I. Introduction
MEC is a promising technology providing cloud-computing capabilities at the wireless edge to handle computation-intensive and latency-sensitive applications from mobile users that have limited computation resources. Usually, computation tasks of mobile users are uploaded to a serving node, and executed at the attached MEC server. Then, the computation results are sent back to the mobile users. Significant amount of research efforts have been devoted to joint allocation of communications and computation resources, such as offloading control [1]–[3] and transmission power and time duration allocation [1] for efficient MEC design [4].