Re: [Discuss-gnuradio] Wideband OFDM Reference Implementation
Hi Yaşar - To address your first paragraph / question: the GR OFDM has not been updated significantly since that post. It can still handle FFT length of 64: yes! It might be able to handle 128 or higher, or 32 or lower, out of the box. The error you provide shows that it is not able to handle the larger incoming PDUs for length 128. An option you have is to set (e.g., in GRC) the "Min Output Buffer" to a larger value, say 10 (bytes), for the GR OFDM hierarchal blocks. This value will be propagated through to the (actual) blocks that make it up and, with a high enough value, should fix the immediate issue. Hope this is useful. - MLD On Tue, Mar 13, 2018, at 6:43 PM, Yaşar Sinan Nasır wrote: > Yes, after some trial with the provided OFDM .grc files of the GNU > Radio, I agree with you on the flexibility of the occupied bins and > pilot tones. However, I have an issue. When, I try FFT length input > that is greater than 64, I get " (14)>]: Buffer too small for min_noutput_items" error. After a > search in the forum I found your comment in > https://lists.gnu.org/archive/html/discuss-gnuradio/2014-08/msg00223.html > Could you please give more details on what needs to be changed. > e.g., do we have to change the source code of the OFDM Carrier > Allocator block? ___ Discuss-gnuradio mailing list Discuss-gnuradio@gnu.org https://lists.gnu.org/mailman/listinfo/discuss-gnuradio
Re: [Discuss-gnuradio] Wideband OFDM Reference Implementation
Sinan, Unfortunately, an LDPC decoder with enough throughput for DVB-T2 (up to 50 Mbps) can't be realized on a general purpose CPU. You have to use a GPU or FPGA. Because of that, there's no DVB-T2 receiver in GNU Radio. If you're willing to use commercial receivers, I have a fully tested IP over DVB-T2 solution for Linux. It's even IPv6 capable. Here's the block diagram. IP over DVB-T2 Ron On 03/13/2018 03:43 PM, Yaşar Sinan Nasır wrote: I also have a general question. We have also seen DVB-T2 transmitter as a possible OFDM implementation with high data rate, but we were not able to find a DVB receiver implemented in GNU Radio. Is it available at this time? Thanks again for your previous responses! Best, Sinan ___ Discuss-gnuradio mailing list Discuss-gnuradio@gnu.org https://lists.gnu.org/mailman/listinfo/discuss-gnuradio
Re: [Discuss-gnuradio] Wideband OFDM Reference Implementation
Hi Marcus, Yes, after some trial with the provided OFDM .grc files of the GNU Radio, I agree with you on the flexibility of the occupied bins and pilot tones. However, I have an issue. When, I try FFT length input that is greater than 64, I get "]: Buffer too small for min_noutput_items" error. After a search in the forum I found your comment in https://lists.gnu.org/archive/html/discuss-gnuradio/2014-08/msg00223.html Could you please give more details on what needs to be changed. e.g., do we have to change the source code of the OFDM Carrier Allocator block? I also have a general question. We have also seen DVB-T2 transmitter as a possible OFDM implementation with high data rate, but we were not able to find a DVB receiver implemented in GNU Radio. Is it available at this time? Thanks again for your previous responses! Best, Sinan On Tue, Mar 13, 2018 at 12:20 PM, Müller, Marcus (CEL) wrote: > OFDMA is a higher-level concept. Since it doesn't really apply to > IEEE802.11, no, gr-ieee802-11 isn't the best place to add it to. > > Use GNU Radio's built-in OFDM framework. It's very flexible. From a > transmitter's point of view, OFDM is a MAC layer choice that only > affects the subcarriers used in every symbol, and you can perfectly > well define that with said framework. > On Tue, 2018-03-13 at 12:14 -0500, Yaşar Sinan Nasır wrote: > > Hi Marcus, > > > > Thanks for the reply. I have an additional question. Is it possible to > implement OFDMA on the top of the gr-ieee802-11 or I need to begin with > basics like benchmark OFDM or raw OFDM. If my intention is to implement > OFDMA, what would you recommend to begin with as a reference? > > > > Best, > > Sinan > > > > On Mon, Mar 12, 2018 at 1:00 PM, Müller, Marcus (CEL) > wrote: > > > Hi Sinan, > > > > > > GNU Radio itself comes with an OFDM implementation. Since it's all > > > software defined Radio, it's totally agnostic of the bandwidth you use > > > it with, assuming sufficient compute power. > > > > > > Also, there's gr-ieee802-11 as you might have noticed, which implements > > > the WiFi PHY. > > > > > > Best regards, > > > Marcus > > > > > > On Mon, 2018-03-12 at 12:41 -0500, Yaşar Sinan Nasır wrote: > > > > Hello, > > > > > > > > I am wondering, is there any good reference implementation of > wideband OFDM (up to 20 MHz) available that you would recommend? > > > > > > > > Best, > > > > Sinan > > > > ___ > > > > 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
