TY - GEN
T1 - Downlink precoding for multiuser MISO systems with imperfect channel knowledge
AU - Vucic, Nikola
AU - Boche, Holger
PY - 2008
Y1 - 2008
N2 - It is well-known that the downlink beamforming problem of minimizing the total transmit power under users' signal-to-interference-plus-noise ratio (SINR) constraints can be reformulated as a conic quadratic optimization problem and efficiently solved, if the transmitter is provided with the perfect information about the channel. In this work, we study the robust counterpart of the latter, convex problem. By robustness it is meant that the base station knows only uncertainty regions where the exact channels lie, and that it is supposed to satisfy the conic quadratic constraints for all channels that belong to these regions. We provide a direct optimal solution for this problem, based on the ellipsoid method from convex optimization theory. By exploiting the structure of the problem, we define also a virtual robust mean square error optimization problem, that can be solved by semidefinite programming methods in a much more efficient manner, and which presents (at least) a tight conservative approximation of the main problem.
AB - It is well-known that the downlink beamforming problem of minimizing the total transmit power under users' signal-to-interference-plus-noise ratio (SINR) constraints can be reformulated as a conic quadratic optimization problem and efficiently solved, if the transmitter is provided with the perfect information about the channel. In this work, we study the robust counterpart of the latter, convex problem. By robustness it is meant that the base station knows only uncertainty regions where the exact channels lie, and that it is supposed to satisfy the conic quadratic constraints for all channels that belong to these regions. We provide a direct optimal solution for this problem, based on the ellipsoid method from convex optimization theory. By exploiting the structure of the problem, we define also a virtual robust mean square error optimization problem, that can be solved by semidefinite programming methods in a much more efficient manner, and which presents (at least) a tight conservative approximation of the main problem.
KW - Antenna arrays
KW - Broadcast channels
KW - Robustness
UR - http://www.scopus.com/inward/record.url?scp=51449117756&partnerID=8YFLogxK
U2 - 10.1109/ICASSP.2008.4518311
DO - 10.1109/ICASSP.2008.4518311
M3 - Conference contribution
AN - SCOPUS:51449117756
SN - 1424414849
SN - 9781424414840
T3 - ICASSP, IEEE International Conference on Acoustics, Speech and Signal Processing - Proceedings
SP - 3121
EP - 3124
BT - 2008 IEEE International Conference on Acoustics, Speech and Signal Processing, ICASSP
T2 - 2008 IEEE International Conference on Acoustics, Speech and Signal Processing, ICASSP
Y2 - 31 March 2008 through 4 April 2008
ER -