New to the forums need some help with signal analysis

[stefan1988]

Im taking This class EEL3135 and I am very lost and confused as to how to study or where to find resources to understand the material.

does anybody know of a good website for beginner signal analysis? or a good reference ebook etc to help me out with it? the ones i seen are far too advanced and complicated for the stuff we doing.

Homework Statement

here is the problem I am looking at.
a.Determine a formula for x(t) as the real part of a sum of complex exponentials.
b.what is the fundamental period for x(t)
c.plot the spectrum for x(t)
X(T)=sin^3(27PI t)

Homework Equations

euler inverse cosθ=(e^θ+e^θ)/(2) i don't really understand why we use this formula

The Attempt at a Solution

i started for first expansion i got
(-e^54pit)/4 +0.5+(e^-54pit)/4

after third expansion i got
(-e^81pit)/(8j)+(3e^27pit/8j)+(-3e^27pit)/(8j)+ (-e^81pit/8j)

is there an easier way to do this than big expansion?

 

[issacnewton]

some resources for DSP

http://ocw.mit.edu/resources/res-6-008-digital-signal-processing-spring-2011/

http://cnx.org/content/col10064/latest/

 

[stefan1988]

sorry for the late reply. thanks for the links =D

 

[divnik]

when a cosine random variable function and a noise signal are convolved the result is a random variable..but will it be a guassian function

 

[rezeew]

Hello and welcome to the forums! Signal analysis can be a challenging subject, especially for beginners. It's great that you are seeking help and resources to better understand the material. One helpful tip for studying signal analysis is to start with the basics and build your understanding from there. It's important to have a strong foundation in concepts such as complex numbers, Fourier series, and the Fourier transform. There are many online resources and textbooks available that explain these concepts in a beginner-friendly way. Some good websites for beginner signal analysis include Khan Academy, All About Circuits, and MIT OpenCourseWare.

In regards to the specific problem you mentioned, it seems like you are on the right track with your expansions. However, there may be a more efficient way to solve it. I would suggest reviewing the properties of trigonometric identities and the Euler formula to see if you can simplify your expansions. It's also helpful to practice with different types of signals to gain a better understanding of how to approach these problems.

Lastly, it's important to understand why we use certain formulas in signal analysis. The Euler formula you mentioned is used to convert complex numbers from rectangular form to polar form. This is important because the Fourier transform deals with complex numbers in polar form.

I hope this helps and good luck with your studies!