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Journal ArticleDOI

Millimeter-Wave Cellular Wireless Networks: Potentials and Challenges

05 Feb 2014-Vol. 102, Iss: 3, pp 366-385
TL;DR: Measurements and capacity studies are surveyed to assess mmW technology with a focus on small cell deployments in urban environments and it is shown that mmW systems can offer more than an order of magnitude increase in capacity over current state-of-the-art 4G cellular networks at current cell densities.
Abstract: Millimeter-wave (mmW) frequencies between 30 and 300 GHz are a new frontier for cellular communication that offers the promise of orders of magnitude greater bandwidths combined with further gains via beamforming and spatial multiplexing from multielement antenna arrays. This paper surveys measurements and capacity studies to assess this technology with a focus on small cell deployments in urban environments. The conclusions are extremely encouraging; measurements in New York City at 28 and 73 GHz demonstrate that, even in an urban canyon environment, significant non-line-of-sight (NLOS) outdoor, street-level coverage is possible up to approximately 200 m from a potential low-power microcell or picocell base station. In addition, based on statistical channel models from these measurements, it is shown that mmW systems can offer more than an order of magnitude increase in capacity over current state-of-the-art 4G cellular networks at current cell densities. Cellular systems, however, will need to be significantly redesigned to fully achieve these gains. Specifically, the requirement of highly directional and adaptive transmissions, directional isolation between links, and significant possibilities of outage have strong implications on multiple access, channel structure, synchronization, and receiver design. To address these challenges, the paper discusses how various technologies including adaptive beamforming, multihop relaying, heterogeneous network architectures, and carrier aggregation can be leveraged in the mmW context.
Citations
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Dissertation
01 Jan 2016
TL;DR: In this article, the authors investigated the practical viability of high-frequency GFETs based on large-area graphene from chemical vapour deposition (CVD) and derived the closed-form expressions for the noise equivalent power.
Abstract: Graphene is a two-dimensional sheet of carbon atoms with numerous envisaged applications owing to its exciting properties. In particular, ultrahigh-speed graphene field effect transistors (GFETs) are possible due to the unprecedented carrier velocities in ideal graphene. Thus, GFETs may potentially advance the current upper operation frequency limit of RF electronics. In this thesis, the practical viability of high-frequency GFETs based on large-area graphene from chemical vapour deposition (CVD) is investigated. Device-level GFET model parameters are extracted to identify performance bottlenecks. Passive mixer and power detector terahertz circuits operating above the present active GFET transit time limit are demonstrated. The first device-level microwave noise characterisation of a CVD GFET is presented. This allows for the de-embedding of the noise parameters and construction of noise models for the intrinsic device. The correlation of the gate and drain noise in the PRC model is comparable to that of Si MOSFETs. This indicates higher long-term GFET noise relative to HEMTs. An analytical power detector model derived using Volterra analysis on the FET large-signal model is verified at frequencies up to 67 GHz. The drain current derivatives, intrinsic capacitors and parasitic resistors of the closed-form expressions for the noise equivalent power (NEP) are extracted from DC and S-parameter measurements. The model shows that a short gate length and a bandgap in the channel are required for optimal FET sensitivity. A power detector integrated with a split bow-tie antenna on a Si substrate demonstrates an optical NEP of 500 pW/Hz^1/2 at 600 GHz. This represents a state-of-the-art result for quasi-optically coupled, rectifying direct detectors based on GFETs operating at room temperature. The subharmonic GFET mixer utilising the electron-hole symmetry in graphene is scaled to operate with a centre frequency of 200 GHz, the highest frequency reported so far for graphene integrated circuits. The down-converter circuit is implemented in a coplanar waveguide (CPW) on Si and exhibits a conversion loss (CL) of 29 ± 2 dB in the 185-210 GHz band. In conclusion, the CVD GFETs in this thesis are unlikely to reach the performance required for high-end RF applications. Instead, they currently appear more likely to compete in niche applications such as flexible electronics.

10 citations


Cites background from "Millimeter-Wave Cellular Wireless N..."

  • ...Nevertheless, more recently, interest and practical implementation of THz in fields closer to everyday life, including security and surveillance [2], medicine and disease diagnostics [3], and future high-speed communication networks [4] have emerged....

