Performance Analysis Of Hybrid Satellite-Terristerial Communication Systems

With the beginning of the deployment of 5G communication networks,and with the rapid growth of more and more intelligent devices,the number of connections is exploding,and the traditional orthogonal resource-based access methods cannot meet the needs of future communication scenarios,especially for massive low-latency low-rate wireless sensing communication networks scenario.The combination of satellite communication and terrestrial mobile communication to form a hybrid satellite-terrestrial communication network is an important component and development trend of future world-wide communication.In order to better integrate the future 5G terrestrial mobile communication system and provide more efficient and broader coverage of communication service requirements,this paper combines the relay-based hybrid satellite-terrestrial communication system and NOMA technology,and studies the cooperative NOMA hybrid satellite-terrestrial communication system and NOMA-based hybrid satellite-terrestrial AF relay communication system,considering the ideal situation and the actual hardware impairments.In practice,the outage probability and ergodic sum rate performance of the cooperative NOMA hybrid satellite-terrestrial communication system and NOMA-based hybrid satelliteterrestrial AF relay communication system are derived.The main contributions and work of this paper are summarized as follows:For the cooperative NOMA hybrid satellite-terrestrial communication system,considering the outage probability performance of each user in the presence and absence of the direct transmission link under ideal conditions,the exact expression and the asymptotic expression of the outage probability are derived,and the situation with OMA are compared.The comparison and simulation verification are carried out.Furthermore,the ergodic sum rate of the system are derived and simulated.The results show that the NOMA scheme is superior to the traditional OMA method.Considering the existence of RHI in the node,the closed-form solution of the system's outage probability is derived.The influence of RHI level on the system's outage performance is studied.The comparison with the ideal situation and OMA reveals that the existence of RHI will make the user's signal to noise ratio tend to a constant value,causing a bit error floor.Furthermore,the ergodic sum rate are deduced and studied.The influence of RHI level on ergodic sum rate of the system is theoretically analyzed and studied.The simulation and comparison with the OMA system are carried out.For the NOMA-based hybrid satellite-terrestrial AF relay communication system,considering the performance of the outage probability of each user under ideal conditions,the exact expression and the asymptotic expression of the outage probability are derived,and compared with the OMA case are carried out,and the simulation is verified.Further,the upper and lower bounds of the ergodic sum rate of the system are derived and verified by simulation.Further considering the existence of RHI in the node,the closed-form solution of the system's outage probability is derived,and compared with the ideal situation and OMA,revealing that the existence of RHI will make the power allocation factor suitable for the ideal situation no longer applicable,so it needs to be carefully design the power allocation factor of the system.Furthermore,the system ergodic sum rate are deduced and studied.The influence of RHI level on ergodic sum rate is theoretically analyzed and studied.The existence of RHI will make the user's ergodic sum rate and OMA ergodic sum rate same at high SNR.But the NOMA solution improves the fairness between users.The research results prove the superiority of NOMA transmission system in spectrum efficiency,user-to-user fairness and connection number,and provide theoretical reference and basis for the actual equipment RHI design and manufacture.