Department of Electrical Engineering

Indian Institute of Technology Palakkad&nbsp;(IIT Palakkad or IIT PKD) is a public autonomous&nbsp;engineering&nbsp;and&nbsp;research&nbsp;institute located in&nbsp;Palakkad,&nbsp;Kerala. It was&nbsp;one of the five new&nbsp;IITs&nbsp;proposed in the&nbsp;2014 Union budget of India. The campus was inaugurated on 3 August 2015. The institute has 94 faculty, 978 students, and 63 non-teaching staffs.

IT Palakkad currently offers four-year Bachelor of Technology (B.Tech) and two years MS programmes in 8 different engineering disciplines including&nbsp;Computer Science, Electrical, Mechanical, Civil among others.

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IIT Palakkad

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arXiv e-prints, arXiv: 1512.

Convergence Analysis of Proportionate-type Least Mean Square Algorithms

Managing inter-cell interference is one of the main challenges in current and next generation wireless systems that aggressively reuse the frequency. Cooperation between interfering cells has been sought to mitigate interference. In this paper, we address the problem of jointly optimizing the transmit powers, user scheduling, and user association in a cellular network to maximize the weighted sum rate (WSR). To this end, we develop a distributed interference penalty algorithm in which the cells update their transmit powers and user schedule to maximize its utility minus an interference cost. The proposed algorithm involves only limited exchange of information via backhaul and has convergence guarantees. Furthermore, we propose a sub-optimal algorithm with lower computational and backhaul overhead. In it, the users are first associated to the base stations (BSs) based on their signal-to-interference-plus-noise-ratios (SINRs). It is then followed by joint optimization of BS transmit powers and user scheduling, for which we develop an interference penalty algorithm as well. We show that the proposed algorithms outperform the computationally complex weighted minimum mean squared error (WMMSE) algorithm. © 2015 IFIP.

2015 13th International Symposium on Modeling and Optimization in Mobile, Ad Hoc, and Wireless Networks, WiOpt 2015

Downlink interference penalty algorithm for power control, scheduling, and user association

A capacitance-to-digital converter (CDC) that gives a digital value proportional to the change in the capacitance of a sensor, independent of its nominal capacitance, is presented in this paper. The CDC presented is suitable for single element capacitive sensors. For most of the CDCs, available in the market, the output depends on the nominal value of the sensor. Thus, a manual intervention for appropriate correction in the output is required whenever a new sensor is connected to such CDCs. The proposed CDC uses a simple automatic calibration, employing a digitally controlled reference voltage in a feedback topology, and provides an output independent of the nominal value of the sensor employed. This automatic calibration also removes the dependence on the accuracy of the absolute value of reference capacitor, in the final output. The proposed CDC is based on a switched-capacitor dual-slope technique and possesses the advantages of the dual-slope conversion method. A prototype CDC has been developed and the test results are presented. The results obtained show that the output of the proposed converter is not a function of the nominal capacitance of the sensor for a wide range (50 pF to 1.15 nF). For this range, the worst error noted from the prototype CDC was less than 0.65 %. © 2015 IEEE.

Conference Record - IEEE Instrumentation and Measurement Technology Conference

A novel switched-capacitor capacitance-to-digital converter for single element capacitive sensors

This paper proposes a synchrophasors-assisted intelligent relaying scheme for transmission lines compensated by Unified Power Flow Controller (UPFC). The algorithm uses a new relaying signal termed as imaginary part of integrated impedance (IPII). The synchronized phasor measurements at both ends of the transmission line are used to extract voltage and current phasors from instantaneous voltage and current signals. The voltage and current phasors are utilized to derive IPII of each phase. Further, IPII of each phase is used as input to a data-mining model termed as decision tree (DT) which provides the final relaying decision. The proposed algorithm is validated on real-time digital simulator (RTDS) platform, and the results obtained indicate that the proposed scheme is both dependable and secure in protecting transmission system compensated by UPFC. © 2015 Walter de Gruyter GmbH.

Fulltext

International Journal of Emerging Electric Power Systems

Synchrophasors-assisted IPII-based intelligent relaying for transmission lines including UPFC

The paper presents a comprehensive intelligent relaying scheme using phase angle of differential impedance (PAODI) for series compensated double circuit transmission lines. The differential impedance (DI) is the ratio of differential voltage phasors of any phase across two ends of the transmission line to the differential current phasors of the same phase of the same transmission line. The PAODI of each phase are used as inputs to the data mining model known as decision tree (DT) to generate final relaying decision to identify the faulty phase(s) involved. The proposed scheme is extensively validated for different fault scenarios including inter-circuit and cross-country faults on the series-compensated parallel transmission developed on Real Time Digital Simulator (RTDS) platform. The test results obtained indicate that the proposed PAODI based intelligent relaying scheme is both dependable and secure in protecting series compensated double circuit transmission lines with a response time of less than 1 and 1/2 cycles. © 2015 Elsevier Ltd. All rights reserved.

