Product Name: Multi-antenna Wireless Communication
Product Description
Next generation wireless systems will use multiple antennas at both the base station and user terminals. The performance of such systems can be improved by using channel information at the transmitters, at the expense of increased control signaling. We have therefore proposed a number of strategies to achieve similar gains with a minimum of feedback and to provide robustness to channel uncertainty. For systems with DFE based receivers, robust precoders have been proposed, that can be based on long-term channel statistics. For systems with (near) ML receivers, a lattice-based precoding approach has been proposed. A combination of long-term channel statistics with heavily quantized information of the channel gain, can be used for both scheduling and spatial processing in multi-user scenarios. A popular alternative is opportunistic beamforming, where we have studied feedback reduction techniques and the optimal choice of the number of simultaneous data streams. When several systems share the same spectrum, distributed adaptive channel allocation can be obtained based on individual utility functions. The equilibria of such schemes have been analyzed based on game theory. Modifications of the utility functions have been proposed to improve the overall spectrum utilization.
In the development and evaluation of transmission schemes, realistic channel models are crucial. In particular, we have studied the joint characteristics of the propagation to a receiver from several transmitters.
Company Details
Björn Engquist - engquist@nada.kth.se Claes Johnson - cgjoh@csc.kth.se; Lennart Johnsson - johnsson@nada.kth.se; Heinz-Otto Kreiss (Em) - hokreiss@nada.kth.se; Jesper Oppelstrup - jespero@nada.kth.se; Axel Ruhe (Em) - ruhe@nada.kth.se; Anders... more
