Matrix analysis
Elements of information theory
Elements of information theory
Convex Optimization
Introduction to Space-Time Wireless Communications
Introduction to Space-Time Wireless Communications
Capacity and power allocation for spectrum-sharing communications in fading channels
IEEE Transactions on Wireless Communications
IEEE Transactions on Wireless Communications
IEEE Transactions on Wireless Communications
On ergodic sum capacity of fading cognitive multiple-access and broadcast channels
IEEE Transactions on Information Theory
Zero-forcing methods for downlink spatial multiplexing in multiuser MIMO channels
IEEE Transactions on Signal Processing
Fundamental limits of spectrum-sharing in fading environments
IEEE Transactions on Wireless Communications
Sensing-Throughput Tradeoff for Cognitive Radio Networks
IEEE Transactions on Wireless Communications
On cognitive radio networks with opportunistic power control strategies in fading channels
IEEE Transactions on Wireless Communications
Achievable rates in cognitive radio channels
IEEE Transactions on Information Theory
On Capacity Under Receive and Spatial Spectrum-Sharing Constraints
IEEE Transactions on Information Theory
Cognitive radio: brain-empowered wireless communications
IEEE Journal on Selected Areas in Communications
IEEE Journal on Selected Areas in Communications
Optimal design of learning based MIMO cognitive radio systems
ISIT'09 Proceedings of the 2009 IEEE international conference on Symposium on Information Theory - Volume 4
IEEE Transactions on Communications
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This paper studies the transmit strategy for a secondary link or the so-called cognitive radio (CR) link under opportunistic spectrum sharing with an existing primary radio (PR) link. It is assumed that the CR transmitter is equipped with multi-antennas, whereby transmit precoding and power control can be jointly deployed to balance between avoiding interference at the PR terminals and optimizing performance of the CR link. This operation is named as cognitive beamforming (CB). Unlike prior study on CB that assumes perfect knowledge of the channels over which the CR transmitter interferes with the PR terminals, this paper proposes a practical CB scheme utilizing a new idea of effective interference channel (EIC), which can be efficiently estimated at the CR transmitter from its observed PR signals. Somehow surprisingly, this paper shows that the learning-based CB scheme with the EIC improves the CR channel capacity against the conventional scheme even with the exact CR-to-PR channel knowledge, when the PR link is equipped with multi-antennas but only communicates over a subspace of the total available spatial dimensions. Moreover, this paper presents algorithms for the CR to estimate the EIC over a finite learning time. Due to channel estimation errors, the proposed CB scheme causes leakage interference at the PR terminals, which leads to an interesting learning-throughput tradeoff phenomenon for the CR, pertinent to its time allocation between channel learning and data transmission. This paper derives the optimal channel learning time to maximize the effective throughput of the CR link, subject to the CR transmit power constraint and the interference power constraints for the PR terminals.