08-02-2013, 09:59 AM
Digital Filter Implementation and Visualization
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Abstract
This work shows the basic of digital filter implementation and it’s
visualization. In today world digital communication is basic need of any
communication system without it we can’t do our activities. So digital filters
are necessary. Digital filters use only multipliers, delays, and adders. It can be
implemented on DSP processors. I had included here, function file for it. It also
includes window function, integration function using symbolic tool box.
Behavior of this filter in presence of input is shown by simulink with level‐2 M
file. At last I have made GUI file for it.
Introduction
�WHAT IS FIR FILTER
It is a non‐recursive filter or we can say Finite Impulse Response filter. The
problem with recursive (IIR) filters is much concern about stability.
Unfortunately, Recursive filters with constant group delay or with amplitude
responses that are not piecewise constant are difficult to design in practice. In
contrast, nonrecursive filters can be easily designed to have constant group
delay, and a variety of amplitude responses can be readily achieved. Filters of
this class are, in addition, naturally suited for certain applications e.g. for the
design of differentiators and interpolator. Furthermore, impulse response of
nonrecursive filters is of finite duration, they can be implemented in terms of
fast Fourier transform
[b]Advantages of using digital filters
The following list gives some of the main advantages of digital over analog filters.
1. A digital filter is programmable, i.e. its operation is determined by a program stored
in the processor's memory. This means the digital filter can easily be changed without
affecting the circuitry (hardware).An analog filter can only be changed by redesigning
the filter circuit.
2. Digital filters are easily designed, tested and implemented on a general‐purpose
computer or Work station.
3. The characteristics of analog filter circuits (particularly those containing active
components) are subject to drift and are dependent on temperature. Digital filters do
not suffer from these problems, and so are extremely stable with respect both to time
and temperature.
4. Unlike their analog counterparts, digital filters can handle low frequency signals
accurately. As the speed of DSP technology continues to increase, digital filters are being
applied to high frequency signals in the RF (radio frequency) domain, which in the past
was the exclusive preserve of analog technology.