25,056 research outputs found

    Design and Simulation of Wave Shaping Schemes for a Virtual Data Communication and Impaired Link Environment System for Advanced ICT Education

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    Design and Simulation of Waves Shaping Schemes for a Virtual Data Communication and Impaired Link Environment System for Advanced ICT Education is aimed at providing a simulator for the performance of digital filtering of signals for data communication experiments with the aid of MATLAB. A fundamental aspect of signal processing is filtering. Filtering involves the manipulation of the spectrum of a signal by passing or blocking certain portions of the spectrum, depending on the frequency of those portions. This work is designed to provide a flexible platform for teaching the operations of waves shaping schemes (lowpass, bandpass and highpass) modelled over an additive white Gaussian noise (AWGN) channel. Keywords – Lowpass, Bandpass, Highpass, MATLAB

    Detection and tracking for radar simulation using MATLAB

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    The objective of the project is to simulate the real time Radar detection and tracking operations using MATLAB software. Radar system use modulated waveforms and directive antennas to transmit electromagnetic energy into a specific volume in space to search for targets. Objects (targets) within a search volume will reflect portions of this energy (radar returns or echoes) back to the radar. These echoes are then processed by radar receiver to extract target information such as range. Velocity, angular position, and other target identifying characteristics. The project mainly concentrates on the radar displays and different radar types to collect the information of the flying objects, such as the range, speed, distance, angles. The display types are A-scope, B-scope, C-scope, PPI, and RHI, which are used in modern radars. While others are either obsolete or are found only in very specialized applications. Signals displayed on these scopes can be raw video, synthetic video (detected video) or computer-generated symbols. The radar types consider in the project are CWT (Continuous Wave Transmission), Pulse, Doppler, and MTI (Moving Target Indicator). For each display, all the values related to the object are calculated in different patterns and graphs for the corresponding formulated values and angles

    Josephson effect in mesoscopic graphene strips with finite width

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    We study Josephson effect in a ballistic graphene strip of length LL smaller than the superconducting coherence length and arbitrary width WW. We find that the dependence of the critical supercurrent IcI_{c} on WW is drastically different for different types of the edges. For \textit{smooth} and \textit{armchair} edges at low concentration of the carriers IcI_{c} decreases monotonically with decreasing W/LW/L and tends to a constant minimum for a narrow strip W/L1W/L\lesssim1. The minimum supercurrent is zero for smooth edges but has a finite value eΔ0/e\Delta_{0}/\hbar for the armchair edges. At higher concentration of the carriers, in addition to this overall monotonic variation, the critical current undergoes a series of peaks with varying WW. On the other hand in a strip with \textit{zigzag} edges the supercurrent is half-integer quantized to (n+1/2)4eΔ0/(n+1/2)4e\Delta_{0}/\hbar, showing a step-wise variation with WW.Comment: 4 pages, 3 figure

    Two-Stage LASSO ADMM Signal Detection Algorithm For Large Scale MIMO

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    This paper explores the benefit of using some of the machine learning techniques and Big data optimization tools in approximating maximum likelihood (ML) detection of Large Scale MIMO systems. First, large scale MIMO detection problem is formulated as a LASSO (Least Absolute Shrinkage and Selection Operator) optimization problem. Then, Alternating Direction Method of Multipliers (ADMM) is considered in solving this problem. The choice of ADMM is motivated by its ability of solving convex optimization problems by breaking them into smaller sub-problems, each of which are then easier to handle. Further improvement is obtained using two stages of LASSO with interference cancellation from the first stage. The proposed algorithm is investigated at various modulation techniques with different number of antennas. It is also compared with widely used algorithms in this field. Simulation results demonstrate the efficacy of the proposed algorithm for both uncoded and coded cases.Comment: 5 pages, 4 figure
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