الفهرس 
AbstractOnly 14 pages are availabe for public view
 |  | from | 191 |  |  |
| | | from | 191 | | |
Abstract
With the advent of the 5G communications, researchers are quick to go through fast development of new hardware and software designs that could fulfill the recent trends in communication systems. In this thesis, we target the antenna design that suits the 5G base station. Furthermore, the spatial modulation using MIMO concepts is also addressed since both targets are related to each other. The antenna design for the MIMO systems has special considerations in the antenna design and the communication protocols are based on the understanding of the multipath propagation problems. A novel design for a 5G base station (BS) antenna is proposed. The proposed antenna consists of two orthogonally polarized antennas. The two antennas are modified compact Vivaldi antennas operating in the two recommended 5G operating bands; 28 and 38 GHz. The orthogonality of the two antennas allows the use of two antennas on the same substrate within one enclosure to serve two sectors separately. So, instead of using two enclosures to serve two sectors, only one enclosure is required. The two elements may be part of two separate MIMO distributions. To minimize the isolation between the MIMO antennas elements with low complexity and low cost, the antenna elements have been distributed along the z-direction with half-wavelength spacing between elements including Electromagnetic band-gap (EBG) structure in between them. Good results are observed when comparing the simulated and measured results. On the other side, the spatial modulation is addressed in this thesis by modifying a precoding algorithm in order to increase the sum rate of the Multi user Multi-Input-Multi-output (MU-MIMO) systems. In this thesis, it is proposed a novel concept to deal with the complex trade off in the performance metrics for the precoding algorithms. Actually, most of the work in literatures turn around the conventional linear precoding (CLP) algorithm such as a Maximum Ratio Transmission (MRT), a Zero-Forcing (ZF), a Regularized Zero-Forcing (RZF), and a Minimum Mean Square Error (MMSE) and the methods of enhancing these algorithms to get good performance. MRT gives better sum rate at low signal-to–noise ratio (SNR) but with the Worst BER. On the other sides, ZF gives better performance at high SNR but doesn’t have much improvement in BER. Therefore, a novel precoding algorithm called unified linear precoding (ULP) algorithm using a precoding selection technique to ensure a minimum BER performance for most CLPs with minimum hardware and mathematical calculations is introduced.