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= Lecture 14 Blog, [[ECE438]] Fall 2011, [[User:Mboutin|Prof. Boutin]] =
 
= Lecture 14 Blog, [[ECE438]] Fall 2011, [[User:Mboutin|Prof. Boutin]] =
Wednesday September 21, 2011 (Week 5) - See [[Lecture Schedule ECE438Fall11 Boutin|Course Outline]].  
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Friday September 23, 2011 (Week 5) - See [[Lecture Schedule ECE438Fall11 Boutin|Course Outline]].  
  
 
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Having obtained the relationship between the DT Fourier transform of  <math>x_1[n]</math> and that of an upsampling of x[n] by a factor D in the previous lecture, we observed that, under certain circumstances, a low-pass filter could be applied to this upsampling so to obtain the signal  
In Lecture 14, we discussed the possibility of an extra credit project involving signal resampling and filtering.
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After this slight diversion, we continued discussing the sampling
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<math>x_1[n]=x(T_1 n)</math>
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of a continuous-time signal x(t). We obtained and discussed the relationship between the DT Fourier transform of  <math>x_1[n]</math> and that of a downsampling <math>y[n]=x_1[Dn]</math>, for some integer D>1.  We then obtained the relationship between the DT Fourier transform of  <math>x_1[n]</math> and that of an upsampling of x[n] by a factor D. In the next lecture, we will use this relationship to figure out how to transform this signal into the (higher resolution) signal  
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<math>x_2[n]=x\left( n \frac{T_1}{D} \right)</math>.  
 
<math>x_2[n]=x\left( n \frac{T_1}{D} \right)</math>.  
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Side notes:
 
*I think this may be a good time to pass some advice to current/future ECE301 students on [[Peer_Legacy_ECE301|the peer legacy page]]. 
 
*Here is a [[Student_summary_sampling_part1_ECE438F09|Rhea page on sampling contributed by a student]].
 
*[[Hw3_ECE438F11|HW3]] is now posted. It is due next Wednesday.
 
  
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We then began discussing the [[Discrete_Fourier_Transform|Discrete Fourier Transform]] (DFT).
  
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==Relevant Rhea pages==
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*[[Student_summary_Discrete_Fourier_transform_ECE438F09|A page about the DFT written by a student]]
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*[[Recommended exercise Fourier series computation DT|Recommended exercises of Fourier series computations for DT signals]] (to brush up on Fourier series))
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==Action items==
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*Keep working on the [[Hw3_ECE438F11|third homework]]
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*Solve the following practice problems and share your answer for feedback
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**[[Compute DFT practice no1 ECE438F11|Compute this DFT]]
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**[[Compute DFT practice no2 ECE438F11|Compute this other DFT]]
 
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<br> Previous: [[Lecture13ECE438F11|Lecture 13]] Next: [[Lecture15ECE438F11|Lecture 15]]  
 
<br> Previous: [[Lecture13ECE438F11|Lecture 13]] Next: [[Lecture15ECE438F11|Lecture 15]]  
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[[2011_Fall_ECE_438_Boutin|Back to ECE438 Fall 2011]]
 
[[2011_Fall_ECE_438_Boutin|Back to ECE438 Fall 2011]]
  
[[Category:2011_Fall_ECE_438_Boutin]] [[Category:Blog]]
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[[[Category:ECE438Fall2011Boutin]]  
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[[Category:ECE438]]
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[[Category:signal processing]]
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[[Category:ECE]]
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[[Category:Blog]]
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[[Category:discrete Fourier transform]]

Latest revision as of 05:24, 11 September 2013


Lecture 14 Blog, ECE438 Fall 2011, Prof. Boutin

Friday September 23, 2011 (Week 5) - See Course Outline.


Having obtained the relationship between the DT Fourier transform of $ x_1[n] $ and that of an upsampling of x[n] by a factor D in the previous lecture, we observed that, under certain circumstances, a low-pass filter could be applied to this upsampling so to obtain the signal

$ x_2[n]=x\left( n \frac{T_1}{D} \right) $.

We then began discussing the Discrete Fourier Transform (DFT).

Relevant Rhea pages

Action items



Previous: Lecture 13 Next: Lecture 15


Back to ECE438 Fall 2011

[[[Category:ECE438Fall2011Boutin]]

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