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Journal ArticleDOI
TL;DR: The proposed techniques provide insights for operating a green cellular backhaul by using the distribute energy sources in a decentralized market setting by identifying the RPSs’ unique equilibrium pricing scheme as well as the operator’s optimal energy storage and wireless service price decisions.
Abstract: This paper considers the problem of renewable energy allocation for a cellular backhaul network where each backhaul node can request renewable energy from a microgrid to forward the traffic. Each microgrid includes multiple renewable power suppliers (RPSs), which directly compete with each other to be the sole supplier of the node. The operator needs to specify the energy storage level for each RPS along the backhaul and the wireless service price for the end users. Then, the RPSs will determine their individual energy prices. The problem is formulated as a Stackelberg game between the leader (the wireless operator) and multiple followers (RPSs). We will identify the RPSs’ unique equilibrium pricing scheme as well as the operator’s optimal energy storage and wireless service price decisions. Our analysis also provides the important observation that direct competition between RPSs on the same backhaul node will induce the operator to store more energy and can thus improve the revenues of both the operator and the RPSs. Furthermore, we consider that RPSs along the backhaul may form coalitions to better coordinate their pricing decisions when they sell energy to the wireless operator. Such a study leads to a hybrid two-level game whose the first level is similar to the Stackelberg game for the non-cooperative scenario. We will show that a coalition formation depends crucially on how the wireless traffic will be affected by the energy price reduction due to the coalition formation. In a nutshell, the proposed techniques provide insights for operating a green cellular backhaul by using the distribute energy sources in a decentralized market setting. Finally, simulation results are presented to compare the solutions of the competitive model with those of the cooperative model. We show that forming coalitions between RPSs benefits both the RPSs and the operator.

10 citations


Cites background from "Millimeter-Wave Cellular Wireless N..."

  • ...The cellular backhaul is regarded as one of the key technologies of future 5G systems for supporting huge highspeed data transmissions over dense small-cell networks [6]....

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  • ...We assume that echo hop transmission over the backhaul follows the free-space propagation model [6]....

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Proceedings Article
22 May 2017
TL;DR: Results show, it is practical to operate 28 GHz licensed signal on the 60 GHz unlicensed frequency band, 5G-U can be coexisted with WiGig, and it is a good neighbourhood to current networks.
Abstract: The enormous proliferation of mobile and personal telecommunications data traffic has brought severe challenges to the current mobile telecommunications system. Regarding the perspectives of both users and operators, the main obstacle is the licensing cost and scarcity of available spectrum. According to recent industrial and academic works, millimetre-wave (mmW) is a potential solution for next fifth generation (5G) mobile telecommunications. 5G on Unlicensed band (5G-U) technology, is an extension of the long-term evolution (LTE) on unlicensed band (LTE-U), which opportunistically transmits LTE signals in the unlicensed spectrum, a viable solution to deal with spectrum scarcity and increased data rates. In particular, 5G-U will aggregate carriers in the mmW band, 28 GHz or 38 GHz licensed spectrum, both candidates of 5G frequency band, and 60 GHz unlicensed spectrum, namely Wireless Gigabit (WiGig). Both systems, 5G and WiGig need to coexist without jeopardising each other. In this work, we study the coexistence of both systems in terms of downlink data rate, comparing three different scenarios: WiGig only, the coexistence of WiGig and 5G-U and 5G-U only. Results show, it is practical to operate 28 GHz licensed signal on the 60 GHz unlicensed frequency band, 5G-U can be coexisted with WiGig, and it is a good neighbourhood to current networks.

10 citations


Cites background from "Millimeter-Wave Cellular Wireless N..."

  • ...Works in [20] shows the equation after the measurement of path loss at lower frequencies; however at higher frequencies for example millimetre-wave, due to stronger penetration ability and foliage loss, path loss are measured in different ways [21], these millimetre-wave includes 60 GHz frequency unlicensed band and 28 GHz frequency licensed band, PL(d)[dB] = PLFS(d0)[dB] + 10β log10( d d0 ), d > d0, (1) ISBN 978-3-8007-4426-8 © VDE VERLAG GMBH ∙ Berlin ∙ Offenbach PLFS(d0)[dB] = 20 log10( 4πd0 ω ), (2) Equation 1 estimates that the path loss consists of three parts: path loss at reference distance are calculated in Equation 2. d is the transmitter to receiver (Tx-Rx) separation distance, d > d0, and d0 is the reference Tx-Rx separation distance....

