Date Added: Sep 2009
With the introduction of orthogonal frequency-division multiplexing and multiple antennas in cellular networks, there are new opportunities to adapt the transmission to propagation and interference conditions. In this paper, the authors describe a practical approach using space-frequency-selective multiuser MIMO scheduling. Frequency-selective feedback is provided on achievable data rates for preferred single- and multi-stream transmission modes. The base station selects the best mode while providing instantaneous fairness. They observe that multiuser transmission increases the probability of using multi-stream transmission. Besides the benefits from optimal combining at the physical layer, there is an additional gain at the MAC layer since the estimation of achievable rates becomes more precise.