  This paper studies the storage-latency tradeoff in the $3\times3$ wireless
interference network with caches equipped at all transmitters and receivers.
The tradeoff is characterized by the so-called fractional delivery time (FDT)
at given normalized transmitter and receiver cache sizes. We first propose a
generic cooperative transmitter/receiver caching strategy with adjustable file
splitting ratios. Based on this caching strategy, we then design the delivery
phase carefully to turn the considered interference channel opportunistically
into broadcast channel, multicast channel, X channel, or a hybrid form of these
channels. After that, we obtain an achievable upper bound of the minimum FDT by
solving a linear programming problem of the file splitting ratios. The
achievable FDT is a convex and piece-wise linear decreasing function of the
cache sizes. Receiver local caching gain, coded multicasting gain, and
transmitter cooperation gain (interference alignment and interference
neutralization) are leveraged in different cache size regions.
