-----BEGIN PGP SIGNED MESSAGE----- Hash: SHA1 Hi Sara,
it seems like there is some confusion between time and frequency domain. In an OFDM system you have subcarriers next to each other in the frequency domain. You will most likely add new subcarriers by putting non-zero values on your vector in the frequency domain. In order to realize a guard band you just put zeros on this vector in the frequency domain. The cyclic prefix, CP, is a guard time. It is a time domain concept. It provides protection between each OFDM symbol. I hope this cleared things up a little happy hacking Johannes On 22.05.2014 11:29, Sara Chérif wrote: > In ofdm transmitter , I want to add 6 subcarriers as a guard band > between symbols , so that each symbol is fft + cp + guard band .. > How to add this guard band ? is there a block which add zeros ? I > think I can make guard band included in CP , I can make cp longer > by 6 then multiplying symbols by a window (multipling fft and > actual cp by ones & multipling last 6 subcarriers by zeros ) . Is > there a window or time domain filter in GNU Radio ? Thanks. -----BEGIN PGP SIGNATURE----- Version: GnuPG v1 Comment: Using GnuPG with Thunderbird - http://www.enigmail.net/ iQIcBAEBAgAGBQJTfdjTAAoJEO7fmkDsqywM0SMP/0x4nHy1MBHi82EvA/UXH1it rGkNUUuXLUbdpY843KVcOeoR91mwjMCHywGiyD+3Zk3XI0gSqKrxpxXYTJxf1/ON G6J2ATe8fMk206mczemk5LgLTx8WnML4LLSECvf1oA5UkYAkdUoxy2e7CvhkNQBR FGShvMkxFi4BFWYNKopMICkHxeUD5uOpi/Y59uQ+h/xT8FAZoLh8ZnYMKh4OhJtN IDiS0QCYKpZEp9Y2M7h/YbFKynwcXAxV5fouKbzWzlysGULEuxa57R+Nt7s5+Ylh pY6kwHx0RZaoEBEB1Ak4jx97Qfawx/xVb4xbpgYH6ipqKwn8EXstS+0lh1A70rak AyYEAoqRizKO5AfSv3yXXs3GaA7PVi6NjsZ7kqSTimOOZ+O1FMIyQ7eKQGOChw4c 2H2UlHCp3XH/LfVLfRUXVh9PumcyajWGwpZnd4O51Sk9UfboPNWC7PH1j6BY+cfX 9l3JEu9oY9Wy381z53nAgIOBdG/xMj6zzHXoPSUNNzsQnwZdxDQ5GLhmpRfX5WCe gk2axSMSCvUedmKjvvqtvL7aaZC5qHkNgvjyxVbPHLPfzIoPDqO7AEv/7noqrSM8 wYg3ikAFvvVXLxXuezeNkt/Cy0YMZ2mqijZmWtlY5CSUW0gDmLqwfHvkWQH3A1aM ArQzOreAmtzPr0ICl/Le =RCub -----END PGP SIGNATURE----- _______________________________________________ Discuss-gnuradio mailing list Discuss-gnuradio@gnu.org https://lists.gnu.org/mailman/listinfo/discuss-gnuradio