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IEEE Vehicular Technology Conference

作者： Xiping Wu Marco Di Renzo Harald Haas Institute for Digital Communications Joint Research Institute for Signal and Image Processing School of Engineering The University of Edinburgh EH9 3JL Edinburgh UK French National Centre for Scientific Research (CNRS) Laboratory for Signals and Systems (LSS) école Supérieure d'électricité (SUPELEC) 3 rue Joliot-Curie 91192 Gif-sur-Yvette (Paris) France

ISBN: (纸本)9781467361866

To improve the performance of spatial modulation (SM) over correlated MIMO channels, transmit optimized spatial modulation (TOSM) has been proposed recently. It trades off traditional signal constellation diagrams with spatial constellation diagrams to minimize the average bit error probability (ABEP). After the optimum number of transmit antennas is determined, the specific antennas need to be carefully chosen from the entire array to provide a minimum ABEP. Like in conventional transmit antenna selection (TAS) schemes, the problem can be solved by an exhaustive search. However, this results in an unaffordable complexity especially when the spectral efficiency is high. In this paper, we propose a creative TAS approach for TOSM. Given a required number of antennas, the novel technique determines the selection solution based on circle packing. Simulation results show that for various channel correlations and spectral efficiencies, the proposed method achieves performance results close to exhaustive search with a gap of less than 0.3 dB. The complexity is reduced to an extremely low level.

关键词： Realistic circle packing (RCP) transmit antenna selection (TAS) transmit optimized spatial modulation (TOSM) correlated MIMO average bit error probability (ABEP)

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Fast regional readout CMOS image Sensor for dynamic MLC tracking

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Journal of Physics: Conference Series 2014年第1期489卷

作者： H Zin E Harris J Osmond P Evans To whom any correspondence should be addressed Joint Department of Physics The Institute of Cancer Research and The Royal Marsden NHS Foundation Trust Downs Road Sutton Surrey SM2 5PT UK Centre for Vision Speech and Signal Processing University of Surrey Guildford Surrey GU2 7XH UK

Advanced radiotherapy techniques such as volumetric modulated arc therapy (VMAT) require verification of the complex beam delivery including tracking of multileaf collimators (MLC) and monitoring the dose rate. This work explores the feasibility of a prototype Complementary metal-oxide semiconductor image Sensor (CIS) for tracking these complex treatments by utilising fast, region of interest (ROI) read out functionality. An automatic edge tracking algorithm was used to locate the MLC leaves edges moving at various speeds (from a moving triangle field shape) and imaged with various sensor frame rates. The CIS demonstrates successful edge detection of the dynamic MLC motion within accuracy of 1.0 mm. This demonstrates the feasibility of the sensor to verify treatment delivery involving dynamic MLC up to ~400 frames per second (equivalent to the linac pulse rate), which is superior to any current techniques such as using electronic portal imaging devices (EPID). CIS provides the basis to an essential real-time verification tool, useful in accessing accurate delivery of complex high energy radiation to the tumour and ultimately to achieve better cure rates for cancer patients.

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Two Statistical Mixture Model vs. Fuzzy C-Means: In the application of edema segmentation

Two Statistical Mixture Model vs. Fuzzy C-Means: In the appl...

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IEEE International Conference on signal and image processing Applications (ICSIPA)

作者： Kushsairy Kadir Hao Gao Alex R Payne John Soraghan Colin Berry British Malaysian Institute Universiti Kuala Lumpur Gombak Selangor Malaysia School of Mathematic University of Glasgow Glasgow BHF Glasgow Cardiovascular Research Centre University of Glasgow Glasgow Centre for Excellence in Signal and Image Processing University of Strathclyde Glasgow

Evaluating salvageable myocardial after myocardial infarction (MI) is an important prognosis in the follow up study of MI. Since the extent of myocardial edema delineates the ischemic area-at-risk (AAR) after MI the AAR can be used to estimate the amount of salvageable myocardial post-MI and therefore has potential clinical utility in the management of acute MI patients. Two methods for the segmentation and quantification of edema from T2 weighted MRI data have been presented. The methods presented in this paper are Two Statistical Mixture Model and Fuzzy C-means. Quantitative evaluations of segmentation accuracy for the two algorithms were performed by comparing to manual segmentation on real T2 weighted CMR data collected from Golden Jubilee National Hospital, Glasgow for 16 adult subjects.

关键词： Myocardium Manuals image segmentation

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An enhanced solutioning design for military tactical voice communication systems

An enhanced solutioning design for military tactical voice c...

