this directory
contains the following:
* The acdc algorithm for finding the
approximate general (non-ORTHOGONAL)
joint diagonalizer (in the direct Least Squares sense) of a set of Hermitian matrices.
[acdc.m]
* The acdc algorithm for finding the
same for a set of Symmetric matrices.
[acdc_sym.m](note that for real-valued matrices the Hermitian and Symmetric cases are similar however, in such cases the Hermitian version
[acdc.m], rather than the Symmetric version[acdc_sym] is preferable.
* A function that finds an initial guess
for acdc by applying hard-whitening
followed by Cardoso s ORTHOGONAL joint
diagonalizer. Note that acdc may also
be called without an initial guess,
in which case the initial guess is set by default to the identity matrix.
The m-file includes the joint_diag
function (by Cardoso) for performing
the ORTHOGONAL part.
[init4acdc.m]
This book gives a comprehensive overview of the technologies for the advances of
mobile radio access networks. The topics covered include linear transmitters,
superconducting filters and cryogenic radio frequency (RF) front head, radio over
fiber, software radio base stations, mobile terminal positioning, high speed
downlink packet access (HSDPA), multiple antenna systems such as smart
antennas and multiple input and multiple output (MIMO) systems, ORTHOGONAL
frequency division multiplexing (OFDM) systems, IP-based radio access networks
(RAN), autonomic networks, and ubiquitous networks.
Emerging technologies such as WiFi and WiMAX are profoundly changing the
landscape of wireless broadband. As we evolve into future generation wireless
networks, a primary challenge is the support of high data rate, integrated multi-
media type traffic over a unified platform. Due to its inherent advantages in
high-speed communication, ORTHOGONAL frequency division multiplexing (OFDM)
has become the modem of choice for a number of high profile wireless systems
(e.g., DVB-T, WiFi, WiMAX, Ultra-wideband).
Multi-carrier modulation? ORTHOGONAL Frequency Division Multi-
plexing (OFDM) particularly? has been successfully applied to
a wide variety of digital communications applications over the past
several years. Although OFDM has been chosen as the physical layer
standard for a diversity of important systems? the theory? algorithms?
and implementation techniques remain subjects of current interest.
This is clear from the high volume of papers appearing in technical
journals and conferences.
All wireless communication standards, existing and under development, adopt or
consider adopting ORTHOGONAL frequency-division multiplexing (OFDM) as the
modulation technique. It is clear that OFDM has become the definitive modulation
scheme in current and future wireless communication systems.
Before delving into the details of ORTHOGONAL frequency division multiplexing (OFDM), relevant
background material must be presented first. The purpose of this chapter is to provide the necessary
building blocks for the development of OFDM principles. Included in this chapter are reviews of stochastic
and random process, discrete-time signals and systems, and the Discrete Fourier Transform (DFT). Tooled
with the necessary mathematical foundation, we proceed with an overview of digital communication
systems and OFDM communication systems. We conclude the chapter with summaries of the OFDM
wireless LAN standards currently in existence and a high-level comparison of single carrier systems versus
OFDM.
Emerging technologies such as WiFi and WiMAX are profoundly changing the
landscape of wireless broadband. As we evolve into future generation wireless
networks, a primary challenge is the support of high data rate, integrated multi-
media type traffic over a unified platform. Due to its inherent advantages in
high-speed communication, ORTHOGONAL frequency division multiplexing (OFDM)
has become the modem of choice for a number of high profile wireless systems
(e.g., DVB-T, WiFi, WiMAX, Ultra-wideband).
Once upon a time, cellular wireless networks provided two basic services: voice
telephony and low-rate text messaging. Users in the network were separated
by ORTHOGONAL multiple access schemes, and cells by generous frequency reuse
patterns [1]. Since then, the proliferation of wireless services, fierce competition,
andthe emergenceof new service classes such as wireless data and multimediahave
resulted in an ever increasing pressure on network operators to use resources in a
moreefficient manner.In the contextof wireless networks,two of the most common
resources are power and spectrum—and, due to regulations, these resources are
typically scarce. Hence, in contrast to wired networks, overprovisioning is not
feasible in wireless networks.
