All Questions
16 questions
0
votes
1
answer
265
views
Generating a sinewave on Matlab with specific harmonics [closed]
I need to generate a sinewave on Matlab so I can use the generated values, I need 1000 samples per cycle for grid simulation using micro-controller. I was able to generate a pure sinewave and it is ...
- 23
0
votes
1
answer
149
views
Why am I getting linear phase?
I'm trying to plot the phase of Fourier transform of the function below:
\begin{gather*}
x[n] = 2e^{-0.9|n|} \: \: n \in [-5,5]\\
x[n] = 0 \:\: n \notin [-5,5]
\end{gather*}
which is equal to the ...
1
vote
0
answers
152
views
Numpy giving the wrong Fourier transform of sine functions
I'm using numpy's FFT to calculate the Fourier transform of \$\cos(\omega_0t)\$ and plot it. By using the definition we can derive its Fourier transform as below:
\begin{equation}
X_3(j\omega) = \pi (...
- 111
0
votes
1
answer
415
views
Reason for frequency steps shown in Simulink FFT analysis tool
While using the FFT in Simulink tool, I have observed that if more number of cycles are selected then frequency steps in which harmonics percentage is shown is also divided accordingly.
For example:
...
0
votes
1
answer
438
views
How can I see the magnitude and frequency of a signal (DFT) in PLECS?
I am trying to obtain the Fourier transform of a signal by using the DFT of PLECS but I got some weird results.
Here is a very simple sinewave generator and the DFT block:
DFT_plecs_1
Here are the ...
- 311
4
votes
1
answer
201
views
FFT of time-compressed signal not outputting correct amplitude spectrum
Given a signal g(t) <--> G(f), a time-compression g(at) <--> 1/(abs(a)) * G(f/abs(a)), but not with the FFT as I've found out. Performing the FFT on g(a*t) doesn't scale the amplitude of ...
- 81
0
votes
1
answer
82
views
Linear Frequency Dependent IQ Distortion
I want to design FD (frequency dependent ) IQ (In-phase,Quadrature) distortion that changes the phase mismatch linearly like a+b*K ( where K is 1 to 64) and amplitude remains constant to test my ...
- 121
0
votes
1
answer
492
views
Estimation of impedance in MATLAB
Good Morning,
I'm developing a bio-impedance system.
To perform the impedance calculation, I am trying to use the method described in this article, and mentioned below:
http://www.ijirset.com/upload/...
- 61
0
votes
1
answer
516
views
Generating FFT on data recived from 20Amp(ACS712) current sensor using arduino & processing IDE
Currently, for generating FFT on the data received from ACS712,i used the following method:
first the data is sent to the Processing IDE from the sensor via arduino. the processing code converts the ...
- 61
0
votes
1
answer
424
views
Sampling frequency and FFT
I have tried this example code for sampling and FFT in MATLAB, but I have noticed that when the signal frequency becomes closer to nyquist frequency , some errors ( small frequency components near the ...
- 103
2
votes
2
answers
826
views
Reduce the impact of gaussian noise on DTMF decoder
I have a Matlab code to decode digits from a given DTMF audio file (wav format). Considering the input signal to be in the form of x(n)+αv(n) where x(n) is the noise-free signal (i.e. the given DTMF ...
- 33
0
votes
2
answers
100
views
applying for loop [closed]
I want to apply for loop. Below is my code. I have applied the for loop which is wrong. Here Length(t) is sample numbers. Here I want to create 'for' loop for a sample number 5 in particular. so how ...
- 59
4
votes
2
answers
3k
views
How to model Phase noise?
I want to model phase noise. Code below shows how I am adding phase noise in the signal. However, i am not getting correct output. That means, the signal sprectrum shoud be spreading in the frequency ...
- 59
2
votes
1
answer
1k
views
Parsing Raw ADC Data into Voltage Levels
I'm collecting single-tone test data on the ADC12J4000EVM using the TSW14J56EVM and the High Speed Data Converter (HSDC) Pro software and ADC12J4000EVM GUI. I am trying to capture raw time domain data ...
- 1,264
0
votes
2
answers
3k
views
first Mini dsp Project using matlab and books
i have basic knowledge of matlab and took signal and system course. i want to do project like below.
but dont know filter on matlab.
are there any books i can learn fft commands etc.(dft, filter,...
-3
votes
2
answers
5k
views
How to obtain sine wave back after fft?
I performed fft in matlab on y=sin(2*pi*t), with a time period of T=0.015. Now I want to get the original function back in the time domain, but I'm not sure how I can use ifft to do that. It gives me ...
- 157