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Latest revision as of 09:01, 14 March 2015

OUTLINE

1. Introduction

2. Theory

3. Example

4. Conclusion

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Introduction

Upsampling is the process of increasing sampling rate of discret-time signal. In this slecture, I will discuss about how it works and example of upsampling.

Theory
Upsampling in the frequency domain. It can be obtain in two different ways.

        or          

Example

Upsampling rate D = 2

Here is the example of sampling signal.

Upsampling rate D = 2 is applied.

Low-Pass filter of cutoff π/2, gain 2 is applied.

Here is the final upsampling signal.

Conclusion

Upsampling by D inserts D - 1 zeros between every element of the original signal. Upsampling can create imaging artifacts. Lowpass filtering following upsampling can remove these imaging artifacts. In the time domain, lowpass filtering interpolates the zeros inserted by upsampling.

Questions and comments

If you have any questions, comments, etc. please post them on this page.

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