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  • ...Currently, one of the unlicensed frequency bands, the 60GHz frequency band is for both academic and industrial use for it capturing a wider bandwidth than that of all other unlicensed bands combined....

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  • ...5G-U is an extension of LTE-U/LAA in the licensed bands of 28 GHz or 38 GHz and 60 GHz unlicensed WiGig frequency band....

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  • ...Also, latest 3GPP efforts have been placed in the study of coexistence in the 5 GHz frequency band....

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  • ...Federal Communications Commission (FCC) initially sets up an unlicensed frequency band around 60 GHz, in 2013, IEEE802....

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Journal ArticleDOI
TL;DR: A highly mobile hybrid mmWave multi-user (MU) multiple input multiple output (MIMO) system based on transition probabilities which can represent moving action of the MU and a dynamic covariance forward-backward pursuit (DCFBP) algorithm which introduces forward and backward mechanisms to reconstruct the Hermitian sparse covariance matrix is proposed.
Abstract: Channel estimation is crucial to beamforming techniques in directional millimetre wave (mmWave) communications, which is generally designed based on channel state information static. However, due to the Doppler effect caused by the mobility of users, such as unmanned aerial vehicles, high-speed trains and autonomous vehicles, the mmWave channel is changing rapidly. Spatial channel covariance, defined by long-term statistic information of channels, is a promising solution to reduce channel estimation frequency and can be used to design hybrid precoders. In this paper, we first proposed a highly mobile hybrid mmWave multi-user (MU) multiple input multiple output (MIMO) system based on transition probabilities which can represent moving action of the MU. Secondly, we investigate compressive sensing based spatial channel covariance estimation based on the proposed dynamic system. We then propose a dynamic covariance forward-backward pursuit (DCFBP) algorithm which introduces forward and backward mechanisms to reconstruct the Hermitian sparse covariance matrix. We further explore the constructed MU sensing matrix quality for conventional sparse Bayesian learning (SBL) framework. The updated sparse Bayesian learning (Updated-SBL) algorithm is developed to reduce the total squared coherence of a constructed sensing matrix with updated receive precoder. Numerical analysis demonstrates the proposed DCFBP method outperforms the benchmark methods. The total squared coherence of the proposed Updated-SBL algorithm is dramatically reduced. and the superiority of this algorithm is validated compared with other benchmark methods with comparable computation complexity.

10 citations


Cites background from "Millimeter-Wave Cellular Wireless N..."

  • ...With the purpose of improving the spectral efficiency and good spatial reuse, it is necessary to simultaneously build multiple links for communication [11]....

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  • ...This is because of the channel coherence time is linear in the carrier frequency, for mmWave range, the channel will change in the order of hundreds of microseconds [11], [13]....

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  • ...In mmWave networks, to have better spectral efficiency and energy efficiency, the base station (BS) with large antenna arrays is expected to serve multiple users simultaneously [11], which is known as mmWave multi-user (MU) MIMO communication system....

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  • ...However, in practice, due to the existence of Doppler shifts in highly mobile scenarios, such as unmanned aerial vehicles [8], high speed trains [9] and autonomous vehicles [10], mmWave channel varies rapidly [11], [12]....

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  • ...= Ã U BS (the reason for the AoA vector is not defined as time-varying is that in the real world, the small scale mobility has rare impact on the large scale scattering environment [11]), the time-varying Doppler shift gain g̃t = [(g̃ 1 t) T, ....

