Abstract
This paper describes a multiuser scenario with several
terminals acceding simultaneously to the same frequency channel.
The objective is to design an optimal multiuser system that may be
used as a comparative framework when evaluating other suboptimal
solutions and to contribute to the already published works on
this topic. The present work assumes that a centralized manager
knows perfectly all the channel responses between all the
terminals. According to this, the transmitters and receivers,
using antenna arrays and leading to the so-called
multiple-input-multiple-output (MIMO) channels, are designed in a
joint beamforming approach, attempting to minimize the total
transmit power subject to quality of service (QoS) constraints.
Since this optimization problem is not convex, the use of the
simulated annealing (SA) technique is proposed to find the optimum
solution.