Rate-Splitting Multiple Access for URLLC Uplink in Physical Layer Network Slicing With eMBB

Abstract

In this paper, we investigate the problem of heterogeneous service coexistence in the scope of 5G and beyond (B5G) networks, where multiple ultra-reliable low-latency communication (URLLC) and enhanced mobile broadband (eMBB) users are connected to a common base station (BS), sharing physical network resources. In contrast to the orthogonal multiple access (OMA) and non-orthogonal multiple access (NOMA) usually adopted in literature, in this work we employ rate splitting multiple access (RSMA) for URLLC transmission, where a URLLC device splits its message into two sub-messages with partial transmission power, which are potentially recovered at the BS by means of successive interference cancellation (SIC). To study the performance of such methods in the presence of eMBB users, we consider both orthogonal and non-orthogonal network slicing approaches to share the network resources between heterogeneous user profiles with diverse requirements. As a result, we show that, in general, RSMA presents an improved performance in terms of sum-rate and reliability, even when transmitting concurrently with eMBB users. Finally, our results also show that the URLLC sum-rate can be increased by properly adjusting the rate splitting factor based on the average signal-to-noise ratio (SNR), not being necessary instantaneous channel state information (CSI).INDEX TERMS Beyond 5G, heterogeneous users, rate splitting multiple access, ultra-reliable and low latency communications.

Rate-Splitting Multiple Access for 6G -- Part I: Principles, Applications and Future Works

“…Nonetheless, because of its powerful interference management capabilities, RSMA significantly benefits uplink transmission and can enable core services where users have intermittent access behaviour such as URLLC and mMTC. Moreover, RSMA is capable of enabling different combinations of core services to serve users with heterogeneous profiles [12].…”

“…6) Network slicing: In 6G, a combination of services such as eMBB and URLLC will require the network to serve heterogeneous user profiles with diverse QoS requirements. [12] utilizes network slicing to share the resources among users with different profiles and shows that RSMA outperforms OMA and NOMA schemes for URLLC service even in the presence of interference from eMBB users. In the future, the role of RSMA to mitigate impact of imperfect CSIT and ensure security in allocation of slice resources to users of different profiles are worth investigating.…”

Cognitive Radio-Inspired Rate-Splitting Multiple Access for Semi-Grant-Free Transmissions

“…Recently, uplink RSMA has been applied to realize physical layer network slicing for ultrareliable and low-latency (URLLC) and enhanced mobile broadband communications (eMMB) [27]. Also, RSMA has been used to support URLLC and eMMB in 6G NR downlink transmissions [28].…”

Rate-Splitting Multiple Access for Short-Packet Uplink Communications: A Finite Blocklength Error Probability Analysis

“…τ is the tolerance of convergence. Since the solution of Problem (17) at iteration n − 1 is a feasible point of Problem (17) at iteration n and the transmit power constraints (11g) and (11h), the objective function t is monotonically increasing which implies that the convergence of this proposed SCAbased algorithm is guaranteed. −1] and denote the optimal objective as t * and the optimal variables as P * , θ * , ρ * ;…”

“…Motivated by the trade-off between achievable rate and error probability, the error probabilities have been derived for NOMA in Additive White Gaussian Noise (AWGN) channel and Rayleigh fading channel with FBL in [13]- [16], and NOMA was shown to achieve higher effective throughput and reduced latency compared to OMA. The authors in [17] have shown RSMA can outperform OMA and NOMA in a network slicing scenario.…”