17-07-2014, 02:33 PM
DIGITAL SIGNAL PROCESSING – An Introduction
[attachment=65926]
What is Signal processing?
Signal processing is the analysis, interpretation, and manipulation of signals like sound, images time-varying measurement values and sensor data etc…
For example biological data such as electrocardiograms, control system signals, telecommunication transmission signals such as radio signals, and many others.
Need of Signal Processing
When a signal is transmitted from one point to another there is every possibility of contamination /deformation of the signal by external noise. So to retrieve the original signal at the receiver suitable filters are to be used. i.e the signal is processed to obtain the pure signal.
Digital signal processing-Block diagram
The digital signal processor consists of anti-aliasing filter, analog to digital converter (ADC), a digital filter represented by the transfer function H(z), a digital to analog converter and a reconstruction filter
Advantages of Digital over analog signal processing
Accuracy: The analog circuits are prone to temperature and external effects, but the digital filters have no such problems.
Flexibility: Reconfiguration of analog filters is very complex whereas the digital filters can be reconfigured easily by changing the program coefficients
Analog filters
Analog filters take the analog signal as input and process the signal and finally gives the analog output.
An analog filter is constructed using resistors, capacitors, active components etc…
Disadvantages
There are few disadvantages also.
Quantization error occurs due to finite word length in the representation of signals and parameters.
Digital filters also suffer from Bandwidth problems
Disadvantages
IIR filters do not have linear phase and also they are not very stable.
Realization of IIR filters is not very easy as compared to FIR filters
As it is a recursive filter the number of coefficients is very large and the memory requirements are also high
Concluding Remarks
The woods are lovely, dark and deep, But I have promises to keep, And miles to go before I sleep, And miles to go before I sleep. ---- Robert Frost
[attachment=65926]
What is Signal processing?
Signal processing is the analysis, interpretation, and manipulation of signals like sound, images time-varying measurement values and sensor data etc…
For example biological data such as electrocardiograms, control system signals, telecommunication transmission signals such as radio signals, and many others.
Need of Signal Processing
When a signal is transmitted from one point to another there is every possibility of contamination /deformation of the signal by external noise. So to retrieve the original signal at the receiver suitable filters are to be used. i.e the signal is processed to obtain the pure signal.
Digital signal processing-Block diagram
The digital signal processor consists of anti-aliasing filter, analog to digital converter (ADC), a digital filter represented by the transfer function H(z), a digital to analog converter and a reconstruction filter
Advantages of Digital over analog signal processing
Accuracy: The analog circuits are prone to temperature and external effects, but the digital filters have no such problems.
Flexibility: Reconfiguration of analog filters is very complex whereas the digital filters can be reconfigured easily by changing the program coefficients
Analog filters
Analog filters take the analog signal as input and process the signal and finally gives the analog output.
An analog filter is constructed using resistors, capacitors, active components etc…
Disadvantages
There are few disadvantages also.
Quantization error occurs due to finite word length in the representation of signals and parameters.
Digital filters also suffer from Bandwidth problems
Disadvantages
IIR filters do not have linear phase and also they are not very stable.
Realization of IIR filters is not very easy as compared to FIR filters
As it is a recursive filter the number of coefficients is very large and the memory requirements are also high
Concluding Remarks
The woods are lovely, dark and deep, But I have promises to keep, And miles to go before I sleep, And miles to go before I sleep. ---- Robert Frost