Title: Uplink Rate-Splitting Multiple Access for Mobile Edge Computing with Short-Packet Communications Show Chinese title

Title: 上行链路速率分割多址接入用于具有短包通信的移动边缘计算

Abstract: In this paper, a Rate-Splitting Multiple Access (RSMA) scheme is proposed to assist a Mobile Edge Computing (MEC) system where local computation tasks from two users are offloaded to the MEC server, facilitated by uplink RSMA for processing. The efficiency of the MEC service is hence primarily influenced by the RSMA-aided task offloading phase and the subsequent task computation phase, where reliable and low-latency communication is required. For this practical consideration, short-packet communication in the Finite Blocklength (FBL) regime is introduced. In this context, we propose a novel uplink RSMA-aided MEC framework and derive the overall Successful Computation Probability (SCP) with FBL consideration. To maximize the SCP of our proposed RSMA-aided MEC, we strategically optimize: (1) the task offloading factor which determines the number of tasks to be offloaded and processed by the MEC server; (2) the transmit power allocation between different RSMA streams; and (3) the task-splitting factor which decides how many tasks are allocated to splitting streams, while adhering to FBL constraints. To address the strong coupling between these variables in the SCP expression, we apply the Alternative Optimization method, which formulates tractable subproblems to optimize each variable iteratively. The resultant non-convex subproblems are then tackled by Successive Convex Approximation. Numerical results demonstrate that applying uplink RSMA in the MEC system with FBL constraints can not only improve the SCP performance but also provide lower latency in comparison to conventional transmission scheme such as Non-orthogonal Multiple Access (NOMA). Show Chinese abstract

Abstract: 在本文中，提出了一种速率分割多址接入（RSMA）方案，以协助一个移动边缘计算（MEC）系统，其中两个用户的本地计算任务被卸载到MEC服务器，通过上行RSMA进行处理。 MEC服务的效率因此主要受到RSMA辅助的任务卸载阶段和随后的任务计算阶段的影响，在此期间需要可靠且低延迟的通信。 考虑到这一点，引入了有限块长度（FBL）范围内的短包通信。 在此背景下，我们提出了一种新颖的上行RSMA辅助MEC框架，并推导了考虑FBL的总体成功计算概率（SCP）。 为了最大化我们提出的RSMA辅助MEC的SCP，我们战略性地优化：(1) 任务卸载因子，该因子决定了要卸载并由MEC服务器处理的任务数量；(2) 不同RSMA流之间的发射功率分配；以及(3) 任务分割因子，该因子决定分配给分割流的任务数量，同时遵守FBL约束。 为了解决SCP表达式中这些变量之间的强耦合，我们应用了交替优化方法，该方法制定了可处理的子问题以迭代优化每个变量。 然后通过连续凸近似来解决产生的非凸子问题。 数值结果表明，在具有FBL约束的MEC系统中应用上行RSMA不仅可以提高SCP性能，还能相比传统的传输方案如非正交多址接入（NOMA）提供更低的延迟。