Abstract
In this work, we study the cooperative and non-cooperative transmission schemes design for live VR video broadcast scenarios by utilizing non-orthogonal multiple access (NOMA), considering that users' viewports partly overlap due to behavioral coherence. To characterize the performance of the proposed cooperative and non-cooperative transmission schemes, the exact and asymptotic expressions of outage probability, as well as the average outage capacity under imperfect successive interference cancellation (SIC), are derived, respectively. Based on the asymptotic outage probability results, we optimize the power allocation to maximize the average outage capacity of the proposed schemes. Finally, simulation results demonstrate that both of the proposed schemes can achieve a considerable performance gain over the traditional orthogonal multiple access (OMA) scheme in average outage capacity, and each of the proposed schemes has its advantages and applicable scenarios.