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Posted Content
TL;DR: In this paper, the suitability of cellular and Wi-Fi in delivering high-speed wireless Internet connectivity is revisited, and the authors conclude that both are likely to play important roles in the future, and simultaneously serve as competitors and complements.
Abstract: In recent years, significant attention has been directed toward the fifth generation of wireless broadband connectivity known as `5G`, currently being deployed by Mobile Network Operators. Surprisingly, there has been considerably less attention paid to `Wi-Fi 6`, the new IEEE 802.1ax standard in the family of Wireless Local Area Network technologies with features targeting private, edge-networks. This paper revisits the suitability of cellular and Wi-Fi in delivering high-speed wireless Internet connectivity. Both technologies aspire to deliver significantly enhanced performance, enabling each to deliver much faster wireless broadband connectivity, and provide further support for the Internet of Things and Machine-to-Machine communications, positioning the two technologies as technical substitutes in many usage scenarios. We conclude that both are likely to play important roles in the future, and simultaneously serve as competitors and complements. We anticipate that 5G will remain the preferred technology for wide-area coverage, while Wi-Fi 6 will remain the preferred technology for indoor use, thanks to its much lower deployment costs. However, the traditional boundaries that differentiated earlier generations of cellular and Wi-Fi are blurring. Proponents of one technology may argue for the benefits of their chosen technology displacing the other, requesting regulatory policies that would serve to tilt the marketplace in their favour. We believe such efforts need to be resisted, and that both technologies have important roles to play in the marketplace, based on the needs of heterogeneous use cases. Both technologies should contribute to achieving the goal of providing affordable, reliable, and ubiquitously available high-capacity wireless broadband connectivity.

10 citations

References
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Book
15 Jan 1996
TL;DR: WireWireless Communications: Principles and Practice, Second Edition is the definitive modern text for wireless communications technology and system design as discussed by the authors, which covers the fundamental issues impacting all wireless networks and reviews virtually every important new wireless standard and technological development, offering especially comprehensive coverage of the 3G systems and wireless local area networks (WLANs).
Abstract: From the Publisher: The indispensable guide to wireless communications—now fully revised and updated! Wireless Communications: Principles and Practice, Second Edition is the definitive modern text for wireless communications technology and system design. Building on his classic first edition, Theodore S. Rappaport covers the fundamental issues impacting all wireless networks and reviews virtually every important new wireless standard and technological development, offering especially comprehensive coverage of the 3G systems and wireless local area networks (WLANs) that will transform communications in the coming years. Rappaport illustrates each key concept with practical examples, thoroughly explained and solved step by step. Coverage includes: An overview of key wireless technologies: voice, data, cordless, paging, fixed and mobile broadband wireless systems, and beyond Wireless system design fundamentals: channel assignment, handoffs, trunking efficiency, interference, frequency reuse, capacity planning, large-scale fading, and more Path loss, small-scale fading, multipath, reflection, diffraction, scattering, shadowing, spatial-temporal channel modeling, and microcell/indoor propagation Modulation, equalization, diversity, channel coding, and speech coding New wireless LAN technologies: IEEE 802.11a/b, HIPERLAN, BRAN, and other alternatives New 3G air interface standards, including W-CDMA, cdma2000, GPRS, UMTS, and EDGE Bluetooth wearable computers, fixed wireless and Local Multipoint Distribution Service (LMDS), and other advanced technologies Updated glossary of abbreviations and acronyms, and a thorolist of references Dozens of new examples and end-of-chapter problems Whether you're a communications/network professional, manager, researcher, or student, Wireless Communications: Principles and Practice, Second Edition gives you an in-depth understanding of the state of the art in wireless technology—today's and tomorrow's.

17,102 citations


"Millimeter-Wave Cellular Wireless N..." refers background in this paper

  • ...Also, the human body and many outdoor materials being very reflective, allow them to be important scatterers for mmW propagation [28], [30]....

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  • ...However, these measurements were performed in an outdoor campus setting with much lower building density and greater opportunities for LOS connectivity than would be found in a typical urban deployment....

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  • ...Despite the potential of mmW cellular systems, there are a number of key challenges to realizing the vision of cellular networks in these bands: • Range and directional communication: Friis’ transmis- sion law [54] states that the free space omnidirectional path loss grows with the square of the…...

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Journal ArticleDOI
TL;DR: The motivation for new mm-wave cellular systems, methodology, and hardware for measurements are presented and a variety of measurement results are offered that show 28 and 38 GHz frequencies can be used when employing steerable directional antennas at base stations and mobile devices.
Abstract: The global bandwidth shortage facing wireless carriers has motivated the exploration of the underutilized millimeter wave (mm-wave) frequency spectrum for future broadband cellular communication networks. There is, however, little knowledge about cellular mm-wave propagation in densely populated indoor and outdoor environments. Obtaining this information is vital for the design and operation of future fifth generation cellular networks that use the mm-wave spectrum. In this paper, we present the motivation for new mm-wave cellular systems, methodology, and hardware for measurements and offer a variety of measurement results that show 28 and 38 GHz frequencies can be used when employing steerable directional antennas at base stations and mobile devices.

