  This paper investigates an active reconfigurable intelligent surface
(RIS)-aided mobile edge computing (MEC) system. Compared with passive RIS, the
active RIS is equipped with active reflective amplifier, which can effectively
circumvent the "double path loss" attenuation. We propose a joint computing and
communication design to minimize the maximum computational latency (MCL),
subject to both the phase shift constraints and the edge computing capability
constraints. Specifically, the original problem is decoupled into four
subproblems, and then the block coordinate descent (BCD) method and the
successive convex approximation (SCA) method are applied to alternately
optimize the subproblems. The simulation results show that with the same power
budget, the performance gain achieved by the active RIS is much larger than
that by the passive RIS.
