Re: [Discuss-gnuradio] Re: Soft-DVB DVB-T transmitter
On Tue, 2008-11-11 at 08:26 +0100, Vincenzo Pellegrini wrote: Martin , sorry for the delay. My exams seem to have gone well even if it's not official yet. Great I also had to do a demo for a company I have a temporary contract with for developing some gnuradio based gsm-r security sentinels. Also the demo was smooth. (i already listed the project on the gnuradio wiki) Good work. so i really hope i'll be able to prepare the 8Mhz stream for you within the next 2/3 days. Would this still be useful? Yes it really would. I am also really looking forward for the sources. One of the things I am planning to do is use the structure of your code as a basis for a DVB-T receiver. It is always easier debugging a receiver when you can make a full loop. (transmitter and receiver back-to-back) Greetings, Martin 2008/11/3, Martin DvH [EMAIL PROTECTED]: On Mon, 2008-11-03 at 14:13 +0100, Martin DvH wrote: Van: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] Namens Vincenzo Pellegrini Verzonden: maandag 3 november 2008 0:16 Aan: Martin DvH CC: discuss-gnuradio Onderwerp: [Discuss-gnuradio] Re: Soft-DVB DVB-T transmitter This is Great... :) Yup, the playback cannot be smooth because of the wrong throughput, definitely. Did you use the USRP1 with interpolation factor = 16 ? Yes I did. I can prepare a modulated signal with the correct throughput for you.. this is not a problem... :) Please do, this would be great. what hard disc are you playing your signal back from? Internal 2.5 harddisk of my acer 6930 notebook (Aspire 6930G-734G32BN LX.AVB0X.135) 2.5 320GB HDD 5400rpm, SATA I checked now. It is a: Western digital Scorpio 320 GB SATA (WDC WD3200BEVT-22ZCT0) 2.5-inch SATA Hard Drive 320 GB, 3 Gb/s, 8 MB Cache, 5400 RPM Benchmark from tomshardware (h2benchw 3.6): http://www.tomshardware.com/charts/2-5-hard-drive-charts/Minimum-Read-Transfer-Performance,687.html minimum read transfer rate 33.5 MB/sec average read transfer rate 52.2 MB/sec maximum read transfer rate 68.2 MB/sec I am not at home right now So I can't check the exact brand and model of the harddisk. It can do around 38 MB/sec so this is just enough (required 32 MB/sec) I also have 4GB of memory in this notebook, so I think it will buffer the complete file. I had to use my notebook because with my desktop PC (ASrock 939-DUAL-SATA2) The USB TX bandwidth is less then 32 MB/sec. (Which is strange because I CAN receive 32 MB/sec) I get UuUuUu on this machine when useing interpolation 16, so unusable. Regards, Martin regards vincenzo 2008/11/3 Martin DvH [EMAIL PROTECTED] Hi, In fact: 8 complex Msps implement a 7 MHz channel while 9.142857143 complex Msps implement an 8 MHz channel. Just try to go as close as possible to such sampling frequency by using USRP2 and let me know what happens... it could turn out that we need a resampler block. So if I use a fractional rate resampler with interpolation factor 10/8=1.25 I get a 7 Mhz channel with 10 Msps samplerate. If I use a fractional rate resampler with interpolation factor 10/9.142857143=1.09375 I get a 8 Mhz channel with 10 Msps samplerate If I use a fractional rate resampler with DECIMATION factor 9.142857143/8=8/7=1.142857143 I get a 8 Mhz channel with 8 Msps samplerate with the out-of-band skirts folded back at the sides. Would be interesting to see if this last one works with a USRP1. I'll let you know how the experiments go. I resampled and scaled your ofdm_40.dump file so it now will use 8 Mhz bandwidth with a 8 Msps samplerate. The reception never can be perfect this way but it seems good enough for tests. My USB DVB-T receiver receives the transport stream without problems. Mplayer playes the stream without problem for two loops and then crashes with a broken frame. My standalone settopbox DVB-T receiver now also receives the stream. (8 MHz channel on UHF) It has big problems displaying it. Sound is only a chop of sound now and then and video stops, then runs for a second, then stops again. I think this is because the timestamps and framerate (playout speed) don't match the data throughput of the MPEG stream anymore. (It is getting the stream too fast) I put my resampled RF file at: http://www.olifantasia.com/projects/gnuradio/mdvh
Re: [Discuss-gnuradio] Re: Soft-DVB DVB-T transmitter
