Browsing Computer Science & Communications by Issue Date

Now showing items 1-20 of 95

    • A New Adaptive EDCA Approach to QoS of Wireless Communications 

      Wang, Huibin; Hu, Yang; Zhang, Lili; Xia, Wei (Scientific Research Publishing, 2010-07)
      Under the background of intelligent transportation application, QoS for various services is different in wireless com-munication. Based on the MAC layer protocol, this paper analyzes the QoS in IEEE 802.11 MAC protocol ...

    • A Perspective on Traffic Measurement Tools in Wireless Networks 

      Siddamallaiah, Ramesh B.; Subramanian, Gowrishankar; Satyanarayana, Piriyapatna S. (Scientific Research Publishing, 2010-07)
      To understand the characteristics of the wireless networks, the network usage data from wireless measurement tools are essential. The data collection is a process of collecting the network time-varying information in ...

    • The Performance Gain of Cognitive Radio in Adaptive Modulation Scheme 

      Foukalas, Fotis (Scientific Research Publishing, 2010-07)
      Cognitive radio is considered as one of the main enablers for provisioning dynamic and flexible spectrum/channel allocation in wireless communications. The reliable data transmission over cognitive radio should employ ...

    • Cognitive Radio Sensing Using Hilbert Huang Transform 

      Narayanankutty, K. A.; A. Nair, Abhijith; Soori, Dilip; Pradeep, Deepak; Teja, V. Ravi; K.B., Vishnu (Scientific Research Publishing, 2010-07)
      Vast segments of the frequency spectrum are reserved for primary (licensed) users. These legacy users often un-der-utilize their reserved spectrum thus causing bandwidth waste. The unlicensed (secondary) users can take ...

    • Sensor Placement to Improve the Positioning Performance Based on Angle of Arrival (AOA) 

      Omidali, Behzad; Shirazi, S. S. (Scientific Research Publishing, 2010-07)
      In this paper, a method for sensor placement to improve the placement quality based on angle of arrival of signal in a specific area is proposed. The installation place of sensors may be constrained with specified boundaries. ...

    • WiMAX System Simulation and Performance Analysis under the Influence of Jamming 

      Jha, Rakesh; Patel, Hardik; Dalal, Upena D.; Vishal, Wankhede A. (Scientific Research Publishing, 2010-07)
      This paper presents simulation of WiMAX based system under jamming. The performance of the system was found out to greatly differ with the use of different jamming signals, allowing central areas to be identified, where ...

    • Design of an Acoustic Communication System Based on FHMA for Multiple Underwater Vehicles 

      Zhao, Zixin; Guo, Shuxiang (Scientific Research Publishing, 2010-07)
      This paper designs an underwater acoustic communication system based on tamed spread spectrum and Frequency Hopping Multiple Access (FHMA) for multiple underwater vehicles. In this system, multiple underwater vehicles can ...

    • Ad Hoc Network Hybrid Management Protocol Based on Genetic Classifiers 

      Garzia, Fabio; Perna, Cristina; Cusani, Roberto (Scientific Research Publishing, 2010-10)
      The purpose of this paper is to solve the problem of Ad Hoc network routing protocol using a Genetic Algorithm based approach. In particular, the greater reliability and efficiency, in term of duration of communication ...

    • Resonant Length Formulations for Dual Band Slot Cut Equilateral Triangular Microstrip Antennas 

      Deshmukh, Amit A.; Ray, K. P. (Scientific Research Publishing, 2010-10)
      The dual band equilateral triangular microstrip antennas are realized by cutting the slots of either quarter wave or half wave in length, inside the patch. In this design, however these simpler approximations of slot length ...

    • Performance of Double-Pole Four-Throw Double-Gate RF CMOS Switch in 45-nm Technology 

      Srivastava, Viranjay M. (Scientific Research Publishing, 2010-10)
      In this paper, we have investigated the design parameters of RF CMOS switch, which will be used for the wireless tele-communication systems. A double-pole four-throw double-gate radio-frequency complementary-metal-oxide-semicon- ...

