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2011 IEEE 73rd Vehicular Technology Conference, VTC2011-Spring

作者： Serafimovski, Nikola Sinanović, Sinan Di Renzo, Marco Haas, Harald Joint Research Institute for Signal and Image Processing School of Engineering University of Edinburgh EH9 3JL Edinburgh United Kingdom France

ISBN: (纸本)9781424483310

In this paper, we introduce Dual-hop Spatial Modulation (Dh-SM). We look at the effect that Dh-SM has on the required signal to noise ratio (SNR) at the destination and how it can help alleviate the multi-hop burden. Initial biterror-ratio (BER) results comparing the performance of Dh-SM with orthogonal decode-and-forward (DF) are presented where Dh-SM is shown to have up to a 10 dB SNR advantage. © 2011 IEEE.

关键词： signal to noise ratio

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Transmission energy consumption in MIMO systems under inter-cell interference

Transmission energy consumption in MIMO systems under inter-...

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Conference on Wireless Advanced (WiAD)

作者： Ivan Ku Cheng-Xiang Wang John Thompson Peter Grant Joint Research Institute of Signal and Image Processing Heriot-Watt University Edinburgh UK Joint Research Institute of Signal and Image Processing University of Edinburgh Edinburgh UK

We investigate the base station (BS) downlink transmission energy for a multiple-input multiple-output (MIMO) communication system operating under an inter-cell interference environment with the receiver equipped with interference cancellation (IC) capability. It is demonstrated that, besides the number of antennas, receiver IC techniques can have an influence on the required BS transmission energy of a MIMO communication system. Specifically, the choice of receiver IC technique impacts the transmission energy more when the number of receive antennas is small. On the other hand, the transmission energy converges to a minimum value regardless of the type of receiver IC technique used when the number of receive antennas is large enough. We also show that inter-cell interference contributed by adjacent BSs have a detrimental effect on the performance of traditional IC techniques, causing the desired BS to use higher transmission energy to maintain the signal quality.

关键词： Interference Receiving antennas Transmitting antennas MIMO Integrated circuits signal to noise ratio

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Cooperative MIMO Channel Modeling and Multi-Link Spatial Correlation Properties

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IEEE Journal on Selected Areas in Communications 2012年第2期30卷 388-396页

作者： Xiang Cheng Cheng-Xiang Wang Haiming Wang Xiqi Gao Xiao-Hu You Dongfeng Yuan Bo Ai Qiang Huo Ling-Yang Song Bing-Li Jiao School of Electronics and Computer Science Peking University Beijing China Key Laboratory of Wireless Sensor Network & Communication Shanghai Institute of Microsystem and Information Technology Chinese Academy of Sciences China State Key Laboratory of Rail Traffic Control and Safety Beijing Jiaotong University China Joint Research Institute for Signal and Image Processing School of Engineering & Physical Sciences Heriot-Watt University Edinburgh UK School of Information Science and Engineering South East University Najing China School of Information Science and Engineering Shandong University Jinan China State Key Laboratory of Rail Traffic Control and Safety Beijing Jiaotong University Beijing China

In this paper, a novel unified channel model framework is proposed for cooperative multiple-input multiple-output (MIMO) wireless channels. The proposed model framework is generic and adaptable to multiple cooperative MIMO scenarios by simply adjusting key model parameters. Based on the proposed model framework and using a typical cooperative MIMO communication environment as an example, we derive a novel geometry-based stochastic model (GBSM) applicable to multiple wireless propagation scenarios. The proposed GBSM is the first cooperative MIMO channel model that has the ability to investigate the impact of the local scattering density (LSD) on channel characteristics. From the derived GBSM, the corresponding multi-link spatial correlation functions are derived and numerically analyzed in detail.

关键词： MIMO Correlation Channel models Scattering Educational institutions Fading Adaptation models

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Uplink interference protection and fair scheduling for power efficient OFDMA networks

Uplink interference protection and fair scheduling for power...

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International Workshop on Multi-Carrier Systems and Solutions

作者： Burchardt, Harald Bharucha, Zubin Haas, Harald Auer, Gunther Institute for Digital Communications Joint Research Institute for Signal and Image Processing University of Edinburgh EH9 3JL Edinburgh United Kingdom DOCOMO Euro-Labs 80687 Munich Germany

ISBN: (纸本)9781612848877

In this paper a new method for uplink inter-cell interference coordination (ICIC) in a full frequency reuse system is proposed. The technique is named uplink interference protection (ULIP). ULIP exploits existing reference signals transmitted by all base stations (BSs). The fact that path loss and lognormal shadowing can be considered reciprocal in such frequency-division duplex (FDD) systems is exploited. Therefore, no additional signalling is required for a new mobile station (MS) to estimate the level of inter-cell interference it would cause to ongoing uplink transmissions in neighbouring cells. Using the acquired knowledge, MSs can adjust their transmit power to ensure that existing links are not forced into outage. A scheduling scheme is suggested in which a fair allocation of priority resource blocks (RBs), based on user signal-to- interference-plus-noise ratios (SINRs), enhances both cell-edge throughput and user throughput fairness. Through this, also significant system throughput gains are generated. Finally, it is demonstrated that as a side effect of the interference reductions, considerable energy savings can be achieved. © 2011 IEEE.

