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The Internet of Things is considered to be the next big opportunity, and challenge, for the
Internet engineering community, users of technology, companies and society as a whole. It
involves connecting embedded devices such as sensors, home appliances, weather stations
and even toys to Internet Protocol (IP) based networks. The number of IP-enabled embedded
devices is increasing rapidly, and although hard to estimate, will surely outnumber the
number of personal computers (PCs) and servers in the future. With the advances made over
the past decade in microcontroller,low-power radio, battery and microelectronic technology,
the trend in the industry is for smart embedded devices (called smart objects) to become
IP-enabled, and an integral part of the latest services on the Internet. These services are no
longer cyber, just including data created by humans, but are to become very connected to the
physical world around us by including sensor data, the monitoring and control of machines,
and other kinds of physical context. We call this latest frontier of the Internet, consisting of
wireless low-power embedded devices, the Wireless Embedded Internet. Applications that
this new frontier of the Internet enable are critical to the sustainability, efficiency and safety
of society and include home and building automation, healthcare, energy efficiency, smart
grids and environmental monitoring to name just a few.
標簽：
Embedded
Internet
Wireless
6LoWPAN
The
上傳時間：
2020-05-26
上傳用戶：shancjb
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Relaying techniques, in which a source node communicates to a destination node
with the help of a relay, have been proposed as a cost-effective solution to address
the increasing demand for high data rates and reliable services over the air. As
such, it is crucial to design relay systems that are able to not only provide high
spectral efficiency, but also fully exploit the diversity of the relay channel.
標簽：
Amplify-and-Forward
Relaying
上傳時間：
2020-05-26
上傳用戶：shancjb
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The growing interest for high data rate wireless communications over the last few decades
gave rise to the emergence of a number of wideband wireless systems. The resulting scarcity
of frequency spectrum has been forcing wireless system designers to develop methods that
will push the spectral efficiency to its limit.
標簽：
Algorithms
Baseband
Receiver
上傳時間：
2020-05-26
上傳用戶：shancjb
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The new digital radio system DAB (Digital Audio Broadcasting, nowadays often called
Digital Radio) is a very innovative and universal multimedia broadcast system which will
replace the existing AM and FM audio broadcast services in many parts of the world in
the future. It was developed in the 1990s by the Eureka 147/DAB project. DAB is very
well suited for mobile reception and provides very high robustness against multipath
reception. It allows use of single frequency networks (SFNs) for high frequency
efficiency.
標簽：
Broadcasting
Principles
Digital
Audio
上傳時間：
2020-05-27
上傳用戶：shancjb
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The recent developments in full duplex (FD) commu-
nication promise doubling the capacity of cellular networks using
self interference cancellation (SIC) techniques. FD small cells
with device-to-device (D2D) communication links could achieve
the expected capacity of the future cellular networks (5G). In
this work, we consider joint scheduling and dynamic power
algorithm (DPA) for a single cell FD small cell network with
D2D links (D2DLs). We formulate the optimal user selection and
power control as a non-linear programming (NLP) optimization
problem to get the optimal user scheduling and transmission
power in a given TTI. Our numerical results show that using
DPA gives better overall throughput performance than full power
transmission algorithm (FPA). Also, simultaneous transmissions
(combination of uplink (UL), downlink (DL), and D2D occur
80% of the time thereby increasing the spectral efficiency and
network capacity
標簽：
Full-Duplex
Cells
Small
上傳時間：
2020-05-27
上傳用戶：shancjb
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In this paper we revisit hybrid analog-digital precoding systems with emphasis on their modelling
and radio-frequency (RF) losses, to realistically evaluate their benefits in 5G system implementations.
For this, we decompose the analog beamforming networks (ABFN) as a bank of commonly used RF
components and formulate realistic model constraints based on their S-parameters. Specifically, we
concentrate on fully-connected ABFN (FC-ABFN) and Butler networks for implementing the discrete
Fourier transform (DFT) in the RF domain. The results presented in this paper reveal that the performance
and energy efficiency of hybrid precoding systems are severely affected, once practical factors are
considered in the overall design. In this context, we also show that Butler RF networks are capable of
providing better performances than FC-ABFN for systems with a large number of RF chains.
標簽：
Analog-Digital
Precoding
Hybrid
上傳時間：
2020-05-27
上傳用戶：shancjb
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To meet the future demand for huge traffic volume of wireless data service, the research on the fifth generation
(5G) mobile communication systems has been undertaken in recent years. It is expected that the spectral and energy
efficiencies in 5G mobile communication systems should be ten-fold higher than the ones in the fourth generation
(4G) mobile communication systems. Therefore, it is important to further exploit the potential of spatial multiplexing
of multiple antennas. In the last twenty years, multiple-input multiple-output (MIMO) antenna techniques have been
considered as the key techniques to increase the capacity of wireless communication systems. When a large-scale
antenna array (which is also called massive MIMO) is equipped in a base-station, or a large number of distributed
antennas (which is also called large-scale distributed MIMO) are deployed, the spectral and energy efficiencies can
be further improved by using spatial domain multiple access. This paper provides an overview of massive MIMO
and large-scale distributed MIMO systems, including spectral efficiency analysis, channel state information (CSI)
acquisition, wireless transmission technology, and resource allocation.
標簽：
Large-scale
Antenna
Systems
上傳時間：
2020-05-27
上傳用戶：shancjb
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In order to improve the spectral efficiency in wireless communications, multiple
antennas are employed at both transmitter and receiver sides, where the resulting
system is referred to as the multiple-input multiple-output (MIMO) system. In
MIMO systems, it is usually requiredto detect signals jointly as multiple signals are
transmitted through multiple signal paths between the transmitter and the receiver.
This joint detection becomes the MIMO detection.
標簽：
Complexity
Detection
MIMO
Low
上傳時間：
2020-05-27
上傳用戶：shancjb
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Wireless metropolitan area networks (WirelessMANs) is emerging as a promising
broadband wireless access (BWA) technology to provide high-speed, high bandwidth
efficiency and high-capacity multimedia services for residential as well as enterprise
applications. It is observed that WirelessMAN (e.g., WiMAX) is even regarded as a 4G
technology. For the success of the WirelessMANs, international standardization organiza-
tions are very actively specifying the standards IEEE 802.16, ETSI HiperMAN and Korea
WiBro.
標簽：
BroadbanMobile WiMAX Toward Broadband Wirelessd
Wireless
Mobile
Toward
WiMAX
上傳時間：
2020-05-30
上傳用戶：shancjb
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Rapid growth of wireless communication services in recent decades has created
a huge demand of radio spectrum. Spectrum scarcity and utilization inefficiency
limit the development of wireless networks. Cognitive radio is a promising tech-
nology that allows secondary users to reuse the underutilized licensed spectrum of
primary users. The major challenge for spectrum sharing is to achieve high spectrum
efficiency while making non-intrusive access to the licensed bands. This requires in-
formation of availability and quality of channel resources at secondary transmitters,
however, is difficult to be obtained perfectly in practice.
標簽：
Opportunistic
Spectrum
Sharing
上傳時間：
2020-05-31
上傳用戶：shancjb
