Journal ArticleDOI
Noncooperative Cellular Wireless with Unlimited Numbers of Base Station Antennas
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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
Massive MIMO Channel Subspace Estimation From Low-Dimensional Projections
TL;DR: Efficient subspace estimation algorithms that require sampling only m = O(2√M) antennas and, for a given p ≪ M, return a p-dim beamformer (subspace) that has a performance comparable with the best p-Dim beamformer designed from the full knowledge of the exact channel covariance matrix are developed.
Journal ArticleDOI
Dealing With Interference in Distributed Large-Scale MIMO Systems: A Statistical Approach
TL;DR: This paper considers the problem of interference control through the use of second-order statistics in massive MIMO multi-cell networks and characterizes the low-rankness of users' channel covariance matrices, as such a property can be exploited towards improved channel estimation as well as interference rejection via spatial filtering.
Journal ArticleDOI
Graph Coloring Based Pilot Allocation to Mitigate Pilot Contamination for Multi-Cell Massive MIMO Systems
TL;DR: A graph coloring based pilot allocation (GC-PA) scheme is proposed to mitigate pilot contamination for multi-cell massive MIMO systems by efficiently allocating pilots among users in the interference graph.
Journal ArticleDOI
An Overview of Enhanced Massive MIMO With Array Signal Processing Techniques
TL;DR: In this paper, the authors present an overview of recent progress on merging array signal processing into massive MIMO communications as well as its promising future directions, and some phenomena of the beam squint effect can be better explained now with array signals processing.
Proceedings ArticleDOI
Conjugate gradient-based soft-output detection and precoding in massive MIMO systems
TL;DR: The proposed conjugate gradient (CG) methods are able to outperform existing methods for massive MIMO systems with realistic antenna configurations and a novel way of computing the SINR directly within the CG algorithm at low complexity is proposed.
References
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Layered space-time architecture for wireless communication in a fading environment when using multi-element antennas
TL;DR: This paper addresses digital communication in a Rayleigh fading environment when the channel characteristic is unknown at the transmitter but is known (tracked) at the receiver with the aim of leveraging the already highly developed 1-D codec technology.
Journal ArticleDOI
On the achievable throughput of a multiantenna Gaussian broadcast channel
Giuseppe Caire,Shlomo Shamai +1 more
TL;DR: Under certain mild conditions, this scheme is found to be throughput-wise asymptotically optimal for both high and low signal-to-noise ratio (SNR), and some numerical results are provided for the ergodic throughput of the simplified zero-forcing scheme in independent Rayleigh fading.
Book
Random Matrix Theory and Wireless Communications
Antonio M. Tulino,Sergio Verdu +1 more
TL;DR: A tutorial on random matrices is provided which provides an overview of the theory and brings together in one source the most significant results recently obtained.
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.