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Small cell networks are expected to heavily be deployed in wireless communication networks due to it ability to enhance signals quality and spectrum utilisation. However, interference is posing a major threat to wireless communication especially cellular femtocell networks whereby its performance is degraded in dense deployment areas. For this reason, an enhanced fractional frequency reuse approach is proposed in this paper to mitigate the interference in femtocell networks. This is achieved by dividing the service area and frequency into three regions and three sets whereby each set is allocated different frequency set. The femtocell location is later obtained and assigned frequency in accordance to the region. The proposed approach helps in reducing the interference, boost the signal to interference plus noise (SINR), and enhance the throughput.

Device-to-device (D2D) communication system plays an extremely important role in fulfilling the demands of fourth generation (4G) and fifth generation (5G) technologies. 4G technology cannot meet high data demands. The D2D communication system is believed to provide major improvements in resource usage, energy efficiency, and overall throughput, which are the main demands for the 5G network. Some of the main issues in the D2D communication system involve spectrum efficiency and interference. Although many studies have been conducted on spectrum efficiency improvement and interference reduction, the issues still remain. A study should be conducted to obtain a better understanding of the D2D communication system and to develop a D2D scheme with efficient spectrum utilization and interference reduction. Many survey papers have been published on these issues, but the fundamental concepts behind the D2D communication system require investigation. In this study, we investigated and analyzed the fundamental concepts behind the D2D communication system to develop an efficient D2D resource allocation scheme with reduced interference.

This paper focuses on the simulation analysis of the conventional Internal Model Control (IMC) technique and the development of two proposed control techniques for the position control of AC Servo Motor. Internal Model Control (IMC) technique [1] was only able to control the AC Servo Motor under static load condition. Also, it had step response problems, and it was not robust against external disturbances. For these reasons, the IMC technique was further improved to control the AC Servo Motor under dynamic load conditions by proposing Amended Internal Model Controller (AIMC). The step response and the robustness of AIMC against external disturbances were further improved by proposing AIMC+FLC. Where a Fuzzy Logic Controller (FLC) is designed and connected with the AIMC.

Fifth-generation (5G) technology plays an essential role in proximate devices that provide a technology where the proximate devices communicate without assisting a base station. Device-to-device (D2D) and vehicle-to-vehicle (V2V) communications are emerging technology used to improve throughput and latency further. D2D communication is considered the most promising technology that utilizes existing cellular frequency bands. This technology plays a vital role in next-generation wireless technology due to its reliability, low-latency, and high-capacity communications. This paper analyzes and investigates the D2D communication based on underlay licensed spectrum in a lower 5G band using a single-cell scenario. This work also provides insights into spectral efficiency improvement based on spectrum sharing between cellular user equipment (CUE) and D2D UE. Simulation results show that the D2D pairs significantly improve the spectrum efficiency through CUEs by increasing the overall sum rate of the cellular network.

The fifth generation (5G) network is an upcoming standard for wireless communications that coexists with the current 4G network to increase the throughput. The deployment of ultra-dense small cells (UDSC) over a macro-cell layer yields multi-tier networks, which are known as heterogeneous networks (HetNets). HetNets play a key role in the cellular network to provide services to numerous users. However, the number of handovers (HOs) and radio link failure (RLF) greatly increase due to the increase in the UDSC in the network. Therefore, mobility management becomes a very important function in a self-organizing network to improve the system performance. In this paper, we propose a velocity-based self-optimization algorithm to adjust the HO control parameters in 4G/5G networks. The proposed algorithm utilizes the user&rsquo, s received power and speed to adjust the HO margin and the time to trigger during the user&rsquo, s mobility in the network. Simulation results demonstrate that the proposed algorithm achieves a remarkable reduction in the rate of ping-pong HOs and RLF compared with other existing algorithms, thereby outperforming such algorithms by an average of more than 70% for all HO performance metrics.