Take the 2-minute tour ×
Mathematics Stack Exchange is a question and answer site for people studying math at any level and professionals in related fields. It's 100% free, no registration required.

The question is:
We specify the fourier series coefficients of a continuous-time signal that is periodic with period 4. Determine the signal x(t).
$a_k=\begin{cases} 0, & k=0\\ j^k\frac{sin\frac{k\pi}{4}}{k\pi}, & \text{otherwise } \end{cases}$

I have no idea where to even begin on this one. I've been able to do fourier series calculations on already given signals, but I have no idea how to work backwards now. Any ideas?

share|improve this question
    
Is $j$ the imaginary unit? Also, the $a_k$ are the coefficients multiplying what basis ($\sin,\,\cos\,e$)? –  Pragabhava Oct 18 '12 at 3:47
    
@Pragabhava yes j is the imaginary unit. –  Charlie Yabben Oct 18 '12 at 3:53
    
And how are the $a_k$'s calculated, do you use the form $$ a_k = \frac{1}{T}\int_0^T x(t) e^{-j 2\pi \frac{k}{T} x} dx $$ where $T$ is the period? –  Pragabhava Oct 18 '12 at 14:53
add comment

Your Answer

 
discard

By posting your answer, you agree to the privacy policy and terms of service.

Browse other questions tagged or ask your own question.