Patel G.S.,ECED |
Sharma S.,Thapar University
Research Journal of Applied Sciences, Engineering and Technology | Year: 2013
In this study, an optimized Direct Digital Frequency Synthesizer (DDFS) utilizing Piecewise Linear Approximation is introduced. The proposed technique allows successive read access to memory cells per one clock cycle using time sharing. The output values will be temporarily stored and read at a later time. The output of this system is a reconstructed signal that is a good approximation of the desired waveform. As a result, the DDFS only needs to store fewer coefficients and the hardware complexity is significantly reduced. The proposed DDFS has been analyzed using MATLAB. The SFDR of synthesized achieved is 84.2 dBc. To prove the better performance of proposed DDS architecture it is compared favorably with several existing DDS architectures. In future it can also be used to improve the performance of Hybrid DDS-PLL Synthesizers. © Maxwell Scientific Organization, 2013.
Proceedings on 2012 1st International Conference on Emerging Technology Trends in Electronics, Communication and Networking, ET2ECN 2012 | Year: 2012
The recent advances in signal processing techniques as well as the VLSI circuits that can handle orders of calculations, have led to rather more efficient and faster data communications possible. This is quite visible with the introduction of 4G wireless services, which introduce OFDM/OFDMA that are quite complex in computations, but are handled easily by the existent technologies. But, with such high processing, battery discharge becomes another issue. Especially when the mobile stations (MS) are experiencing highly mobile environments, it becomes a serious issue. In this paper the upshot of power optimization in Mobile stations has been observed, optimized and simulated. This paper utilizes the rich topic of Multi-hop relay communications and compares their battery utilizations with the existent network topology under highly mobile environments. Qualnet 5.1 Network Simulator has been used to design and test the network topologies and henceforth acquire the generated data. Also a heterogeneous network topology is proposed and it's certain discernible advantages over existing and other heterogeneous networks have been mentioned. © 2012 IEEE.
Inamdar K.,ECED |
Kosta Y.P.,MEFGI |
Patnaik S.,St Xaviers Institute Of Engg
Progress In Electromagnetics Research C | Year: 2014
In this paper, we present the design of a metamaterial based microstrip patch antenna, optimized for bandwidth and multiple frequency operations. A Criss-Cross structure has been proposed. This shape is inspired by the famous Jerusalem Cross. The theory and design formulas to calculate various parameters of the proposed antenna have been presented. The software analysis of the proposed unit cell structure has been validated experimentally thus giving negative response of and 1. Following this, a metamaterial-based-microstrip-patch-antenna is designed. A detailed comparative study is conducted exploring the response of the designed patch made of metamaterial and that of the conventional patch. Finally, antenna parameters such as gain, bandwidth, radiation pattern and multiple frequency responses are investigated and optimised and presented in tables and response-graphs. It is also observed that the physical dimension of the metamaterial based patch antenna is smaller than its conventional counterpart operating at the same fundamental frequency. The response of the patch antenna has also been veri-ed experimentally. The challenging part was to develop metamaterial based on some signature structures and techniques that would o®er advantage in terms of bandwidth and multiple frequency operation, which is demonstrated in this paper. The unique shape proposed in this paper gives improvement in bandwidth without reducing the gain of the antenna.
Computers and Mathematics with Applications | Year: 2012
It has been shown that when perfect or partial channel state information (CSI) is available at the transmitter, the performance and capacity of a space-time coded system can be further improved. Multilevel space-time trellis codes (MLSTTC's) are capable of simultaneously providing bandwidth efficiency, diversity improvement and coding gain with significantly reduced decoding complexity, especially for larger constellations and higher throughputs. In this paper, we present a design of combined multilevel space-time trellis codes and beam forming based on feedback from receiver, henceforth referred to as weighted multilevel space-time trellis codes (WMLSTTCs). The channel profile is used to provide a beam forming scheme that achieves the better performance by properly weighting transmitted signals. Weights are selected that matches best with a channel profile feedback from the receiver indicative of long-term characteristics of the wireless channel. WMLSTTCs provide improvement in performance of MLSTTCs. © 2011 Elsevier Ltd. All rights reserved.
Kumar R.,ECED |
Khanna R.,Thapar University
Proceedings - 2012 IEEE Int. Conf. on Green Computing and Communications, GreenCom 2012, Conf. on Internet of Things, iThings 2012 and Conf. on Cyber, Physical and Social Computing, CPSCom 2012 | Year: 2012
QoS means providing consistent, predictable data delivery service. QoS is dealt with providing real-time (e.g., voice) as well as non-real-time services. Real time services are required to be more dominant over non real time for QoS prospective. In this paper a fuzzy based approach is presented using ns-2 for handover between UMTS and WLAN networks. It has been observed that the results obtained with proposed approach are improved and better than the conventional approach. © 2012 IEEE.