关键词： Frequency division multiple access

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Double-Sided signal Clipping in ACO-OFDM Wireless Communication Systems

Double-Sided Signal Clipping in ACO-OFDM Wireless Communicat...

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IEEE International Conference on Communications (ICC)

作者： Svilen Dimitrov Sinan Sinanovic Harald Haas Institute of Digital Communications Joint Research Institute of Signal and Image Processing University of Edinburgh Edinburgh UK

In this paper, the impact of double-sided signal clipping on optical wireless communication (OWC) systems employing asymmetrically clipped optical orthogonal frequency division multiplexing (ACO-OFDM) is investigated. Time domain signal clipping is introduced due to biasing issues or physical limitations of the front-ends. These include insufficient forward biasing of the emitter and the maximum driving power limit of the emitter and/or the detector. The clipping noise can be modeled according to the Bussgang theorem and the central limit theorem as attenuation of the subcarriers at the receiver and addition of zero-mean complex Gaussian noise. The attenuation factor and the clipping noise variance are determined semi-analytically and employed in the derivation of the signal-to-noise ratio (SNR) at the receiver. Finally, the theoretical SNR is verified through a bit-error ratio (BER) simulation.

关键词： Optical transmitters Optical distortion Optical receivers OFDM Nonlinear optics Integrated optics Noise

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A comparison of OFDM-based modulation schemes for OWC with clipping distortion

A comparison of OFDM-based modulation schemes for OWC with c...

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IEEE Globecom Workshops

作者： Svilen Dimitrov Sinan Sinanovic Harald Haas Institute for Digital Communications Joint Research Institute for Signal and Image Processing University of Edinburgh Edinburgh UK

In this paper, the electrical power requirement and spectral efficiency of multi-carrier transmission schemes for optical wireless communications (OWC) are compared in the presence of front-end-induced double-sided signal clipping. The two existing multi-carrier modulation techniques based on orthogonal frequency division multiplexing (OFDM), direct-current-biased optical OFDM (DCO-OFDM) and asymmetrically clipped optical OFDM (ACO-OFDM), are studied. The clipping noise can be modeled according to the Bussgang theorem and the central limit theorem (CLT) as attenuation of the data-carrying subcarriers and addition of zero-mean complex-valued Gaussian noise. Presented closed-form expressions for the attenuation factor and the clipping noise variance are employed in the derivation of the effective electrical signal-to-noise ratio (SNR). Using multi-level quadrature amplitude modulation (M-QAM), the electrical power requirement of optical OFDM (O-OFDM) transmission is obtained from the bit-error ratio (BER) system performance. It is shown that in a practical front-end biasing setup DCO-OFDM has a lower electrical power requirement to achieve a target BER as compared to ACO-OFDM for modulation orders with equal spectral efficiencies above 1 bit/s/Hz.

关键词： OFDM Optical distortion Optical transmitters Optical receivers Optical attenuators Nonlinear optics signal to noise ratio

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COSPARSE ANALYSIS MODELING - UNIQUENESS AND ALGORITHMS

COSPARSE ANALYSIS MODELING - UNIQUENESS AND ALGORITHMS

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IEEE International Conference on Acoustics, Speech and signal processing

作者： Sangnam Nam Michael E. Davies Michael Elad Remi Gribonval IRISA INRIA Rennes Bretagne Atlantique France IDCOM & Joint Research Institute of Signal and Image Processing Edinburgh University UK Department of Computer Science Technion-Israel Institute of Technology Israel

In the past decade there has been a great interest in a synthesis-based model for signals, based on sparse and redundant representations. Such a model assumes that the signal of interest can be composed as a linear combination of few columns from a given matrix (the dictionary). An alternative analysis-based model can be envisioned, where an analysis operator multiplies the signal, leading to a cosparse outcome. In this paper, we consider this analysis model, in the context of a generic missing data problem (e.g., compressed sensing, inpainting, source separation, etc.). Our work proposes a uniqueness result for the solution of this problem, based on properties of the analysis operator and the measurement matrix. This paper also considers two pursuit algorithms for solving the missing data problem, an L1-based and a new greedy method. Our simulations demonstrate the appeal of the analysis model, and the success of the pursuit techniques presented.

