Department of Electrical Engineering

Indian Institute of Technology Hyderabad (IITH) is a premier institute of science and technology established in 2008. IITH has been consistently ranked in the&nbsp;<a href="https://iith.ac.in/reports/" rel="noopener noreferrer">top 10 institutes</a>&nbsp;in India for Engineering&nbsp;<a href="https://www.nirfindia.org/2021/EngineeringRanking.html" rel="noopener noreferrer" target="_blank">according to NIRF</a>&nbsp;making it one of the most coveted schools for science and technology in the country.

IITH offers&nbsp;<a href="https://iith.ac.in/academics/under-graduate/">undergraduate programs</a>&nbsp;in all the classical engineering disciplines, applied sciences, design, as well as several modern interdisciplinary areas. Students are given a flexibility to explore a broad set of areas, and potentially pursue a minor or double major in a discipline that is not their own. Students who wish to seek a deeper understanding of their own discipline are strongly encouraged to get involved in cutting-edge research with the help of a faculty to mentor them, and earn an Honors in their own field.

The very foundation of IIT Hyderabad is based on&nbsp;<a href="https://iith.ac.in/research/">research and innovation</a>. The vibrant research culture is evident from the number of patents and publications that IITH produces consistently every year. IITH offers&nbsp;<a href="https://iith.ac.in/academics/programmes-offered/">graduate programs</a>&nbsp;at both a masters, and a doctoral level, in several diverse areas. There are separate programs for technology, design, science, and liberal arts. The&nbsp;<a href="https://iith.ac.in/academics/post-graduate/">MTech program</a>&nbsp;is offered in various modes and durations to cater to the ever-growing need of postgraduate level professionals in the country.

IITH encourages and supports&nbsp;<a href="https://iic-iith.netlify.app/index.html" rel="noopener noreferrer" target="_blank">innovation and entrepreneurship</a>&nbsp;at every stage. The minor program in entrepreneurship is open to all students of IITH, and many of the courses are offered by industrialists who are entrepreneurs themselves. There are various&nbsp;<a href="https://iith.ac.in/research/centres-incubators/">innovation centers and incubators</a>&nbsp;that promote entrepreneurship and help mentor young innovators. IITH has been very successful in building tie-ups with leading academic institutions around the globe.

IITH enjoys a very special relationship with Japanese universities and industries that goes beyond academic and research collaborations. In fact, some of the iconic buildings in IITH campus will carry the signature of Japanese architecture.

IITH creates a unique holistic ecosystem for education that offers interactive learning, a very flexible academic structure, cutting-edge research, strong industry collaboration, and entrepreneurship. This is an environment which enables students and faculty to translate their dreams into realities.

IIT Hyderabad

A low complexity decoding technique with an essentially-ML performance for the Golden code and the 3 antenna Perfect code was introduced by Sirianunpiboon, Howard &amp; Calderbank. Though no theoretical analysis of the decoder was given, the simulations showed that this decoding technique has almost maximum-likelihood (ML) performance. Inspired by this technique, in this paper we introduce two new low complexity decoders for Space-Time Block Codes (STBCs) - the Adaptive Conditional Zero-Forcing (ACZF) decoder and the ACZF decoder with successive interference cancellation (ACZF-SIC), which include as a special case the decoding technique of Sirianunpiboon et al. We show that both ACZF and ACZF-SIC decoders are capable of achieving full-diversity under Rayleigh fading, and we give sufficient conditions for an STBC to give full-diversity with these decoders. We then show that the Golden code, the 3 and 4 antenna Perfect codes, the 3 antenna Threaded Algebraic Space-Time code and the 4 antenna rate 2 code of Srinath &amp; Rajan are all full-diversity ACZF/ACZF-SIC decodable with complexity strictly less than that of their ML decoders. Simulations show that the proposed decoding method performs identical to ML decoding for all these five codes. These STBCs along with the proposed decoding algorithm outperform all known codes in terms of both decoding complexity and error performance for Nt ≤ 4 transmit antennas. We further provide a lower bound on the complexity of full-diversity ACZF/ACZF-SIC decoding. The proposed decoders for all the five codes listed above achieve this lower bound and hence are optimal in terms of minimizing the ACZF/ACZF-SIC decoding complexity. © 2012 IEICE Institute of Electronics Informati.

