Volume 26, Issue 2 August 2014

Design and Analysis of Planer, Single Feed, Four-Band Microstrip Antenna Operating in the Same Polarization Plane [Full Text]

Falih M. Alnahwi, Mohammad S. Zidan, and Naz E. Islam

Abstract—The design and analysis of a single compact antenna, that can operate at Global System for Mobile (GSM), Mobile Satellite Service (MSS), Industrial Scientific Medical (ISM), and Fixed Satellite Service (FSS) frequencies is presented. The design is based on the utilization of a chip resistor to split the two frequency bands of the step-slotted patch antenna into four frequency bands. The four frequency bands that are generated by the proposed antenna are all in the same polarization plane. The proposed antenna is easy to fabricate and is expected to be used in modern communication devices to replace multi antennas to handle different frequency bands. The analysis of the antenna is done by using an in house FDTD code to provide an in-depth study of the physics of the radiation mechanism. Results from the code were validated through commercial simulation suit and are in good agreement. Some discrepancy in the return loss appears to be due to the mesh generation methodology implemented in each code.


Design of proposed STBC-MC-DS- WIMAX Systems Based on DWT and Phase Matrix [Full Text]

Laith Ali Abdul-Rahaim

Abstract - In this paper a proposed technique is used to improve the performance of Space Time Block Coding Multicarrier Direct sequence World Interoperability for Microwave Access STBC-MC-DS-WIMAX based on Discrete wavelet Transform DWT and Phase Matrix (PM). Several structures of STBC-MC-DS-WIMAX systems based on FFT, DWT and PM were designed. Simulation results will presented for AWGN, flat fading and selective fading channels. By isolating individual propagation affects, and examine changing for different values of maximum Doppler shift values (8Hz, 8Hz and 400Hz) (which is the most significant impact channel parameters) on the BER performances. The phase matrix (PM) was chosen in the MC-DS-WIMAX structure to improve the capability of stand the variation of phase of noise. The Fourier domain approach was found to be the more suitable way for obtaining the forward and inverse (PM). This structure has resulted in a more suitable realization of FFT-based MC-DS-WIMAX. As a result, a modification will be performed in this work by adding FFT and 1D and 2D-DWT PM and IPM. This modification will may be given a significant improvement in the BER performance in comparison with the conventional MC-DS-WIMAX. Also the new structures will tested for different channel types. One of the features of the proposed modified structure is that the bandwidth efficiency must be kept as good as the conventional FFT-based MC-DS-WIMAX as well as the Bit per Hertz. We suppose that transmitted symbols are recovered easily with adequate BER performance when the channel is just AWGN without the need for any channel estimation; while a pilot-assisted channel estimation technique is used to compensate for the impairments due to the multi- path fading this is simple and very efficient. 


Real Time Portable Health Care PP, GSR,
 BG, EMG with Alarm System Based on WSN [Full Text]

Mahmoud Shaker Nasr, Samir Jasim Mohammed, and Ali Jasim Ramadhan

Abstract — Patient's health monitoring / diagnostic systems have become the focus of attention of researchers today. This paper presents a design of a portable real time wireless medical system for monitoring / diagnosing the patients' status based on E-health and wireless sensor network (WSN) under ZigBee protocol. The system measures the biomedical data utilizing a group of sensors, which are patient position sensor (PPS), galvanic skin response sensor (GSR), blood glucose sensor (BGS) and electromyography sensor (EMG). The system monitors the sleep position and skin conductance (indicator to patient's calm) of the patients in real time with alarm of each abnormal case in the base station (BS) and in the lobbies, and it follows up the patient's blood glucose rate and diagnosis the patient's electromyography status too. Moreover, the system stores the patient information and his health data in order to use it for any archiving process or statistical study. In the achieved system, three nodes are considered according to the facilities available but it stays monitor / diagnosis for an open node number. The system is implemented practically and applied for some persons under supervision of the specialist physicians, and the results obtained are very positive and present a great service to human care. All obtained results are presented in this paper. In future we will present a development system which is the use of Internet and GSM for remotely following up the patient status by his supervisor doctor.