Field Programmable Gate Array Based Testbed for Investigating Multiple Input Multiple Output Signal Transmission in Indoor Environments

Field Programmable Gate Array Based Testbed for Investigating Multiple Input Multiple Output Signal Transmission in Indoor Environments

Konstanty Bialkowski (University of Queensland, Australia), Adam Postula (University of Queensland, Australia), Amin Abbosh (University of Queensland, Australia) and Marek Bialkowski (University of Queensland, Australia)
DOI: 10.4018/978-1-59904-988-5.ch022
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This chapter introduces the concept of Multiple Input Multiple Output (MIMO) wireless communication system and the necessity to use a testbed to evaluate its performance. A comprehensive review of different types of testbeds available in the literature is presented. Next, the design and development of a 2×2 MIMO testbed which uses in-house built antennas, commercially available RF chips for an RF front end and a Field Programmable Gate Array (FPGA) for based signal processing is described. The operation of the developed testbed is verified using a Channel Emulator. The testing is done for the case of a simple Alamouti QPSK based encoding and decoding scheme of baseband signals.
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Evolution Of Smart Antennas And Mimo

In the past two decades, wireless communication systems have grown with an unprecedented speed from radio paging, cordless telephone, and cellular telephony to multimedia platforms offering voice and video streaming, interactive services, and even a global positioning information of the user. One undesired outcome of this expansion is a heavy utilization of the available frequency spectrum. A particular pressure comes from new multimedia applications, which require larger operational bandwidth for their implementations. Conventional coding and modulation techniques that are based on frequency, time or code division have difficulty to provide a suitable solution to this problem. For example, allocating new users or new applications leads to consuming of an additional frequency band in frequency division multiplexing systems. In time division and code division multiplexing systems this results in an increased level of a man-made noise, which in turn adversely affects the signal to noise (SNR) ratio and thus the quality of the received signal.

As the conventional coding and modulation techniques are unable to overcome the problem associated with the limited frequency spectrum, the designers turn to the space/angle domain to improve capacity and reliability of wireless systems. This approach is already in use in many currently available terrestrial and satellite communication systems. The best known example is the cellular telephony. By creating physically separated cells, the same frequency spectrum is re-used only at an expense of small interference between adjacent cells. A further extension of the cellular concept is via the introduction of sectors within cells. This task is realized by antennas at base stations having sectoral radiation patterns instead of omnidirectional ones. More advanced versions of this concept are antennas serving a variable width sector. This is required, to overcome a bottleneck caused by an excessive number of users in a particular time of the day in this sector (Rosol, 1995). Such an intelligent antenna system is an example of the simplest type of smart antenna (Liberti and Rappaport, 1999). A more advanced form, known as an adaptive antenna, can follow individual mobile users by forming narrow beams towards them. At the same time, they can produce nulls or low side lobes towards undesired users. In all of these cases, multiple element antennas (MEAs) are instrumental to divide space into angular slots and adapt their width in time so that the wireless system can serve an increased number of users. It is apparent that such intelligent systems are capable to fight co-channel interference and thus, they are able to improve the quality of a communication link.

All of these benefits are possible if an MEA systems are capable to distinguish between signals coming from desired and undesired directions. Such a task is relatively easy to accomplish under Line of Sight (LOS) signal propagation conditions. As a result, adaptive antennas rely on LOS conditions for their proper operation. In order to achieve this condition in practice, base station antennas are located on elevated platforms so their operation is unaffected by the presence of surrounding objects. Such conditions are usually difficult to fulfill for mobile units. This is because they operate at low heights and therefore their operation is affected by the presence of various scattering, refracting or reflecting objects that surround them.

Meeting LOS conditions becomes more challenging for indoor scenarios, as the signal’s propagation is affected by walls, indoor furniture, equipment and humans. Under such conditions, signals of similar strength arrive from many directions on antennas. As a result, there is not much benefit from forming narrow beams. This is because there are too many directions at which these beams need to be formed.

Complete Chapter List

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Table of Contents
Jack H. Winters
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
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
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
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
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
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
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
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
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
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
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
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
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
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
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
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
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
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
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
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
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
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
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
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
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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