smart antennas can be generally divided into three main groups depending upon the level of intelligence. These are (i) fixed beam systems (Osseiran, 2006) or fixed multi-beam (also called switched beam) systems (Allen, 2004), (ii) phased arrays (Janaswamy, 2001) and (iii) adaptive array antennas (Godara, 1997). Adaptive implementations have better performance than fixed or switched beam systems, at the expense of higher implementation cost and complexity. The advent of low cost Digital Signal Processor (DSP) chips, Application Specific Integrated Circuits (ASIC’s), system-in-a-package or system-on-a-chip realizations have made adaptive antenna systems practical for commercial use (Kaiser, 2005).

According to (Alexiou, 2004), “the adoption of smart antennas in future wireless systems relies on two main investigation approaches to be performed:

  • Consideration of the smart antenna features early in the design phase of future systems.

  • Realistic performance evaluation of smart antennas according to the critical parameters associated with system requirements”.

As far as first approach is concerned, smart antennas are already an integral part of Universal Mobile Telecommunications System (UMTS) and third generation Code Division Multiple Access (CDMA) standards and their evolutionary roadmaps (Boche, 2006). Furthermore, there is currently increasing interest in the incorporation of smart antenna techniques for IEEE wireless LAN/MAN (802.11n, 802.16 and 802.20) and smart antennas are expected to play a significant role in enabling broadband wireless communication (Alexiou, 2004). As far as second approach is concerned, performance evaluation based on accurate modeling with suitable simulation methodology is required.

This chapter addresses these two approaches and provides an overview of smart antenna technologies for Code Division Multiple Access system. The remainder of the chapter is organised as follows. In Section 2, we first summarize the background information and then present the state of the art in smart antenna systems from key system architecture and performance analysis perspectives. In Section 3, we discuss smart antenna system modeling for CDMA and present a performance analysis based on analytical expressions, including simulation results for verification. Finally in Section 4, we present conclusions and identify some avenues for future work.

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Smart Antenna Technologies

This section is devoted to the review of background information for smart antenna technologies. The emphasis is on summarizing the state of the art by focusing on well-chosen highlights, i.e. classification, system architecture and modeling and performance analysis aspects. The presented considerations are limited to the narrowband case. By the narrowband system, we mean the system whose operational frequency band is no more than a few percents.