关键词： Analytical models Data models Algorithm design and analysis Matching pursuit algorithms Optimization Dictionaries Computational modeling

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Enhanced subcarrier index modulation (SIM) OFDM

Enhanced subcarrier index modulation (SIM) OFDM

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IEEE Globecom Workshops

作者： Dobroslav Tsonev Sinan Sinanovic Harald Haas Institute for Digital Communications Joint Research Institute for Signal and Image Processing University of Edinburgh Edinburgh UK

A novel modulation technique coined SIM-OFDM was recently proposed. SIM-OFDM uses different frequency carrier states to convey information and leads to increased performance in comparison to conventional OFDM. Additionally, its innovative structure can lead to a decrease of the peak system power, which is highly beneficial in the context of optical wireless communication. One of the issues of the original SIM-OFDM scheme is a potential bit error propagation which could lead to significant burst errors. The current paper proposes a modified technique which avoids bit error propagation whilst retaining the benefits of the concept.

关键词： Bit error rate Peak to average power ratio Quadrature amplitude modulation Wireless communication Demodulation

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On the throughput of an OFDM-based cellular optical wireless system for an aircraft cabin

On the throughput of an OFDM-based cellular optical wireless...

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作者： Dimitrov, Svilen Haas, Harald Cappitelli, Mario Olbert, Michael University of Edinburgh Institute for Digital Communications Joint Research Institute for Signal and Image Processing EH9 3JL Edinburgh United Kingdom EADS Germany D-21129 Hamburg Germany

ISBN: (纸本)9788882020743

In this paper, a cellular optical wireless communication system based on orthogonal frequency division multiplexing (OFDM) is simulated inside an aircraft cabin. Asymmetrically clipped optical OFDM (ACO-OFDM) and direct-currentbiased optical OFDM (DCO-OFDM) transmission schemes are compared in terms of throughput and cell coverage. Cellular networks with wavelength reuse factors of 1 (full reuse), 2 and 3 are modeled, and off-the-shelf optical front-end components are assumed. signal-to-interference-and-noise ratio (SINR) maps are determined via a Monte Carlo ray-tracing (MCRT) global irradiation simulation in a computer-aided design (CAD) cabin model. Due to the use of OFDM, adaptive modulation and coding (AMC) can be applied to the SINR maps to arrive at the spatial throughput. It is shown that throughput within the range of 1.56 30 Mbps is achievable with the considered ACO-OFDM system, whereas DCO-OFDM doubles the throughput to 3.1360 Mbps. In addition, wavelength reuse factors of 3 or higher are needed to ensure full cell support for both transmission schemes. © 2011 EurAAP.

关键词： Orthogonal frequency division multiplexing

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On the Throughput of an OFDM-based Cellular Optical Wireless System for an Aircraft Cabin

On the Throughput of an OFDM-based Cellular Optical Wireless...

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European Conference on Antennas and Propagation

作者： Svilen Dimitrov Harald Haas Mario Cappitelli Michael Olbert The University of Edinburgh Institute for Digital Communications Joint Research Institute for Signal and Image Processing EADS Germany

ISBN: (纸本)9781457702501

In this paper, a cellular optical wireless communication system based on orthogonal frequency division multiplexing (OFDM) is simulated inside an aircraft cabin. Asymmetrically clipped optical OFDM (ACO-OFDM) and direct-current-biased optical OFDM (DCO-OFDM) transmission schemes are compared in terms of throughput and cell coverage. Cellular networks with wavelength reuse factors of 1 (full reuse), 2 and 3 are modeled, and off-the-shelf optical front-end components are assumed. signal-to-interference-and-noise ratio (SINR) maps are determined via a Monte Carlo ray-tracing (MCRT) global irradiation simulation in a computer-aided design (CAD) cabin model. Due to the use of OFDM, adaptive modulation and coding (AMC) can be applied to the SINR maps to arrive at the spatial throughput. It is shown that throughput within the range of 1.56 - 30 Mbps is achievable with the considered ACO-OFDM system, whereas DCO-OFDM doubles the throughput to 3.13-60 Mbps. In addition, wavelength reuse factors of 3 or higher are needed to ensure full cell support for both transmission schemes.

关键词： ACO-OFDM DCO-OFDM Throughput Cellular optical wireless system Adaptive modulation and coding Throughput Aircraft cockpits Orthogonal frequency division multiplexing modulation coding Optical wireless SINR CARRIER SYSTEM Reuse reuse Cells

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