16-01-2013, 02:18 PM
ADAPTIVE FILTER
ADAPTIVE FILTER.ppt (Size: 1.49 MB / Downloads: 30)
INTRODUCTION
Filter is used to remove unwanted signal
Different categories:
Low Pass Filter
High Pass Filter
Band Pass Filter
Band Reject Filter
Linear filters :
the filter output is a linear function of the filter input
Design methods:
1 The classical approach
frequency-selective filters such as
lowpass / bandpass / notch filters etc
2 Optimal filter design
Mostly based on minimizing the mean-square value
of the error signal
Adaptive filter
the signal and/or noise characteristics are often nonstationary and the statistical parameters vary with time
An adaptive filter has an adaptation algorithm, that is meant to monitor the environment and vary the filter transfer function accordingly
based in the actual signals received, attempts to find the optimum filter design
Because of complexity of the optimizing algorithms most adaptive filters are digital filters that perform digital signal processing
When processing
analog signals,
the adaptive filter
is then preceded
by A/D and D/A
convertors.