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The rapid spread of the Internet has brought a significant increase in energy consumption of network equipment. Since the energy crisis and environmental protection are of increasing concern in recent years, many research efforts are in use to save energy. In this context, the present research focuses on reducing the energy consumption of an IP over WDM backbone network using the lightpath bypass...
In modern, competitive, and dynamic access networks the underlying bandwidth distribution mechanism has to be capable of understanding user requirements, meeting stringent quality of service (QoS) demands, and satisfying a broad spectrum of user traffic dynamics. Undoubtedly, optical fiber is the dominant transmission medium enabling practical and cost-effective optical infrastructures in the last...
Energy-aware lightpath routing and establishment in optical backbone networks can reduce energy consumption. A heuristic method suitable for network's Planning phase, based on Swarm Intelligence and Grooming practices is proposed that reduces the energy footprint by taking advantage of asymmetric bandwidth split across multiple streams routed to the same destination through different paths. The Ant...
The aim of this paper is to demonstrate the ability of a fiber optical parametric amplifier to increase the number of carriers two times in a 32 channel wavelength-division-multiplexed active optical network. The parametric amplifier is placed at the receiver section. The 32 carriers are obtained by using 16 initial carriers, which while processing through the high non-linearity fiber, initiated the...
An iterative low-complexity channel estimation algorithm for OFDM signals in frequency domain is presented. Algorithm uses initial channel estimation based on pilot subcarriers, 1-D adaptive Wiener filtering in the time direction and Maximum a-posteriori probability (MAP) estimation that uses both pilot and weighted data subcarriers. The final step is the simplified version of an iterative Expectation-Maximization...
Relaying is considered in LTE-A networks as a promising solution to increase the capacity and improve the coverage. Resource sharing among different nodes and links and inter-cell interference coordination (ICIC) are challenging issues to obtain a real performance gain linked to relay deployments. This paper focuses on Type 1 half-duplex inband relaying. We propose a dynamic resource allocation (RA)...
Relaying is a promising solution to increase the capacity and improve the experience of users in LTE-A networks. Nevertheless, inter-cell interference coordination (ICIC) and resource sharing among different nodes and links are important challenges in order to obtain a real benefit from relay deployments. This paper focuses on Type 1 half-duplex inband relaying. Several strategies related to resource...
In this paper we introduce an adaptive channel estimation scheme for two-way relay with node capability. The adaptive filter used is called Block Fast Array Multichannel 2D-Recursive Least Square (BFAM 2D-RLS). The modulation used is Orthogonal Frequency Division Multiplexing (OFDM) and channel estimation is done in the frequency domain. The proposed channel estimator considers correlation of channel...
In this paper, the ergodic capacity maximization problem in case of coexistence between digital video broadcasting (DVB) and long term evolution (LTE) systems is studied. A full interference scenario, i.e. where the DVB and LTE systems spectrally overlap, is assumed. The objective function, defined as the summation of the LTE and DVB system capacities, is shown to be constituted by a convex and concave...
Evolved Multimedia Broadcast Multicast Service (eMBMS) is used for efficient content delivery to multiple users in Long Term Evolution (LTE) networks. In most cases eMBMS allows to use radio resources more efficiently comparing to unicast content delivery. It will be shown in this paper how many users should receive the same content to activate broadcasting instead of unicast delivery.
Nowadays simplified mathematical models and numerical simulation are widely used for the analysis of QPSK Costas loop. In the work it is shown that the use of simplified mathematical models and the application of non-rigorous methods of analysis may lead to wrong conclusions concerning the operability of real model of QPSK Costas loop.
The paper deals with the robust algorithm for consensus control of dynamical networks where each local subsystem is described by nonlinear differential equation with delay, unknown parameters and disturbances. The algorithm provides the network synchronization and compensates uncontrollable disturbances with a given accuracy. Analytical results are presented by network consisting of four nodes.
In the present work for checking conjecture on pull-in range of two-phase Costas loop, a number of numerical experiments in MatLab Simulink has been made. In addition, the analytical approach to the proof of the conjecture is presented.
Nonlinear analysis of BPSK Costas loop is a difficult task, so for its analysis simplified mathematical models and their simulation are widely used. In the work it is shown that the use of simplified mathematical models and the application of non-rigorous methods of analysis may lead to wrong conclusions concerning the operability of real model of BPSK Costas loop. Corresponding examples of BPSK Costas...
A modification of BPSK Costas loop, where low pass filters are applied separately from the loop, is considered. Such modification of the loop can work with non-sinusoidal signals or with some special phase detectors instead of multipliers. In this paper a general approach to the analytical computation of phase detector characteristic of the loop for general periodic signal waveforms is demonstrated...
In this paper, we analyzed how does life and reliability of an integrated circuit is affected when it is operated in different regions under different temperatures. We have taken Fibonacci generator as our target circuit and LVCMOS as I/O standards. WPA and WPA2 (Wi-Fi Protected Access) key can be generated with Fibonacci generator. Here, thermal efficient green Fibonacci Generator is used to generate...
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