Improved performance of MIMO antenna systems for various fading channels
18 Mar 2012-pp 13-16
TL;DR: The 2 × 2 MIMO system process applies an adaptive approach in order to reduce the impact of wireless channel impairments such as multipath fading to compare BER results with SISO and MISO systems.
Abstract: This paper presents the design and performance analysis of MIMO antennas for wireless communication systems. The 2 × 2 MIMO system process applies an adaptive approach in order to reduce the impact of wireless channel impairments such as multipath fading. The MIMO system was applied in AWGN and single Rayleigh fading channel that uses QPSK modulation schemes to simulate the BER performance for QPSK in MIMO system and finally compares BER results with SISO and MISO systems.
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Posted Content•
TL;DR: This report investigates multiple signal scenarios utilizing various antenna geometries, which includes uniform linear array (ULA) and uniform circular array (UCA), and develops a combined RSS/DOA method, based on UCA, which has the tolerance of detecting both uncorrelated and coherent signals simultaneously.
Abstract: The report focuses on three areas in particular: the first is the Received Signal Strength indicator technique, Direction of Arrival technique, and the integration of two algorithms, RSS and DOA, in order to build a hybrid, more robust algorithms.
In the Received Signal Strength (RSS), the unknown node location is estimated using trilateration. This report examines the performance of different estimators such as Least Square, Weighted Least Square, and Huber robustness in order to obtain the most robust performance.
In the direction of arrival (DOA) method, the estimation is carried out using Multiple Signal Classification (MUSIC), Root-MUSIC, and Estimation of Signal Parameters Via Rotational Invariance Technique (ESPRIT) algorithms. We investigate multiple signal scenarios utilizing various antenna geometries, which includes uniform linear array (ULA) and uniform circular array (UCA). Specific attention is given for multipath scenarios in which signals become spatially correlated (or coherent). This required the use of pre-processing techniques, which include phase mode excitation (PME), spatial smoothing (SS), and Toeplitz.
Further improvements of existing localization techniques are demonstrated through the use of a hybrid approach in which various combinations of RSS and DOA are explored, simulated, and analyzed. This has led to two major contributions: the first contribution is a combined RSS/DOA method, based on UCA, which has the tolerance of detecting both uncorrelated and coherent signals simultaneously. The second major contribution is a combined Root-MUSIC/Toepltiz method, based on UCA, which is outperforms other techniques in terms of increased number of detected signals and reduced computationally load.
25 citations
Posted Content•
TL;DR: The challenges that exist in the various Open Systems Interconnection (OSI) layers are addressed and future research areas concerning the utilization of wireless sensors in healthcare applications are illustrated.
Abstract: Continuous health monitoring using wireless body area networks (WBANs) of wearable, epidermal and implantable medical devices is envisioned as a transformative approach to healthcare. Rapid advances in biomedical sensors, low-power electronics, and wireless communications have brought this vision to the verge of reality. However, key challenges still remain to be addressed. This paper surveys the current state-of-the-art in the area of wireless sensors for medical applications. Specifically, it focuses on presenting the recent advancements in wearable, epidermal and implantable technologies, and discusses reported ways of powering up such sensors. Furthermore, this paper addresses the challenges that exist in the various Open Systems Interconnection (OSI) layers and illustrates future research areas concerning the utilization of wireless sensors in healthcare applications.
4 citations
01 Jan 2014
TL;DR: In this paper, the authors proposed three random frequency hopping schemes that generate a hopping pattern with the property of being random over the total bandwidth of the channel but good sub-bands tend to be selected more frequently.
Abstract: Frequency hopping spread spectrum is widely used in military applications to
provide communication between command posts, soldiers, vehicles, sensors, missile
launchers, etc. It provides good protection against the effects of frequency selective
fading, and can be robust in jamming environments. Traditional frequency hopping
spread spectrum involves dividing the available spectrum into a large number of
sub-bands, and hopping over these sub-bands in a pseudo-random fashion, but there
are different implementations within this general framework that can deliver better
performance.
In
this thesis, we present several existing frequency hopping spread spectrum
schemes and we investigate their performance in the presence of frequency selective
fading and adaptive partial band jamming. We optimize the control parameters
of matched frequency hopping, clipped matched frequency hopping and advanced
frequency hopping to enhance their throughput performance. We also propose three
new random frequency hopping schemes that generate a hopping pattern with the
property of being random over the total bandwidth of the channel but good sub-bands
tend to be selected more frequently.