Hello people, I'm following the discussion about the Soft-DVB, and I'm thinking about use of the WBX0510 daughterboard (50 MHz to 1 GHz) w/ Soft-DVB - Will then be possible to transmitt in any VHF/UHF channel? Bye, Rafael Diniz Em Tuesday 11 November 2008, Vincenzo Pellegrini escreveu: Martin , sorry for the delay. My exams seem to have gone well even if it's not official yet. I also had to do a demo for a company I have a temporary contract with for developing some gnuradio based gsm-r security sentinels. Also the demo was smooth. (i already listed the project on the gnuradio wiki) so i really hope i'll be able to prepare the 8Mhz stream for you within the next 2/3 days. Would this still be useful? 2008/11/3, Martin DvH [EMAIL PROTECTED]: On Mon, 2008-11-03 at 14:13 +0100, Martin DvH wrote: Van: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] Namens Vincenzo Pellegrini Verzonden: maandag 3 november 2008 0:16 Aan: Martin DvH CC: discuss-gnuradio Onderwerp: [Discuss-gnuradio] Re: Soft-DVB DVB-T transmitter This is Great... :) Yup, the playback cannot be smooth because of the wrong throughput, definitely. Did you use the USRP1 with interpolation factor = 16 ? Yes I did. I can prepare a modulated signal with the correct throughput for you.. this is not a problem... :) Please do, this would be great. what hard disc are you playing your signal back from? Internal 2.5 harddisk of my acer 6930 notebook (Aspire 6930G-734G32BN LX.AVB0X.135) 2.5 320GB HDD 5400rpm, SATA I checked now. It is a: Western digital Scorpio 320 GB SATA (WDC WD3200BEVT-22ZCT0) 2.5-inch SATA Hard Drive 320 GB, 3 Gb/s, 8 MB Cache, 5400 RPM Benchmark from tomshardware (h2benchw 3.6): http://www.tomshardware.com/charts/2-5-hard-drive-charts/Minimum-Read-Tra nsfer-Performance,687.html minimum read transfer rate 33.5 MB/sec average read transfer rate 52.2 MB/sec maximum read transfer rate 68.2 MB/sec I am not at home right now So I can't check the exact brand and model of the harddisk. It can do around 38 MB/sec so this is just enough (required 32 MB/sec) I also have 4GB of memory in this notebook, so I think it will buffer the complete file. I had to use my notebook because with my desktop PC (ASrock 939-DUAL-SATA2) The USB TX bandwidth is less then 32 MB/sec. (Which is strange because I CAN receive 32 MB/sec) I get UuUuUu on this machine when useing interpolation 16, so unusable. Regards, Martin regards vincenzo 2008/11/3 Martin DvH [EMAIL PROTECTED] Hi, In fact: 8 complex Msps implement a 7 MHz channel while 9.142857143 complex Msps implement an 8 MHz channel. Just try to go as close as possible to such sampling frequency by using USRP2 and let me know what happens... it could turn out that we need a resampler block. So if I use a fractional rate resampler with interpolation factor 10/8=1.25 I get a 7 Mhz channel with 10 Msps samplerate. If I use a fractional rate resampler with interpolation factor 10/9.142857143=1.09375 I get a 8 Mhz channel with 10 Msps samplerate If I use a fractional rate resampler with DECIMATION factor 9.142857143/8=8/7=1.142857143 I get a 8 Mhz channel with 8 Msps samplerate with the out-of-band skirts folded back at the sides. Would be interesting to see if this last one works with a USRP1. I'll let you know how the experiments go. I resampled and scaled your ofdm_40.dump file so it now will use 8 Mhz bandwidth with a 8 Msps samplerate. The reception never can be perfect this way but it seems good enough for tests. My USB DVB-T receiver receives the transport stream without problems. Mplayer playes the stream without problem for two loops and then crashes with a broken frame. My standalone settopbox DVB-T receiver now also receives the stream. (8 MHz channel on UHF) It has big problems displaying it. Sound is only a chop of sound now and then and video stops, then runs for a second, then stops again. I think this is because the timestamps and framerate (playout speed) don't match the data throughput of the MPEG stream anymore. (It is getting the stream too fast) I put my resampled RF file at: http://www.olifantasia.com/projects/gnuradio/mdvh/OTA/DVB-T/ofdm_40_bw8M hz_s amplerate_8Msps_cshort.raw format is complex signed short integers (I 16 bit, Q 16 bit) at 8 Msamples/sec
[Discuss-gnuradio] Re: Soft-DVB DVB-T transmitter
Sure rafael. I'm also looking forward to be able to buy my own WB50... Is it availale yet? If not, you know when will it be? 2008/11/12, rafael2k [EMAIL PROTECTED]: Hello people, I'm following the discussion about the Soft-DVB, and I'm thinking about use of the WBX0510 daughterboard (50 MHz to 1 GHz) w/ Soft-DVB - Will then be possible to transmitt in any VHF/UHF channel? Bye, Rafael Diniz Em Tuesday 11 November 2008, Vincenzo Pellegrini escreveu: Martin , sorry for the delay. My exams seem to have gone well even if it's not official yet. I also had to do a demo for a company I have a temporary contract with for developing some gnuradio based gsm-r security sentinels. Also the demo was smooth. (i already listed the project on the gnuradio wiki) so i really hope i'll be able to prepare the 8Mhz stream for you within the next 2/3 days. Would this still be useful? 