Minimum probability of error multiuser transmit beamforming

Motivated by the poor performance of the existing transmit beamforming methods in low signal to noise ratio regime, and assuming that the knowledge of the modulation type could result in a more intelligent design of beamformers, this paper proposes a transmit beamforming method based on the concept of minimum probability of error (MPE) beamforming. We calculate the error probability of each user in the downlink of a multiuser scenario and design an objective function based on the weighted sum of these error probabilities. We take a convex optimization approach to solve this ill-behaved nonconvex optimization problem. It is shown that by minimizing this objective function, the performance of the system could be dramatically improved.