Wednesday, 15 March 2017

Filtering of Data sequence

In order to reduce the delay and the data latency obtained during long data sequences overlap add and overlap save method is employed. These methods do not require the entire data to be present before carrying out the convolution. In case of overlap add method, the entire signal is divided into small length signals and the convolution of the signals are carried out with the response of the system. After carrying out the convolution the overlap portion is added to get the output. In case of overlap save method, the overlapped portion is saved to get the result. The result is same as that of time domain convolution. This methods are used to obtain the output of the system. 

14 comments:

  1. Which method is more efficient?

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  2. Both OAM and OSM are computationally same.

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  3. It is also used for finding output of FIR Filter

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    Replies
    1. Yes. Output of FIR filter can be calculated using OAM by FFT and OSM by FFT

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  4. Can we use it for IIR filter ?

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    1. No.
      For IIR Filter h[n] is of infinite length, hence it is not possible to compute output using it for signal of infinite duration.
      Instead difference equations are used to determine its output

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  5. Processing is faster because of use of FFT for OAM and OSM

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    Replies
    1. Yes. Because FFT performs parallel operations

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  6. OSM uses circular convolution. Hence, OSM is preferred. The length of the output signal after circular convolution must be selected such that optimum system performance is obtained.

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  7. These methods are suitable for real time signal processing.

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    Replies
    1. Yes because it does not require the entire data to available simultaneously.

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  8. OAM and OSM are block processing techniques and and are used for real time signal processing applications.

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    Replies
    1. Yes. One such example real time monitoring is ECG monitoring

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