Yes johnny for a while i need only OFDM transmitter and reciever via USRP for my project. I just want that this OFDM system can transmit and receive via USRP, that is my aim at the moment. Thanks once again for your detailed clarification. i will try that and let you know the results. Thank you so much for your help i really appriciate that.
Regards, Waqas. Tuan Ta-2 wrote: > > As far as I know there's no open source code for an OFDM transceiver > available. I was trying to build one half a year back but wasn't > successful > before I had to move on to something else. The benchmark_ofdm code will > give > you a simplex OFDM system. Ie you can run the transmitter on 1 USRP and > receiver on another. > > Ie. run this on 1 USRP > ./benchmark_ofdm_tx.py -f 2.412G > > And this on the other > ./benchmark_ofdm_rx.py -f 2.412G > > The value of the frequency depends on the daughterboards you're using. If > you're using USRP1 make sure the decimation rate is 1/2 of the > interpolation > rate as the ADC is 2 times faster than the DAC on the USRP1 (or the other > way around, you should chek that). > > Watch out for the frequency offset, it killed the system for me. If the > above doesn't work, run the transmitter on 1 USRP and usrp_fft.py on the > other. Check the center frequency of the FFT plot and manually adjust the > receiver center frequency. I used the RFX2400 boards and the offset for me > was ~ 40kHz. > > Good luck, > Johnny > > > > On Fri, Sep 9, 2011 at 2:30 AM, sumitstop > <sumit.ku...@research.iiit.ac.in>wrote: > >> >> http://pwnhome.files.wordpress.com/2011/04/simple_transceiver1.png >> see carefully....... it has a gmsk modulator in the bottom.u can make the >> bottom modulator part in another pc >> >> benchmark programs are quite good to start with... >> u can type benchmark_ofdm.py -h to see all the parameters u can play >> with. >> >> >> waqasme wrote: >> > >> > And sorry to mention in the last mail that i will be suing USRP 1 . >> > >> > waqasme wrote: >> >> >> >> Hi Sumit, >> >> Thank you so much for your quick response. yah i understand what your >> >> saying and i am trying to understand this document but it doesnot help >> >> much . As you mentioned use the same Tranceiver setup and only replace >> >> OFDM blocks with that. My question is in this basic tranciver diagram >> the >> >> used two UHD's source and sink and in the middle they use GMSK >> >> Demodulator right. but they didnot use any modulator any where in the >> >> design. Now i am confused what blocks i have to replace with OFDM >> >> blocks??? Please try to explain in bit detail so i can design it >> properly >> >> . >> >> OR you mentioned other option that use benchmark_OFDM.py file . >> Somebody >> >> already told me about this benchmark file. but its just C++ code . i >> am >> >> quite new to GNU radio and dont know much about the functions how it >> >> works. >> >> Please let me know how to use that benchmark_OFDM.py file in order to >> >> make the simulation design? do i have to download the file or what? >> how >> >> it works ?? let me know if you know about the process how to compile >> and >> >> run that code in GNU radio. >> >> >> >> Thanks for ur help and support really appriciate that... >> >> >> >> Regards, >> >> >> >> Waqas. >> >> >> >> >> >> sumitstop wrote: >> >>> >> >>> Try to understand these >> >>> >> >>> >> http://pwnhome.wordpress.com/2011/04/26/intro-to-gnuradio-and-the-usrp-part-5-simple-transceiver/ >> >>> >> >>> here u need to put those ofdm blocks .. thats it.... also go through >> >>> some modifications as written in umit, >> >>> >> >>> >> >>> >> http://pwnhome.wordpress.com/2011/04/19/intro-to-gnuradio-and-the-usrp-part-4/ >> >>> >> >>> or else work with benchmark_ofdm.py its very easy.. :) >> >>> >> >>> may i know what daughter boards do you have... >> >>> >> >>> >> >>> >> >>> >> >>> >> >>> waqasme wrote: >> >>>> >> >>>> >> >>>> Hello sumit, >> >>>> Thanks for your help i went through that document that you refered >> to, >> >>>> and i tried to implement that OFDM transmitter part. This document >> only >> >>>> explain about OFDM flow graph or transmitter. Is there any other >> >>>> document or information related to OFDM modulator and demodulator >> >>>> (Transceiver)? i haver to implement OFDM transmission and reception >> via >> >>>> USRP. i will really appriciate if you can help me that or someone >> else >> >>>> who knows how to implement by using GNU radio companion. >> >>>> Thanks in advance. >> >>>> Regards, >> >>>> Waq. >> >>>> >> >>>> >> >>> >> >>> >> >> >> >> >> > >> > >> >> >> ----- >> Sumit Kr. >> Research Assistant >> Communication Research center >> IIIT Hyderabad >> India >> -- >> View this message in context: >> http://old.nabble.com/OFDM-Implementation-tp32380874p32429184.html >> Sent from the GnuRadio mailing list archive at Nabble.com. >> >> >> _______________________________________________ >> Discuss-gnuradio mailing list >> Discuss-gnuradio@gnu.org >> https://lists.gnu.org/mailman/listinfo/discuss-gnuradio >> > > _______________________________________________ > Discuss-gnuradio mailing list > Discuss-gnuradio@gnu.org > https://lists.gnu.org/mailman/listinfo/discuss-gnuradio > > -- View this message in context: http://old.nabble.com/OFDM-Implementation-tp32380874p32444265.html Sent from the GnuRadio mailing list archive at Nabble.com. _______________________________________________ Discuss-gnuradio mailing list Discuss-gnuradio@gnu.org https://lists.gnu.org/mailman/listinfo/discuss-gnuradio