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<math>x_(f) \,\!= \frac{1}{2}( \delta (f - \frac{1}{4}) + \delta (f + \frac{1}{4}))sinc(t/2)</math>
 
<math>x_(f) \,\!= \frac{1}{2}( \delta (f - \frac{1}{4}) + \delta (f + \frac{1}{4}))sinc(t/2)</math>
 
+
*Hum.... I don't think this is what the question was asking: you should figure out a way to compute it using the CTFT properties and also the rep and comb operations. --[[User:Mboutin|Mboutin]] 10:45, 9 February 2009 (UTC)
  
 
b)
 
b)
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<math>x_(f) \,\!= \frac{1}{T}\sum_{k} ( \delta (f - \frac{1}{4}) + \delta (f + \frac{1}{4}))( \delta (f - \frac{k}{4}))</math>
 
<math>x_(f) \,\!= \frac{1}{T}\sum_{k} ( \delta (f - \frac{1}{4}) + \delta (f + \frac{1}{4}))( \delta (f - \frac{k}{4}))</math>
 +
* Same comment as for a). --[[User:Mboutin|Mboutin]] 10:45, 9 February 2009 (UTC)

Revision as of 06:45, 9 February 2009

1 a)

$ x_(t) \,\!= \cos(\frac{\pi}{2})rect(\frac{t}{2}) $

Based on the Prof Alen's note page 179

$ x_(f) \,\!= \frac{1}{2}( \delta (f - \frac{1}{4}) + \delta (f + \frac{1}{4}))sinc(t/2) $

  • Hum.... I don't think this is what the question was asking: you should figure out a way to compute it using the CTFT properties and also the rep and comb operations. --Mboutin 10:45, 9 February 2009 (UTC)

b)

$ x_(t) \,\!= repT[x0_(t)] = \frac {1}{T} \sum_{k} cos(\frac{\pi}{2})rect(\frac{t}{4}) $

Based on the Prof Alen's note page 184

$ x_(f) \,\!= \frac{1}{T}\sum_{k} ( \delta (f - \frac{1}{4}) + \delta (f + \frac{1}{4}))( \delta (f - \frac{k}{4})) $

  • Same comment as for a). --Mboutin 10:45, 9 February 2009 (UTC)

Alumni Liaison

Ph.D. 2007, working on developing cool imaging technologies for digital cameras, camera phones, and video surveillance cameras.

Buyue Zhang