الفهرس 
BASIC PRINCIPLES OF SAMPLING AND SAMPLING RATE CONVERSIONOnly 14 pages are availabe for public view
 |  | from | 187 |  |  |
| | | from | 187 | | |
Abstract
Since the invention of the Fast Fourier Transform
1965, acousticians have found the digital methods for
analysis increasingly attractive. This attractivness
augmented by the commercial development of small
digital processors suitable for laboratory, field and
use.
The need for a spectral representation which reflects the time
varying properties of a waveform ( the speech for example) leads
to the definition of a Short-Time Fourier Analysis. Several
different procedures for spectral analysis can be described by the
unified representation of the Short-Time Fourier Analysis.
In this thesis, Two algorithms for digital spectral analysis
are compared. The first is the conventional Discrete Fourier
Transform (OFT). The second is the digital spectral analysis using
the polyphase technique. The polyphase technique is an efficient
structure of the Generalized Filter Bank based on the definition
of the Short-Time Spectral Analysis. Close relations as well as
differences between these two analyzers are demonstrated using the
concept of the multirate systems. Simulation measurments’ of the
chracteristics of both algorithms are carried on demonstrating the
superpriority of the polyphase spectrum analyzer compared to the
conventional OFT for more general signals.
A hardware interface circuit is implemented to build a model
of a real time digital spectrum analyzer based on a simulation of
the polyphase structure. A practical digital analysis of
deterministic signals and speech waveforms is carried on using
this practical model. A comment on the theoretical and practical
results is presented.
(FFT) in
spectrum
has been
dependable
shipboard