Software Radio (SR) is one of the most important emerging technologies for the
future of wireless communication services. By moving radio functionality into
software, it promises to give flexible radio systems that are multi-service, multi-
standard, multi-band, reconfigurable and reprogrammable by software.
Today’s radios are matched to a particular class of signals that are well defined
bytheircarrierfrequencies,modulationformatsandbandwidths.Aradiotransmitter
today can only up convert signals with well-defined bandwidths over defined center
frequencies, while, on the other side of the communication chain, a radio receiver
can only down convert well-defined signal bandwidths, transmitted over specified
carrier frequencies.
標簽：
Software
Radio
上傳時間：
2020-06-01
上傳用戶：shancjb
n the first part of this book, we give an introduction to the basic applications of wireless com-
munications, as well as the technical problems inherent in this communication paradigm. After a
brief history of wireless, Chapter 1 describes the different types of wireless services, and works
out their fundamental differences. The subsequent Section 1.3 looks at the same problem from
a different angle: what data rates, ranges, etc., occur in practical systems, and especially, what
combination of performance measures are demanded (e.g., what data rates need to be transmitted
over short distances; what data rates are required over long distances?) Chapter 2 then describes
the technical challenges of communicating without wires, putting special emphasis on fading and
co-channel interference. Chapter 3 describes the most elementary problem of designing a wireless
system, namely to set up a link budget in either a noise-limited or an interference-limited system.
After studying this part of the book, the reader should have an overview of different types of
wireless services, and understand the technical challenges involved in each of them. The solutions
to those challenges are described in the later parts of this book.
標簽：
Communications
Wireless
Edition
2nd
上傳時間：
2020-06-01
上傳用戶：shancjb
