26,139 research outputs found
Detection and tracking for radar simulation using MATLAB
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
We study Josephson effect in a ballistic graphene strip of length smaller
than the superconducting coherence length and arbitrary width . We find that
the dependence of the critical supercurrent on is drastically
different for different types of the edges. For \textit{smooth} and
\textit{armchair} edges at low concentration of the carriers decreases
monotonically with decreasing and tends to a constant minimum for a
narrow strip . The minimum supercurrent is zero for smooth edges
but has a finite value 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 . On the other
hand in a strip with \textit{zigzag} edges the supercurrent is half-integer
quantized to , showing a step-wise variation with
.Comment: 4 pages, 3 figure
Two-Stage LASSO ADMM Signal Detection Algorithm For Large Scale MIMO
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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