2008/11/3, Martin DvH [EMAIL PROTECTED]: On Mon, 2008-11-03 at 14:13 +0100, Martin DvH wrote: Van: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] Namens Vincenzo Pellegrini Verzonden: maandag 3 november 2008 0:16 Aan: Martin DvH CC: discuss-gnuradio Onderwerp: [Discuss-gnuradio] Re: Soft-DVB DVB-T transmitter This is Great... :) Yup, the playback cannot be smooth because of the wrong throughput, definitely. Did you use the USRP1 with interpolation factor = 16 ? Yes I did. I can prepare a modulated signal with the correct throughput for you.. this is not a problem... :) Please do, this would be great. what hard disc are you playing your signal back from? Internal 2.5 harddisk of my acer 6930 notebook (Aspire 6930G-734G32BN LX.AVB0X.135) 2.5 320GB HDD 5400rpm, SATA I checked now. It is a: Western digital Scorpio 320 GB SATA (WDC WD3200BEVT-22ZCT0) 2.5-inch SATA Hard Drive 320 GB, 3 Gb/s, 8 MB Cache, 5400 RPM Benchmark from tomshardware (h2benchw 3.6): http://www.tomshardware.com/charts/2-5-hard-drive-charts/Minimum-Read-Tra nsfer-Performance,687.html minimum read transfer rate 33.5 MB/sec average read transfer rate 52.2 MB/sec maximum read transfer rate 68.2 MB/sec I am not at home right now So I can't check the exact brand and model of the harddisk. It can do around 38 MB/sec so this is just enough (required 32 MB/sec) I also have 4GB of memory in this notebook, so I think it will buffer the complete file. I had to use my notebook because with my desktop PC (ASrock 939-DUAL-SATA2) The USB TX bandwidth is less then 32 MB/sec. (Which is strange because I CAN receive 32 MB/sec) I get UuUuUu on this machine when useing interpolation 16, so unusable. Regards, Martin regards vincenzo 2008/11/3 Martin DvH [EMAIL PROTECTED] Hi, In fact: 8 complex Msps implement a 7 MHz channel while 9.142857143 complex Msps implement an 8 MHz channel. Just try to go as close as possible to such sampling frequency by using USRP2 and let me know what happens... it could turn out that we need a resampler block. So if I use a fractional rate resampler with interpolation factor 10/8=1.25 I get a 7 Mhz channel with 10 Msps samplerate. If I use a fractional rate resampler with interpolation factor 10/9.142857143=1.09375 I get a 8 Mhz channel with 10 Msps samplerate If I use a fractional rate resampler with DECIMATION factor 9.142857143/8=8/7=1.142857143 I get a 8 Mhz channel with 8 Msps samplerate with the out-of-band skirts folded back at the sides. Would be interesting to see if this last one works with a USRP1. I'll let you know how the experiments go. I resampled and scaled your ofdm_40.dump file so it now will use 8 Mhz bandwidth with a 8 Msps samplerate. The reception never can be perfect this way but it seems good enough for tests. My USB DVB-T receiver receives the transport stream without problems. Mplayer playes the stream without problem for two loops and then crashes with a broken frame. My standalone settopbox DVB-T receiver now also receives the stream. (8 MHz channel on UHF) It has big problems displaying it. Sound is only a chop of sound now and then and video stops, then runs for a second, then stops again. I think this is because the timestamps and framerate (playout speed) don't match the data throughput of the MPEG stream anymore. (It is getting the stream too fast) I put my resampled RF file at: http://www.olifantasia.com/projects/gnuradio/mdvh/OTA/DVB-T/ofdm_40_bw8M hz_s
[Discuss-gnuradio] Re: Soft-DVB DVB-T transmitter
Martin , sorry for the delay. My exams seem to have gone well even if it's not official yet. I also had to do a demo for a company I have a temporary contract with for developing some gnuradio based gsm-r security sentinels. Also the demo was smooth. (i already listed the project on the gnuradio wiki) so i really hope i'll be able to prepare the 8Mhz stream for you within the next 2/3 days. Would this still be useful? 2008/11/3, Martin DvH [EMAIL PROTECTED]: On Mon, 2008-11-03 at 14:13 +0100, Martin DvH wrote: Van: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] Namens Vincenzo Pellegrini Verzonden: maandag 3 november 2008 0:16 Aan: Martin DvH CC: discuss-gnuradio Onderwerp: [Discuss-gnuradio] Re: Soft-DVB DVB-T transmitter This is Great... :) Yup, the playback cannot be smooth because of the wrong throughput, definitely. Did you use the USRP1 with interpolation factor = 16 ? Yes I did. I can prepare a modulated signal with the correct throughput for you.. this is not a problem... :) Please do, this would be great. what hard disc are you playing your signal back from? Internal 2.5 harddisk of my acer 6930 notebook (Aspire 6930G-734G32BN LX.AVB0X.135) 2.5 320GB HDD 5400rpm, SATA I checked now. It is a: Western digital Scorpio 320 GB SATA (WDC WD3200BEVT-22ZCT0) 2.5-inch SATA Hard Drive 320 GB, 3 Gb/s, 8 MB Cache, 5400 RPM Benchmark from tomshardware (h2benchw 3.6): http://www.tomshardware.com/charts/2-5-hard-drive-charts/Minimum-Read-Transfer-Performance,687.html minimum read transfer rate 33.5 MB/sec average read transfer rate 52.2 MB/sec maximum read transfer rate 68.2 MB/sec I am not at home