TY - GEN
T1 - Vector broadcast channels
T2 - 2011 IEEE International Symposium on Information Theory Proceedings, ISIT 2011
AU - Samarasinghe, Tharaka
AU - Inaltekin, Hazer
AU - Evans, Jamie
PY - 2011
Y1 - 2011
N2 - Beamforming techniques utilizing only partial channel state information (CSI) has gained popularity over other communication strategies requiring perfect CSI thanks to their lower feedback requirements. The amount of feedback in beamforming based communication systems can be further reduced through selective feedback techniques in which only the users with channels good enough are allowed to feed back by means of a decentralized feedback policy. In this paper, we prove that thresholding at the receiver is the rate-wise optimal decentralized feedback policy for feedback limited systems with prescribed feedback constraints. This result is highly adaptable due to its distribution independent nature, provides an analytical justification for the use of threshold feedback policies in practical systems, and reinforces previous work analyzing threshold feedback policies as a selective feedback technique without proving its optimality. It is robust to selfish unilateral deviations. Finally, it reduces the search for rate-wise optimal feedback policies subject to feedback constraints from function spaces to a finite dimensional Euclidean space.
AB - Beamforming techniques utilizing only partial channel state information (CSI) has gained popularity over other communication strategies requiring perfect CSI thanks to their lower feedback requirements. The amount of feedback in beamforming based communication systems can be further reduced through selective feedback techniques in which only the users with channels good enough are allowed to feed back by means of a decentralized feedback policy. In this paper, we prove that thresholding at the receiver is the rate-wise optimal decentralized feedback policy for feedback limited systems with prescribed feedback constraints. This result is highly adaptable due to its distribution independent nature, provides an analytical justification for the use of threshold feedback policies in practical systems, and reinforces previous work analyzing threshold feedback policies as a selective feedback technique without proving its optimality. It is robust to selfish unilateral deviations. Finally, it reduces the search for rate-wise optimal feedback policies subject to feedback constraints from function spaces to a finite dimensional Euclidean space.
UR - http://www.scopus.com/inward/record.url?scp=80054826943&partnerID=8YFLogxK
U2 - 10.1109/ISIT.2011.6033745
DO - 10.1109/ISIT.2011.6033745
M3 - Conference proceeding contribution
AN - SCOPUS:80054826943
SN - 9781457705960
SP - 1292
EP - 1296
BT - 2011 IEEE International Symposium on Information Theory Proceedings
PB - Institute of Electrical and Electronics Engineers (IEEE)
CY - Piscataway, NJ
Y2 - 31 July 2011 through 5 August 2011
ER -