Rate-Splitting Enabled Multi-Connectivity in Mixed-Criticality Systems

TL;DR

This paper explores how rate-splitting multiple access (RSMA) can improve uplink multi-connectivity reliability in 5G/6G systems, especially for high-criticality data, by enabling resource-efficient, low-latency, and highly reliable communication.

Contribution

It introduces a criticality-aware RSMA scheme with short blocklength coding and an iterative power allocation algorithm, enhancing reliability and rate regions in multi-connectivity scenarios.

Findings

Expanded stability rate region compared to baseline schemes

Less impact from short blocklength coding

Significant rate gains at high SNR

Abstract

The enormous quality of service (QoS) demands posed by mission-critical use-cases of future 5G/6G wireless communication raise the need for resource-efficient highly reliable and low latency connectivity solutions. Multi-connectivity is considered a promising yet resource demanding approach to enhance reliability. In this work, we study the potential of the rate-splitting multiple access (RSMA) framework as an efficient way to enable uplink multi-connectivity for data transmissions with particularly high reliability requirements. Mapping high-criticality data onto the common stream allows it to be decoded at multiple access points (APs), which enhances reliability, while the private stream is utilized to serve applications with less stringent requirements. We propose a criticality-aware RSMA-based transmission scheme with short blocklength coding and derive an iterative power allocation algorithm by means of successive convex approximation (SCA). The proposed scheme is shown to achieve an expanded stability rate region compared to two baseline schemes. Moreover, it turns out to be less impacted by short blocklength while leading to substantial rate gains, particularly in the high SNR regime.