right now So I can't check the exact brand and model of the harddisk. It can do around 38 MB/sec so this is just enough (required 32 MB/sec) I also have 4GB of memory in this notebook, so I think it will buffer the complete file. I had to use my notebook because with my desktop PC (ASrock 939-DUAL-SATA2) The USB TX bandwidth is less then 32 MB/sec. (Which is strange because I CAN receive 32 MB/sec) I get UuUuUu on this machine when useing interpolation 16, so unusable. Regards, Martin regards vincenzo 2008/11/3 Martin DvH [EMAIL PROTECTED] Hi, In fact: 8 complex Msps implement a 7 MHz channel while 9.142857143 complex Msps implement an 8 MHz channel. Just try to go as close as possible to such sampling frequency by using USRP2 and let me know what happens... it could turn out that we need a resampler block. So if I use a fractional rate resampler with interpolation factor 10/8=1.25 I get a 7 Mhz channel with 10 Msps samplerate. If I use a fractional rate resampler with interpolation factor 10/9.142857143=1.09375 I get a 8 Mhz channel with 10 Msps samplerate If I use a fractional rate resampler with DECIMATION factor 9.142857143/8=8/7=1.142857143 I get a 8 Mhz channel with 8 Msps samplerate with the out-of-band skirts folded back at the sides. Would be interesting to see if this last one works with a USRP1. I'll let you know how the experiments go. I resampled and scaled your ofdm_40.dump file so it now will use 8 Mhz bandwidth with a 8 Msps samplerate. The reception never can be perfect this way but it seems good enough for tests. My USB DVB-T receiver receives the transport stream without problems. Mplayer playes the stream without problem for two loops and then crashes with a broken frame. My standalone settopbox DVB-T receiver now also receives the stream. (8 MHz channel on UHF) It has big problems displaying it. Sound is only a chop of sound now and then and video stops, then runs for a second, then stops again. I think this is because the timestamps and framerate (playout speed) don't match the data throughput of the MPEG stream anymore. (It is getting the stream too fast) I put my resampled RF file at: http://www.olifantasia.com/projects/gnuradio/mdvh/OTA/DVB-T/ofdm_40_bw8Mhz_s amplerate_8Msps_cshort.raw format is complex signed short integers (I 16 bit, Q 16 bit) at 8 Msamples/sec. Greetings, Martin more details will follow as soon as I find some time... Thanks and success with your second group
RE: [Discuss-gnuradio] Re: Soft-DVB DVB-T transmitter
Van: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] Namens Vincenzo Pellegrini Verzonden: maandag 3 november 2008 0:16 Aan: Martin DvH CC: discuss-gnuradio Onderwerp: [Discuss-gnuradio] Re: Soft-DVB DVB-T transmitter This is Great... :) Yup, the playback cannot be smooth because of the wrong throughput, definitely. Did you use the USRP1 with interpolation factor = 16 ? Yes I did. I can prepare a modulated signal with the correct throughput for you.. this is not a problem... :) Please do, this would be great. what hard disc are you playing your signal back from? Internal 2.5 harddisk of my acer 6930 notebook (Aspire 6930G-734G32BN LX.AVB0X.135) 2.5 320GB HDD 5400rpm, SATA I am not at home right now So I can't check the exact brand and model of the harddisk. It can do around 38 MB/sec so this is just enough (required 32 MB/sec) I also have 4GB of memory in this notebook, so I think it will buffer the complete file. I had to use my notebook because with my desktop PC (ASrock 939-DUAL-SATA2) The USB TX bandwidth is less then 32 MB/sec. (Which is strange because I CAN receive 32 MB/sec) I get UuUuUu on this machine when useing interpolation 16, so unusable. Regards, Martin regards vincenzo 2008/11/3 Martin DvH [EMAIL PROTECTED] Hi, In fact: 8 complex Msps implement a 7 MHz channel while 9.142857143 complex Msps implement an 8 MHz channel. Just try to go as close as possible to such sampling frequency by using USRP2 and let me know what happens... it could turn out that we need a resampler block. So if I use a fractional rate resampler with interpolation factor 10/8=1.25 I get a 7 Mhz channel with 10 Msps samplerate. If I use a fractional rate resampler with interpolation factor 10/9.142857143=1.09375 I get a 8 Mhz channel with 10 Msps samplerate If I use a fractional rate resampler with DECIMATION factor 9.142857143/8=8/7=1.142857143 I get a 8 Mhz channel with 8 Msps samplerate with the out-of-band skirts folded back at the sides. Would be interesting to see if this last one works with a USRP1. I'll let you know how the experiments go. I resampled and scaled your ofdm_40.dump file so it now will use 8 Mhz bandwidth with a 8 Msps samplerate. The reception never can be perfect this way but it seems good enough for tests. My USB DVB-T receiver receives the transport stream without problems. Mplayer playes the stream without