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2012 International Symposium on Information Theory and Its Applications, ISITA 2012

An adaptive conditional zero-forcing decoder with full-diversity, least complexity and essentially-ML performance for STBCs

A physics-based dc compact model for SOI tunnel field-effect transistors (TFETs) has been developed in this paper utilizing Landauer approach. The important transistor electrical parameters, i.e., threshold voltage V th, charge in the channel Q, gate capacitance C G, drain current I DS, subthreshold swing S, transconductance g m, and output conductance g DS, have been modeled. The model predicts the low subthreshold swing values (less than 60 mV/dec) observed in TFETs and shows a good match with the technology computer aided design (TCAD) results. Model validation was carried out using TCAD simulation for different TFET structures with abrupt junctions, i.e., 40-nm Si nTFET and pTFET, a 0.4-μm Si nTFET, and a 40-nm Ge nTFET. The compact model predictions are in good agreement with the TCAD simulation results. © 2012 IEEE.

IEEE Transactions on Electron Devices

DC compact model for SOI tunnel field-effect transistors

We design and implement a software-radio system for Superposition Coding (SC), a multiuser transmission scheme that deliberately introduces interference among user signals at the transmitter, using a library of off-the-shelf point-to-point channel codes. We experimentally determine the set of rate-pairs achieved by this transmission scheme under a packet-error constraint. Our results suggest that SC can provide substantial gains in spectral efficiencies over those achieved by orthogonal schemes such as Time Division Multiplexing. Our findings also question the practical utility of the Gaussian approximation for the inter-user interference in Superposition-Coded systems. © 2012 IEEE.

Fulltext

IEEE Transactions on Wireless Communications

Superposition coding strategies: Design and experimental evaluation

Large size single crystals of undoped and Ce doped Li6Gd(BO 3)3 oriented in &lt;010&gt; direction have been grown using the Czochralski technique. The Transparency of these crystals was &gt;85%. The Low temperature photoluminescence study of these crystals revealed that the temperature quenching of Ce3+ emission is compensated, to some extent, by an increased energy transfer between Gd3+ →Ce 3+ with temperature. © 2012 American Institute of Physics.

AIP Conference Proceedings

Growth and luminescence properties of Ce doped Li6Gd(BO 3)3 single crystals

Nano-particles of CaF2: Mn were synthesized by a co-precipitation method. Optically transparent ceramics were obtained by vacuum hot-pressing at 1000°C under 20 MPa pressure for 2 h. The duration of pressure and dehydration of the initial powder was found important to achieve the transparency. 50% transparency was observed for a polished disc of 1 mm thickness. SEM micrographs revealed the absence of voids in hot pressed samples. These samples were found to be highly sensitive and linear for TLD and can measure doses from mGy to kGy. © 2012 American Institute of Physics.

Synthesis of optically transparent ceramic of CaF2 doped with Mn and Ce for thermoluminescent dosimetry

