544 research outputs found
Fabrication and characterization of integrated photonic crystal cavities for sensing applications
Experimental investigation of RF fading channels and receiver detection
This thesis includes experimental investigation of Multiple Input Multiple Output (MIMO) Radio Frequency (RF) fading channels and detection of superregenerative receivers. Details of experiment design and hardware implementation, data acquisition and analysis, and results for both studies are chronicled into two papers. The first paper investigates the validity of the discrete time triply selective fading channel model for fixed mobile-to-mobile MIMO channels. A 2x2 MIMO-OFDM testbed using the Altera Stratix III EP3SL150F field programmable gate array (FPGA) DSP development kit is used for acquiring experimental data. Subsequent offline signal processing and analysis are done in MATLAB. The Channel Impulse Response (CIR) is estimated using the Time domain Least Squares (LS) method. The channel coefficient covariance matrix is decomposed into its Kronecker factors - the spatial correlation matrix, inter-tap correlation matrix, and temporal correlation matrix. This study verifies the theoretical hypothesis and simulation results. The second paper proposes a novel method for detection of the superregnerative RF receivers. The algorithm is based on active stimulation and correlation of long pseudonoise (PN) sequences. An experimental setup is established using the Universal Software Radio Peripheral (USRP) as the primary component. Simulation results show that the maximum length PN sequences exhibit the best correlation properties among different potential stimulation signals. Proposed method improves range and accuracy of detection as compared to the passive detection and power detection methods --Abstract, page iv
Minimizing Age of Information under Latency and Throughput Constraints
We consider a scheduling problem pertinent to a base station (BS) that serves
heterogeneous users (UEs). We focus on a downlink model, with users that are
either interested in large throughput, low latency (the time difference between
the packet arrival at the BS, and reception at the UE), or low
age-of-information (AoI, the difference between the current time and the
arrival time of the latest packet at the BS that has been received at the UE).
In each time step, the BS may serve a limited number of UEs. The objective is
to find a scheduling algorithm that meets the individual service requirements
of all the UEs. In this paper, we formulate the aforementioned objective as an
optimization problem, and propose candidate solutions (algorithms) that
rationalize the tradeoff between throughput, latency and the AoI. Then, we
analyze the performance of the proposed algorithms both analytically and
numerically, and discuss techniques to extend their applicability to other
general setups.Comment: 12 pages, 10 figure
ENHANCE PREDICTION PERFORMANCE THROUGH CONTINUOUS MONITORING OF WIND TURBINE
India lost first place in worldwide ranking on total installed wind capacity to china. Due to some issues like, grid issue, unavailability of infrastructure, monitoring wind turbine, offshore wind related R & D activities in the country, etc. This makes attributed to the slower pace to addition of wind power capacity; due to unavailability of on-shore wind sites with sufficiently high wind velocity is expected to take centre stage in the next few years. Low wind velocity makes the investment unattractive to developers. In current situation, monitoring and R & D is an investment option. Which has already seen favourable response in a country like china Germany, Denmark would begins in India. This analyses the present situation of wind energy farm at District Devas, Madhya Pradesh and investigates the possibilities of monitor the wind turbine to enhance the performance. In this paper, wind speed, peak speed, standard deviation, wind power density is to estimated monthly at different altitude. Monitor capacity factor, energy generated through wind turbine, X-chart and R-chart drawn, maintenance and environmental impact have been analyzed
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