problem for two loops and then crashes with a broken frame. My standalone settopbox DVB-T receiver now also receives the stream. (8 MHz channel on UHF) It has big problems displaying it. Sound is only a chop of sound now and then and video stops, then runs for a second, then stops again. I think this is because the timestamps and framerate (playout speed) don't match the data throughput of the MPEG stream anymore. (It is getting the stream too fast) I put my resampled RF file at: http://www.olifantasia.com/projects/gnuradio/mdvh/OTA/DVB-T/ofdm_40_bw8Mhz_s amplerate_8Msps_cshort.raw format is complex signed short integers (I 16 bit, Q 16 bit) at 8 Msamples/sec. Greetings, Martin more details will follow as soon as I find some time... Thanks and success with your second group of tests. Martin best regards and greetings to all fellow GNURadioers vincenzo PS Rafael, just have a look back a this thread and you'll find all the info you need to do your test broadcast. Thanks for your interest 2008/10/31 Martin Dudok van Heel [EMAIL PROTECTED] Hi Vincenzo. How are things going with your exams. I hope well. Thanks for your help so far
RE: [Discuss-gnuradio] Re: Soft-DVB DVB-T transmitter
On Mon, 2008-11-03 at 14:13 +0100, Martin DvH wrote: Van: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] Namens Vincenzo Pellegrini Verzonden: maandag 3 november 2008 0:16 Aan: Martin DvH CC: discuss-gnuradio Onderwerp: [Discuss-gnuradio] Re: Soft-DVB DVB-T transmitter This is Great... :) Yup, the playback cannot be smooth because of the wrong throughput, definitely. Did you use the USRP1 with interpolation factor = 16 ? Yes I did. I can prepare a modulated signal with the correct throughput for you.. this is not a problem... :) Please do, this would be great. what hard disc are you playing your signal back from? Internal 2.5 harddisk of my acer 6930 notebook (Aspire 6930G-734G32BN LX.AVB0X.135) 2.5 320GB HDD 5400rpm, SATA I checked now. It is a: Western digital Scorpio 320 GB SATA (WDC WD3200BEVT-22ZCT0) 2.5-inch SATA Hard Drive 320 GB, 3 Gb/s, 8 MB Cache, 5400 RPM Benchmark from tomshardware (h2benchw 3.6): http://www.tomshardware.com/charts/2-5-hard-drive-charts/Minimum-Read-Transfer-Performance,687.html minimum read transfer rate 33.5 MB/sec average read transfer rate 52.2 MB/sec maximum read transfer rate 68.2 MB/sec I am not at home right now So I can't check the exact brand and model of the harddisk. It can do around 38 MB/sec so this is just enough (required 32 MB/sec) I also have 4GB of memory in this notebook, so I think it will buffer the complete file. I had to use my notebook because with my desktop PC (ASrock 939-DUAL-SATA2) The USB TX bandwidth is less then 32 MB/sec. (Which is strange because I CAN receive 32 MB/sec) I get UuUuUu on this machine when useing interpolation 16, so unusable. Regards, Martin regards vincenzo 2008/11/3 Martin DvH [EMAIL PROTECTED] Hi, In fact: 8 complex Msps implement a 7 MHz channel while 9.142857143 complex Msps implement an 8 MHz channel. Just try to go as close as possible to such sampling frequency by using USRP2 and let me know what happens... it could turn out that we need a resampler block. So if I use a fractional rate resampler with interpolation factor 10/8=1.25 I get a 7 Mhz channel with 10 Msps samplerate. If I use a fractional rate resampler with interpolation factor 10/9.142857143=1.09375 I get a 8 Mhz channel with 10 Msps samplerate If I use a fractional rate resampler with DECIMATION factor 9.142857143/8=8/7=1.142857143 I get a 8 Mhz channel with 8 Msps samplerate with the out-of-band skirts folded back at the sides. Would be interesting to see if this last one works with a USRP1. I'll let you know how the experiments go. I resampled and scaled your ofdm_40.dump file so it now will use 8 Mhz bandwidth with a 8 Msps samplerate. The reception never can be perfect this way but it seems good enough for tests. My USB DVB-T receiver receives the transport stream without problems. Mplayer playes the stream without problem for two loops and then crashes with a broken frame. My standalone settopbox DVB-T receiver now also receives the stream. (8 MHz channel on UHF) It has big problems displaying it. Sound is only a chop of sound now and then and video stops, then runs for a second, then stops again. I think this is because the timestamps and framerate (playout speed) don't match the data throughput of the MPEG stream anymore. (It is getting the stream too fast) I put my resampled RF file at: http://www.olifantasia.com/projects/gnuradio/mdvh/OTA/DVB-T/ofdm_40_bw8Mhz_s amplerate_8Msps_cshort.raw format is complex signed short integers (I 16 bit, Q 16 bit) at 8 Msamples/sec. Greetings, Martin more details will follow as soon as I find some time... Thanks and success with your second group of tests. Martin best regards and greetings to all fellow GNURadioers vincenzo PS Rafael, just have a look back a this thread and you'll find all the info you need to do your test broadcast. Thanks for your interest