Lithium borate (LBO) single crystals doped with Cu and Ag (0.25 mol% each) (Li 2B 4O 7:Cu,Ag) are grown by the Czochralski method. The thermoluminescence readout on Li 2B 4O 7:Cu,Ag crystals showed three glow peaks at∼375, 441 and 516 K for the heating rate of 1 K/s. The thermoluminescence sensitivity of the grown Li 2B 4O 7:Cu,Ag single crystals is found to be 5 times TLD-100 and a linear dose response in the range 1 mGy to 1 kGy. The glow curve deconvolution reveals nearly first order kinetics for all the three peaks with trap depths 0.77, 1.25 and 1.34 eV respectively and corresponding frequency factors 1.6×10 9, 1.3×10 13 and 6.8×10 11 s -1. The continuous wave optically stimulated luminescence (CW-OSL) measurements were performed on the LBO:Cu,Ag single crystals using blue light stimulation. The traps responsible for the three thermoluminescence peaks in Li 2B 4O 7:Cu,Ag are found to be OSL sensitive. The qualitative correlation between TL peaks and CW-OSL response is established. The photoluminescence studies show that in case of co-doping of Ag in LBO:Cu the emission at 370 nm in Cu states dominates over the transitions in Ag states implying doping of Ag plays a role as sensitizer when co-doped with Cu and increases overall emission. © 2012 Elsevier B.V. All rights reserved.

Journal of Luminescence

TL and OSL studies on lithium borate single crystals doped with Cu and Ag

New plasmonic materials such as transparent conducting oxides and transition-metal nitrides could replace conventional silver and gold in optical metamaterials and offer many advantages including low loss, compatibility with standard semiconductor nanofabrication processes, and tunability. © 2012 OSA.

Integrated Photonics Research, Silicon and Nanophotonics, IPRSN 2012

The road ahead for metamaterials: Improved material building blocks

Sampling of ECG signals has been studied for several decades. However, nonuniform sampling at low average rate has received much less attention. While uniform sampling rate needs to be at least twice the bandwidth of a signal (Nyquist rate), in theory, nonuniform sampling at sub-Nyquist rate should be adequate for faithful reconstruction if the signal is sufficiently sparse. Noting the known sparsity ECG signals, we attempt to demonstrate sub-Nyquist sampling of such signals. However, alongside this opportunity, reconstruction from nonuniform samples also poses a particular challenge. While uniform sampling admits universal (signal-independent) reconstruction (via sinc interpolation), reconstruction from nonuniform samples is generally data-dependent. In this paper, we make use of compressive sampling theory to demonstrate that nonuniform sampling does provide universal performance guarantee. In our experiments, we use ANSI/AAMI standard test ECG signals, and tune the orthogonal mathing pursuit algorithm for those to obtain superior performance. Our results potentially facilitates development of low-power ECG recording devices with potential application in remote locations without grid power. ©2012 IEEE.

5th 2012 Biomedical Engineering International Conference, BMEiCON 2012

Universal nonuniform sampling of ECG signals: Opportunities and obstacles

Single crystals of CsI having different Tl concentrations have been grown by a gradient freeze technique. Carbon films were deposited on the inside surface of fused silica crucibles to avoid sticking of the grown crystals. The crystals could be extracted easily from the crucibles without involving the inversion process at higher temperatures. Effects of varying growth parameters and after-growth thermal treatment on crystal properties like daylight coloration and radiation hardness were studied. Characterization techniques including high resolution X-ray diffraction, induced absorption, photoluminescence, afterglow and thermally stimulated luminescence were employed to evaluate the grown crystals. Gamma-ray detectors were fabricated using the grown crystals that showed good linearity and nearly 7.5% resolution at 662 keV. This established a very simple and low cost method to grow small to medium size (35 mm in diameter and 25 mm in length) CsI crystals for various applications. © 2012 ElsevierB.V. All rights reserved.

Journal of Crystal Growth

Growth of CsI:Tl crystals in carbon coated silica crucibles by the gradient freeze technique

A Barium Strontium Titanate (BST) based reconfigurable Aperture-coupled patch antenna on high resistivity silicon substrates with beam steering capability using PIN doides has been proposed in this paper. For low dielectric constant region in silicon substrate, Micromachined technique is used. Varying voltage across BST layer changes its permittivity thereby tunable frequency is achieved and switching p-i-n diodes will steer the beam. A Novel structure is proposed which gives high directivity (&gt; 6 dB), Good gain (&gt; 5 dB), low VSWR (&lt;1.5), low control voltages (&lt;80V) &amp; 60° HPBWS. © 2012 IEEE.