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| − | 1. DT signal with period N= | + | ==Question== |
| + | 1. DT signal is real and even with period N=12 | ||
<br> | <br> | ||
2. a2=a3=6 | 2. a2=a3=6 | ||
<br> | <br> | ||
| − | 3. <math>\sum_{n=0}^{ | + | 3. <math>1/12\sum_{n=0}^{11}|x[n]|^2=144</math>. |
<br> | <br> | ||
| + | ==Answer== | ||
| + | Because the signal is even, a2=a(N-2) and a3=a(N-3. Using Parseval's relation, we find that the x[n]in part 3 is equal to ak. Since the sum of all 4 given ak values is 144, we know that all other values of ak =0. | ||
Revision as of 09:07, 26 September 2008
Question
1. DT signal is real and even with period N=12
2. a2=a3=6
3. $ 1/12\sum_{n=0}^{11}|x[n]|^2=144 $.
Answer
Because the signal is even, a2=a(N-2) and a3=a(N-3. Using Parseval's relation, we find that the x[n]in part 3 is equal to ak. Since the sum of all 4 given ak values is 144, we know that all other values of ak =0.
