  We propose a cache-enabled opportunistic cooperative MIMO (CoMP) framework
for wireless video streaming. By caching a portion of the video files at the
relays (RS) using a novel MDS-coded random cache scheme, the base station (BS)
and RSs opportunistically employ CoMP to achieve spatial multiplexing gain
without expensive payload backhaul. We study a two timescale joint optimization
of power and cache control to support real-time video streaming. The cache
control is to create more CoMP opportunities and is adaptive to the long-term
popularity of the video files. The power control is to guarantee the QoS
requirements and is adaptive to the channel state information (CSI), the cache
state at the RS and the queue state information (QSI) at the users. The joint
problem is decomposed into an inner power control problem and an outer cache
control problem. We first derive a closed-form power control policy from an
approximated Bellman equation. Based on this, we transform the outer problem
into a convex stochastic optimization problem and propose a stochastic
subgradient algorithm to solve it. Finally, the proposed solution is shown to
be asymptotically optimal for high SNR and small timeslot duration. Its
superior performance over various baselines is verified by simulations.
