Digital Signal Processing
A Practitioner's Approach
Chapter One
Processing of Signals
Any sequence or set of numbers, either continuous or discrete, defines a signal in
the broad sense. Signals originate from various sources. They occur in data
processing or share markets, human heartbeats or telemetry signals, a space shuttle
or the golden voice of the Indian playback singer Lata Mangeshkar, the noise of a
turbine blade or submarine, a ship or instrumented signal inside a missile.
Processing of signals, whether analogue or digital, is a prerequisite to understanding
and analysing them. Conventionally, any signal is associated with time.
Typically, a one-dimensional signal has the form x(t) and a two-dimensional signal
has the form f(x,y,t). Understanding the origin of signals or their source is of
paramount importance. In strict mathematical form, a signal is a mapping function
from the real line to the real line, or in the case of discrete signals, it is a mapping
from the integer line to the real line; and finally it is a mapping from the i ... read full excerpt from Digital Signal Processing: A Practitioner's Approach ebook
