iosr-JECE   Volume-6 ~ Issue-4

Abstract: This paper numerically examines an array of four dielectric resonant antenna of equilateral triangle shape. The Structure provides wideband low profile monopole-like antenna. As much as 30.90 % matching bandwidth (S11<-10 dB) with monopole-like radiation pattern over the entire band has been achieved with 6.357 dBi peak gain. The geometry is a four equilateral triangular dielectric volume over a ground plane, and is centrally excited by a coaxial probe to provide a broadside radiation pattern. An approximate expression is used to compute the resonance frequency. Results are simulated using CST (Computer Simulation Technology) Microwave Studio Suite 10.

Keywords-Dielectric resonator (DR), triangular dielectric resonator antenna (TDRA), S11 (S-Parameter), perfect conductor (PEC), Impedance Bandwidth (IBW).

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Abstract: This paper presents design of operational transconductance amplifier is to amplify the ECG signal having low frequency of 300Hz, with the supply voltage of 0.8v. To reduce the power dissipation of 779nW, by using fifth order low pass filter. The OTA-C filter is to eliminate noise voltage and increases the reliability of the system. A chip is fabricated in a 0.18μm CMOS process is simulated and measured to validate the system performance using HSPICE.

[1] Razavi, Behzad "Design of analog CMOS Integrated Circuits."

[2] R.Jacob Baker, Harry W.Li and David E.Boyce, "CMOS Circuit Design, Layout andSimulation."

[3] Mohamed O. Shaker , Sollman A. Mahmoud, Ahmed A. Sollman, "A CMOS Fifth-Order Low -Pass Current- Mode Filter Using a Linear Transconductor."

[4] KimmoLasanen, "Integrated analogue cmos circuits and structures for heart rate detectors and others low-voltage, low power applications."

[5] S. Koziel and S. Szczepanski, "Designof highly linear tunable CMOS-OTA for continuous-time filters."

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Abstract: Multiple Input Multiple Output is a wireless technology that uses multiple transmitters and receivers to transfer more data at the same time. Orthogonal Frequency Division Multiplexing, an FDM modulation technique which splits the signal into multiple smaller sub-signals that are then transmitted simultaneously at different frequencies to the receiver. OFDM technique spreads the data over number of carriers which are at specific predefined frequencies. This reduces or eliminates the ISI. Forward error correction or channel coding is a technique used for controlling errors in data transmission over unreliable or noisy communication channels. The objective of our proposed paper is to implement the FEC into the MIMO OFDM systems and its performance is analysed by using MATLAB over different fading channels. For modulation it employs M-QAM which combines both ASK and PSK thereby enabling several bits to be transmitted per symbol. The performance of MIMO-OFDM system is evaluated by BER Vs SNR when the bits propagates through the different fading channels.

Keywords– OFDM, MIMO, QAM, FEC, BER.

[1]. R.Prasad, "Introduction" in OFDM for Wireless Communications Systems, London, United Kingdom: Artech House, 2004, pp. 11-14.
[2]. Implementation of MIMO-OFDM System, Muhammad Atif Gulzar, Rashid Nawaz , Devendra Thapa, Linnaeus university,2011
[3]. Implementation of a WiMAX simulation in Simulink by Amalia da Roca.
[4]. Coding for the Fading Channel: a Survey, Signal Processing for Multimedia, J.S. Byrnes (Ed.), IOS Press.
[5]. Simulation Study of Some Spatial Diversity Techniques for MIMO Wireless Communication Systems" International Journal of Emerging Technology and Advanced Engineering, Volume 2, Issue 12, December 2012.
[6]. "BER Comparison of Rayleigh Fading, Rician Fading and AWGN Channel using Chaotic Communication based MIMO-OFDM System" - Suchita Varade, Kishore Kulat, International Journal of Soft Computing and Engineering (IJSCE) ISSN: 2231-2307, Volume-1, Issue-6, January 2012.
[7]. "Concatenated Convolutional Codes for Deep Space Mission" Deepak Mishra, T.V.S Ram, K S Dasgupta & S.Jit International Journal of Information and Communication Technology Research , Volume 2 No. 6, June 2012 .
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