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

Cardiovascular disease (CVD) is one of the most widespread health problems with unpredictable and life-threatening consequences. The electrocardiogram (ECG) is commonly recorded for computer-aided CVD diagnosis, human emotion recognition and person authentication systems. For effective detection and diagnosis of cardiac diseases, the ECG signals are continuously recorded, processed, stored, and transmitted via wire/wireless communication networks. But long-term continuous cardiac monitoring system generates huge volume of ECG data daily. Therefore, a reliable and efficient ECG signal compression method is highly demanded to meet the real-time constraints including limited channel capacity, memory and battery-power of remote cardiac monitoring, ECG record management and telecardiology systems. In such scenarios, the main objective of the ECG signal compression is to reduce the data rate for effective transmission and/or storage purposes without significantly distorting the clinical features of different kinds of PQRST morphologies contained in the recorded ECG signal. Numerous ECG compression methods have been proposed by exploiting the intra-beat correlation, inter-beat correlation and intra-channel correlation of the ECG signals. This paper presents a prospective review of wavelet-based ECG compression methods and their performances based upon findings obtained from various experiments conducted using both clean and noisy ECG signals. This paper briefly describes different kinds of compression techniques used in the one-dimensional wavelet-based ECG compression methods. Then, the performance of each of the wavelet-based compression methods is tested and validated using the standard MIT-BIH arrhythmia databases and performance metrics. The pros and cons of different wavelet-based compression methods are demonstrated based upon the experimental results. Finally, various practical issues involved in the validation procedures, reconstructed signal quality assessment, and performance comparisons are highlighted by considering the future research studies based on the recent powerful digital signal processing techniques and computing platform. (C) 2014 Elsevier Ltd. All rights reserved.

World University root node

Biomedical Signal Processing and Control

Wavelet-based electrocardiogram signal compression methods and their performances: A prospective review

A radio frequency microelectromechanical system (RF MEMS)-based true-time-delay (TTD) phase shifter is one of the key components in a modern electronically steerable phased array for satellite communication, radar systems, and high precision instrumentation. The phase shifter controls the signal phase in order to steer the direction of the beam [3]. RF microelectromechanical systems (MEMS) technology provides a superior performance in terms of low loss, low power consumption, and excellent linearity compared to other technologies. MEMS-based digital phase shifters provide a large phase shift and low sensitivity to electrical noise with a high tuning ratio compared to analog versions. This chapter describes different types of TTD phase shifters utilizing MEMS switches and MEMS varactors. A gold-based surface micromachining process is used to develop different kinds of MEMS phase shifters on alumina (εr = 9.8) substrates. All phase shifters are implemented using coplanar waveguide (CPW) transmission lines and actuated by electrostatic actuations. These include the analog-type distributed MEMS transmission line (DMTL) phase shifter using push-pull actuation, a 5-bit DMTL phase shifter using MEMS bridge and a fixed capacitor, 5-bit switched line phase shifter using DC-contact MEMS switches and a 2-bit and 5-bit phase shifter using MEMS SP4T and SPDT switches. This chapter includes details on the design, development, and characterization of MEMS phase shifters. Furthermore, all experimental results are validated with a circuit analysis and full-wave EM simulation. © 2014, Springer India.

Springer Tracts in Mechanical Engineering

RF MEMS true-time-delay phase shifter

In this article, we consider a receding horizon control of discrete-time state-dependent jump linear systems, a particular kind of stochastic switching systems, subject to possibly unbounded random disturbances and probabilistic state constraints. Due to the nature of the dynamical system and the constraints, we consider a one-step receding horizon. Using inverse cumulative distribution function, we convert the probabilistic state constraints to deterministic constraints, and obtain a tractable deterministic receding horizon control problem. We consider the receding horizon control law to have a linear state-feedback and an admissible offset term. We ensure mean square boundedness of the state variable via solving linear matrix inequalities off-line, and solve the receding horizon control problem on-line with control offset terms. We illustrate the overall approach applied on a macroeconomic system. © 2014 Elsevier B.V. All rights reserved.

Fulltext

Systems and Control Letters

On control of discrete-time state-dependent jump linear systems with probabilistic constraints: A receding horizon approach

The paper presents a decision tree (DT) induced fuzzy rule-based intelligent differential relaying scheme for transmission lines including unified power flow controller (UPFC) and wind-farms. The conventional distance relaying scheme fails miserably in protecting transmission lines including flexible AC transmission systems controllers such as UPFC and further, the protection issues become more challenging when wind-farm is integrated. The proposed protection scheme extracts features from the instantaneous voltage and current signals from both ends of the transmission line using discrete Fourier transform based pre-processor and computes corresponding differential features. The differential features are used to build the fault classification tree using a data-mining algorithm known as DT. Further, the fuzzy membership functions are drawn using the DT thresholds and the corresponding fuzzy rule-base is developed for final relaying decision. The proposed technique has been extensively tested (in MATLAB environment) for single circuit and double circuit transmission lines including UPFC and wind-farms with wide variations in operating conditions. The test results indicate that the proposed DTinduced fuzzy rule-based relaying scheme is highly reliable and robust for protection of complex transmission line including UPFC and wind-farm. © The Institution of Engineering and Technology 2014.