[Discuss-gnuradio] Re: Soft-DVB DVB-T transmitter
Hi Vincenzo, On Sun, 2008-11-02 at 01:28 +0100, Vincenzo Pellegrini wrote: Hi Martin, sorry for the delayed replies but now I've passed my first cluster of PhD tests (went well) Congratulations. and I've got to carry out some work + preparing the second group of tests. Success. Well, really glad to know that you managed to receive my signals. Yup dvb-t sticks can actually receive 7 MHz channels everywhere, I found that some of them need special australian 7MHz at UHF firmware to get this to work. Luckily my DVB-T usb stick doesn't need this trick. Well, actually any DVB-T chipset can but typically manufacturers impose strange limitations on set-top-boxes such as 7 MHz chanels accepted only in VHF I don't really know why. The signal I provided you with is suitable for both 7 and 8 MHz channels without any modification needed. The only thing you have to do is to set your sampling frequency a bit higher. this should be possible with USRP2. The receiver might still have a problem that it is getting in the MPEG streams at a higher rate then realtime. In fact: 8 complex Msps implement a 7 MHz channel while 9.142857143 complex Msps implement an 8 MHz channel. Just try to go as close as possible to such sampling frequency by using USRP2 and let me know what happens... it could turn out that we need a resampler block. So if I use a fractional rate resampler with interpolation factor 10/8=1.25 I get a 7 Mhz channel with 10 Msps samplerate. If I use a fractional rate resampler with interpolation factor 10/9.142857143=1.09375 I get a 8 Mhz channel with 10 Msps samplerate If I use a fractional rate resampler with DECIMATION factor 9.142857143/8=8/7=1.142857143 I get a 8 Mhz channel with 8 Msps samplerate with the out-of-band skirts folded back at the sides. Would be interesting to see if this last one works with a USRP1. I'll let you know how the experiments go. more details will follow as soon as I find some time... Thanks and success with your second group of tests. Martin best regards and greetings to all fellow GNURadioers vincenzo PS Rafael, just have a look back a this thread and you'll find all the info you need to do your test broadcast. Thanks for your interest 2008/10/31 Martin Dudok van Heel [EMAIL PROTECTED] Hi Vincenzo. How are things going with your exams. I hope well. Thanks for your help so far. I finally got your DVB-T dump streams working. I first tried using an undersampled basicTX but never got it to work. (use a niquist mirror in the VHF range on channel 11 or 12 (219.5 Mhz or 226.5 Mhz)) I now use a RFX900 and that works with a pinnacle PCTV-Solo 72e usb DVB-T receiver card plugged into my PC. I use 858.0 Mhz (channel 69) I used a 10 dB attenuator on the antenna output to limit output power. I also modified the RFX900 to enable transmitting outside of the ISM band. (disable saw-filter. add 220 pF capacitor) Apparantly the pinnacle 72e can receive 7 Mhz channels on the UHF channels. My standalone settopbox DVB-T receiver can't handle it. I noticed you don't use the full possible range in your 16 bit streams. (only goes from -80 to +80 while you could use -8192 to 8192) Is this on purpose? I can multiply samples by 64 and get a cleaner signal. (But also more output power) I do have a request, I hope it is not too much work. Could you make a stream with 10 Msamples/sec samplerate and 8 Mhz wide channel. This way I can use standard standalone DVB-T receivers and don't have the 7Mhz bandwith on UHF problem. For the 10 Msps stream I would have to use my USRP2 to output it. It has a 100 Mhz DAC (in stead of 64 Msps in the USRP1) It has a gbit ethernet connection for the samples, so I can go up to 25 Msps. It can only do fixed interpolation rates so I have to choose from the table below. (8 Msamples/sec is not supported on the USRP2) USRP2 dac_rateinterp ethernet_sample_rate 100 4 25 100 5 20 100 6 16.67 100 7 14.29 100 8 12.5 100 9 11.11 100 10 10 I think 10 Msamples/sec should be optimal 100 11 9.09 100 12 8.33 100 13 7.69 100 14 7.14 I think 10 Msamples/sec would be a good candidate. Have you also tried using 8
[Discuss-gnuradio] Re: Soft-DVB DVB-T transmitter
