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#1 2010-Jan-13 19:57:23

marslan
Member
Registered: 2009-Jun-09
Posts: 19

OFDM with WarpLab

Hey folks,

do we have any OFDM implementation on Warplab?

If not, I am guessing that using FFT and IFFT functions of Matlab when transmitting the Tx samples
would be enough. Is this correct? How would one go with assigning symbols to carriers and using pilots
for specific carriers?

Is this all doable in Matlab itself?

Thanks.

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#2 2010-Jan-14 14:43:43

murphpo
Administrator
From: Mango Communications
Registered: 2006-Jul-03
Posts: 5159

Re: OFDM with WarpLab

We don't have an OFDM design in WARPLab, but it's certainly possible. I suggest looking for a m-code OFDM implementation to use as a reference. the ifft/fft functions will be part of it, but there's a lot of other processing required (modulation, cyclic prefix insertion/removal, symbol timing, CFO/phase error estimation, etc.).

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#3 2010-Jan-14 15:01:32

marslan
Member
Registered: 2009-Jun-09
Posts: 19

Re: OFDM with WarpLab

Thanks a lot for the info. I have one small question about RSSI.

It might sound weird but is it possible to measure the signal strength per subcarrier in OFDM?
When the board reports RSSI in OFDM refdes for example, is it the total magnitude of subcarrier signals?
Can we just divide the RSSI by the number of subcarriers to get the signal strength per subcarrier?

Can we also measure Eb/No, SNR per bit/symbol?

Thank you,

Mustafa

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#4 2010-Jan-14 15:27:32

murphpo
Administrator
From: Mango Communications
Registered: 2006-Jul-03
Posts: 5159

Re: OFDM with WarpLab

The RSSI signal comes from the RF transceiver, which has no idea what waveform is being transmitted/received. Any per-subcarrier statistics will have to be calculated by your receiver implementation (either in the FPGA for real-time designs, or MATLAB for WARPLab).

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