This Interface Control Document (ICD) defines the requirements related to the interface between the Space Segment (SS) of the Global positioning System (GPS) and the Navigation User Segment (US) of the GPS.
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.
This introduction takes a visionary look at ideal cognitive radios (CRs) that inte-
grate advanced software-defined radios (SDR) with CR techniques to arrive at
radios that learn to help their user using computer vision, high-performance
speech understanding, global positioning system (GPS) navigation, sophisticated
adaptive networking, adaptive physical layer radio waveforms, and a wide range
of machine learning processes.
Mobile radio communications are evolving from pure telephony systems to multimedia
platforms offering a variety of services ranging from simple file transfers and audio and
video streaming, to interactive applications and positioning tasks. Naturally, these services
have different constraints concerning data rate, delay, and reliability (quality-of-service
(QoS)). Hence, future mobile radio systems have to provide a large flexibility and scal-
ability to match these heterogeneous requirements.
Software-defined radios (SDRs) have been around for more than a decade. The
first complete Global positioning System (GPS) implementation was described
by Dennis Akos in 1997. Since then several research groups have presented their
contributions. We therefore find it timely to publish an up-to-date text on the sub-
ject and at the same time include Galileo, the forthcoming European satellite-
based navigation system. Both GPS and Galileo belong to the category of Global
Navigation Satellite Systems (GNSS).
The purpose of this book is to present detailed fundamental information on a
global positioning system (GPS) receiver. Although GPS receivers are popu-
larly used in every-day life, their operation principles cannot be easily found
in one book. Most other types of receivers process the input signals to obtain
the necessary information easily, such as in amplitude modulation (AM) and
frequency modulation (FM) radios. In a GPS receiver the signal is processed
to obtain the required information, which in turn is used to calculate the user
position. Therefore, at least two areas of discipline, receiver technology and
navigation scheme, are employed in a GPS receiver. This book covers both
areas.
Many applications have required the positioning accuracy of a Global Navigation
Satellite System (GNSS). Some applications exist in environments that attenuate
GNSS signals, and, consequently, the received GNSS signals become very weak.
Examplesofsuchapplicationsarewirelessdevicepositioning,positioninginsensor
networks that detect natural disasters, and orbit determination of geostationary
and high earth orbit (HEO) satellites. Conventional GNSS receivers are not
designed to work with weak signals. This book presents novel GNSS receiver
algorithms that are designed to work with very weak signals.
Of the various applications that satellites have been used for, one of
the most promising is that of global positioning. Made possible by
Global Navigation Satellite Systems, global positioning enables any
user to know his or her exact position on Earth. Nowadays, the only
fully functioning system is the American Global positioning System
(GPS). However, the European system, known as Galileo, is expected to
be operative in 2012.
STM32F驅動L6470 ■ Operating voltage: 8 - 45 V■ 7.0 A out peak current (3.0 A r.m.s.)■ Low RDS(on) Power MOSFETs■ Programmable speed profile and positioning■ Programmable power MOS slew rate■ Up to 1/128 microstepping■ Sensorless stall detection■ SPI interface■ Low quiescent and standby currents■ Programmable non-dissipative overcurrentprotection on high and low-side■ Two levels of overtemperature protection
