Asish Kumar Mukhopadhyay

Majority-layered T hybridization using quantum-dot cellular automata

Abstract The atomistic quantum-dot cellular automata (QCA) based implementations of the reversible circuits have got tremendous exposures in the last few days, due to “room-temperature workability” of the QCA. The researchers are in serious need of a methodology that can realize the area-efficient QCA counterparts of reversible benchmark circuits. In this work, a novel methodology named majority-layered T hybridization is proposed to synthesize the reversible circuits using QCA. Firstly the reversible library consisting of CNTS Gates have been generated to validate the usability of the proposed methodology. Then, an elementary QCA module of 3×3 Toffoli Gate have been proposed and extended in the realization of 4×4, 5×5 and 6×6 Toffoli Gates (multi-control Toffoli Gates). The proper mathematical modelling of the several QCA design metrics like effective area, delay and O-cost has been established. The QCA counterpart of 3×3 Toffoli Gate reports 18.61% less effective area and 8.33% less O-cost compared to the previous Toffoli Gate designs. Moreover, the QCA layout of rd-32 reversible benchmark using multi-control Toffoli Gate has been employed to verify the scalability and reproducibility of the proposed methodology. The QCA layouts are generated, tested and simulated by renowned computer aided design tool QCADesigner 2.0.3.

Wide-Banding of Half-Mode Substrate Integrated Waveguide (HMSIW) Filters Using L-Slots

The technique of wide-banding of Half-Mode Substrate Integrated Waveguide (HMSIW) Bandpass Filters has been presented in this paper. Single and simultaneous arrays of L-shaped slots have been used to achieve the purpose successfully. Effects of variation of several slots parameters have been studied in detail and are presented with their outcomes. The filter comes with minimal insertion loss over the entire passband. Entire experiments have been carried out over a material of dielectric constant of 3.2 and thickness of 30 mils. The filter finds applications in Ku-band operations with advantages like low insertion loss, convenient integration, compact size, low cost and ease of fabrication.

Performance analysis of service classes for IEEE 802.16m QoS optimization

Future generation of wireless mobile communication aims to provide high speed Internet access along with support for high mobility to the end users. Mobile WiMAX (IEEE 802.16e) has been developed in this direction in 2005 which provides broadband wireless Internet access up to 70Mbit/s. Its high speed enables various multimedia applications along with the conventional telephony service. These applications are categorized into classes like Platinum, Gold, Silver and Bronze according to their priority. In this paper we investigate the behavior of different scheduling algorithms for OFDMA/MIMO based WiMAX (IEEE 802.16m) architecture and analyze the quality of service (QoS) issues like throughput, end to end delay, interference, signal to noise ratio, call blocking probability and call dropping probability. For simulation, we used OPNET Modeler. The simulation results show high values of the QoS parameters although there is lack of consistency in some of those values that calls for further improvement in design, architecture and deployment strategy.

Mobile WiMAX Physical Layer Optimization and Performance Analysis Towards Sustainability and Ubiquity

Mobile WiMAX is emerging as a means for low cost reliable wireless broadband connection compared to traditional DSL cable. The system requirement of next generation mobile WiMAX is supposed to be based on IEEE 802.16 m which is still in letter ballot stage. This paper attempts to make in depth performance evaluation of Mobile WiMAX under various PHY parameters such as modulation and coding schemes (MCS), cyclic prefixes and different path-loss models. Moreover it also present an optimized adaptive modulation scheme that senses the SNR and adaptively switches to required MCS towards achieving the desired level of Quality of Service (QoS) and link stability. Simulation results show that dynamic adaptation of modulation and coding scheme based channel conditions can offer enhanced throughput, load, reduced delay, SNR and BER.

Thermal noise analysis of SGMOSFET for different substrate and gate oxides

In improving field of Metal Oxide Semiconductor technology (MOS-technology), highly gate controllable structures are continuously developed in research labs. With increased controllability of gate, the size of the semiconductor devices is also decreasing. Similarly in MOS physics, the channel length have been decreased below 0.1µm but with MOSFET scaling several important parameters have to be analyzed whether they are showing Quantum effects or not. To understand the overall picture of thermal noise performance of SGMOSFET the short channel parameters such as length, radius of gate, working temperature, doping concentration and the other parameters varied. These results shaped by different simulation results can be taken as standard and optimum device constraints. By having these data we can understand which configurations are giving the best thermal noise performance under the same set of parameters-related simulation environment. In this paper we give the thermal noise performance of various substrates with respect to different oxides and propose best cases.