Balanced-QoS power allocation schemes for NOMA in the finite blocklength regime

Abstract

Non-orthogonal multiple Access (NOMA) technology may find its way into sixth-generation (6G) mobile networks thanks to its ability to support heterogeneous services and improve spectral efficiency. In this context, shorter packet usage is imperative for reducing latency and strengthening reliability. However, this approach results in the liability of necessitating metrics adaptation to accommodate the finite blocklength (FBL) regime. This paper explores power allocation optimization for low-latency applications in multi-user downlink NOMA systems with imperfect successive interference cancellation (SIC) and FBL coding. The optimization aims to maximize the effective sum rate while complying with balanced QoS constraints. Two optimization approaches are presented: one optimizing power allocation based on a modified rate equation, and the other based on achievable signal-to-noise ratio (SNR). We obtained substantial performance improvements in achieving a balanced QoS among users while maintaining system efficiency.