In this paper, imposing the Hadamard Transform (HDT) on Orthogonal Space-Time Block Codes (OSTBC) schemes using multiple transmit antennas is proposed in order to increase the reliability and improve the error performance of wireless communications. It is referred to as joint Hadamard transform and OSTBC schemes with multiple transmit antennas. However, HDT is used to change the location of constellation points by converting the transmit symbols of OSTBC system, and hence extending the Euclidean distance between transmit symbols for a precise detection. Simulation results demonstrated that increasing the number of transmit antennas in OSTBC systems employing 8-PSK improves the Bit Error Rate (BER) performance as in the case of OSTBC 2×2 scheme where an SNR of about 13.5 dB is required to achieve a BER of 〖10〗^(-6), while only about 7 dB in OSTBC 8×8 scheme is required to obtain the same error probability. It is also demonstrated that imposing the Hadamard criteria on the OSTBC 2×2, 4×4, and 8×8 schemes has showed a performance improvement of about 3 dB, 6 dB and 9 dB, respectively, as compared to the conventional OSTBC systems.
Taissir Y. Elganimi, Marwan B. Elkhoja(4-2019)

Abstract The increased amount of electromagnetic radiation in the environment has increased the common concern over the possible health risks of wireless devices (e.g. mobile phone ). However, to minimize the amount of energy absorbed by the user is an advantageous from the technical point of view, as well. The reduction of power absorbed by the user not only reduces any possible health hazards but also makes the antenna more efficient. In this master’s thesis, interaction between modern mobile phone antennas and user is studied by using numerical full-wave EM methods. The thesis aims at improving, understanding how mobile terminal antennas behave in the vicinity of the user and how different numerical EM methods can be used to solve the interaction problem. The results give valuable information for antenna designers in order to design antennas which have low interaction with the user as possible. Furthermore this master’s thesis introduces a simple optimization technique to enhance the performance of planar inverted F antenna (PIFA) one of common modern mobile phone antenna in vicinity of user and reduce its effect on health.
محمد على المنصورى (2008)

In this paper, we present an analytical traffic model for the Universal Mobile Telecommunication Systems (UMTS). In 3G networks we have dynamic capacity that depends on the interference levels in the covered area and the number of active users. This implies that the distance of the mobile user from the base station is also an important factor because of the signal fading. The first part of this paper is an algorithm written in c++ programming language that distributes users in different zones assuming that the cell area is virtually divided into Z zones depending on the number of users. The last part of this paper we build a mathematical model of a 3G cell using the above assumption , and to prove, that the product form holds in the case of two cells with uniform and non uniform traffic. By this result more complicated networks can be analyzed, to calculate the performance measures of the network.
WAEL S. ABUGHRES, MIKE E. WOODWARD(6-2006)