  Mobile edge caching (MEC) has received much attention as a promising
technique to overcome the stringent latency and data hungry requirements in the
future generation wireless networks. Meanwhile, full-duplex (FD) transmission
can potentially double the spectral efficiency by allowing a node to receive
and transmit in the same time/frequency block simultaneously. In this paper, we
investigate the delivery time performance of full-duplex enabled MEC (FD-MEC)
systems, in which the users are served by distributed edge nodes (ENs), which
operate in FD mode and are equipped with a limited storage memory. Firstly, we
analyse the FD-MEC with different levels of cooperation among the ENs and take
into account a realistic model of self-interference cancellation. Secondly, we
propose a framework to minimize the system delivery time of FD-MEC under both
linear and optimal precoding designs}. Thirdly, to deal with the non-convexity
of the formulated problems, two iterative optimization algorithms are proposed
based on the inner approximation method, whose convergence is analytically
guaranteed. Finally, the effectiveness of the proposed designs are demonstrated
via extensive numerical results. {It is shown that the cooperative scheme
mitigates inter-user and self interference significantly better than the
distributed scheme at an expense of inter-EN cooperation. In addition, we show
that minimum mean square error (MMSE)-based precoding design achieves the best
performance-complexity trade-off, compared with the zero-forcing and optimal
designs.
