General Rank Multiuser Downlink Beamforming With Shaping Constraints Using Real-Valued OSTBC
2015 (English)In: IEEE Transactions on Signal Processing, ISSN 1053-587X, E-ISSN 1941-0476, Vol. 63, no 21, 5758-5771 p.Article in journal (Refereed) Published
In this paper, we consider optimal multiuser downlink beamforming in the presence of a massive number of arbitrary quadratic shaping constraints. We combine beamforming with full-rate high dimensional real-valued orthogonal space time block coding (OSTBC) to increase the number of beamforming weight vectors and associated degrees of freedom in the beamformer design. The original multi-constraint beamforming problem is converted into a convex optimization problem using semidefinite relaxation (SDR) which can be solved efficiently. In contrast to conventional (rank-one) beamforming approaches in which an optimal beamforming solution can be obtained only when the SDR solution (after rank reduction) exhibits the rank-one property, in our approach optimality is guaranteed when a rank of eight is not exceeded. We show that our approach can incorporate up to 79 additional shaping constraints for which an optimal beamforming solution is guaranteed as compared to a maximum of two additional constraints that bound the conventional rank-one downlink beamforming designs. Simulation results demonstrate the flexibility of our proposed beamformer design.
Place, publisher, year, edition, pages
2015. Vol. 63, no 21, 5758-5771 p.
Downlink beamforming, orthogonal space time block coding (OSTBC), semidefinite relaxation (SDR), shaping constraints
Electrical Engineering, Electronic Engineering, Information Engineering
IdentifiersURN: urn:nbn:se:kth:diva-175905DOI: 10.1109/TSP.2015.2455516ISI: 000362414700013ScopusID: 2-s2.0-84959450050OAI: oai:DiVA.org:kth-175905DiVA: diva2:867173
FunderEU, FP7, Seventh Framework Programme, ADEL-619647
QC 201511042015-11-042015-10-262015-11-04Bibliographically approved