Rakesh Kumar Sarin

Summary: For a multiple input multiple output relay system, the overall system performance is dependent on the effectiveness of the channel estimation technique adopted. In real time, communicating nodes have Doppler offset influences associated with them owing to high mobility that largely affects the characteristics of underlying channels. Thus, for the complete characterisation of the channel under fast time varying fading conditions, the estimation of the Doppler offset influences along with the channel coefficients becomes inevitable. However, the combined estimation of the channel and the Doppler influences renders the overall estimation problem nonlinear. In literature, majority of the channel estimation methods assume that the Doppler offset influences are already known to the receiver node or nodes are assumed to be stationary. In this paper, a novel hybrid interval type‐2 fuzzy aided Kalman filter method is proposed for the nonlinear channel estimation problem in one‐way two‐hop multiple input multiple output relay system. This channel estimation issue is represented as a nonlinear state space model, and the proposed hybrid method that combines the merits offered by the interval type‐2 fuzzy interpolation and the Kalman filter approach is applied to address the issue. For type reduction, Nie‐Tan method is adopted which is a low computational load extension of the widely used Karnik‐Mendel approach. Furthermore, a computational complexity analysis has been performed. The proposed hybrid interval type‐2 fuzzy based Kalman filter approach shows good performance‐complexity trade off under fast time varying channel conditions for one‐way two‐hop multiple input multiple output relay system.

In this paper, a novel circular slotted rectangular patch antenna with three triangle shape Defected Ground Structure (DGS) has been proposed. Radiating patch is made by cutting circular slots of radius 3 mm from the three sides and center of the conventional rectangular patch structure and three triangle shape defects are presented on the ground layer. The size of the proposed antenna is 38 X 25 mm2. Optimization is performed and simulation results have been obtained using Empire XCcel 5.51 software. Thus, a miniaturized antenna is designed which has three impedance bandwidths of 0.957 GHz, 0.779 GHz, 0.665 GHz with resonant frequencies at 3.33 GHz, 6.97 GHz and 8.59 GHz and the corresponding return loss at the three resonant frequencies are -40 dB, -43 dB and -38.71 dB respectively. A prototype is also fabricated and tested. Fine agreement between the measured and simulated results has been obtained. It has been observed that introducing three triangle shape defects on the ground plane results in increased bandwidth, less return loss, good radiation pattern and better impedance matching over the required operating bands which can be used for wireless applications and future 5G applications.

In nanoscale administration, Tunnel field effect transistor (TFET) has demonstrated the most encouraging device as it gives higher Ion/Ioff ratio and steeper Subthreshold swing (SS) than traditional MOSFET. In any case, doped devices experience the ill effects of unexpected intersection and irregular dopant variance (RDF) issues. Along these lines, out of the blue we have propose a 2-D expository model for a surface potential and electric field for a single material gate dual electrode doping less tunnel field effect transistor (SMG-DEDLTFET). Since the proposed show accomplish the coveted focus with the assistance of charge plasma method, we don't have to complete a physical doping which will bring about the concealment of above issues. The model articulation for surface potential and electric field are produced by settling 2-D Poisson's condition under reasonable limit conditions and the outcomes are approved with reenactment aftereffect of SILVACO TCAD device.

Emerging nanoscale computing structure quantum‐dot cellular automata (QCA) is evolving as a possible replacement for complementary metal–oxide–semiconductor technology in near future. Being a new technology, it is prone to various types of fabrication‐related faults and process variations. So, QCA‐based circuits are prone to errors, and therefore pose significant reliability‐related issues. Hence, there is an emerging need to design fault‐tolerant QCA‐based circuits to mitigate the reliability issues. This study first presents QCA‐based new designs of 2‐input Exclusive‐OR gate and 1 bit full adder using conventional design approach without redundant QCA cells. Then, the fault tolerance has been implemented in these designs by introducing redundant QCA cells. The proposed circuits exhibit significant improvements in fault‐tolerant capability against cell omission, misalignment, displacement, and extra cell deposition defects. The proposed fault‐tolerant designs have been compared with existing designs in terms of generalised design metrics of QCA circuits. Energy dissipation results have been computed for the proposed fault‐tolerant circuits using accurate QCAPro power estimator tool. Influence of temperature variations on the polarisation of the proposed fault‐tolerant circuits has also been investigated. The functionality of the proposed circuits has been verified with QCADesigner version 2.0.3 tool.