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On the optimality of multiantenna broadcast scheduling using zero-forcing beamforming
It is shown that a zero-forcing beamforming (ZFBF) strategy, while generally suboptimal, can achieve the same asymptotic sum capacity as that of DPC, as the number of users goes to infinity. Expand
Energy-efficiency of MIMO and cooperative MIMO techniques in sensor networks
We consider radio applications in sensor networks, where the nodes operate on batteries so that energy consumption must be minimized, while satisfying given throughput and delay requirements. In thisExpand
Capacity of fading channels with channel side information
The Shannon capacity of a fading channel with channel side information at the transmitter and receiver, and at the receiver alone is obtained, analogous to water-pouring in frequency for time-invariant frequency-selective fading channels. Expand
Energy-constrained modulation optimization
It is shown that up to 80% energy savings is achievable over nonoptimized systems and that the benefit of coding varies with the transmission distance and the underlying modulation schemes. Expand
Duality, achievable rates, and sum-rate capacity of Gaussian MIMO broadcast channels
It is shown that the dirty paper achievable region achieves the sum-rate capacity of the MIMO BC by establishing that the maximum sum rate of this region equals an upper bound on the sum rate. Expand
Variable-rate variable-power MQAM for fading channels
We propose a variable power and rate adaptive MQAM modulation scheme for high-speed data transmission on fading channels. We show that using just five or six different signal constellations achievesExpand
Breaking Spectrum Gridlock With Cognitive Radios: An Information Theoretic Perspective
This information-theoretic survey provides guidelines for the spectral efficiency gains possible through cognitive radios, as well as practical design ideas to mitigate the coexistence challenges in today's crowded spectrum. Expand
Degrees of freedom in adaptive modulation: a unified view
This work finds the general form of power, BER and data rate adaptation that maximizes spectral efficiency for a large class of modulation techniques and fading distributions. Expand
Capacity limits of MIMO channels
An overview of the extensive results on the Shannon capacity of single-user and multiuser multiple-input multiple-output (MIMO) channels is provided and it is shown that the capacity region of the MIMO multiple access and the largest known achievable rate region (called the dirty-paper region) for the M IMO broadcast channel are intimately related via a duality transformation. Expand
Multi-Antenna Downlink Channels with Limited Feedback and User Selection
This work analyzes the sum-rate performance of a multi- antenna downlink system carrying more users than transmit antennas, with partial channel knowledge at the transmitter due to finite rate feedback, and shows that having more users reduces feedback load. Expand