Journal ArticleDOI
Noncooperative Cellular Wireless with Unlimited Numbers of Base Station Antennas
TLDR
A cellular base station serves a multiplicity of single-antenna terminals over the same time-frequency interval and a complete multi-cellular analysis yields a number of mathematically exact conclusions and points to a desirable direction towards which cellular wireless could evolve.Abstract:
A cellular base station serves a multiplicity of single-antenna terminals over the same time-frequency interval. Time-division duplex operation combined with reverse-link pilots enables the base station to estimate the reciprocal forward- and reverse-link channels. The conjugate-transpose of the channel estimates are used as a linear precoder and combiner respectively on the forward and reverse links. Propagation, unknown to both terminals and base station, comprises fast fading, log-normal shadow fading, and geometric attenuation. In the limit of an infinite number of antennas a complete multi-cellular analysis, which accounts for inter-cellular interference and the overhead and errors associated with channel-state information, yields a number of mathematically exact conclusions and points to a desirable direction towards which cellular wireless could evolve. In particular the effects of uncorrelated noise and fast fading vanish, throughput and the number of terminals are independent of the size of the cells, spectral efficiency is independent of bandwidth, and the required transmitted energy per bit vanishes. The only remaining impairment is inter-cellular interference caused by re-use of the pilot sequences in other cells (pilot contamination) which does not vanish with unlimited number of antennas.read more
Citations
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Journal ArticleDOI
Future steps of LTE-A: evolution toward integration of local area and wide area systems
TL;DR: The views on the evolution concept and candidate technologies for future steps of LTE-A taking into account the ever increasing importance of local area (small cells) and the need for further spectrum extension to higher frequency bands are presented.
Posted Content
Quantized Massive MU-MIMO-OFDM Uplink
Christoph Studer,Giuseppe Durisi +1 more
TL;DR: This paper investigates the uplink performance of a quantized massive MU-MIMO system that deploys orthogonal frequency-division multiplexing (OFDM) for wideband communication and proposes new algorithms for quantized maximum a posteriori channel estimation and data detection.
Posted Content
Low-Complexity Soft-Output Signal Detection Based on Gauss-Seidel Method for Uplink Multi-User Large-Scale MIMO Systems
TL;DR: In this paper, the Gauss-Seidel (GS) method was used to iteratively realize the MMSE algorithm without the complicated matrix inversion, and a diagonal-approximate initial solution to the GS method was proposed to accelerate the convergence rate and reduce the complexity.
Journal ArticleDOI
Integrated Sensing and Communications: Toward Dual-Functional Wireless Networks for 6G and Beyond
TL;DR: In this paper , the authors provide a comprehensive review on the background, range of key applications and state-of-the-art approaches of Integrated Sensing and Communications (ISAC).
Journal ArticleDOI
A Full-Space Spectrum-Sharing Strategy for Massive MIMO Cognitive Radio Systems
TL;DR: A new spatial spectrum-sharing strategy for massive multiple-input multiple-output (MIMO) cognitive radio (CR) systems and a full-space coverage concept by employing two CBSs at the adjacent sides of each cell, which diminishes the sheltering effect from the primary radio.
References
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Journal ArticleDOI
Duality, achievable rates, and sum-rate capacity of Gaussian MIMO broadcast channels
TL;DR: 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.