  In this paper, we consider a full-duplex (FD) amplify-and-forward (AF) relay
system and optimize its power allocation and relay location to minimize the
system symbol error rate (SER). We first derive the asymptotic expressions of
the outage probability and SER performance by taking into account the residual
self interference (RSI) in FD systems. We then formulate the optimization
problem based on the minimal SER criterion. Analytical and numerical results
show that optimized relay location and power allocation can greatly improve
system SER performance, and the performance floor caused by the RSI can be
significantly reduced via optimizing relay location or power allocation.
