1 / 33

Unit-V

Unit-V. MULTI-RATE DIGITAL SIGNAL PROCESSING. Multi-rate Digital Signal Processing. Basic Sampling Rate Alteration Devices Up-sampler - Used to increase the sampling rate by an integer factor Down-sampler - Used to decrease the sampling rate by an integer factor. DECIMATION. DECIMATION.

jamiethomas
Download Presentation

Unit-V

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Unit-V MULTI-RATE DIGITAL SIGNAL PROCESSING

  2. Multi-rate Digital Signal Processing Basic Sampling Rate Alteration Devices • Up-sampler - Used to increase the sampling rate by an integer factor • Down-sampler - Used to decrease the sampling rate by an integer factor

  3. DECIMATION

  4. DECIMATION

  5. y[n] x[n] M Down-Sampler Time-Domain Characterization • An down-sampler with a down-sampling factorM, where M is a positive integer, develops an output sequence y[n] with a sampling rate that is (1/M)-th of that of the input sequencex[n] • Block-diagram representation

  6. Down-Sampler • Down-sampling operation is implemented by keeping every M-th sample of x[n] and removing in-between samples to generate y[n] • Input-output relation y[n] = x[nM]

  7. D Decimation by a factor D In downsampling by an integer factor D>1, every D-th samples of the input sequence are kept and others are removed:

  8. Input sequence Output sequence Periodic train of impulses Decimation by a factor D • Relationship in time domain

  9. Decimation by a factor D • Relationship in frequency domain C

  10. C

  11. h(n) D Decimation by a factor D • Using a digital low-pass filter to prevent aliasing

  12. INTERPOLATION

  13. INTERPOLATION

  14. x[n] L Up-Sampler Time-Domain Characterization • An up-sampler with an up-sampling factorL, where L is a positive integer, develops an output sequence with a sampling rate that is L times larger than that of the input sequencex[n] • Block-diagram representation

  15. Up-Sampler • Up-sampling operation is implemented by inserting equidistant zero-valued samples between two consecutive samples ofx[n] • Input-output relation

  16. Up-Sampler • In practice, the zero-valued samples inserted by the up-sampler are replaced with appropriate nonzero values using some type of filtering process • Process is called interpolation and will be discussed later

  17. I h(n) Interpolation by a factor I In up-sampling by an integer factor I>1, I-1 equidistant zeros-valued samples are inserted between each two consecutive samples of the input sequence. Then a digital low-pass filter is applied.

  18. Input sequence Interpolation by a factor I Relationship in frequency domain

  19. I D Sampling period If is a rational number h1(n) h2(n) interpolation decimation Sampling rate conversion by a rational factor I/D

  20. I D h(n) Sampling Rate Conversion

More Related