Συντάχθηκε 28-06-2012 12:01
από Athanasios Liavas
Email συντάκτη: aliavas<στο>tuc.gr
Ενημερώθηκε:
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Ιδιότητα: ΔΕΠ ΗΜΜΥ.
Την Παρασκευή, 29 Ιουνίου 2012, στις 12:00, ο καθηγητής κ. Νικόλαος Σιδηρόπουλος θα δώσει ομιλία στο κεντρικό Αμφιθέατρο του κτιρίου Επιστημών.
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Title: Joint Multicast Beamforming and Antenna Selection
Speaker: Nikos Sidiropoulos [Joint work with Omar Mehanna and G. Giannakis]
Abstract:
Multicast beamforming exploits subscriber channel state information at the base station to steer the
transmission power towards the subscribers, while minimizing interference to other users and systems.
Such functionality has been provisioned in the long-term evolution (LTE) enhanced multimedia broadcast
multicast service (EMBMS). As antennas become smaller and cheaper relative to up-conversion chains,
transmit antenna selection at the base station becomes increasingly appealing in this context. In this talk,
we will address the problem of joint multicast beamforming and antenna selection. Whereas this problem
(and even plain multicast beamforming) is NP-hard, it is shown that the ell-one norm *squared* is a fortuitous
sparsity inducing convex regularization, in that it naturally yields a suitable semidefinite relaxation, which is
further shown to be the Lagrange bi-dual of the original NP-hard problem. Careful simulations indicate that
the proposed algorithm significantly reduces the number of antennas required to meet prescribed service levels, at relatively small excess transmission power. Furthermore, its performance is close to that attained by exhaustive search, at far lower complexity.
As a bonus, at the end of the talk I will discuss emerging research areas in the U.S., and briefly flash some of our very recent results on tensor compressed sensing for big data [Joint work with fellow TUCer Anastasios Kyrillidis]
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