Friday, 22 April 2016

EXP 1 - Convolution & Correlation Algorithms


This experiment was divided into two parts 
1) Convolution algorithms
2) Correlation algorithms
1) ---> To start with we learned how to use terminal in LINUX system and also how to compile and execute programs using command prompt. After getting used to the command prompt we started with the actual C code for implementation of algorithms.
In the first part functions were created to compute linear and circular convolution of two signals . For linear convolution the number of values in the convoluted was equal to N+M-1  whereas for circular convolution it is max(N,M).
For circular convolution it was observed that it gives aliased output for L<N+M-1. For L=N+M-1 the circular convolution gives same output as of linear convolution
2) ---> In the second part functions were created compute correlation of two signals. The value at n=o of auto-correlated signal gives the energy of the signal, whereas the auto-correlated signal of delayed was delayed as compared to normal signal.
The output was also scaled by same factor when cross-correlation of input signal and scaled input signal was taken.

9 comments:

  1. You guys mean "n" and not "N",right? Big difference as one represents sampled time and other length

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  2. In the circular convolution aliasing takes place where the last few values get aliased with ones in the start.

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  3. we use Linear convolution for non periodic sequence and Circular convolution for periodic sequence.

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    Replies
    1. I missed to add this part... Thanks for highlighting this ....

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  4. Correlation is used in radar technology by correlation received signal and transmitted signal.

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