FFT coefficients and frequencies

Click For Summary
SUMMARY

The discussion focuses on understanding the relationship between FFT coefficients and their corresponding normalized and real frequencies in a discrete Fourier Transform (DFT) computation. The user is working with a 16-point FFT of data sampled at 10 kHz and seeks clarification on how to interpret the frequency values associated with each FFT coefficient. It is established that for k=0, the frequency is 0 Hz, k=1 corresponds to 10 kHz, and k=2 corresponds to 20 kHz, continuing this pattern for subsequent coefficients.

PREREQUISITES
  • Understanding of discrete Fourier Transform (DFT)
  • Familiarity with Fast Fourier Transform (FFT) algorithms
  • Basic knowledge of frequency sampling and Nyquist theorem
  • Proficiency in using Excel for data analysis
NEXT STEPS
  • Study the mathematical foundations of the discrete Fourier Transform (DFT)
  • Learn about the Fast Fourier Transform (FFT) algorithm and its applications
  • Explore the concepts of normalized frequency and real frequency in signal processing
  • Practice using Excel to compute and visualize FFT results
USEFUL FOR

Students in signal processing, engineers working with digital signals, and anyone interested in understanding the application of FFT in analyzing frequency components of sampled data.

smcmon
Messages
1
Reaction score
0

Homework Statement



The following is the output of a 16 point computation of the discrete Fourier Transform for data taken at 10 kHz. Complete the table below by determining the frequencies associated with each of the FFT values.

I attached an Excel workbook with the table.

Homework Equations



This is what I need help with. I need help with how the FFT coefficients relate to normalized and real frequencies.

The Attempt at a Solution



I need help with understanding FFT so I have not gotten this far.
 

Attachments

Physics news on Phys.org
I can tell you how FFT's work and what the numbers mean.
However, I do not know what is expected exactly for a "Frequency normalized" or the "Real frequency".

Do you have definitions from your book for those?

I'd guess that the real frequency is the frequency associated with each row in Excel.
So k = 0 has frequency 0 Hz
k=1 has freq 10 kHz
k=2 has freq 20 kHz
and so forth.
 

Similar threads

  • · Replies 1 ·
Replies
1
Views
3K
  • · Replies 7 ·
Replies
7
Views
2K
  • · Replies 6 ·
Replies
6
Views
2K
  • · Replies 5 ·
Replies
5
Views
2K
  • · Replies 4 ·
Replies
4
Views
5K
  • · Replies 3 ·
Replies
3
Views
2K
  • · Replies 6 ·
Replies
6
Views
5K
  • · Replies 6 ·
Replies
6
Views
13K
  • · Replies 8 ·
Replies
8
Views
3K
  • · Replies 2 ·
Replies
2
Views
3K