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2012 7th IEEE Conference on Industrial Electronics and Applications, ICIEA 2012

作者： Lim, Wee-Tong Singh, Hargobind Sinanović, Sinan Haas, Harald Faculty of Engineering National University of Singapore Singapore Singapore Joint Research Institute for Signal and Image Processing University of Edinburgh United Kingdom

ISBN: (纸本)9781457721175

Great emphasis has always been placed on military communication especially in the wireless spectrum. There is a need for more robust links with higher probability of intercept at the reception end and lower bit error rate (BER) at the transmission front. This is coupled with the requirement to have minimum exposure to loss or distortion of information. In this paper, we propose an enhanced solutioning design based on receiver and transmitter implementation to develop a wider encompassing solution. The receiver implementation will include the integration of a Speech Enhancement System (SES) where methods for noise estimation and reduction will be briefly introduced. The emphasis is on the employment of Arc-Tangent Square Root (ATSR) nonlinear device in the speech enhancement module for harmonic regeneration. For transmitter implementation, we propose a new modulation scheme - Simultaneous Spatial Modulation (SSM) - that reduces power consumption for the same bit error rate (BER) or given the same power, reduces transmission error, thereby increasing the rate of effective communication. Simulation results are presented to verify the effectiveness of the proposed modulation scheme. © 2012 IEEE.

关键词： Transmitters

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Energy Evaluation of Spatial Modulation at a Multi-Antenna Base Station

Energy Evaluation of Spatial Modulation at a Multi-Antenna B...

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IEEE Vehicular Technology Conference

作者： Athanasios Stavridis Sinan Sinanovi? Marco Di Renzo Harald Haas Institute for Digital Communications Joint Research Institute for Signal and Image Processing School of Engineering The University of Edinburgh Edinburgh UK School of Engineering and Built Environment Glasgow Caledonian University Glasgow UK Laboratory of Signals and Systems (L2S) French National Center for Scientific Research (CNRS) école Supérieure d'électricité (SUPéLEC) University ofParis-Sud XI (UPS) Paris France

ISBN: (纸本)9781467361866

In this paper, we aim to study the Energy Efficiency (EE) of Spatial Modulation (SM) at different Base Stations (BSs) taking into account the total power consumption. Compared to conventional Multiple-Input Multiple-Output (MIMO) schemes, SM benefits from a single Radio Frequency (RF) chain which results in decreased power supply (W), higher EE (Mbits/J), and reduced complexity. Using the fundamental limits of Shannon capacity, we show that SM achieves a range of average data rates with only a fraction, which can be as low as 24% for four transmit antennas, of the total power supply of conventional MIMO. In addition, we demonstrate that the EE of the studied schemes is maximized for a certain average data rate and that SM achieves the highest EE among them. Finally, we note that a BS employing SM can be up to 67% more energy efficient compared to a BS under a conventional MIMO transmission scheme, for four transmit antennas.

关键词： EE SM BSs

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Globally convergent 3D dynamic PET reconstruction with patch-based non-convex low rank regularization

Globally convergent 3D dynamic PET reconstruction with patch...

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IEEE International Symposium on Biomedical Imaging

作者： K. S. Kim Y. D. Son Z. H. Cho J. B. Ra J. C. Ye Bio Imaging & Signal Processing Laboratory Department of Bio& Brain Engineering Korea Advanced Institute of Science and Technology South Korea Neuroscience Research Institute Gachon University of Medicine and Science South Korea Image Systems Laboratory Electrical Engineering Korea Advanced Institute of Science and Technology South Korea

ISBN: (纸本)9781467364560

Dynamic positron emission tomography (PET) is widely used to measure variations of radiopharmaceuticals within the organs over time. However, conventional reconstruction algorithm can produce a noisy reconstruction if there are not sufficient photon counts. Hence, the main goal of this paper is to develop a novel spatio-temporal regularization approach that exploits inherent similarities within intra- and inter-frames to overcome the limitation. One of the main contributions of this paper is to demonstrate that such correlations can be exploited using a low rank constraint of overlapping similarity blocks. The resulting optimization framework is, however, non-smooth and non Lipschitz due to the low-rank penalty terms and Poisson log-likelihood. Therefore, we propose a novel globally convergent optimization method using the concave-convex procedure (CCCP) by exploiting Legendre-Fenchel transform, which overcomes the memory and computational limitations. We confirm that the proposed algorithm can provide significantly improved image quality and extract accurate kinetic parameters.

关键词： image reconstruction Positron emission tomography Heuristic algorithms Graphics processing units Minimization Optimization Biomedical imaging

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Spectral-Energy Efficiency Tradeoff in Multicell Cellular Networks with Adaptive Relay Cooperation

Spectral-Energy Efficiency Tradeoff in Multicell Cellular Ne...

