Technical discussion about Matlab and issues related to Digital Signal Processing.
Search Results for "ifft"
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ping...@hotmail.com - Jun 12 2005
Can we use directly the FFT and IFFT functions in Matlab for OFDM simulation? I found IFFT(AWGN) will result in strange mean and variance.
... 
edu_forme - Jun 29 2008
i want to compute the ifft of the following data
data=[0 1 1 0]
in matlab it should return me a single value but it is giving me a
column of values can anybody explain th... 
eddylamhk - Oct 28 2003
Hi,
I want to ask if I FFT an image, how can I recover the image using
IFFT. I try to use it directly, but turn out some a totally bright
picture. However, when i... 
saini_s1978 - Sep 18 2005
Hi everybody,
My problem is as follows:
I get data from a fft analyser after numerous averaging in order
to remove the noise. Now in order to use it i have to take the IF... 
- Mar 14 2005
Hi,
Currently,I have an 10x10 array of channel impulse response data. I
need to get spatial angle of arrival,azimuth and elevation angle
image informatio... 
vcte...@yahoo.com - Jul 27 2005
I'm currently doing a project on OFDM signal generation.
I plan to write my codes in Matlab and later convert it into C and then download it into DSPs.
My question is... 
noriakk - Feb 11 2005
Hi,
I compute the cross spectrum, using the CSD function, and I am trying
to represent it in time-domain using IFFT (see example below). But
what I got i... 
sundar janaa - Jun 10 2005
Hi all,
I have some problems in simulating the OFDM using
matlab. I will list them one by one.
1). Normailsation of the signal after ifft & fft.
Do we have to multiply b... 
marc...@gmail.com - Apr 13 2008
Hi!!
I am new to matlab so please bear with me. I don't understand the IFFT and FFT matlab functions. Here is the code i am using:
[sig,fs]=wavread('aemixed.wav');
time=(1:l... 
Sreeram - Feb 28 2006
sig=wavread('path to signal file');
reconstructed_sig=ifft(fft(sig));
subplot(2,1,sig);
plot(sig);
subplot(2,2.reconstructed_sig);
plot(reconstructed_sig);
i know that to anal... 
ygamez - Jan 2 2004
Here is the code snipet i need help with...
for i = 1:end_frame
for j = 1:1024
fout(i,j) = ifft(Z(i,j));
end
end
As you can see, if the end_frame is l... 
Johnny - Jul 19 2007
so i'm venturing into communications research and i'm stuck on how to
change symbols into the time domain. i have modulated bits, say [0 1]
which in bpsk is just -1 and 1. how do... 
nishchal chaudhary - Mar 25 2005
hii all,
I am trying to make a simulation program for OFDM.My
modulation technique is BPSK.after doing the mapping of original to
BPSK signal space, I am taking sa... 
sandeep kumar - Jun 8 2005
Hi all
I have basic question regarding OFDM symbol genration.IFFT is taken
to genrate a OFDM symbol.that part is undersood.
My question is that whether that IFFT taken... 
mb_for2003 - Aug 23 2003
I have signal x = sin(2*pi*2*t) + sin (2*pi*5*t) + noise(0.1).
Could any one tell me how to obtain signal y = x - noise(0.1) in time
domain? I do not know how to us... 
ajabx - Aug 3 2005
Hello
anyone can please explain me when filtering by FFT,
what is the diference between filtering the normal spectrum and iFFT
and filtering the power spectrum and t... 
hat_zak2002 - Feb 25 2004
I write this code to get IFFT for y but only spectrum drawn not time
domain siganal ploted:
t = -5:0.001:5;
y1 = sin(pi*(t+1))./(pi*(t+1));
y2 = sin(pi*(t+2)... 
disa...@gmail.com - Oct 23 2007
hi all, i'm trying to plot ofdm normalized (dBr) psd after ifft function.
i.e:
carriers=NFFT.*ifft(tx);
%plot normalized PSD
i've tried pwelch(), psd() and their varients ... 
vcteo - Apr 17 2006
Hi, i've forgotten where i read about this but i know for OFDM, if i
want the output of my IFFT to be real, i can only use half of the
subcarriers with the other half the complex... 
rongfenc - Mar 9 2002
I have a question. There is a signal which x-axis is freq. and y-axis
is Power Spectrum Density. After convert this freq. domain signal to
time domain(using IFFT), ... 
jahn...@yahoo.co.in - Dec 26 2006
I am doing a project regarding OFDM.I used 64 QAM to modulate the data . The output of QAM is complex.