These new random frequency hopping schemes
provide greater resilience to adaptive jamming and give much higher throughput than
the existing schemes.
2 citations
TL;DR: From the simulation results, it was found that the proposed scheme MIMO VBLAST PNC has a 45.2 % higher BER performance compared to the traditional MIMo scheme with an increase in the BER using MMSE and ZF respectively in both two and four antennas.
Abstract: Abstract Paper aims to enhance the performance of bit error rate (BER) in wireless communication based on the multiple-input multiple-output (MIMO) system of vertical Bell laboratories layered space-time (VBLAST) algorithm. The VBLAST algorithm uses zero-forcing (ZF) and the minimum mean square error (MMSE) to evaluate the BER of wireless communication. MIMO VBLAST techniques function as an adaptive filter and can minimize the interference and multipath fading in the received signal of the channel. Physical layer network coding (PNC) is a new technique used to exploit the spatial diversity of the MIMO VBLAST system to improve the throughput and performance of wireless communication. The bit-error-rate (BER) of proposed VBLAST MIMO with PNC with binary phase-shift keying (BPSK) and quadrature phase-shift keying (QPSK) modulation over the additive white Gaussian noise and Rayleigh fading channel are analyzed. The performance of both BPSK and QPSK modulation in two and four antennas are compared. From the simulation results, it was found that the proposed scheme MIMO VBLAST PNC has a 45.2 % higher BER performance compared to the traditional MIMO scheme with an increase in the BER using MMSE and ZF respectively in both two and four antennas.
2 citations
Cites methods from "Improved performance of MIMO antenn..."
...MIMO is utilized in helping to mitigate the fading channel and interference [3]....
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References
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Book•
15 Jan 1996
TL;DR: WireWireless Communications: Principles and Practice, Second Edition is the definitive modern text for wireless communications technology and system design as discussed by the authors, which covers the fundamental issues impacting all wireless networks and reviews virtually every important new wireless standard and technological development, offering especially comprehensive coverage of the 3G systems and wireless local area networks (WLANs).
Abstract: From the Publisher:
The indispensable guide to wireless communicationsnow fully revised and updated!
Wireless Communications: Principles and Practice, Second Edition is the definitive modern text for wireless communications technology and system design. Building on his classic first edition, Theodore S. Rappaport covers the fundamental issues impacting all wireless networks and reviews virtually every important new wireless standard and technological development, offering especially comprehensive coverage of the 3G systems and wireless local area networks (WLANs) that will transform communications in the coming years. Rappaport illustrates each key concept with practical examples, thoroughly explained and solved step by step.
Coverage includes:
An overview of key wireless technologies: voice, data, cordless, paging, fixed and mobile broadband wireless systems, and beyond
Wireless system design fundamentals: channel assignment, handoffs, trunking efficiency, interference, frequency reuse, capacity planning, large-scale fading, and more
Path loss, small-scale fading, multipath, reflection, diffraction, scattering, shadowing, spatial-temporal channel modeling, and microcell/indoor propagation
Modulation, equalization, diversity, channel coding, and speech coding
New wireless LAN technologies: IEEE 802.11a/b, HIPERLAN, BRAN, and other alternatives
New 3G air interface standards, including W-CDMA, cdma2000, GPRS, UMTS, and EDGE
Bluetooth wearable computers, fixed wireless and Local Multipoint Distribution Service (LMDS), and other advanced technologies
Updated glossary of abbreviations and acronyms, and a thorolist of references
Dozens of new examples and end-of-chapter problems
Whether you're a communications/network professional, manager, researcher, or student, Wireless Communications: Principles and Practice, Second Edition gives you an in-depth understanding of the state of the art in wireless technologytoday's and tomorrow's.
17,102 citations
AT&T1
TL;DR: This paper presents a simple two-branch transmit diversity scheme that provides the same diversity order as maximal-ratio receiver combining (MRRC) with one transmit antenna, and two receive antennas.
