Our current research focus includes :
Next generation multiple access
Non-orthogonal multiple access (NOMA)
The principle of NOMA allows multiple users to be superimposed on the same resource, this leads to interference for such systems. Consequently, existing resource management and interference mitigation techniques, especially for ultra-dense networks, need to be revisited due to the incorporation of additional interference this new technology brings. For the similar reason, beamforming and the resultant other problems (e.g., precoding) in massive-MIMO systems introduce additional challenges and need to be solved in order to achieve full utilization of these technologies.
Rate splitting multiple access (RSMA)
RSMA is a more general and more powerful multiple access for downlink multi-antenna systems that contains SDMA and NOMA as special cases. RSMA relies on linearly precoded rate-splitting with SIC to decode part of the interference and treat the remaining part of the interference as noise. This capability of RSMA to partially decode interference and partially treat interference as noise enables to softly bridge the two extremes of fully decoding interference and treating interference as noise and provides room for rate and QoS enhancements and complexity reduction.
UAV assisted wireless communication
Unmanned Aerial Vehicles (UAV), also known as drones, have seen recently an increasing interest in a wide range of domains due to the numerous advantages they present, in terms of mobility, flexibility, and easy deployment.
With the challenges faced by communication networks to handle the growing demand and various services, UAVs represent an interesting solution to many problems, ranging from ensuring coverage in emergency situations and rural areas to network densification for highly dense areas. However, to be deployed, several challenges need to be addressed, such as limited energy, backhaul link, mobility and handover, etc.
The scope of this Special Issue is to address the potential research areas in UAV-assisted communications.
Full duplex UAV relay
UAV as Aerial base station
UAV aided terrestrial communication
Beyond 5G and 6G communication
5G New Radio (5G NR) network rollouts are in full swing globally, with standardization advancing and the evolution of the global standard to address new market verticals such as automotive and industrial internet of things (IIoT) progressing.
However, the initial network deployments do not use all the capabilites currently defined for 5G. While the optimization of networks and early 5G devices is an ongoing process, researchers have initiated discussions on the future, what comes beyond 5G and leads to the next generation of wireless communication.
Reconfigurable Intelligent surfaces (RIS) aided communication
RIS assisted V2V and V2I communication
Artificial intelligence and Machine learning for wireless communications
The unmanned aerial vehicles (UAVs) can be deployed as aerial base stations or wireless relays to enhance the coverage and guarantee the quality of service (QoS) of wireless networks. In this thesis, the positioning of a full-duplex (FD) UAV as a relay to provide coverage for an FD vehicular network is investigated. This problem is solved using two different methods. In both of the methods, the problem is formulated using a predefined set of locations for the UAV.
Airborne base stations (BSs) (carried by drones) have a great potential to enhance the coverage and capacity of 6G cellular networks. However, one of the main challenges facing the deployment of airborne BSs is the limited available energy at the drone, which curtails the flight time. In fact, most current unmanned aerial vehicles (UAVs) can only operate for a maximum of 1 h. The need to frequently visit the ground station (GS) to recharge limits the performance of the UAV-enabled cellular network and leaves the UAV’s coverage area temporarily out of service.
UAVs can be deployed to complement existing cellular systems by providing additional capacity to hotspot areas as well as to provide network coverage in emergency and public safety situations. On the other hand, UAVs can operate as flying mobile terminals within the cellular networks.
Reconfigurable Intelligent Surfaces (RIS) have gained significant attention as a leading technology to produce intelligent and reconfigurable wireless radio/propagation environment for the sixth-generation (6G) wireless networks. The most important advantage of the RIS technology is controlling the transmission environment by guiding the reflected signals in a specific direction. In wireless communications, the achievable appealing functions of RIS technology are multi-fold and include improving the received signal-to-noise ratio (SNR) at the legitimate receiver, mitigating the unwanted interference, extending the coverage area, and improving the physical layer security (PLS). Compared to the relay-aided transmission systems, the RIS-aided wireless systems obviously provide high reliability and security provisioning.
Conventional backscattering communication systems, the receivers (i.e., WTRDs) have to be equipped with a power source to transmit RF signals to the transmitter (i.e., WTDs). Second, the transmitters do not need to be equipped with a power source to transmit data because they will reflect signals received by the receivers instead of generating their own signals. The second feature is the most important characteristic and also the main objective for the development of conventional backscattering communication systems. This special communication feature of CBCSs has received a great deal of attention, mainly because of the successful implementation of RFID systems and the potential use in sensor devices that are small in size and have a low power supply.
Vehicular fog computing provide efficient solution to challenges faced in a vehicular network and vehicle-to-vehicle (V2V) communication and vehicle-to-infrastructure (V2I) communication further enhances the quality of network by sharing idle computation resources among the vehicles. Such network setup consists of continuous data transmission and data exchange among the units. Therefore, it is important to improve the spectrum and effeciency of the wireless communication for better network performance which can be achieved by incorporating reconfigurable intelligent surfaces (RIS). RIS is a programmable structure that can be used to control the propagation of electromagnetic waves by changing the electric and magnetic properties of the surface. Properties of the communical channel can be controlled by installation of these surfaces and it improves the quality of the network communication thereby enhancing the efficiency of communication in the vehicular network.
Digital Twin based communication
Digital twin (DT) technology is recently emerging as an exquisite technology which provides high-fidelity digital representation of the physical entities in the virtual world using simulated data while monitoring the physical entities in real-time. In vehicular networks, DTs can monitor the status of the physical network in real time and provide more precise offloading decisions according to the requirements of the network.
The study of intelligent wireless communication and machine learning provide ample of opportunities in both industry and academia with the goal of enhancing network capabilities to serve a large number of diverse mobile applications. Artificial intelligence manifestations can invoke various problems ranging from signal recognition, classification, routing etc. Hence, our team aims at incorporating the AI and machine learning strategies to develop enhanced wireless communication models and address the challenges regarding the same.