Hi, In fact: 8 complex Msps implement a 7 MHz channel while 9.142857143 complex Msps implement an 8 MHz channel. Just try to go as close as possible to such sampling frequency by using USRP2 and let me know what happens... it could turn out that we need a resampler block. So if I use a fractional rate resampler with interpolation factor 10/8=1.25 I get a 7 Mhz channel with 10 Msps samplerate. If I use a fractional rate resampler with interpolation factor 10/9.142857143=1.09375 I get a 8 Mhz channel with 10 Msps samplerate If I use a fractional rate resampler with DECIMATION factor 9.142857143/8=8/7=1.142857143 I get a 8 Mhz channel with 8 Msps samplerate with the out-of-band skirts folded back at the sides. Would be interesting to see if this last one works with a USRP1. I'll let you know how the experiments go. I resampled and scaled your ofdm_40.dump file so it now will use 8 Mhz bandwidth with a 8 Msps samplerate. The reception never can be perfect this way but it seems good enough for tests. My USB DVB-T receiver receives the transport stream without problems. Mplayer playes the stream without problem for two loops and then crashes with a broken frame. My standalone settopbox DVB-T receiver now also receives the stream. (8 MHz channel on UHF) It has big problems displaying it. Sound is only a chop of sound now and then and video stops, then runs for a second, then stops again. I think this is because the timestamps and framerate (playout speed) don't match the data throughput of the MPEG stream anymore. (It is getting the stream too fast) I put my resampled RF file at: http://www.olifantasia.com/projects/gnuradio/mdvh/OTA/DVB-T/ofdm_40_bw8Mhz_samplerate_8Msps_cshort.raw format is complex signed short integers (I 16 bit, Q 16 bit) at 8 Msamples/sec. Greetings, Martin more details will follow as soon as I find some time... Thanks and success with your second group of tests. Martin best regards and greetings to all fellow GNURadioers vincenzo PS Rafael, just have a look back a this thread and you'll find all the info you need to do your test broadcast. Thanks for your interest 2008/10/31 Martin Dudok van Heel [EMAIL PROTECTED] Hi Vincenzo. How are things going with your exams. I hope well. Thanks for your help so far. I finally got your DVB-T dump streams working. I first tried using an undersampled basicTX but never got it to work. (use a niquist mirror in the VHF range on channel 11 or 12 (219.5 Mhz or 226.5 Mhz)) I now use a RFX900 and that works with a pinnacle PCTV-Solo 72e usb DVB-T receiver card plugged into my PC. I use 858.0 Mhz (channel 69) I used a 10 dB attenuator on the antenna output to limit output power. I also modified the RFX900 to enable transmitting outside of the ISM band. (disable saw-filter. add 220 pF capacitor) Apparantly the pinnacle 72e can receive 7 Mhz channels on the UHF channels. My standalone settopbox DVB-T receiver can't handle it. I noticed you don't use the full possible range in your 16 bit streams. (only goes from -80 to +80 while you could use -8192 to 8192) Is this on purpose? I can multiply samples by 64 and get a cleaner signal. (But also more output power) I do have a request, I hope it is not too much work. Could you make a stream with 10 Msamples/sec samplerate and 8 Mhz wide channel. This way I can use standard standalone DVB-T receivers and don't have the 7Mhz bandwith on UHF problem. For the 10 Msps stream I would have to use my USRP2 to output it. It has a 100 Mhz DAC (in stead of 64 Msps in the USRP1) It has a gbit ethernet connection for the samples, so I can go up to 25 Msps. It can only do fixed interpolation rates so I have to choose from the table below. (8 Msamples/sec is not supported on the USRP2) USRP2 dac_rateinterp ethernet_sample_rate 100 4 25 100 5 20 100 6 16.67 100 7 14.29 100 8 12.5 100 9 11.11 100 10 10 I think 10 Msamples/sec should be optimal 100 11 9.09 100 12 8.33 100 13 7.69 100 14 7.14 I think 10 Msamples/sec would be a good candidate. Have you also tried using 8
[Discuss-gnuradio] Re: Soft-DVB DVB-T transmitter
This is Great... :) Yup, the playback cannot be smooth because of the wrong throughput, definitely. Did you use the USRP1 with interpolation factor = 16 ? I can prepare a modulated signal with the correct throughput for you.. this is not a problem... :) what hard disc are you playing your signal back from? regards vincenzo 2008/11/3 Martin DvH [EMAIL PROTECTED] Hi, In fact: 8 complex Msps implement a 7 MHz channel while 9.142857143 complex Msps implement an 8 MHz channel. Just try to go as close as possible to such sampling frequency by using USRP2 and let me know what happens... it could turn out that we need a resampler block. So if I use a fractional rate resampler with interpolation factor 10/8=1.25 I get a 7 Mhz channel with 10 Msps samplerate. If I use a fractional rate resampler with interpolation factor 10/9.142857143=1.09375 I get a 8 Mhz channel with 10 Msps samplerate If I use a fractional rate resampler with DECIMATION factor 9.142857143/8=8/7=1.142857143 I get a 8 Mhz channel with 8 Msps samplerate with the out-of-band skirts folded back at the sides. Would be interesting to see if this last one works with a USRP1. I'll let you know how the experiments go. I resampled and scaled your ofdm_40.dump file so it now will use 8 Mhz bandwidth with a 8 Msps samplerate. The reception never can