Complete Chapter List

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Table of Contents
Foreword
Jack H. Winters
Acknowledgment
Chen Sun, Jun Cheng, Takashi Ohira
Chapter 1
Constantin Siriteanu, Steven D. Blostein
This chapter unifies the principles and analyses of conventional signal processing algorithms for receive-side smart antennas, and compares their... Sample PDF
Eigencombining: A Unified Approach to Antenna Array Signal Processing
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Chapter 2
Zhu Liang Yu, Meng Hwa Er, Wee Ser, Chen Huawei
In this chapter, we first review the background, basic principle and structure of adaptive beamformers. Since there are many robust adaptive... Sample PDF
Robust Adaptive Beamforming
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Chapter 3
Sheng Chen
Adaptive beamforming is capable of separating user signals transmitted on the same carrier frequency, and thus provides a practical means of... Sample PDF
Adaptive Beamforming Assisted ReceiverAdaptive Beamforming
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Chapter 4
Thomas Hunziker
Many common adaptive beamforming methods are based on a sample matrix inversion (SMI). The schemes can be applied in two ways. The sample covariance... Sample PDF
On the Employment of SMI Beamforming for Cochannel Interference Mitigation in Digital Radio
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Chapter 5
Hideki Ochiai, Patrick Mitran, H. Vincent Poor, Vahid Tarokh
In wireless sensor networks, the sensor nodes are often randomly situated, and each node is likely to be equipped with a single antenna. If these... Sample PDF
Random Array Theory and Collaborative Beamforming
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Chapter 6
W. H. Chin, C. Yuen
Space-time block coding is a way of introducing multiplexing and diversity gain in wireless systems equipped with multiple antennas. There are... Sample PDF
Advanced Space-Time Block Codes and Low Complexity Near Optimal Detection for Future Wireless Networks
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Chapter 7
Xiang-Gen Xia, Genyuan Wang, Pingyi Fan
Modulated codes (MC) are error correction codes (ECC) defined on the complex field and therefore can be naturally combined with an intersymbol... Sample PDF
Space-Time Modulated Codes for MIMO Channels with Memory
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Chapter 8
Javier Vía, Ignacio Santamaría, Jesús Ibáñez
This chapter analyzes the problem of blind channel estimation under Space-Time Block Coded transmissions. In particular, a new blind channel... Sample PDF
Blind Channel Estimation in Space-Time Block Coded Systems
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Chapter 9
Chen Sun, Takashi Ohira, Makoto Taromaru, Nemai Chandra Karmakar, Akifumi Hirata
In this chapter, we describe a compact array antenna. Beamforming is achieved by tuning the load reactances at parasitic elements surrounding the... Sample PDF
Fast Beamforming of Compact Array Antenna
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Chapter 10
Eddy Taillefer, Jun Cheng, Takashi Ohira
This chapter presents direction of arrival (DoA) estimation with a compact array antenna using methods based on reactance switching. The compact... Sample PDF
Direction of Arrival Estimation with Compact Array Antennas: A Reactance Switching Approach
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Chapter 11
Santana Burintramart, Nuri Yilmazer, Tapan K. Sarkar, Magdalena Salazar-Palma
This chapter presents a concern regarding the nature of wireless communications using multiple antennas. Multi-antenna systems are mainly developed... Sample PDF
Physics of Multi-Antenna Communication Systems
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Chapter 12
MIMO Beamforming  (pages 240-263)
Qinghua Li, Xintian Eddie Lin, Jianzhong ("Charlie") Zhang
Transmit beamforming improves the performance of multiple-input multiple-output antenna system (MIMO) by exploiting channel state information (CSI)... Sample PDF
MIMO Beamforming
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Chapter 13
Biljana Badic, Jinho Choi
This chapter introduces joint beamforming (or precoding) and space-time coding for multiple input multiple output (MIMO) channels. First, we explain... Sample PDF
Joint Beamforming and Space-Time Coding for MIMO Channels
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Chapter 14
Zhendong Zhou, Branka Vucetic
This chapter introduces the adaptive modulation and coding (AMC) as a practical means of approaching the high spectral efficiency theoretically... Sample PDF
Adaptive MIMO Systems with High Spectral Efficiency
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Chapter 15
Joakim Jaldén, Björn Ottersten
This chapter takes a closer look at a class of MIMO detention methods, collectively referred to as relaxation detectors. These detectors provide... Sample PDF
Detection Based on Relaxation in MIMO Systems
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Chapter 16
Wolfgang Utschick, Pedro Tejera, Christian Guthy, Gerhard Bauch
This chapter discusses four different optimization problems of practical importance for transmission in point to multipoint networks with a multiple... Sample PDF
Transmission in MIMO OFDM Point to Multipoint Networks
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Chapter 17
Salman Durrani, Marek E. Bialkowski
This chapter discusses the use of smart antennas in Code Division Multiple Access (CDMA) systems. First, we give a brief overview of smart antenna... Sample PDF
Smart Antennas for Code Division Multiple Access Systems
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Chapter 18
Aimin Sang, Guosen Yue, Xiaodong Wang, Mohammad Madihian
In this chapter, we consider a cellular downlink packet data system employing the space-time block coded (STBC) multiple- input-multiple-output... Sample PDF
Cross-Layer Performance of Scheduling and Power Control Schemes in Space-Time Block Coded Downlink Packet Systems
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Chapter 19
Yimin Zhang, Xin Li, Moeness G. Amin
This chapter introduces the concept of multi-beam antenna (MBA) in mobile ad hoc networks and the recent advances in the research relevant to this... Sample PDF
Mobile Ad Hoc Networks Exploiting Multi-Beam Antennas
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Chapter 20
Toru Hashimoto, Tomoyuki Aono
The technology of generating and sharing the key as the representative application of smart antennas is introduced. This scheme is based on the... Sample PDF
Key Generation System Using Smart Antenna
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Chapter 21
Nemai Chandra Karmakar
Various smart antennas developed for automatic radio frequency identification (RFID) readers are presented. The main smart antennas types of RFID... Sample PDF
Smart Antennas for Automatic Radio Frequency Identification Readers
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Chapter 22
Konstanty Bialkowski, Adam Postula, Amin Abbosh, Marek Bialkowski
This chapter introduces the concept of Multiple Input Multiple Output (MIMO) wireless communication system and the necessity to use a testbed to... Sample PDF
Field Programmable Gate Array Based Testbed for Investigating Multiple Input Multiple Output Signal Transmission in Indoor Environments
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Chapter 23
Masahiro Watanabe, Sadao Obana, Takashi Watanabe
Recent studies on directional media access protocols (MACs) using smart antennas for wireless ad hoc networks have shown that directional MACs... Sample PDF
Ad Hoc Networks Testbed Using a Practice Smart Antenna with IEEE802.15.4 Wireless Modules
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Chapter 24
Monthippa Uthansakul, Marek E. Bialkowski
This chapter introduces the alternative approach for wideband smart antenna in which the use of tapped-delay lines and frequency filters are... Sample PDF
Wideband Smart Antenna Avoiding Tapped-Delay Lines and Filters
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Chapter 25
Jun Cheng, Eddy Taillefer, Takashi Ohira
Three working modes, omni-, sector and adaptive modes, for a compact array antenna are introduced. The compact array antenna is an electronically... Sample PDF
Omni-, Sector, and Adaptive Modes of Compact Array Antenna
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