Transmit Antenna Selection using Orthogonal Space-Time Block Codes (TAS-OSTBC) aided Millimeter-wave (mmWave) communications is proposed in this paper. The TAS transmitter is characterized by a lower number of Radio Frequency (RF) chains than the number of transmit antennas, hence it is capable of reducing both the energy consumption as well as the transmitter cost. The proposed scheme combines TAS-OSTBC system with Hybrid Analog-Digital Beamforming for 60 GHz mmWave communications and using Hadamard transform. The computer simulation results demonstrate that the TAS-OSTBC scheme with fully digital SVD-based precoding has better Bit Error Rate (BER) performance than that of the conventional TAS system with OSTBC scheme. Furthermore, the error performance is significantly improved by applying Uniform Linear Array (ULA) antennas which improve the system performance as the number of array elements increases due to providing a beamforming gain. It is also found that the BER performance is further improved by applying Hadamard transform with an SNR improvement of about 3dB over the conventional systems without using Hadamard transform.
Taissir Y. Elganimi, Mohammed S. Alshawish, Moustafa M. Abdalla(4-2019)

Abstract In practical environment most of physical systems that are existed, have nonlinear behavior. In most cases the accuracy of these systems, and their responses aren’t acceptable. Therefore to improve the performance of these systems, a modern control methodology must be applied. In the case of nonlinear systems most problems can be divided into two basic types of nonlinear control problems; nonlinear regulation and nonlinear tracking problems. Due to existing of high nonlinearities parts in theses nonlinear systems the use of classical linearization methods don’t provide an acceptable level of accuracy and therefore these problems have gained a great attention in recent years; and there are numbers of methods can be found to solve these nonlinear problems, such as trail and error, feedback linearization, Robust control, Adaptive control, Gain-scheduling and…etc. In This thesis the feedback linearization is choose as a control methodology to solve these problems; The central idea of the feedback linearization approach is to algebraically transform a nonlinear system dynamics into a (fully or partly) linear one, so that linear control techniques can be applied. This differs entirely from conventional linearization (i.e., Jacobian linearization [4]) in that feedback linearization is achieved by exact state transformations and feedback, rather than by linear approximations of the dynamics.
فرج على عبدالسلام بشير (2008)

Mobile terminals allow users to access services while on the move. This unique feature has driven the rapid growth in the mobile network industry, changing it from a new technology into a massive industry within less than two decades. In this thesis, we address admission control problems in a cellular wireless environment. The admission control is responsible for deciding whether an incoming call or connection can be accepted or not, which are based on the available codes . We provide an extensive survey of the existing admission control algorithms. The issues related to and the approaches for designing admission control in third generation(3G) cellular wireless networks are discussed. An admission control method considering the quality of service(QoS) requirements in wireless is presented along with 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 a mobile user from the base station, which is called Node B, is also an important factor because of the signal fading. The first part of this work is an algorithm written in C++ programming language that distributes users in different zones assuming that the cell area is divided into Z virtual zones, where Z depends on the number of users. In the rest of this thesis we present a simulation model for the Universal Mobile Telecommunication Systems(UMTS). For validation purposes, we have developed a much more detailed simulation of the system written in C language. The results of the mathematical model showed that, a product form equilibrium distribution holds in the case of two cells. Theses results are used to validate a simulation, and to show that the behaviour of the system is similar to that in the mathematical model. Once the product form of Jackson’s Theorem is known to hold, then it is possible to go to a more advanced stage to analyze the 3G network, and to get the performance measures, which will help in making decisions at the design stage of a network. To be more realistic, we used traffic distributions in the simulator, where a user can generate world wide web sessions(www), file transfer sessions, and Emails. These followed recommendations in the ETSI standard and further demonstrated the feasibility of the model.
Wael Saleh Abughres(7-2008)