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Energy efficient virtual MIMO communication for wireless sensor networks

TELECOMMUNICATION SYSTEMS 2009年第1-2期42卷 139-149页

作者： Hussain, Sajid Azim, Anwarul Park, Jong Hyuk Acadia Univ Jodrey Sch Comp Sci Wolfville NS B0P 1X0 Canada Kyungnam Univ Dept Comp Sci & Engn Kyungnam South Korea

Virtual multiple input multiple output (MIMO) techniques are used for energy efficient communication in wireless sensor networks. In this paper, we propose energy efficient routing based on virtual MIMO. We investigate virtual MIMO for both fixed and variable rates. We use a cluster based virtual MIMO cognitive model with the aim of changing operational parameters (constellation size) to provide energy efficient communication. We determine the routing path based on the virtual MIMO communication cost to delay the first node death. For larger distances, the simulation results show that virtual MIMO (2x2) based routing is more energy efficient than SISO (single input single output) and other MIMO variations.

关键词： Cognitive network Virtual MIMO space-time block code Diversity Data rate

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Transmit Antenna Selection Schemes with Reduced Feedback Rate

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IEEE TRANSACTIONS ON WIRELESS COMMUNICATIONS 2009年第2期8卷 1006-1016页

作者： Chen, Zhuo Collings, Iain B. Zhou, Zhendong Vucetic, Branka CSIRO ICT Ctr Wireless Technol Lab Marsfield NSW 2122 Australia Univ Sydney Sch Elect & Informat Engn Sydney NSW 2006 Australia

In this paper, we propose and analyze three new transmit antenna selection schemes with reduced feedback rate requirement compared with the conventional scheme. In Scheme 1, L-t, available transmit antennas are divided as equally as possible into two groups with consecutive antennas. The best single antenna within each group is selected. In Scheme 2, only the best one among Lt antennas is made known to the transmitter, and the other one is selected at random. In Scheme 3, Lt antennas are divided into multiple subsets each consisting of two adjacent antennas, and the best subset is selected. Bit error rate (BER) expressions for the proposed schemes with Alamouti code are derived for independent flat Rayleigh fading channels. It is found that all the three schemes achieve a full diversity order. The relative merit of each proposed scheme is delineated based on the trade-off between the asymptotic performance loss and feedback reduction, both relative to the conventional scheme. We conclude that Schemes I and 3 are more favorable for practical applications, and the appropriate application scenarios are also identified. The proposed schemes enrich the choices for antenna selection system design for various feedback channel bandwidths and different requirements for quality of service.

关键词： Antenna selection diversity fading channels space-time block code

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Adaptive Joint Decoding and Equalization for space-time block-coded Amplify-and-Forward Relaying Systems

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IEEE TRANSACTIONS ON SIGNAL PROCESSING 2009年第3期57卷 1163-1176页

作者： Firag, Abdulla Garth, Lee M. Univ Canterbury Dept Elect & Comp Engn Christchurch 1 New Zealand Adv Syst & Technol BAE Syst Nashua NH 03061 USA

We develop practical time- and frequency-domain adaptive equalizers for distributed time-reversal space-time block-coded (TR-STBC) systems. The adaptive equalizers eliminate the need for explicit channel impulse response estimation at the receiver. The length of the time-domain adaptive equalizer is also independent of the data block length, making it particularly suitable for frequency selective fading channels with short delay spreads. We derive the block minimum mean square error solutions for both time- and frequency-domain distributed TR-STBC systems and from these we develop recursive least squares adaptive algorithms for the block structures. We use computer simulations to compare both the time- and frequency-domain adaptive equalizers for amplify-and-forward relay networks. We show that the adaptive algorithms work well for Protocols I and III proposed by Nabar et al. The time-domain adaptive algorithms perform better than the frequency-domain algorithms, and overall the Protocol I receivers outperform the Protocol III receivers. We also show that, if only the Protocol M receiver is used, it can be susceptible to noise amplification due to a weaker source-to-relay link compared to the relay-to-destination link. This problem can be mitigated by using the Protocol I receivers with some extra complexity but much superior diversity performance.

