Hi, I am quite confused with the variance of the noise in the OFDM system. Should it be equal to N0 or N0/2? N0: Single sided noise power...

Hi, I am quite confused with the variance of the noise in the OFDM system. Should it be equal to N0 or N0/2? N0: Single sided noise power spectral density. Please help. Thanks.

Hi Would like to know how to do frame synchronization in OFDM systems. Seems like many folks like to correlate a copy of what is received with...

Hi Would like to know how to do frame synchronization in OFDM systems. Seems like many folks like to correlate a copy of what is received with a delayed copy of itself, but this method is not robust esp in the presence of multipath. What is the best way? Thanks all.

Dear all, I want to know what is the difference of power spectrum of OFDM with no added cyclic prefix and power spectrum of OFDM with added...

Dear all, I want to know what is the difference of power spectrum of OFDM with no added cyclic prefix and power spectrum of OFDM with added cyclic prefix. Please help me to overcome this problem. Thanks in advance. Best regards, awi

How in OFDM the size and type of a cyclic prefix gets out? What characteristics of a liaison channel and a signal influence a prefix?

How in OFDM the size and type of a cyclic prefix gets out? What characteristics of a liaison channel and a signal influence a prefix?

Sirs, I have some questions on OFDM method 1) what is meant by orthogonality in frequency domain. I understand orthogonality in time...

Sirs, I have some questions on OFDM method 1) what is meant by orthogonality in frequency domain. I understand orthogonality in time domain 2) what is the significance of keeping the inter carrier seperation equal to 1/symbol time Thanks, Manish

Hi, I'm working on ofdm synchronization with wimax now. is there any reading or paper can give a full insight view? I found it's quite...

Hi, I'm working on ofdm synchronization with wimax now. is there any reading or paper can give a full insight view? I found it's quite different with cdma synchronization, so i wonder know the key point in solving the synchronization in ofdm and sampling related. Thanks very much. Laron B. R.

I have seen some paper demonstrating the benefit of SCFDE over OFDM, basically low PAPR performance, comparable complexity, improved performance...

I have seen some paper demonstrating the benefit of SCFDE over OFDM, basically low PAPR performance, comparable complexity, improved performance especially when convolutional code rate is high. But why we see many standards still using OFDM, but not SCFDE?

From what little I've read on OFDM, it seems that its claim to fame is its resistance to frequency-selective fading (at least I think that's the...

From what little I've read on OFDM, it seems that its claim to fame is its resistance to frequency-selective fading (at least I think that's the proper term - correct me if I'm wrong). That resistance comes via the multiple carriers. If one or two carriers fade, no problem - you've got a horde of others which are more than the coherence bandwidth away, so you still get a lot of usable data...

Hi! I am looking for some help on how to calculate or plot CCDF of OFDM PAPR. A malab code or necessary lines of codes would be highly...

Hi! I am looking for some help on how to calculate or plot CCDF of OFDM PAPR. A malab code or necessary lines of codes would be highly appreciated. Thanks in advance for your generous help.

i am doing CFO in STBC-OFDM as my M.Tech project.....I am not avaliable to find how to estimate frequency offset at receiver....I am using...

i am doing CFO in STBC-OFDM as my M.Tech project.....I am not avaliable to find how to estimate frequency offset at receiver....I am using MATLAB......Please help me it is urgent for my project.....

Hi All! I have written a section of codes according to the J.J. van de Beek's , but the result is wrong. I do not know why, I hope someone can...

Hi All! I have written a section of codes according to the J.J. van de Beek's , but the result is wrong. I do not know why, I hope someone can help me,thanks! clear all; %********************** preparation part *************************** para=128; % Number of parallel channel to transmit (points) fftlen=128; % FFT length no

Hi, I'm currently doing project on OFDM based. I want to transmit my signal through a Rayleigh channel. assume that the received signal should...

