An Overview of Massive MIMO: Benefits and Challenges

By Lu Lu, Geoffrey Y. Li, A. L. Swindlehurst, Alexei E. Ashikhmin, Rui Zhang. IEEE Journal on Selected Topics in Signal Processing, 2014

2,815 citations recorded by the source corpus.

Massive multiple-input multiple-output (MIMO) wireless communications refers to the idea equipping cellular base stations (BSs) with a very large number of antennas, and has been shown to potentially allow for orders of magnitude improvement in spectral and energy efficiency using relatively simple (linear) processing. In this paper, we present a comprehensive overview of state-of-the-art research on the topic, which has recently attracted considerable attention. We begin with an information theoretic analysis to illustrate the conjectured advantages of massive MIMO, and then we address implementation issues related to channel estimation, detection and precoding schemes. We particularly focus on the potential impact of pilot contamination caused by the use of non-orthogonal pilot sequences by users in adjacent cells. We also analyze the energy efficiency achieved by massive MIMO systems, and demonstrate how the degrees of freedom provided by massive MIMO systems enable efficient single-carrier transmission. Finally, the challenges and opportunities associated with implementing massive MIMO in future wireless communications systems are discussed.

Subfields: Computer Networks and Communications, Electrical and Electronic Engineering

View Paper: https://www.semanticscholar.org/paper/e0dbad7fa1bd8886f6eeede47076db3a358bb4c8

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Citations in the corpus

Millimeter Wave MIMO With Lens Antenna Array: A New Path Division Multiplexing Paradigm (2015, background): “In a parallel work [29], the lens antenna array is applied to the massive MIMO cellular system with large number of antennas at the base station (BS) [37]–[39], which is shown to achieve signiﬁcant performance gains as well as cost reduction as compared to the conventional arrays without lens.”
Grant-Free Non-Orthogonal Multiple Access for IoT: A Survey (2019, neutral): “multiplexing [227].”
Communications and Signals Design for Wireless Power Transmission (2016, background): “Massive MIMO is a key enabling technology for the fifthgeneration (5G) wireless communication systems by tremendously increasing the spectrum efficiency via deploying a large number of antennas (say, hundreds or even more) at the BSs [129], [175]–[177].”
5G network-based Internet of Things for demand response in smart grid: A survey on application potential (2020, background): “The number of antennas in 4G communication equipment is generally 8, while the number of antennas for a 5G device can reach 32 to 256 [92].”
Fundamental Green Tradeoffs: Progresses, Challenges, and Impacts on 5G Networks (2016, neutral): “…and identify research challenges of the fundamental green tradeoffs in 5G networks, where the most promising features, including non-orthogonal aggregation (NOA) [34]–[36], massive MIMO (M-MIMO) [37] and an ultra dense network (UDN) [38], are re-evaluated under the same framework, respectively.”
Millimeter-Wave Massive MIMO Communication for Future Wireless Systems: A Survey (2018, methodology): “And unlike intra-cell interference, the generated directed interference does not disappear as the number of transmit antennas increases [29], which thus degrades system”
Understanding Operational 5G: A First Measurement Study on Its Coverage, Performance and Energy Consumption (2020, background): “The heavy energy consumption of 5G radio attributes to its more powerful baseband and RF hardware [86], e.g. , wide-band data converters (100 MHz vs. 20 MHz in 4G) and 4 × 4 MIMO [65].”
Quantized Precoding for Massive MU-MIMO (2016, background): “2723000 elements, promises significant improvements in spectral efficiency, energy efficiency, reliability, and coverage compared to traditional cellular systems [1]–[3].”
Channel Estimation and Performance Analysis of One-Bit Massive MIMO Systems (2016, background): “It has been shown that, with channel state information (CSI) available at the BS, relatively simple signal processing techniques such as maximum-ratio combining (MRC) or zero-forcing (ZF) can be employed to reduce the noise and interference at the terminals, and can lead to improvements not only in ”
MIMO Capacity Characterization for Movable Antenna Systems (2022, background): “To reduce the number of RF chains, antenna selection (AS) is a practical solution for capturing a large portion of the channel capacity in MIMO systems by properly selecting a small number of antennas with favorable channels from the a large candidate set [6], [7].”
Throughput Optimization for Massive MIMO Systems Powered by Wireless Energy Transfer (2014, background): “Finally, massive antenna arrays [24], [25] with tens to hundreds of elements can be used to form sharp energy beams towards users to achieve a point-to-point WET efficiency of close to one.”
Beamforming for Millimeter Wave Communications: An Inclusive Survey (2016, background): “Energy efficiency assumes particular importance for LSAS based massive MIMO technology [100].”
Massive MIMO Systems for 5G and beyond Networks—Overview, Recent Trends, Challenges, and Future Research Direction (2020, methodology): “However, the number of orthogonal pilot signals in given bandwidth and period is limited, which forces the reuse of the orthogonal pilots in neighboring cells [54].”
Modeling and Performance Analysis for Movable Antenna Enabled Wireless Communications (2022, background): “Next, in the case of stochastic channels, the expected value of an upper bound on the maximum channel gain of the MA in an infinitely large receive region is derived for different numbers of channel paths.”
A Survey on Hybrid Beamforming Techniques in 5G: Architecture and System Model Perspectives (2018, background): “In massive MIMO systems, the traditional baseband digital beamforming (DB) requires one distinct radio frequency (RF) chain per antenna [11], [15], [16].”
Fifty Years of MIMO Detection: The Road to Large-Scale MIMOs (2015, background): “the employment of massive/large-scale multiple-input multipleoutput (LS-MIMO) transmission techniques, which invoke a large number of antenna elements at the transmitter and/or receiver for achieving a high spectral-efficiency [21]–[29] and high energy-efficiency [25], [30]–[32].”
Intelligent Reflecting Surface Meets OFDM: Protocol Design and Rate Maximization (2019, background): “Although massive MIMO and mmWave, seen as the key enablers for 5G, are expected to achieve dramatic spectral efficiency improvements, the deployment of large-scale antenna arrays usually results in high implementation cost and increased power consumption [3].”
Precoding and Power Optimization in Cell-Free Massive MIMO Systems (2017, neutral): “, see [8], [9] and references therein.”