关键词： Adaptive equalization multiantenna systems relaying systems space-time block code

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Spatially and temporally correlated MIMO channels: Performance evaluating of space-time block code

Spatially and temporally correlated MIMO channels: Performan...

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International Conference on Wireless Communications, Networking and Mobile Computing

作者： Gao, JB Zhou, ML Zhang, BJ Huazhong Univ Sci & Technol Dept Elect & Informat Engn Wuhan 430074 Peoples R China

ISBN: (纸本)078039335X

Most existing space-time block code (STBC) schemes have been developed for flat and quasi-static fading channels. Recently, Geoffrey et al. propose a general geometric spatially and temporally correlated multiple-input multiple-output (MIMO) channel model, which considers motion of the receiver and nonisotropic scattering at both ends of the radio link and give the compact closed-form space-time cross-correlation function. Simultaneously, the outage and ergodic capacity of this channel is investigated based on this model. In this paper, we investigate the STBC performance based on the above channel model. On the one hand, we further testify the validity of this general model, on the other hand, we evaluate the influence of the channel time variation on the STBC performance.

关键词： space-time block code MIMO correlated channel time variation

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Blind ML detection of orthogonal space-time block codes: Identifiab ility and code construction

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IEEE TRANSACTIONS ON SIGNAL PROCESSING 2007年第7期55卷 3312-3324页

作者： Ma, Wing-Kin Natl Tsing Hua Univ Inst Commun Engn Hsinchu 30013 Taiwan Natl Tsing Hua Univ Dept Elect Engn Hsinchu 30013 Taiwan

The blind maximum-likelihood (ML) detection of a general space-time block code (STBC) is considered a challenging implementation problem. Recent work has revealed that for the orthogonal STBCs (OSTBCs), their special code structures can be exploited to formulate highly effective blind ML-based algorithms. Attracted by this realization merit, this paper investigates the blind ML identifiability of OSTBCs, with an emphasis on the binary PSK (BPSK) and quaternary PSK (QPSK) constellations. We find a class of OSTBCs, called the nonrotatable OSTBCs, that can be uniquely identified up to a sign.(UIUTS) almost surely under a few mild assumptions. For example, for an independently distributed Rayleigh channel with any number of receiver antennas, a nonrotatable OSTBC can be UIUTS with probability 1. While this identifiability looks appealing already, we further examine a subclass of nonrotatable OSTBCs, called the nonintersecting subspace (NIS) OSTBCs. We prove that NIS-OSTBCs are UIUTS for any nonzero channel. However, NIS-OSTBCs are not available in the existing literature. To fill this gap, we devise a code construction procedure that can convert any (BPSK or QPSK) OSTBC to an NIS-OSTBC.

关键词： blind and semiblind detection blind identifiability decoding maximum likelihood detection performance analysis space-time block code

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On the Issue of Decoupled Decoding of codes Derived from Quaternion Orthogonal Designs

On the Issue of Decoupled Decoding of Codes Derived from Qua...

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3rd International Conference on Signal Processing and Communication Systems

作者： Wysocki, Tadeusz A. Wysocki, Beata J. Adams, Sarah Spence Univ Nebraska Lincoln Dept Elect & Comp Engn Peter Kiewit Inst Omaha NE 68182 USA Franklin W Olin Coll Engn Olin Ctr Needham MA 02492 USA

ISBN: (纸本)9781424444731

Quaternion orthogonal designs (QODs) have been previously introduced as a basis for orthogonal space-time polarization block codes (OSTPBCs). This note will serve to correct statements concerning the optimality of a decoupled maximum-likelihood (ML) decoding algorithm. It will be shown that when compared to coupled decoding, the decoupled decoding is only optimal in certain cases. This raises several open problems concerning the decoding of OSTPBCs.

