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In this paper, a Metascheduler architecture is proposed to be used on Cloud Computing environments. The aim of this Metascheduler architecture is to handle the submission of a service and to manage the infrastructure of the Grid resources belonging to the Cloud. Futhermore, this Metascheduler also aims of building the best pool of available resources for the implementation of the requests issued by...
The bidirectional broadcast channel denotes a broadcast channel with two receivers where each receiver knows the message intended for the other. Exponentially decreasing upper bounds on the average error probability using maximum likelihood decoders are derived based on Gallager's results for the point-to-point channel. The bounds are coupled by the common input distribution and provide an alternative...
This paper studies the problem of limited feedback design for heterogeneous multiuser transmissions over time- and frequency-selective (doubly selective) multiple-input multiple-output (MIMO) downlink channels. In limited feedback design over the channels, the discrete prolate spheroidal basis expansion model (DPS-BEM) is used as a fitting parametric model for capturing the time-variation of the multiuser...
Out-of-Band (OOB) radiations in Orthogonal Frequency Division Multiplexing (OFDM) system leads to the wastage of the scarce spectral resources and may pose severe interference threats to the legacy user in dynamic spectrum sharing environment. In this paper, we propose a novel technique for reducing OOB radiations caused by the high sidelobes in OFDM system. The principle of this technique is to map...
The cost of an optical network in Wavelength-Division Multiplexing (WDM) networks can be reduced by using optical add/drop multiplexers (OADMs) which allow traffic to pass through without the need for an expensive optical-electro-optical (O-E-O) conversion. OADMs can be used to add/drop specific wavelengths as in the case of fixed OADMs (FOADMs), or more flexible as in reconfigurable OADMs (ROADMs)...
A mathematical model is introduced for performance evaluation of an OBS core node employing either no or full wavelength conversion strategies. Furthermore, the model assumes long-range dependent (LRD) traffic arrivals to the OBS intermediate node which are accurately modeled by Pareto distribution. In our proposed model, each output port is imitated by a GI/M/w/w queue for which a single performance...
In this paper, we propose a statistical channel model, named as Double-Weibull, to describe the irradiance fluctuations in moderate and strong turbulence for free-space optical (FSO) systems. The proposed stochastic model is based on the scintillation theory and derived via the product of two Weibull random variables. Closed-form expressions of probability and cumulative density functions are provided...
We consider a wireless relay network with one source, one relay and one destination, where communications between nodes are preformed over N orthogonal channels. This, for example, is the case when orthogonal frequency division multiplexing is employed for data communications. Since the power available at the source and relay is limited, we study optimal power allocation strategies at the source and...
The performance of various modulation schemes for 100 Gbit/s single channel serial transmission is investigated by means of numerical simulations. Different ASK and PSK modulation formats are compared in terms of total system reach for a 10-9 BER requirement. RZ-DQPSK format with a 1,920 km reach, without FEC and the support of additional Raman amplification, outperforms all the other schemes including...
Due to inconsistent atmospheric conditions, scattering and scintillation of free space optical (FSO) signal can occur, thus negatively influencing the received signal intensity. The channel is usually modeled as a normalized fading coefficient with additive Gaussian noise. Optimal detection of the received signal is designed based on a decision rule, e.g., Maximum Likelihood (ML), assuming the receiver...
Due to the advance in WDM technology and real-time applications, multicast communication is discussed recently. An important issue for real-time communication, fault restoration schemes, lets multicast communication reliable. In this paper, a novel QoS restoration scheme based on domination set (HFR-DS) is proposed. The domination node can provide dynamic method to generate the restoration path. This...
Multi-mode systems make it possible to achieve multiple services on one platform, typically an FPGA. However, reconfiguration time and power, limit the extent to which reconfiguration can be applied. Traditionally, either complete modules have to be swapped out or they can co-exist on chip. In this work, we propose a methodology for exploring a larger reconfiguration space for a class of systems that...
In this paper we extended a previously investigated modular method that is designed to compensate for interpolation distortions of one-dimensional signals, to two dimensions (2-D). Next the proposed 2-D modular technique was applied in an iterative fashion and was shown through both simulations and theoretical analyses to enhance the convergence of the iterative technique. In fact, with only a few...
Wireless Networks based on WIFI or WIMAX become popular and are used in many places as compliment network to wired LAN to support mobility. There is performance issues associated with the usage of WLAN that put some restriction on adapting this technology everywhere. Securing the open access to avoid attacks at the physical and MAC layer with high speed performance during authentication is considered...
In this paper, we propose a new architecture for tunable Fabry-Perot (FP) interferometer using fiber Bragg gratings (FBGs). The main feature of the architecture is its ability to increase the finesse using a potentially low cost technique. Furthermore, it decreases the power loss of the filtered channel and can be implemented easily in practice.
Recently, hardware and software engineers have been showing considerable attention to high-level parallelization and hardware synthesis methodologies. State-of-the-art approaches have benefited from the emergence of modern high-density Field Programmable Gate Arrays. In this paper, we explore the effectiveness of a formal methodology in the design of pipelined versions of a matrix multiplication algorithm...
In this paper, a novel Bitplane-LVQ technique to compress subbands bitplane coefficients is proposed for multiple description coding (MDC) system. The MDC system utilizes three descriptions with one central decoder and three side decoders. The significant bitplanes subband coefficients are encoded using lattice D2 which the number of bitplanes (k) ties with the amount of compression ratio. The residual...
Dynamic software reconfiguration is the process of updating the system software during its execution. A dynamic software reconfiguration mechanism for an embedded system must be simple, transparent to applications, and use the minimum amount of resources (e.g. memory, processing) possible, since it shares resources with the target embedded system. We present Epos Live Update System (Elus), an operating...
A performance analysis of a core node in an OBS network having wavelength converters in the node resources is presented. The analysis assumes that the wavelength converters are deployed at the input ports of the node such that the node may have variable wavelength conversion capability. This means that the node may have no, partial or full conversion capability. The no and partial wavelength conversion...
In this paper, we investigate the optimization problem of resource allocation in downlink of multiuser MISO-OFDM system. Multiple users with different BER and minimum transmission rate requirements are considered. We propose a novel heuristic allocation algorithm (HAA) of radio resource, which minimizes the total transmit power of the base station while meeting individual users'QoS requirements. The...
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