One traditional view of how wireless networks evolve is of a continuous, inevitable progres-
sion to higher link speeds, combined with greater mobility over wider areas. This standpoint
certainly captures the development from first and second generation cellular systems focused
on voice support, and the early short-range wireless data networks, through to today’s 3G
cellular and mobile broadband systems; there is every confidence that the trend will continue
some way into the future.
Cognitive radio has emerged as a promising technology for maximizing the utiliza-
tion of the limited radio bandwidth while accommodating the increasing amount of
services and applications in wireless networks. A cognitive radio (CR) transceiver
is able to adapt to the dynamic radio environment and the network parameters to
maximize the utilization of the limited radio resources while providing flexibility in
wireless access. The key features of a CR transceiver are awareness of the radio envi-
ronment (in terms of spectrum usage, power spectral density of transmitted/received
signals, wireless protocol signaling) and intelligence.
Designing for Networked Communications: Strategies and Development is a book
about how we plan, use, and understand the products, dynamic social processes,
and tasks upon which depend some of the most vital innovations in the knowledge
society—social as well as technological ones. Focusing on various forms of design,
implementation, and integration of computer-mediated communication (CMC), the
book bridges the academic fields of computer science and communication stud-
ies.
This thesis is about wireless communication in shared radio spectrum. Its origin and
motivation is ideally represented by the two quotations from above. In this thesis, the
support of Quality-of-Service (QoS) in cognitive radio networks is analyzed. New
approaches to distributed coordination of cognitive radios are developed in different
spectrum sharing scenarios. The Wireless Local Area Network (WLAN) 802.11 proto-
col of the Institute of Electrical and Electronics Engineers (IEEE) (IEEE, 2003) with
its enhancement for QoS support (IEEE, 2005d) is taken as basis. The Medium Access
Control (MAC) of 801.11(e) is modified to realize flexible and dynamic spectrum
assignment within a liberalized regulation framework.
Multiuser multiple-input-multiple-output (MU-
MIMO) systems are known to be hindered by dimensionality
loss due to channel state information (CSI) acquisition overhead.
In this paper, we investigate user-scheduling in MU-MIMO
systems on account of CSI acquisition overhead, where a base
station dynamically acquires user channels to avoid choking the
system with CSI overhead.
During the past decade, many wireless communication techniques have been
developedto achievevariousgoals suchas higherdata rate,morerobustlink quality,
and higher number of users in a given bandwidth. For wireless communication
systems, depending on the availability of a feedback link, two approaches can be
considered: namely open and closed loop. Open loop communication system that
does not exploit the channel knowledge at the transmitter is now well understood
from both a theoretical and practical point of view.
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
With the rapid expansion of wireless consumer products,there has been a con-
siderable increase in the need for radio-frequency (RF) planning, link plan-
ning, and propagation modeling.A network designer with no RF background
may find himself/herself designing a wireless network. A wide array of RF
planning software packages can provide some support, but there is no substi-
tute for a fundamental understanding of the propagation process and the lim-
itations of the models employed. Blind use of computer-aided design (CAD)
programs with no understanding of the physical fundamentals underlying the
process can be a recipe for disaster. Having witnessed the results of this
approach, I hope to spare others this frustration.
