  The exploitation of interference in a constructive manner has recently been
proposed for the downlink of multiuser, multi-antenna transmitters. This novel
linear precoding technique, herein referred to as constructive interference
zero forcing (CIZF) precoding, has exhibited substantial gains over
conventional approaches; the concept is to cancel, on a symbol-by-symbol basis,
only the interfering users that do not add to the intended signal power. In
this paper, the power allocation problem towards maximizing the performance of
a CIZF system with respect to some metric (throughput or fairness) is
investigated. What is more, it is shown that the performance of the novel
precoding scheme can be further boosted by choosing some of the constructive
multiuser interference terms in the precoder design. Finally, motivated by the
significant effect of user selection on conventional, zero forcing (ZF)
precoding, the problem of user selection for the novel precoding method is
tackled. A new iterative, low complexity algorithm for user selection in CIZF
is developed. Simulation results are provided to display the gains of the
algorithm compared to known user selection approaches.
