Cooperative MIMO beamforming performance using measured urban channels

This paper uses coherent measurements from three BS sites to a single MS in a macrocellular environment to study the potential gains achievable with cooperative BS communication. The analysis compares the performance achieved using transmit beamforming with either a sum-power and a per-BS power constraint to that achieved using uninformed cooperative transmitters as well as the best BS-to-MS link. The results demonstrate that under low SNR conditions, transmit beamforming offers notable performance improvements for either power constraint. However, as the SNR increases, only the sum-power constraint can offer significant improvements.