Distributed cognitive two-way relay beamformer designs under perfect and imperfect CSI

Ubaidulla Pandarakkottilil, Sonia Aissa

Research output: Chapter in Book/Report/Conference proceedingConference contribution

8 Scopus citations


In this paper, we present distributed two-way relay beamformer designs for a cognitive radio network (CRN) in which a pair of cognitive (or secondary) transceiver nodes communicate with each other assisted by a set of cognitive two-way relay nodes. The secondary nodes share the spectrum with a licensed primary user (PU) node, and each node is assumed to be equipped with a single transmit/receive antenna. The interference to the PU resulting from the transmission from the cognitive nodes is kept below a specified limit. First, we consider relay beamformer designs assuming the availability of perfect channel state information (CSI). For this case, a mean-square error (MSE)-constrained beamformer that minimizes the total relay transmit power, and an MSE-balancing beamformer with a constraint on the total relay transmit power are proposed. Next, we consider relay beamformer designs assuming that the available CSI is imperfect. For this case too, we consider the same problems as those in the case of perfect CSI, and propose beamformer designs that are robust to the errors in the CSI. We show that the proposed designs can be reformulated as convex optimization problems that can be solved efficiently. Through numerical simulations, we illustrate the performance of the proposed designs. © 2011 IEEE.
Original languageEnglish (US)
Title of host publication2011 IEEE 22nd International Symposium on Personal, Indoor and Mobile Radio Communications
PublisherInstitute of Electrical and Electronics Engineers (IEEE)
Number of pages6
ISBN (Print)9781457713484
StatePublished - Sep 2011

Bibliographical note

KAUST Repository Item: Exported on 2020-10-01


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