be perfect this way but it seems good enough for tests. My USB DVB-T receiver receives the transport stream without problems. Mplayer playes the stream without problem for two loops and then crashes with a broken frame. My standalone settopbox DVB-T receiver now also receives the stream. (8 MHz channel on UHF) It has big problems displaying it. Sound is only a chop of sound now and then and video stops, then runs for a second, then stops again. I think this is because the timestamps and framerate (playout speed) don't match the data throughput of the MPEG stream anymore. (It is getting the stream too fast) I put my resampled RF file at: http://www.olifantasia.com/projects/gnuradio/mdvh/OTA/DVB-T/ofdm_40_bw8Mhz_samplerate_8Msps_cshort.raw format is complex signed short integers (I 16 bit, Q 16 bit) at 8 Msamples/sec. Greetings, Martin more details will follow as soon as I find some time... Thanks and success with your second group of tests. Martin best regards and greetings to all fellow GNURadioers vincenzo PS Rafael, just have a look back a this thread and you'll find all the info you need to do your test broadcast. Thanks for your interest 2008/10/31 Martin Dudok van Heel [EMAIL PROTECTED] Hi Vincenzo. How are things going with your exams. I hope well. Thanks for your help so far. I finally got your DVB-T dump streams working. I first tried using an undersampled basicTX but never got it to work. (use a niquist mirror in the VHF range on channel 11 or 12 (219.5 Mhz or 226.5 Mhz)) I now use a RFX900 and that works with a pinnacle PCTV-Solo 72e usb DVB-T receiver card plugged into my PC. I use 858.0 Mhz (channel 69) I used a 10 dB attenuator on the antenna output to limit output power. I also modified the RFX900 to enable transmitting outside of the ISM band. (disable saw-filter. add 220 pF capacitor) Apparantly the pinnacle 72e can receive 7 Mhz channels on the UHF channels. My standalone settopbox DVB-T receiver can't handle it. I noticed you don't use the full possible range in your 16 bit streams. (only goes from -80 to +80 while you could use -8192 to 8192) Is this on purpose? I can multiply samples by 64 and get a cleaner signal. (But also more output power) I do have a request, I hope it is not too much work. Could you make a stream with 10 Msamples/sec samplerate and 8 Mhz wide channel. This way I can use standard standalone DVB-T receivers and don't have the 7Mhz bandwith on UHF problem. For the 10 Msps stream I would have to use my USRP2 to output it. It has a 100 Mhz DAC (in stead of 64 Msps in the USRP1) It has a gbit ethernet connection for the samples, so I can go up to 25 Msps. It can only do fixed interpolation rates so I have to choose from the table below. (8 Msamples/sec is not supported on the USRP2) USRP2 dac_rateinterp ethernet_sample_rate 100 4 25 100 5 20 100 6 16.67 100 7 14.29 100 8 12.5 100 9 11.11 100
[Discuss-gnuradio] Re: Soft-DVB DVB-T transmitter
Hi Martin, thanks for the FTP. I already have a location online at my father's lawyer's office. So, there you can find all old posted videos (which won't get removed for the foreseeable future) and some new, more descriptive ones: PREFIX= www.legalepellegrini.it/ing/ and then: Soft-DVB-Karlsruhe.mp4//the video of the conference we met at ofdm_RAI_MUXA2.dump//a training DVB-T OFDM signal for receivers that want broadcast-level channel tables. allows you to teach the receiver on what pids to look for channels when you send the real signal ofdm_40.dump //a signal with some content within (if your receiver is smart enough this is the only thing you have to send) @Grandmas.mp4 //an on the air broadcast with RFX900 at a 30odd meters distance with 5 concrete and brick walls within signals are interleaved short samples (I/Q) with sampling frequency 8Msps the receiver must therefore be able to receive a 7 MHz channel the vast majority of DVBT receivers accept 7 MHz channels in VHF but only a few accept such channels in the UHF spectrum. I'm actually curious about the receivers that will be used within the demo you described.. I had to search intensively to find receivers capable of such an oddity and it turned out that all receivers built for Australian market, actually are. Any way as soon as Matt will provide the project with the promised sub-1GHz transceiver it will be possible to broadcast DVB-T signals towards almost any existing receiver. If you wold like signals carrying some other content I can help. But let's first test these signals. Currently I can prepare a signal with 2 or 3 standard resolution channels or up to 10 hand-held resolution channnels PS I decided to make this communication public because it contains a few resources that could even be useful for somebody within the project. ___ Discuss-gnuradio mailing list Discuss-gnuradio@gnu.org http://lists.gnu.org/mailman/listinfo/discuss-gnuradio
