Integration of non-terrestrial network for 5G NR and future 6G: LEO satellite-to-device performance and interference analysis

Non-Terrestrial Networks (NTN) are considered pivotal for the development of 6G, aiming to provide ubiquitous and continuous mobile broadband coverage. With ongoing standardisation efforts by 3GPP, 5G NTN promises seamless connection moving between terrestrial and satellite networks, using existing or next-generation smartphone devices. This paper focuses on the integration of NTN, particularly Low Earth Orbit (LEO) constellations, for 5G NR services. We explore the latest developments in direct satellite-to-device communication and the significant challenge posed by interference. We assess the performance of 5G NTN by simulating and analysing the downlink performance of LEO constellations providing continuous service to moving User Equipment (UE) in unserved and remote areas, addressing the challenges of achieving higher data rates and managing signaling interference. Based on our baseline Link Budget calculation result, higher Effective Isotropic Radiated Power (EIRP) and additional spectrum bandwidth are essential for enhancing data rates and user coverage. However, given the limited availability of spectrum, increasing EIRP becomes a more practical option to increase data rates, which in turn increases the risk of interference. Our simulation findings indicate that LEO constellations can provide continuous coverage for moving UEs, supporting low data rate services such as text, voice and Internet of Things (IoT), but the limited spectrum bandwidth and interference proved to be some of the main challenges for achieving higher data rates. Interference management strategies, such as reducing sidelobe power and employing advanced technologies such as beamforming [1] and beam-hopping [2], are critical to mitigate interference and improve performance.