Hi, I'm currently doing project on OFDM based. I want to transmit my signal through a Rayleigh channel. assume that the received signal should be y(t)=x(t)*h(t)+n(t) or Y(f)=X(f)H(f)+N(f). I understand that in order to get y(t), we need to do a convolution between x(t) and h(t). let say, after IFFT in OFDM part, then I change the signal into serial where the data is in time domain. Now, I don...

While sorting through some old stuff, I came upon the introductory comms book I used at college. This book was published in 1971. In the section...

While sorting through some old stuff, I came upon the introductory comms book I used at college. This book was published in 1971. In the section on information theory it goes through Shannon and Hartley's work on channel capacity. It then describes one possible way to get close to that limit, which is pretty much what we call OFDM (though it doesn't call it that - when was the term OFDM ...

Dear comp.dsp, I am going to try to learn a bit more about the wireless channel (specifically using OFDM) by first creating a set of symbols...

Dear comp.dsp, I am going to try to learn a bit more about the wireless channel (specifically using OFDM) by first creating a set of symbols and perform a transmit and receive. It is a simple begining I want to make, and I will probably use GNU Octave and, later, when I do know the basics, shift to IT++. My doubts are: 1. Let us say I am going to use just BPSK over OFDM. Then, I can l...

Hi I am trying to generate a OFDM signal with CFO, of which i am trying to plot a BER Vs the CFO for various SNR.... I started by...

Hi I am trying to generate a OFDM signal with CFO, of which i am trying to plot a BER Vs the CFO for various SNR.... I started by transmitting a signal and receiving it over a flat fading channel, using cyclic prefix, and zero padding the data.... which I was successful But when i tried it over the CFO .....i am not getting it... The following is the section of the CFO which I use in t...

I have some questions.... Given the elegance of FDE, why has FDE lagged behind in use compared to TDE? Also, why is OFDM so popular when SC-FDE...

I have some questions.... Given the elegance of FDE, why has FDE lagged behind in use compared to TDE? Also, why is OFDM so popular when SC-FDE is so much better? (No ICI, no peak to average issues)

hi all DSP giants and experts, i am struggling on one problem..lemme share with you people.. Thanks...

hi all DSP giants and experts, i am struggling on one problem..lemme share with you people.. Thanks in advance for all answers its like this i have OFDM Symbols say 256 ifft which has a cylic prefix of 32 say a system is taking fft at some sample offset..i need to know..at what sample offset from start. the FLOW is like this step1-===...

hi all, I"m working on a simulation of comparing OFDM with different modulation schemes (QPSK,QAM) etc'... My question is about the conversion...

hi all, I"m working on a simulation of comparing OFDM with different modulation schemes (QPSK,QAM) etc'... My question is about the conversion from Es/No to Eb/No I'm not sure if I need to take the cyclic prefix under consideration for instance: Es/No=Eb/No+10log10(log2M * Nc) + 10log10(CodeRate) + ... .. 10log10(Tinf/(Tinf+Tcp)) is the last part correct? where Tinf - is the inf...

Hi all i am basically from GPS doing usual Acuistion, tracking stuff for CDMA signal... recently moved in to ofdm... still...

Hi all i am basically from GPS doing usual Acuistion, tracking stuff for CDMA signal... recently moved in to ofdm... still learning..this site doing a great favour.. after going thorugh all basics i have few points to comment and ask.. 1. IFFT will genrate the complex valued signal,as input is output of QAM mapper and placement of carriers is assymetrical, how do we ...

Hello, How is a baseband OFDM symbol upconverted to a set intermediate frequency? Basically after the IFFT, we have carriers that are...

Hello, How is a baseband OFDM symbol upconverted to a set intermediate frequency? Basically after the IFFT, we have carriers that are centered around zero (DC). How can this be shifted to a frequency that is more suitable for transmission? I am trying to implement this in simulink, but am having difficulties. Can anyone please give me some clues/examples? Thanks, Rohith