In this paper, we investigate a mobile edge computing (MEC) network with two computational access points (CAPs), where the source is equipped with multiple antennas and it has some computational tasks to be accomplished by the CAPs through Nakagami- $m$ distributed wireless links. Since the MEC network involves both communication and computation, we first define the outage probability by taking into account the joint impact of latency and energy consumption. From this new definition, we then employ receiver antenna selection (RAS) or maximal ratio combining (MRC) at the receiver, and apply selection combining (SC) or switch-and-stay combining (SSC) protocol to choose a CAP to accomplish the computational task from the source. For both protocols along with the RAS and MRC, we further analyze the network performance by deriving new and easy-to-use analytical expressions for the outage probability over Nakagami- $m$ fading channels, and study the impact of the network parameters on the outage performance. Furthermore, we provide the asymptotic outage probability in the low regime of noise power, from which we obtain some important insights on the system design. Finally, simulations and numerical results are demonstrated to verify the effectiveness of the proposed approach. It is shown that the number of transmit antenna and Nakagami parameter can help reduce the latency and energy consumption effectively, and the SSC protocol can achieve the same performance as the SC protocol with proper switching thresholds of latency and energy consumption.

中文翻译：

---

移动边缘计算网络的机会接入点选择

在本文中，我们研究了具有两个计算接入点 (CAP) 的移动边缘计算 (MEC) 网络，其中源配备多个天线，并且有一些计算任务需要由 CAP 通过 Nakagami-$m$ 分布式无线链接。由于 MEC 网络涉及通信和计算，我们首先通过考虑延迟和能耗的联合影响来定义中断概率。根据这个新定义，我们然后在接收器处采用接收器天线选择 (RAS) 或最大比率组合 (MRC)，并应用选择组合 (SC) 或切换保持组合 (SSC) 协议来选择一个 CAP 来完成从源头计算任务。对于两个协议以及 RAS 和 MRC，我们通过推导出新的和易于使用的 Nakagami-$m$ 衰落信道中断概率的分析表达式来进一步分析网络性能，并研究网络参数对中断性能的影响。此外，我们提供了低噪声功率范围内的渐近中断概率，从中我们获得了对系统设计的一些重要见解。最后，通过仿真和数值结果验证了所提出方法的有效性。结果表明，发射天线数量和 Nakagami 参数有助于有效降低时延和能耗，并且 SSC 协议可以在适当的时延和能耗切换阈值下达到与 SC 协议相同的性能。