关键词： space-time block code quaternion orthogonal design decoupled decoding maximum-likelihood decoding

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space-time block codes with Limited Feedback Using Antenna Grouping

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IEICE TRANSACTIONS ON COMMUNICATIONS 2008年第10期E91B卷 3387-3390页

作者： Chae, Chan-Byoung Shim, Seijoon Heath, Robert W., Jr. Univ Texas Austin Dept Elect & Comp Engn Wireless Networking & Commun Grp Austin TX 78712 USA Samsung Elect Telecommun R&D Ctr Suwon South Korea

We propose an antenna grouping method that improves the error rate performance of space-time codes in a wide range of mobility environments. The idea is to group symbols to antennas baked on limited feedback from the mobile station to utilize all antennas. Our approach requires only two bits of feedback information to achieve better link performance and full rate for a certain four transmit antenna system. Numerical results confirm the bit/frame error gains over the Alamouti-based space-time block code and antenna Subset selection strategies.

关键词： space-time block code full-diversity full-rate system antenna selection antenna grouping

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The comparison between space-time blocks codes and trellis codes under maximum likelihood sequence estimator

The comparison between space-time blocks codes and trellis c...

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International Conference on Wireless Networks and Information Systems

作者： Liu, Jingping Zhao, Huichang Nanjing Univ Sci & Technol Sch Elect Engn & Optoelect Technol Nanjing 210094 Peoples R China

ISBN: (纸本)9780769539010

In multiple input and multiple output (MIMO) system, the channel code is very important and complex compare single antenna system. space-time codes (STC) were proposed to solve the problem. In space-time codes family the space-time block code and space-time trellis code are applied in many cases. In this paper we proposed the maximum likelihood detector used in space-time trellis codes system, and compare the difference between these two kinds of codes under maximum likelihood sequence estimator, get which situation is better to these two kinds of STC.

关键词： MIMO space-time block code space-time trellis code

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Maximum-likelihood detection of orthogonal space-time block coded OFDM in unknown block fading channels

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IEEE TRANSACTIONS ON SIGNAL PROCESSING 2008年第4期56卷 1637-1649页

作者： Chang, Tsung-Hui Ma, Wing-Kin Chi, Chong-Yung Natl Tsing Hua Univ Inst Commun Engn Hsinchu Taiwan Natl Tsing Hua Univ Dept Elect Engn Hsinchu Taiwan Chinese Univ Hong Kong Dept Elect Engn Hong Kong Hong Kong Peoples R China

For orthogonal space-time block coded orthogonal frequency division multiplexing (OSTBC-OFDM) systems, many of the existing blind detection and channel estimation methods rely on the assumption that the channel is static for many OSTBC-OFDM blocks. This paper considers the blind (semiblind) maximum-likelihood (NIL) detection problem of OSTBC-OFDM with a single OSTBC-OFDM block only. The merit of such an investigation is the ability to accommodate channels with shorter coherence time. We examine both the implementation and identifiability issues, with a focus on BPSK or QPSK constellations. In the implementation, we propose reduced-complexity detection schemes using subchannel grouping. In the identifiability analysis, we show that the proposed schemes can ensure a probability one identifiability condition using very few number of pilots. For example, the proposed semiblind detection scheme only requires a single pilot code for unique data identification;while the conventional pilot-based channel estimation method requires L pilots where L denotes the channel length. Our simulation results demonstrate that the proposed schemes can provide performance close to that of their nonblind counterparts.

关键词： blind and semiblind detection maximum likelihood detection MIMO systems OFDM space-time block code

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Spatially and Temporally Correlated MIMO Channels: Performance Evaluating of space-time block code

Spatially and Temporally Correlated MIMO Channels: Performan...

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2005年无线通信、网络和移动计算国际会议

作者： Jingbo Gao Manli Zhou Bijun Zhang Department of Electronics & Information Engineering Huazhong University of Science & Technology Wuhan 430074 P.R.China

ISBN: (纸本)078039335X

Most existing space-time block code (STBC) schemes have been developed for flat and quasi-static fading channels. Recently, Geoffrey et al. propose a general geometric spatially and temporally correlated multiple-input multiple-output (MIMO) channel model, which considers motion of the receiver and nonisotropic scattering at both ends of the radio link and give the compact closed-form space-time cross-correlation function. Simultaneously, the outage and ergodic capacity of this channel is investigated based on this model. In this paper,we investigate the STBC performance based on the above channel *** the one hand, we further testify the validity of this general model, on the other hand, we evaluate the influence of the channel time variation on the STBC performance.

关键词： space-time block code MIMO correlated channel time variation

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