IET Generation, Transmission and Distribution

Decision tree-induced fuzzy rule-based differential relaying for transmission line including unified power flow controller and wind-farms

In contemporary wideband orthogonal frequency division multiplexing (OFDM) systems, such as Long Term Evolution (LTE) and WiMAX, different subcarriers over which a codeword is transmitted may experience different signal-to-noise-ratios (SNRs). Thus, adaptive modulation and coding (AMC) in these systems is driven by a vector of subcarrier SNRs experienced by the codeword, and is more involved. Exponential effective SNR mapping (EESM) simplifies the problem by mapping this vector into a single equivalent flat-fading SNR. Analysis of AMC using EESM is challenging owing to its non-linear nature and its dependence on the modulation and coding scheme. We first propose a novel statistical model for the EESM, which is based on the Beta distribution. It is motivated by the central limit approximation for random variables with a finite support. It is simpler and as accurate as the more involved ad hoc models proposed earlier. Using it, we develop novel expressions for the throughput of a point-to-point OFDM link with multi-antenna diversity that uses EESM for AMC. We then analyze a general, multi-cell OFDM deployment with co-channel interference for various frequency-domain schedulers. Extensive results based on LTE and WiMAX are presented to verify the model and analysis, and gain new insights. © 2014 IEEE.

IEEE Transactions on Wireless Communications

EESM-based link adaptation in point-to-point and multi-cell OFDM systems: Modeling and analysis

This paper presents frequency reconfigurable RF MEMS phase shifter using distributed MEMS transmission line (DMTL) theory. The insertion phase of the circuit is controlled by torsional MEMS actuators. Bridge actuation mechanism followed by capacitance variation is the main source of the band tuning in this study. Two stages of actuation mechanisms (push and pull) are used to obtain differential phase shift over the band of interest. A constant resolution of 11.25° is obtained within a wide spectrum of 10-35 GHz. Measurement results show that a single bit phase shifter demonstrates return loss of better than 18 dB, worst case insertion loss of 1 dB and maximum phase error of 0.7° over the band of interest. Finally, push-pull tuning is verified on the complete 5-bit phase shifter with the same set of actuation voltages in different bands for 180° phase shifter. To the best of our knowledge, this is the first reported frequency reconfigurable wide band phase shifter with constant resolution. © 2014 IEEE.

IEEE MTT-S International Microwave and RF Conference 2014, IMaRC 2014 - Collocated with Intemational Symposium on Microwaves, ISM 2014

10-35-GHz frequency reconfigurable RF MEMS 5-bit DMTL phase shifter uses push-pull actuation based toggle mechanism

With the increasing deployment of Wireless Sensor Networks (WSN) there has been a demand for power efficient, reliable, Wireless network based Distributed Computing system (WDC). The fading nature of the wireless channel offer several challenges to WDC over traditional distributed computing system. Orthogonal Frequency Division Multiple Access (OFDMA) based wireless communication systems offer several advantages and are increasingly replacing single carrier communication systems. In this paper we propose resource allocation for OFDMA based wireless distributed computing system. The performance of the proposed system is analyzed using computer simulation. © 2014 IEEE.

Souvenir of the 2014 IEEE International Advance Computing Conference, IACC 2014

Resource and subcarriers allocation for OFDMA based wireless distributed computing system

21st International Symposium on Mathematical Theory of Networks and Systems {\ldots}

Exponential Attitude Stabilization and Synchronization of Rigid Bodies

In orthogonal frequency division multiplexing (OFDM) systems, such as long term evolution (LTE) and WiMAX, a codeword is transmitted over a group of subcarriers. Since the subcarriers see different channel gains in a frequency-selective channel, 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) simplifies this problem by mapping the vector of SNRs into a single, equivalent flat-fading SNR. 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, which make the choice of the MCS partially outdated by the time data transmission takes place. To this end, we first propose a novel bivariate gamma distribution to model the joint statistics of EESM at the times of estimation and data transmission. We then derive a novel expression for the throughput as a function of feedback delay. Our framework works for both correlated and independent subcarriers and for various multiple antenna diversity modes, and is accurate over a wide range of delays. © 2014 IEEE.

2014 IEEE Global Communications Conference, GLOBECOM 2014

Impact of feedback delays on EESM-based wideband link adaptation: Modeling and analysis

Atmospheric water vapor is known to affect many processes, including cloud formation and precipitation. Water vapor can be measured using both in situ instruments, including radiosondes and remote sensing instruments, including Raman lidar. Radiosondes provide measurements of atmospheric water vapor and temperature that are some of the most widely used in numerical weather prediction models. They have high vertical resolution but poor temporal and horizontal sampling since they are launched every 12 hours and radiosondes are launched regularly in the U.S. from sites at an average separation of approximately 100 km. Therefore, there is a paucity of information on the horizontal, vertical and temporal variability of water vapor and temperature. Sensitivity studies indicate that severe storm forecasting is limited by a lack of accurate observations of water vapor aloft in the lower troposphere. Therefore, the availability of fine-resolution and accurate 2D and 3D water vapor field measurements would substantially improve numerical weather prediction model initialization. Microwave radiometers have the capability to measure atmospheric water vapor and temperature at sufficiently high spatial and temporal resolution to aid in advance forecasting of the onset, timing and location of severe weather.