Adaptive bitrate streaming in multi-user downlink NOMA edge caching systems with imperfect SIC

Recently, mobile networks have witnessed an increasing dominance of video traffic streams to simultaneously distribute real-time contents to massive number of user devices. In this context, fifth-generation (5G) technologies and beyond expose their advanced new radio access interfaces to facilitate multi-user associations with successive interference cancellation (SIC)-based non-orthogonal multiple access (NOMA) mechanisms. However, the imperfectness of the SIC in reality may result in significant performance decrease in NOMA owing to inter-channel interference existence. Motivated by this observation, this paper studies adaptive bitrate streaming services given such a challenging transmission environment assumed. In this context, our objectives are to maximize the video bitrate (accordingly the video resolution) of the online streams while retaining the playback smoothness. The problem is transformed into a drift-plus-penalty balancing optimization, which is then resolved by an approximation algorithm. Numerical results highlight the outperformance of the proposed approach compared to existing algorithms in terms of video quality and smoothness in various system scenarios.