Interference management techniques for non-terrestrial networks in 5G/6G systems"

Non-Terrestrial Network can be defined as communication systems that use air-/space-borne platforms to establish communication links among various points on Earth’s surface. In the context of (5G), NTN aims at the use of NTN platforms to enhance the flexibility, adaptability and the resilience of 5G Terrestrial Network system as well as to extend its coverage and provide connectivity to rural and underserved/un-served areas. In 6G, NTN is expected to play an even more pivotal role, potentially forming a significant part of the global communication infrastructure. The unification of TN and NTN in 6G is envisioned to enable global coverage, low-latency communication, and support for massive Internet of Things (IoT) deployments. This unification will require advances in satellite and aerial communication technologies, as well as seamless integration with terrestrial networks to ensure ubiquitous and reliable connectivity. Furthermore, the use of NTN in 6G is expected to bring about new challenges in terms of network architecture and spectrum management. The scarcity of spectrum resources to meet the demanding requirements of future Beyond 5G (B5G)/6G communication systems is considered one of the main challenges. To this aim, the current state of the art considers several strategies aimed at efficient utilization of the available spectrum bandwidth through either dynamic spectrum utilization schemes, such as Cognitive Radio solutions, or by fully exploiting the spectrum by decreasing the frequency reuse factor down to Full Frequency Reuse. However, the latter solution introduces substantial Co-Channel Interference or also known as Inter-Beam Interference, thus calling for the use of advanced interference management techniques at the transmitter side, i.e, at the satellite. This issue is addressed throughout the thesis by introducing interference management schemes and solutions by evaluation MIMO beamforming algorithms.