Journal ArticleDOI
On the optimality of multiantenna broadcast scheduling using zero-forcing beamforming
Taesang Yoo,Andrea Goldsmith +1 more
TLDR
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.Abstract:
Although the capacity of multiple-input/multiple-output (MIMO) broadcast channels (BCs) can be achieved by dirty paper coding (DPC), it is difficult to implement in practical systems. This paper investigates if, for a large number of users, simpler schemes can achieve the same performance. Specifically, we show 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. In proving this asymptotic result, we provide an algorithm for determining which users should be active under ZFBF. These users are semiorthogonal to one another and can be grouped for simultaneous transmission to enhance the throughput of scheduling algorithms. Based on the user grouping, we propose and compare two fair scheduling schemes in round-robin ZFBF and proportional-fair ZFBF. We provide numerical results to confirm the optimality of ZFBF and to compare the performance of ZFBF and proposed fair scheduling schemes with that of various MIMO BC strategies.read more
Citations
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Journal ArticleDOI
Intelligent Reflecting Surface Enhanced Wireless Network via Joint Active and Passive Beamforming
Qingqing Wu,Rui Zhang +1 more
TL;DR: Simulation results demonstrate that an IRS-aided single-cell wireless system can achieve the same rate performance as a benchmark massive MIMO system without using IRS, but with significantly reduced active antennas/RF chains.
Journal ArticleDOI
MIMO Broadcast Channels With Finite-Rate Feedback
TL;DR: A key finding is that the feedback rate per mobile must be increased linearly with the signal-to-noise ratio (SNR) (in decibels) in order to achieve the full multiplexing gain.
Journal ArticleDOI
Joint Spatial Division and Multiplexing—The Large-Scale Array Regime
TL;DR: JSDM achieves significant savings both in the downlink training and in the CSIT uplink feedback, thus making the use of large antenna arrays at the base station potentially suitable also for frequency division duplexing systems, for which uplink/downlink channel reciprocity cannot be exploited.
Journal ArticleDOI
Shifting the MIMO Paradigm
TL;DR: Multi-user MIMO (MU-MIMO) networks reveal the unique opportunities arising from a joint optimization of antenna combining techniques with resource allocation protocols, and brings robustness with respect to multipath richness, yielding the diversity and multiplexing gains without the need for multiple antenna user terminals.
Journal ArticleDOI
Limited Feedback Hybrid Precoding for Multi-User Millimeter Wave Systems
TL;DR: In this article, a low-complexity hybrid analog/digital precoding for downlink multiuser mmWave systems is proposed, which involves a combination of analog and digital processing that is inspired by the power consumption of complete radio frequency and mixed signal hardware.
References
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Book
Convex Optimization
Stephen Boyd,Lieven Vandenberghe +1 more
TL;DR: In this article, the focus is on recognizing convex optimization problems and then finding the most appropriate technique for solving them, and a comprehensive introduction to the subject is given. But the focus of this book is not on the optimization problem itself, but on the problem of finding the appropriate technique to solve it.
Journal ArticleDOI
Capacity of Multi‐antenna Gaussian Channels
TL;DR: In this paper, the authors investigate the use of multiple transmitting and/or receiving antennas for single user communications over the additive Gaussian channel with and without fading, and derive formulas for the capacities and error exponents of such channels, and describe computational procedures to evaluate such formulas.
Journal ArticleDOI
On Limits of Wireless Communications in a Fading Environment when UsingMultiple Antennas
G. J. Foschini,M. J. Gans +1 more
TL;DR: In this article, the authors examined the performance of using multi-element array (MEA) technology to improve the bit-rate of digital wireless communications and showed that with high probability extraordinary capacity is available.
Journal ArticleDOI
Writing on dirty paper (Corresp.)
TL;DR: It is shown that the optimal transmitter adapts its signal to the state S rather than attempting to cancel it, which is also the capacity of a standard Gaussian channel with signal-to-noise power ratio P/N.
Book
Introduction to Space-Time Wireless Communications
TL;DR: This book is an accessible introduction to every fundamental aspect of space-time wireless communications and a powerful tool for improving system performance that already features in the UMTS and CDMA2000 mobile standards.