There are three generic services in 5G: enhanced mobile broadband (eMBB), ultra-reliable low-latency communications (URLLC), and massive machine-type communications (mMTC). To guarantee the performance of heterogeneous services, network slicing is proposed to allocate resources to different services. Network slicing is typically done in an orthogonal multiple access (OMA) fashion, which means different services are allocated non-interfering resources. However, as the number of users grows, OMA-based slicing is not always optimal, and a non-orthogonal scheme may achieve a better performance. This work aims to analyse the performances of different slicing schemes in uplink, and a promising scheme based on rate-splitting multiple access (RSMA) is studied. RSMA can provide a more flexible decoding order and theoretically has the largest achievable rate region than OMA and non-orthogonal multiple access (NOMA) without time-sharing. Hence, RSMA has the potential to increase the rate of users requiring different services. In addition, it is not necessary to decode the two split streams of one user successively, so RSMA lets suitable users split messages and designs an appropriate decoding order depending on the service requirements. This work shows that for network slicing RSMA can outperform NOMA counterpart, and obtain significant gains over OMA in some region.

翻译：5G包含三种通用服务类型：增强型移动宽带（eMBB）、超可靠低延迟通信（URLLC）以及大规模机器类通信（mMTC）。为保障异构服务的性能，网络切片被提出用于为不同服务分配资源。传统网络切片通常采用正交多址接入（OMA）方式，即为不同服务分配互不干扰的资源。然而，随着用户数量增长，基于OMA的切片并非始终最优，非正交方案可能实现更优性能。本文旨在分析上行链路中不同切片方案的性能，并重点研究一种基于速率分割多址接入（RSMA）的潜在方案。RSMA能够提供更灵活的解码顺序，理论上在无时间共享条件下可获得比OMA和非正交多址接入（NOMA）更广的可达速率域。因此，RSMA具备提升不同服务类型用户速率的潜力。此外，由于无需对单个用户的两个分离数据流进行连续解码，RSMA允许适合的用户进行消息分割，并根据服务需求设计相应的解码顺序。研究表明，在网络切片场景中，RSMA的性能优于NOMA方案，并在某些区域相较OMA可获得显著增益。