Re: [Discuss-gnuradio] Wideband OFDM Reference Implementation
OFDMA is a higher-level concept. Since it doesn't really apply to IEEE802.11, no, gr-ieee802-11 isn't the best place to add it to. Use GNU Radio's built-in OFDM framework. It's very flexible. From a transmitter's point of view, OFDM is a MAC layer choice that only affects the subcarriers used in every symbol, and you can perfectly well define that with said framework. On Tue, 2018-03-13 at 12:14 -0500, Yaşar Sinan Nasır wrote: > Hi Marcus, > > Thanks for the reply. I have an additional question. Is it possible to > implement OFDMA on the top of the gr-ieee802-11 or I need to begin with > basics like benchmark OFDM or raw OFDM. If my intention is to implement > OFDMA, what would you recommend to begin with as a reference? > > Best, > Sinan > > On Mon, Mar 12, 2018 at 1:00 PM, Müller, Marcus (CEL) wrote: > > Hi Sinan, > > > > GNU Radio itself comes with an OFDM implementation. Since it's all > > software defined Radio, it's totally agnostic of the bandwidth you use > > it with, assuming sufficient compute power. > > > > Also, there's gr-ieee802-11 as you might have noticed, which implements > > the WiFi PHY. > > > > Best regards, > > Marcus > > > > On Mon, 2018-03-12 at 12:41 -0500, Yaşar Sinan Nasır wrote: > > > Hello, > > > > > > I am wondering, is there any good reference implementation of wideband > > > OFDM (up to 20 MHz) available that you would recommend? > > > > > > Best, > > > Sinan > > > ___ > > > Discuss-gnuradio mailing list > > > Discuss-gnuradio@gnu.org > > > https://lists.gnu.org/mailman/listinfo/discuss-gnuradio > > smime.p7s Description: S/MIME cryptographic signature ___ Discuss-gnuradio mailing list Discuss-gnuradio@gnu.org https://lists.gnu.org/mailman/listinfo/discuss-gnuradio
Re: [Discuss-gnuradio] Wideband OFDM Reference Implementation
Hi Marcus, Thanks for the reply. I have an additional question. Is it possible to implement OFDMA on the top of the gr-ieee802-11 or I need to begin with basics like benchmark OFDM or raw OFDM. If my intention is to implement OFDMA, what would you recommend to begin with as a reference? Best, Sinan On Mon, Mar 12, 2018 at 1:00 PM, Müller, Marcus (CEL) wrote: > Hi Sinan, > > GNU Radio itself comes with an OFDM implementation. Since it's all > software defined Radio, it's totally agnostic of the bandwidth you use > it with, assuming sufficient compute power. > > Also, there's gr-ieee802-11 as you might have noticed, which implements > the WiFi PHY. > > Best regards, > Marcus > > On Mon, 2018-03-12 at 12:41 -0500, Yaşar Sinan Nasır wrote: > > Hello, > > > > I am wondering, is there any good reference implementation of wideband > OFDM (up to 20 MHz) available that you would recommend? > > > > Best, > > Sinan > > ___ > > 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
Re: [Discuss-gnuradio] Wideband OFDM Reference Implementation
Hi Sinan, GNU Radio itself comes with an OFDM implementation. Since it's all software defined Radio, it's totally agnostic of the bandwidth you use it with, assuming sufficient compute power. Also, there's gr-ieee802-11 as you might have noticed, which implements the WiFi PHY. Best regards, Marcus On Mon, 2018-03-12 at 12:41 -0500, Yaşar Sinan Nasır wrote: > Hello, > > I am wondering, is there any good reference implementation of wideband OFDM > (up to 20 MHz) available that you would recommend? > > Best, > Sinan > ___ > Discuss-gnuradio mailing list > Discuss-gnuradio@gnu.org > https://lists.gnu.org/mailman/listinfo/discuss-gnuradio smime.p7s Description: S/MIME cryptographic signature ___ Discuss-gnuradio mailing list Discuss-gnuradio@gnu.org https://lists.gnu.org/mailman/listinfo/discuss-gnuradio