Abstract: This paper presents a simple two-branch transmit diversity scheme. Using two transmit antennas and one receive antenna the scheme provides the same diversity order as maximal-ratio receiver combining (MRRC) with one transmit antenna, and two receive antennas. It is also shown that the scheme may easily be generalized to two transmit antennas and M receive antennas to provide a diversity order of 2M. The new scheme does not require any bandwidth expansion or any feedback from the receiver to the transmitter and its computation complexity is similar to MRRC.
13,706 citations
01 Nov 1999
TL;DR: In this paper, the authors investigate the use of multiple transmitting and/or receiving antennas for single user communications over the additive Gaussian channel with and without fading, and derive formulas for the capacities and error exponents of such channels, and describe computational procedures to evaluate such formulas.
Abstract: We investigate the use of multiple transmitting and/or receiving antennas for single user communications over the additive Gaussian channel with and without fading. We derive formulas for the capacities and error exponents of such channels, and describe computational procedures to evaluate such formulas. We show that the potential gains of such multi-antenna systems over single-antenna systems is rather large under independenceassumptions for the fades and noises at different receiving antennas.
12,542 citations
01 Nov 1985
TL;DR: This month's guest columnist, Steve Bible, N7HPR, is completing a master’s degree in computer science at the Naval Postgraduate School in Monterey, California, and his research area closely follows his interest in amateur radio.
Abstract: Spread Spectrum It’s not just for breakfast anymore! Don't blame me, the title is the work of this month's guest columnist, Steve Bible, N7HPR (n7hpr@tapr.org). While cruising the net recently, I noticed a sudden bump in the number of times Spread Spectrum (SS) techniques were mentioned in the amateur digital areas. While QEX has discussed SS in the past, we haven't touched on it in this forum. Steve was a frequent cogent contributor, so I asked him to give us some background. Steve enlisted in the Navy in 1977 and became a Data Systems Technician, a repairman of shipboard computer systems. In 1985 he was accepted into the Navy’s Enlisted Commissioning Program and attended the University of Utah where he studied computer science. Upon graduation in 1988 he was commissioned an Ensign and entered Nuclear Power School. His subsequent assignment was onboard the USS Georgia, a trident submarine stationed in Bangor, Washington. Today Steve is a Lieutenant and he is completing a master’s degree in computer science at the Naval Postgraduate School in Monterey, California. His areas of interest are digital communications, amateur satellites, VHF/UHF contesting, and QRP. His research area closely follows his interest in amateur radio. His thesis topic is Multihop Packet Radio Routing Protocol Using Dynamic Power Control. Steve is also the AMSAT Area Coordinator for the Monterey Bay area. Here's Steve, I'll have some additional comments at the end.
8,781 citations
Book•
01 Dec 1950
TL;DR: In this article, Lehto and Vainikainen discuss the relationship between aperture distribution and far-field pattern and the Fourier Transform Relation between Aperture Distribution and Far-Field Pattern.
Abstract: 1 Introduction 2 Antenna Basics 3 The Antenna Family 4 Point Sources 5 Arrays of Point Sources 6 The Electric Dipole and Thin Linear Antennas 7 The Loop Antenna 8 End Fire Antennas: The Helical Beam Antenna and the Yagi-Uda Array 9 Slot, Patch and Horn Antennas 9II Slot and Horn Antennas II 10 Flat Sheet, Corner and Parabolic Reflector Antennas 11 Broadband and Frequency-Independent Antennas 12 Antenna Temperature, Remote Sensing and Radar Cross-Section 13 Self and Mutual Impedances 14 The Cylindrical Antenna and the Moment Method (MM) 15 The Fourier Transform Relation Between Aperture Distribution and Far-Field Pattern 16 Arrays of Dipoles and of Apertures 17 Lens Antennas 18 Frequency-Selective Surfaces and Periodic Structures by Ben A. Munk 19 Practical Design Considerations of Large Aperture Antennas 20 Some Examples of Large or Unique Antennas 21 Antennas for Special Applications 22 Terahertz Antennas 23 Baluns, etc. By Ben A. Munk 24 Antenna Measurements. By Arto Lehto and Pertti Vainikainen Appendix A Tables for Reference Appendix B Books and Video Tapes Appendix C Computer Programs (Codes) Appendix D Absorbing Materials Appendix E Measurement Error
1,130 citations
"Improved performance of MIMO antenn..." refers background in this paper
...Smart antenna gained a lot of popularity in the past few years because of the continued growth in the consumers as well as the availability and development of advanced high rate technological services....
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