Can the complex output be given directly to perform IFFT ?
... 
er_gaurav_rastogi - May 10 2006
Hi all ,=20
I am trying to implement IFFT in vhdl . I tried to use the=20
matlab , but not sure how can i get the twiddle factor . Is it=20
possible to get the twi... 
bclark2125 - Apr 4 2003
I am having trouble getting the following problem to work-can anybody
help me?
problem:Obtain the 1024-point inverse FFT of a sequence of numbers
whose imag... 
rongfenc - Mar 4 2002
I meet a problem which is to convert a signal from frequency domain
into time domain. I tried to use IFFT to convert it but I did not
succeed.
If you are interes... 
ping...@hotmail.com - Jun 11 2005
I have met the same problem in simulating an OFDM system in baseband. When I
finished a single-user BPSK modulated simulation in flat Rayleigh fading
channel. The BER per... 
phil...@nrc.ac.uk - Jan 31 2008
I have a question that has been bugging me fo rsome time and I am hoping someone here can help me get to the bottom of it. It is a zero padding & FFT issue.
Here goes;
If I tak... 
cool...@hotmail.com - Oct 4 2006
Hello, maybe someone can shed a little light on this subject. I've been researching the different PAPR reduction techniques and I feel like I have a pretty good handle on the subje... 
kamr...@gmail.com - Jul 9 2008
Hi all! My question is about getting the impulse response from the transfer function of a system.
I have simulation data for the transfer function of an LTI system. I make the ... 
burkaycan - Aug 13 2007
Hi everbody,
I am doing my M.SC thesis on the topic "ICI cancellation in OFDM". I
have very limited time, if you can help me I will be grateful to you....
I can implement th... 
phil...@nrc.ac.uk - Jan 8 2008
I am de-convolving A and B by the standard method of taking FFTs of both time signals and dividing FFT of B by FFT of A, then taking the iFFT of the result to get the de-convolved ... 
Jeff Brower - Aug 15 2006
Alex-
> I've been trying to correct for phase wrapping in my wavefront and I
> understand now why it occurs when I plot say angle(wavefront)...the
> inverse tan function in... 
PAPR [2 Articles]
mohamed hussien - Apr 10 2008
Hi,
I’m trying to calculate the PAPR in OFDM system, but I
don’t know why there is no result? I know there is
something wrong! Can any one help me to get it?
this is my progra... 
Maria Mount - Jan 21 2004
Hi,
Thank u all for being so nice and supporting . Now there is another
technique of getting higher resolution fft i have learned from mathematical
journal withou... 
"Orlando C. Rodriguez" - Apr 1 2008
Hi there.
I'm working with realizations of random correlated data using a given
power spectra (no correlation matrix is given).
What I do to perform such realizations is that... 
jahn...@yahoo.co.in - Dec 22 2006
I am doing a project related to OFDM. My doubt is whether the no of subcarriers and the IFFT size should be equal or not?
... 
mohamed hussien - Apr 18 2008
Hi,
I'm trying to get the BER for OFDM system but the
result is not correct. Can any one tell me what is the
wrong in my program?
Regards
M. Hussien
This is my program
clear... 
chan...@yahoo.com - Nov 7 2006
http://www.mathworks.com/matlabcentral/fileexchange/loadFile.do?objectId=6957
hi.. follow this link and download the m-fil... ofdm code is there... r u working in only ... 
Moayid Ahmed - Jun 25 2008
Hi,
I'm new member in this group. I'm trying to do MATLAB code for OFDM Tx and Rx and measure and plot all the system parameters like BER, PAPR, Synchronization, Channel Estimatio... 
mohamed hussien - Jun 6 2008
Hi
I want to do a program for OFDM transceiver and add
all the channel effects and measure all the OFDM
parameters. Can any one help me to complete this
program? Check the foll... 
sundar janaa - Oct 6 2005
Dear all,
I am simulating Single Carrier Frequency Domain
Equalizer in AWGN Channel.. I used the QPSK BER curve
and modified that to make the SC-FDE. I am using 512
fft ... 