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IEEE Global Communications Conference

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

ISBN: (纸本)9781467309202

By observing that the relay stations (RSs) will receive a signal replica of the users' transmissions during the broadcast phase, we propose an adaptive relay cooperation scheme. The RSs will utilize the readily available signal replica and the additional diversity naturally inherent in them to either perform cooperative multipoint (COMP) relaying or remain silent with only the direct transmission being considered. We investigate this scheme in a 7 cell network to demonstrate system level capacity and energy efficiency improvements. Results show that the proposed scheme outperforms the conventional adaptive relay scheme and is able to benefit from the more aggressive full bandwidth frequency reuse plan at low relay transmit power.

关键词： Green communication Adaptive relay cooperation MIMO Spectral-energy efficiency tradeoff multiple input multiple output systems relay SPECTRAL ENERGY Transmitter power Cellular networks multicell Self tuning Scheme tradeoffs

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Optimum signal Shaping in OFDM-based Optical Wireless Communication Systems

Optimum Signal Shaping in OFDM-based Optical Wireless Commun...

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IEEE Vehicular Technology Conference

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

ISBN: (纸本)9781467318808

In this paper, a framework for optimum signal shaping in multi-carrier modulation is presented for optical wireless communications (OWC). The two fundamental multi-carrier transmission schemes based on orthogonal frequency division multiplexing (OFDM), direct-current-biased optical OFDM (DCO-OFDM) and asymmetrically clipped optical OFDM (ACO-OFDM), are studied. The optimum signal shaping is denned as optimum biasing and optimum scaling of the time domain signal within the optical power constraints of the transmitter front-end. These include the boundaries of the limited linear dynamic range, such as minimum and maximum radiated optical power, and the desired average optical power level. As a result, the minimum required electrical signal-to-noise ratio (SNR) to maintain a target bit-error ratio (BER) is obtained for a desired multilevel quadrature amplitude modulation (M-QAM) scheme and a given combination of optical power constraints. The average optical power is varied over dynamic ranges of 10 dB, 20 dB and 30 dB. With the increase of the dynamic range and for a major portion of the average optical power levels, DCO-OFDM demonstrates a lower minimum electrical SNR requirement for a target BER as compared to ACO-OFDM for modulation orders with similar spectral efficiencies.

关键词： signal shaping Optimization DCO-OFDM ACO-OFDM Optical wireless communication signal shaping average optical power signal to noise ratios Orthogonal frequency division multiplexing Dynamic range Wireless communication systems TIME-DOMAIN Multicarrier modulation Optical wireless multilevel quadrature amplitude modulation Optimum optical

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Novel Unipolar Orthogonal Frequency Division Multiplexing (U-OFDM) for Optical Wireless

Novel Unipolar Orthogonal Frequency Division Multiplexing (U...

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IEEE Conference on Vehicular Technology (VTC)

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 U-OFDM is proposed. U-OFDM uses different time sample states and an innovative rearrangement of the Orthogonal Frequency Division Multiplexing (OFDM) frame which allow for the creation of unipolar OFDM signals required for Optical Wireless Communication (OWC) with Light Emitting Diodes (LEDs). In comparison to similar techniques like DC-biased Optical OFDM (DCO-OFDM) and Asymmetrically Clipped Optical OFDM (ACO-OFDM), U-OFDM is both optically and electrically more power efficient in an Additive White Gaussian Noise (AWGN) channel, which is prevalent in an optical wireless system.

关键词： OFDM Wireless communication Time domain analysis Demodulation Bit error rate Optical receivers

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Energy efficient resource allocation in wireless systems with control channel overhead

Energy efficient resource allocation in wireless systems wit...

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IEEE Wireless Communications and Networking Conference Workshops (WCNCW)

作者： Stefan Videv Harald Haas John S. Thompson Peter M. Grant School of Engineering Joint Research Institute for Signal and Image Processing University of Edinburgh Edinburgh UK

This paper presents a novel resource scheduling technique named Time Compression Mode (TCoM) that allows energy aware schedulers to decrease the energy consumption within orthogonal frequency division multiple access (OFDMA) type systems - for example the Long Term Evolution (LTE) system. TCoM allows users whose energy consumption is dominated by control channel overhead, to reduce their overall energy expenditure by reducing the number of resource blocks (RBs) allocated to them. This leads to an overall reduction in the used energy due to the decrease in energy used for overhead transmission. To ensure correct operation, TCoM has to be coupled with an energy aware scheduler. This combination not only reduces the used energy, but is also able to increase the achieved user data rate. Simulation results show that the data rate performance is equivalent for 86.8% of the users, however the remaining 13.2% enjoy approximately double the data rate delivered by the benchmark. The overall used energy is decreased by 26% on average. These results are achieved for an future base station (BS) overall hardware efficiency model.

关键词： Resource management Interference Radio frequency Modulation signal to noise ratio Hardware Energy consumption

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