    • Design of Aperture Coupled Microstrip Antenna Using Radial Basis Function Networks 

      Bose, Tanushree; Gupta, Nisha (Scientific Research Publishing, 2010-10)
      This paper, two Artificial Neural Network (ANN) models using radial basis function (RBF) nets are developed for the design of Aperture Coupled Microstrip Antennas (ACMSA) for different number of design parameters. The ...

    • On the Design of Circular Fractal Antenna with U-Shape Slot in CPW-Feed 

      Kumar, Raj (Scientific Research Publishing, 2010-10)
      new ultawideband circular fractal antenna with notched-band characteristics is presented. A notched-band characteristic is achieved by employing a U-shape slot in 50 Ω feed lines. The ultra-wideband impedance matching and ...

    • Rain Attenuation at Terahertz 

      Ishii, S. (Scientific Research Publishing, 2010-10)
      Rain attenuation values were calculated using empirical raindrop-size distributions, which were, Marshall-Palmer (M-P), Best, Polyakova-Shifrin (P-S) and Weibull raindrop-size distributions, and also calculated using a ...

    • Interference Mitigation in Satellite Personal Communication Networks Using Adaptive Antenna Arrays and Filtering Technique 

      Iwasokun, Sunday E.; Kolawole, Michael O. (Scientific Research Publishing, 2010-10)
      We address the problem of interference as related to Satellite Personal Communication Networks (S-PCNs). Basic low Earth orbit (LEO) constellation is considered. The paper uses combined adaptive antenna arrays and adaptive ...

    • Sampling and Reconstruction of Zero-Order Hold Signals by Parallel RC Filters 

      Olkkonen, J.T; Olkkonen, H (Scientific Research Publishing, 2011)
      In this work we describe a reconstruction algorithm for zero-order hold (ZOH) waveforms measured by a parallel sam-pling scheme. In the method the ZOH signal is fed to a parallel network consisting of resistor-capacitor ...

    • Bandwidth Enhancement and Size Reduction of Microstrip Patch Antenna by Magnetoinductive Waveguide Loading 

      Joshi, Jayant G.; Pattnaik, Shyam S.; Devi, Swapna; Lohokare, Mohan R. (Scientific Research Publishing, 2011-01)
      A planar magnetoinductive (MI) waveguide loaded rectangular microstrip patch antenna is presented and discussed. The MI waveguide consists of two planar metamaterial split squared ring resonators (SSRRs) placed in between ...

    • Experimental Analysis of a Node B Coverage Based on the CPICH and Ec/Io Values 

      Zamudio-Castro, Iván; Vidal-Beltrán, Sergio; Ponce-Rojas, Jazmín; Sosa-Pedroza, Jorge (Scientific Research Publishing, 2011-01)
      This paper presents experimental results of a coverage analysis in a WCDMA network using the 850 MHz band; an urban electromagnetic propagation environment is considered. Obtained coverage estimation maps are based on Krige ...

    • Experimental Analysis of Voice and Data Transmission Parameters for Mobile Terminals in Cellular Data Networks 

      Jiménez-Licea, Montserrat; Vidal-Beltrán, Sergio; López-Bonilla, José L. (Scientific Research Publishing, 2011-01)
      This work presents the experimental results related to performance measurements in GSM and GPRS cellular data networks. Two Mobile Terminals were used, in order to take place the scenario. Power Level, Power vs Time, ...

    • An Efficient Method to Reduce the Numerical Dispersion in the HIE-FDTD Scheme 

      Chen, Juan; Zhang, Anxue (Scientific Research Publishing, 2011-01)
      A parameter optimized approach for reducing the numerical dispersion of the 3-D hybrid implicit-explicit finite-difference time-domain (HIE-FDTD) is presented in this letter. By adding a parameter into the HIE-FDTD formulas, ...

    • Capacitive Model and S-Parameters of Double-Pole Four-Throw Double-Gate RF CMOS Switch 

      Srivastava, Viranjay M.; Yadav, Kalyan S.; Singh, Ghanashyam (Scientific Research Publishing, 2011-01)
      In this paper, we have analyzed the Double-Pole Four-Throw Double-Gate Radio-Frequency Complementary Metal-Oxide-Semiconductor (DP4T DG RF CMOS) switch using S-parameters for 1 GHz to 60 GHz of frequency range. DP4T DG RF ...