Multiuser precoders for Þxed receivers

—We consider the problem of designing precoders for multiuser systems using Þxed receivers. We Þrst derive a precoder that minimizes the transmitted power subject to signal to interference plus noise ratio (SINR) constraints, and then derive a precoder that maximizes the worst case SINR subject to a power constraint. We show that both problems can be solved using standard optimization packages. In contrast to most of the existing precoders, our precoder design is not limited to full rank systems, and is applicable to systems in which the number of users is smaller, equal or larger than the processing gain. Simulation results in a multiuser system show that the proposed precoders can signiÞcantly outperform existing linear precoders.