International Journal of Electrical Power and Energy Systems

Intelligent relaying scheme for series-compensated double circuit lines using phase angle of differential impedance

Ground-based microwave radiometers operating at frequencies near the 22.235 GHz (K-band) water vapor absorption line have been used extensively for remote sensing of water vapor in the troposphere, both the integrated amount and its profile. This paper explores the potential to use ground-based, zenith-pointing K-band radiometer measurements along with optimized background data sets consisting of radiosonde profiles to detect dynamic changes and gradients in water vapor profiles. To explore this capability, the HUMidity EXperiment 2011 (HUMEX11) was conducted at the U.S. Department of Energy's (DOE) Atmospheric Radiation Measurement (ARM) Southern Great Plains (SGP) Site near Lamont, OK, USA. This enables the choice of appropriate retrieval parameters to monitor temporal changes in atmospheric water vapor profiles. The results of this study illustrate that in a retrieval algorithm both the choice of the size of the background data set measured near the radiometer measurement time and the choice of atmospheric layer thickness affect the ability to remotely sense dynamic changes in water vapor. In general, it is found that background data sets of larger size provide better accuracy in a statistical sense but inhibit the ability to detect gradients. © 2015 IEEE.

IEEE Journal of Selected Topics in Applied Earth Observations and Remote Sensing

Optimization of Background Information and Layer Thickness for Improved Accuracy of Water-Vapor Profile Retrieval from Ground-Based Microwave Radiometer Measurements at K-Band

We report a series of metal insulator semiconductor devices with embedded Pt nano particles (NPs) fabricated using a low temperature atomic layer deposition process. Optically sensitive nonvolatile memory cells as well as optical sensors: (i) varactors, whose capacitance-voltage characteristics, nonlinearity, and peak capacitance are strongly dependent on illumination intensity; (ii) highly linear photo detectors whose responsivity is enhanced due to the Pt NPs. Both single devices and back to back pairs of diodes were used. The different configurations enable a variety of functionalities with many potential applications in biomedical sensing, environmental surveying, simple imagers for consumer electronics and military uses. The simplicity and planar configuration of the proposed devices makes them suitable for standard CMOS fabrication technology. © 2015 AIP Publishing LLC.

Journal of Applied Physics

Optically sensitive devices based on Pt nano particles fabricated by atomic layer deposition and embedded in a dielectric stack

In contemporary orthogonal frequency division multiplexing (OFDM) systems, such as Long Term Evolution (LTE), LTE-Advanced, and WiMAX, a codeword is transmitted over a group of subcarriers. Since different subcarriers see different channel gains in frequency-selective channels, the modulation and coding scheme (MCS) of the codeword must be selected based on the vector of signal-to-noise-ratios (SNRs) of these subcarriers. Exponential effective SNR mapping (EESM) maps the vector of SNRs into an equivalent flat-fading SNR, and is widely used to simplify this problem. We develop a new analytical framework to characterize the throughput of EESM-based rate adaptation in such wideband channels in the presence of feedback delays. We derive a novel accurate approximation for the throughput as a function of feedback delay. We also propose a novel bivariate gamma distribution to model the time evolution of EESM between the times of estimation and data transmission, which facilitates the analysis. These are then generalized to a multi-cell, multi-user scenario with various frequency-domain schedulers. Unlike prior work, most of which is simulation-based, our framework encompasses both correlated and independent subcarriers and various multiple antenna diversity modes; it is accurate over a wide range of delays. © 2015 IEEE.

IEEE Transactions on Wireless Communications

Characterizing the impact of feedback delays on wideband rate adaptation

This paper explores the consequences of introducing a piezoelectric gate barrier in a normal field-effect transistor. Because of the positive feedback of strain and piezoelectric charge, internal charge amplification occurs in such an electromechanical capacitor resulting in a negative capacitance. The first consequence of this amplification is a boost in the ON-current of the transistor. As a second consequence, employing the Lagrangian method, we find that using the negative capacitance of a highly compliant piezoelectric barrier, one can potentially reduce the subthreshold slope of a transistor below the room-temperature Boltzmann limit of 60 mV/decade. However, this may come at the cost of hysteretic behavior in the transfer characteristics. © 2014 IEEE.

IEEE Journal on Exploratory Solid-State Computational Devices and Circuits

Transistor Switches Using Active Piezoelectric Gate Barriers

This paper presents tracking control laws for two different objectives of a nonholonomic system - a spherical robot - using a geometric approach. The first control law addresses orientation tracking using a modified trace potential function. The second law addresses contact position tracking using a $right$ transport map for the angular velocity error. A special case of this is position and reduced orientation stabilization. Both control laws are coordinate free. The performance of the feedback control laws are demonstrated through simulations.