[Discuss-gnuradio] TVRX question
Hi all For some reason I always thought that the TVRX daughterboards support IQ sampling. Turns out I was wrong. How do I modify my applications for I sampling? Can I just wire up a whole IQ chain, save files in IQ format, use read_complex_binary.m to read it in and discard the Q part? How do I setup the USRP to only have an I path on the inside? Do I just use usrp_source_s and then read saved files using read_float_binary.m? Thanks in advance. Sebastiaan -- Sebastiaan Heunis Radar Remote Sensing Group, University of Cape Town, South Africa Tel: +27 83 305 5667 ___ Discuss-gnuradio mailing list Discuss-gnuradio@gnu.org http://lists.gnu.org/mailman/listinfo/discuss-gnuradio
[Discuss-gnuradio] USRP1 + FLEX900 - receive transmitted message
Dear all,I am using bbn 802.11 simple mac code, and I encountered a problem. The packets which to be sent are read by the code of os.read(tun_fd,10*1024). Just in the second round of transmission, usrp will receive the packet which is sent in the last round of transmission. For testing, I removed the antenna and it was still the same. Could anyone here give any idea?? Thank you all, sincerely. ___ Discuss-gnuradio mailing list Discuss-gnuradio@gnu.org http://lists.gnu.org/mailman/listinfo/discuss-gnuradio
Re: [Discuss-gnuradio] TVRX question
On Sun, 2009-06-21 at 15:15 +0200, Sebastiaan Heunis wrote: Hi all For some reason I always thought that the TVRX daughterboards support IQ sampling. Turns out I was wrong. You are only partly wrong. The TVRX is only sampled in I. But the usrp firmware transforms this into IQ samples at the stage which converts the signal from the IF to baseband. The samples you get in the PC are IQ samples. You don't have to modify your processing chain in your application. You only have to take care of the I sampling at the place where you set the ADC mux (only sample the I part of the IF using only one ADC). Greetings, Martin How do I modify my applications for I sampling? Can I just wire up a whole IQ chain, save files in IQ format, use read_complex_binary.m to read it in and discard the Q part? How do I setup the USRP to only have an I path on the inside? Do I just use usrp_source_s and then read saved files using read_float_binary.m? Thanks in advance. Sebastiaan ___ Discuss-gnuradio mailing list Discuss-gnuradio@gnu.org http://lists.gnu.org/mailman/listinfo/discuss-gnuradio
Re: [Discuss-gnuradio] GnuRadio and CUDA
On Fri, 2009-06-19 at 03:28 -0400, Yu-Hua Yang wrote: Continuing from this thread http://lists.gnu.org/archive/html/discuss-gnuradio/2008-11/msg00293.html Has there been any progress made since 2008? No, not much. I am waiting for the OpenCL implementations from nvidia and ATI to become available to the general public. Then I plan on rewriting the code from CUDA to OpenCL. This way we only have to support one codebase for a multitude of hardware platforms. (nvidia GPU, ATI GPU, cell processor, multicore-CPU) The current codebase in my development brache is usable though. Anybody is welcome to work further on this. I myself are not planning on working on it untill openCL becomes available. I registered for early developer access to the nvidia OpenCL implementation but I never heard from then since. Greetings, Martin Dudok van Heel Thank you ___ Discuss-gnuradio mailing list Discuss-gnuradio@gnu.org http://lists.gnu.org/mailman/listinfo/discuss-gnuradio ___ Discuss-gnuradio mailing list Discuss-gnuradio@gnu.org http://lists.gnu.org/mailman/listinfo/discuss-gnuradio
Re: [Discuss-gnuradio] TVRX question
Martin Thanks for the reply. How do I set the mux then? Is 0xf2f0f2f0 correct when I have 2 TV tuner modules and 0xf0f0f0f0 correct when I have only one? Just to recap, in case you can't remember what the mux, etc. looks like. ADC 0 and 1 are on the first IC and ADC 2 and 3 are on the second IC. The mux bits look as follows. Chan3 Chan2 Chan1 Chan0 Q I Q I Q I Q I So 0xf2f0f2f0 connects ADC0 to the I of Chan0, a zero to the Q of Chan0, ADC2 to the I of Chan1 and a zero to the Q of Chan1. Is this fine? Then I just use a deinterlever on the PC and connect Chan0 and Chan1 to separate file sinks? Thanks Sebastiaan ___ Discuss-gnuradio mailing list Discuss-gnuradio@gnu.org http://lists.gnu.org/mailman/listinfo/discuss-gnuradio
[Discuss-gnuradio] 802.11 and filter bank scaling
Hey All, With barker code problem mostly solved, I want to look more in depth at higher modulation (CCK) rates, 5.5 and 11 Mbps. I've read through the IEEE specs and for the most part understand the scheme. Since the sample rate is not high enough to send/receive enough samples per chip, the same estimation method used for the barker sequence is necessary. Basically, the chipped sequence is smoothed with a sinc and sampled to fit inside a code word window(25 samples). The downside of that is I don't think efficient methods(FWT) can be used to decode CCK due to this hack. To properly decode the CCK sequence there needs to be 64 correlation filters with 25 taps to detect the CCK code words. My worry is that the computation cost would be too high and a computer would not be able to process it. Does anyone have experience with high rate filter banks in gnuradio? How did the process scale with filter order and bank size? I know this question is a bit vague and narrow. --Colby ___ Discuss-gnuradio mailing list Discuss-gnuradio@gnu.org http://lists.gnu.org/mailman/listinfo/discuss-gnuradio
[Discuss-gnuradio] Re: xcvr2450, v3.2 and usrp1
The xcvr transmits at the incorrect frequency. I just looked at it with a wider span of the spectrum analyser. Asking it to transmit at 2.45GHz, it instead transmits signals at 2.58GHz. What could be causing this? -- Posted via http://www.ruby-forum.com/. ___ Discuss-gnuradio mailing list Discuss-gnuradio@gnu.org http://lists.gnu.org/mailman/listinfo/discuss-gnuradio
