Performance of Uplink NOMA With Hybrid Long and Short Packets in Satellite Systems

To meet the diversified quality of service requirements for heterogeneous users, this article proposes an uplink nonorthogonal multiple access scheme with hybrid long and short packets transmission and analyzes its performance in satellite systems. In particular, based on the statistic channel correlation, a user grouping and scheduling method combining with 3-D analog beamforming is first presented so that the delay-tolerant users with long packets and delay-sensitive users with short packets enable to simultaneously access the satellite network. Then, considering the different delay requirements and achievable service rates of long and short packets, we derive the closed-form effective capacity expressions for the heterogeneous users while exploiting the proposed scheme under the assumption that the satellite channel obeys shadowed-Rician fading. Finally, simulation results are presented to demonstrate the validity and superiority of the proposed schemes.