6,708 citations


"Millimeter-Wave Cellular Wireless N..." refers background or methods in this paper

  • ...In both 28- and 73-GHz measurements, each point was classified as either being in a NLOS or LOS situation, based on a manual classification made at the time of the measurements; see [26] and [28]–[33]....

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  • ...• Empirical NYC: These curves are based on the omnidirectional path loss predicted by our linear model (1) for the mmW channel with the parameters from Table 1, as derived from the directional measurements in [26]....

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  • ...Details of the measurements can be found in [26], [28]– [33], [81]....

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  • ...This tremendous potential has led to considerable recent interest in mmW cellular both in industry [7]–[9], [18], [19] and academia [20]–[26], with a growing belief that mmW bands will play a significant role in beyond 4G and 5G cellular systems [27]....

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  • ...In particular, we survey our own measurements [26], [28]–[33] made in New York City (NYC) in both 28- and 73-GHz bands and the statistical models for the channels developed in [34]....

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Journal ArticleDOI
TL;DR: The gains in multiuser systems are even more impressive, because such systems offer the possibility to transmit simultaneously to several users and the flexibility to select what users to schedule for reception at any given point in time.
Abstract: Multiple-input multiple-output (MIMO) technology is maturing and is being incorporated into emerging wireless broadband standards like long-term evolution (LTE) [1]. For example, the LTE standard allows for up to eight antenna ports at the base station. Basically, the more antennas the transmitter/receiver is equipped with, and the more degrees of freedom that the propagation channel can provide, the better the performance in terms of data rate or link reliability. More precisely, on a quasi static channel where a code word spans across only one time and frequency coherence interval, the reliability of a point-to-point MIMO link scales according to Prob(link outage) ` SNR-ntnr where nt and nr are the numbers of transmit and receive antennas, respectively, and signal-to-noise ratio is denoted by SNR. On a channel that varies rapidly as a function of time and frequency, and where circumstances permit coding across many channel coherence intervals, the achievable rate scales as min(nt, nr) log(1 + SNR). The gains in multiuser systems are even more impressive, because such systems offer the possibility to transmit simultaneously to several users and the flexibility to select what users to schedule for reception at any given point in time [2].

5,158 citations


"Millimeter-Wave Cellular Wireless N..." refers background in this paper

  • ...These multiple antenna systems can be used to form very high gain, electrically steerable arrays, fabricated at the base station (BS), in the skin of a cellphone, or even within a chip [6], [10]–[17]....

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Journal ArticleDOI
TL;DR: In this article, the authors describe five technologies that could lead to both architectural and component disruptive design changes: device-centric architectures, millimeter wave, massive MIMO, smarter devices, and native support for machine-to-machine communications.
Abstract: New research directions will lead to fundamental changes in the design of future fifth generation (5G) cellular networks. This article describes five technologies that could lead to both architectural and component disruptive design changes: device-centric architectures, millimeter wave, massive MIMO, smarter devices, and native support for machine-to-machine communications. The key ideas for each technology are described, along with their potential impact on 5G and the research challenges that remain.

3,711 citations

Journal ArticleDOI
TL;DR: The technical and business arguments for femtocells are overview and the state of the art on each front is described and the technical challenges facing femtocell networks are described and some preliminary ideas for how to overcome them are given.
Abstract: The surest way to increase the system capacity of a wireless link is by getting the transmitter and receiver closer to each other, which creates the dual benefits of higher-quality links and more spatial reuse. In a network with nomadic users, this inevitably involves deploying more infrastructure, typically in the form of microcells, hot spots, distributed antennas, or relays. A less expensive alternative is the recent concept of femtocells - also called home base stations - which are data access points installed by home users to get better indoor voice and data coverage. In this article we overview the technical and business arguments for femtocells and describe the state of the art on each front. We also describe the technical challenges facing femtocell networks and give some preliminary ideas for how to overcome them.

3,298 citations


"Millimeter-Wave Cellular Wireless N..." refers background in this paper

  • ...Heterogeneous networks, or HetNets, have been one of the most active research areas in cellular standards bodies in the last five years [45], [48], [67], [68], with the main focus being intercell interference coordination and load balancing....

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