On Limits of Wireless Communications in a Fading Environment when UsingMultiple Antennas
Wireless Personal Communications: An International Journal
IEEE Transactions on Wireless Communications
On capacity of cognitive radio networks with average interference power constraints
IEEE Transactions on Wireless Communications
Opportunistic spectrum sharing in cognitive MIMO wireless networks
IEEE Transactions on Wireless Communications
Sum-rate analysis of multiuser MIMO system with zero-forcing transmit beamforming
IEEE Transactions on Communications
Trade-off of multiplexing streams in MIMO broadcast channels
IEEE Communications Letters
Cross-Layer Optimized Call Admission Control in Cognitive Radio Networks
Mobile Networks and Applications
Optimization of OFDMA-based cellular cognitive radio networks
IEEE Transactions on Communications
Duality of MIMO multiple access channel and broadcast channel with amplify-and-forward relays
IEEE Transactions on Communications
Adaptive joint scheduling of spectrum sensing and data transmission in cognitive radio networks
IEEE Transactions on Communications
Delay-limited capacity: multiple antennas, moment constraints, and fading statistics
IEEE Transactions on Wireless Communications
An Empirical Study of the Achievable Rates of Several Indoor Network-MIMO Techniques
IEEE Transactions on Wireless Communications
On the User Selection for MIMO Broadcast Channels
IEEE Transactions on Information Theory
Joint Beamforming and Power Allocation for Multiple Access Channels in Cognitive Radio Networks
IEEE Journal on Selected Areas in Communications
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This paper investigates the sum rate capacity of MIMO broadcast channels (MIMO-BCs) in cognitive radio networks. A suboptimal user-selection algorithm is proposed to achieve a large sum rate capacity with reduced complexity. This algorithm consists of two steps. First, zero-forcing beamforming is utilized as a downlink precoding technique that precancels inter-user interference. Second, singular value decomposition is applied to the channel matrices of all the secondary users and only consider the singular vectors corresponding to the maximum singular values. The proposed user-selection algorithm chooses singular vectors which are nearly orthogonal to each other and nearly orthogonal to the vector of primary users. With this algorithm, the sum rate capacity of MIMO-BCs in CR networks with interference power constraints and transmit power constraints is derived. We formulate the sum rate capacity as a multi-constraint optimization problem and develop an algorithm to solve the problem in its equivalent form. Finally, numerical simulations are conducted to corroborate our theoretical results in flat Rayleigh fading environments. It is shown that the proposed algorithms are capable of achieving a large sum rate capacity with a very low complexity.