چكيده به لاتين
Due to the increasing availability of users and the need for broadband services, telecommunication networks are being driven to capacity and performance. For this purpose, recently, an electromagnetic wave characteristic, called Orbital Angular Momentum (OAM), has been studied. The waves with its orbital angular momentum have two unique features. The first feature is the OAM mode based on topological charge and the second feature is azimuthal or spiral phase. The use of OAM waves and its features in the radio domain provides new degrees of freedom. Therefore, it can be used to improve the performance of the system in terms of spectral capacity and efficiency in telecommunication systems.
In this thesis, a multi-antenna array system based on orbital angular momentum is presented with uniform linear antenna array on both sides. The system is then configured using a specific OAM generator. Each OAM generator antenna alone can produce the desired OAM mode, so simultaneously several OAM signals can be sent differently with different phases at a same frequency. Then, considering the importance of the antenna arrays and the properties of OAM, optimization of the mentioned system is made using the optimal spiral phase property. Using the linear antenna configuration and its combination with the OAM system, and the use of a particular type of OAM generator and its combination with the linear arrangement of antenna on the OAM system is different from that of previous studies. In addition to the other innovations, this system is compared with the OAM system with a circular array and a multi-input OAM multi-input system in terms of capacity and capacity utilization.
To evaluate and compare the system model presented with the previous methods, computer simulation has been used. Results and comparisons show that the proposed system model due to the use of the spiral phase and the optimal OAM mode has a higher capacity than a non-OAM multi-antenna system with a uniform linear and circular array and a multi-objective OAM system with a circular array uniformly. Also, the increase in the number of antennas on both sides of the sending and receiving increases the capacity of the system provided. The system capacity utilization is also optimized for higher OAM properties compared to non-OAM multiprotection systems.
