Power Allocation for Layered Multicast Video Streaming in Non-Orthogonal Multiple Access System

Non-orthogonal multiple access (NOMA) scheme is emerging as an enabling technology for 5G wireless networks, which address the growing demand for capacity that is mostly made up of high quality video content. In this paper, by combining the principles of NOMA and layered coding, the sum rate is enhanced for multicast video streaming. An optimization problem for power allocation is formulated to maximize the overall sum rate whilst achieving the total transmission power constraints and target rates. A near-optimal scheme and a low-complexity closed form solution are proposed. Numerical simulation results show that the proposed schemes offer better sum rate performance than the existing schemes. The closed form solution incurs performance degradation relative to the near-optimal solution but with a much lower complexity. Furthermore, the proposed schemes provide a superior degree of fairness towards the users with poor channel conditions.