References of "Paulraj, Arogyaswami"
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See detailRobust Collaborative-Relay Beamforming
Zheng, Gan UL; Wong, Kai-Kit; Paulraj, Arogyaswami et al

in IEEE Transactions on Signal Processing (2009), 57(8), 3130-3143

Relay communications is a promising technique to extend the range of wireless communications by forwarding the message from the sender to the intended destination. While fixed or variable-power relays ... [more ▼]

Relay communications is a promising technique to extend the range of wireless communications by forwarding the message from the sender to the intended destination. While fixed or variable-power relays have been previously investigated, this paper addresses the collaborative use of variable-phase variable-power amplify-and-forward (AF) relays for robust beamforming, with the aid of imperfect channel state information (CSI) at the sender. In particular, the maximization of the worst-case signal-to-noise ratio (SNR) at the destination terminal is studied under a bounded spherical region for the norm of the CSI error vector from the relays to the destination. Our main contribution is that we prove, under a condition on the quality of the estimated CSI, the robust-optimal collaborative-relay beamforming (CRBF) can be obtained by S-procedure and rank relaxation techniques. In addition, a distributed algorithm is developed by examining the structure of the optimal CRBF solution. Results demonstrate a significant gain of CRBF over non-robust approaches. [less ▲]

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See detailCollaborative-Relay Beamforming with Perfect CSI: Optimum and Distributed Implementation
Zheng, Gan UL; Wong, Kai-Kit; Paulraj, Arogyaswami et al

in IEEE Signal Processing Letters (2009), 16(4), 257260

This letter studies the collaborative use of amplify-and-forward (AF) relays to form a virtual multiple-input single-output (MISO) beamforming system with the aid of perfect channel state information (CSI ... [more ▼]

This letter studies the collaborative use of amplify-and-forward (AF) relays to form a virtual multiple-input single-output (MISO) beamforming system with the aid of perfect channel state information (CSI) in a flat-fading channel. In particular, we optimize the relay weights jointly to maximize the received signal-to-noise ratio (SNR) at the destination terminal with both individual and total power constraints at the relays. We show that the optimal collaborative-relay beamforming (CRB) solution achieves the full diversity of a MISO antenna system. Another main contribution of this letter is a distributed algorithm that allows each individual relay to learn its own weight, based on the Karush-Kuhn-Tucker (KKT) analysis. [less ▲]

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See detailOn the Asymptotic Optimality of Opportunistic Norm-based User Selection with Hard SINR Constraint
Zhang, Xi; Jorswieck, Eduard A.; Ottersten, Björn UL et al

in EURASIP Journal on Advances in Signal Processing (2009)

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See detailFeedback Reduction in Uplink MIMO OFDM Systems by Chunk Optimization
Jorswieck, Eduard; Sezgin, Aydin; Ottersten, Björn UL et al

in EURASIP Journal on Applied Signal Processing (2008)

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See detailGuaranteed Performance Region in Fading Orthogonal Space-Time Coded Broadcast Channels
Jorswieck, Eduard; Ottersten, Björn UL; Sezgin, Aydin et al

in EURASIP Journal on Wireless Communications & Networking (2008)

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See detailFeedback Reduction in Uplink MIMO OFDM Systems by Chunk Optimization
Jorswieck, Eduard; Sezgin, Aydin; Ottersten, Björn UL et al

in IEEE International Conference on Communications (ICC) (2008)

Detailed reference viewed: 104 (0 UL)