Hi, I am having trouble with low-pass interpolation in comb-type channel estimation. The model in use is a 802.11a model with 64-pt FFT, 48...

Hi, I am having trouble with low-pass interpolation in comb-type channel estimation. The model in use is a 802.11a model with 64-pt FFT, 48 data subcarriers and 4 pilot subcarriers. At the receiver, I find the LS estimate at these pilot sub-carriers by simply dividing the received pilot by the transmitted pilots. Hence the channel estimate contains 4 samples for each OFDM symbol. The probl...

accoding to the ETSI EN 300 744 "In the 2K mode, interleaved vectors shall be mapped onto four consecutive OFDM symbols. For even interleaved...

accoding to the ETSI EN 300 744 "In the 2K mode, interleaved vectors shall be mapped onto four consecutive OFDM symbols. For even interleaved vectors these shall start with symbols 0,8,16,24, etc. and for odd interleaved vectors these shall start with symbols 4,12,20,28, etc. in every super-frame." I have an question about symbol index of 2K mode & in-depth mode. 1. 4 consecutive OFDM sym...

Hello, I'm working on MIMO-OFDM system simulation in Matlab. I assume a 3 tap multipath channel. My problem is with a Space-Time decoding...

Hello, I'm working on MIMO-OFDM system simulation in Matlab. I assume a 3 tap multipath channel. My problem is with a Space-Time decoding block. Ussually in MIMO systems you use pseudo-inverse matrix for decoding purposes (zero forcing, MMSE, SIC, OSIC). When you don't have a multipath channel, the solution is straightforward, you just calculate the inverse of H (channel matrix). However, here ...

Hi, I have a doubt. May be, someone on this list can help me out here... In IEEE 802.11a (OFDM system), packet data given at end of...

Hi, I have a doubt. May be, someone on this list can help me out here... In IEEE 802.11a (OFDM system), packet data given at end of the standard document (for verification, i assume) can be generated if IFFT-FFT vectors are NOT normalized. unnormalized IFFT vectors have energy = 1/Nfft (Used in transmitter). unnormalized FFT vectors have energy = Nfft (used in receiver). (Nfft-> FFT leng

Dear all, Could you please tell me how can I remove effect of fading in an BPSK OFDM receiver? My channel is a static flat...

Dear all, Could you please tell me how can I remove effect of fading in an BPSK OFDM receiver? My channel is a static flat fading: gnoise = (noise_var) * sqrt(1/2) * (randn(1,symbol_size) + j*randn(1,symbol_size)) a = randn(1,symbol_size) + j*randn(1,symbol_size) r = a.*ofdm_symbol + gnoise at the receiver I have tried the following techniques to remove t...

Hi, Would greatly appreciate your opinions. Would the ber of a OFDM with nulled carriers be the same as one without null carriers, given the...

Hi, Would greatly appreciate your opinions. Would the ber of a OFDM with nulled carriers be the same as one without null carriers, given the same Eb/No(dB)? For eg, let nfft = no of FFT points = 128. Case 1 : noUsedCarriers = no of used carriers = 128 Case 2 : noUsedCarriers = 70 Would the ber of case 1 and case 2 be the same (assume awgn)? Is there any performance degradation to the null ...

I have a basic question here regarding OFDM digital front end. if i have a very efficient clock of say 10ppm, can i downsample the signal to the...

I have a basic question here regarding OFDM digital front end. if i have a very efficient clock of say 10ppm, can i downsample the signal to the sampling frequency of transmitter. i.e. the sampling frequency at which i will get 64 samples for a 64 sample FFT block? for example, the FFT output at the transmitter is at 500 kHz. Now can i directly down sample this signal to 500 kHz baseband sign...

Dear all, I now have question about channel frequency response (CFR) for OFDM system as follows: My channel model is power delay profile, so...

Dear all, I now have question about channel frequency response (CFR) for OFDM system as follows: My channel model is power delay profile, so I can obtain the time domain channel impulse response (CIR), let?s say h, then I have transmitted signal as x; so I could obtain the received signal using matlab function as y=conv(x, h). However, as for the frequency domain signal, the received signal

Hi there, I calculate SINR for OFDM system as: (TP. pathloss.|CG|^2)/(cov + TP_ou. pathloss_ou.|CG_ou|^2) where, TP: Transmit...

Hi there, I calculate SINR for OFDM system as: (TP. pathloss.|CG|^2)/(cov + TP_ou. pathloss_ou.|CG_ou|^2) where, TP: Transmit Power TP_ou: Transmit Power of other users CG: Channel Gain CG_OU: Channel Gain of other users cov: Covariance of AWGN Then, how can I calculate SINR for OFDMA systems. What will be the effect of multiple access on SINR? Thank you!

(This question is coming from an OFDM perspective but is obviously not confined to OFDM) If you are computing the peak to average power ratio...

(This question is coming from an OFDM perspective but is obviously not confined to OFDM) If you are computing the peak to average power ratio (PAPR) of a block of data, do you include the peak in computing the average power? For example, do you compare the peak power with the average of all the rest? Or do you compare the peak with the whole block including itself? I am pretty sure that ...

Hi, I want to delay an OFDM signal in time domain (MATLAB): sig= signal ipIndex = interpolation...

Hi, I want to delay an OFDM signal in time domain (MATLAB): sig= signal ipIndex = interpolation index -------------------------------------------------------------------- % Interpolation iq_ip = interp(sig,ipIndex); % Delay the signal delayed_iq_ip = [iq_ip(end-delayIndex+1:end); iq_ip(1:end-delayIndex)]; % Reduce the sampling rate r=1; for sample = 1:ipIndex:length(delayed_...

Any body having AOFDM code(matlab)

Any body having AOFDM code(matlab)

hi friends how to introduce Carrier Frequency offset in OFDM ?

hi friends how to introduce Carrier Frequency offset in OFDM ?

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Or DAB for short. I heard it was great in the home but doesn't work well at all in cars due to multipath. The system uses OFDM I think....

Or DAB for short. I heard it was great in the home but doesn't work well at all in cars due to multipath. The system uses OFDM I think. Can anybody confirm? Naebad