# GNU Radio **URL:** https://www.ruby-forum.com/c/gnu-radio/15.md?page=77 [Latest](https://www.ruby-forum.com/latest.md) · [Categories](https://www.ruby-forum.com/categories.md) · [Tags](https://www.ruby-forum.com/tags.md) **Page:** 78 --- ## [OFDM benchmarking with UHD](https://www.ruby-forum.com/t/ofdm-benchmarking-with-uhd/240629)
**Author:** [@musicdenotation](https://www.ruby-forum.com/u/musicdenotation)\ **Replies:** 1\ **Last updated:** [April 23, 2014, 9:23pm UTC](https://www.ruby-forum.com/t/ofdm-benchmarking-with-uhd/240629 "2014-04-23T21:23:11Z")
Hi all, (Ubuntu 1304 gnuradio 3.7) I want to test OFDM in gr\_digital using tx\_ofdm.grc and rx\_ofdm.grc. (simultaneously using usrp n200 devices) Where are UHD source and sink in that flow g.? Since I do not want to … --- ## [How to start with stream tags](https://www.ruby-forum.com/t/how-to-start-with-stream-tags/240595)
**Author:** [@musicdenotation](https://www.ruby-forum.com/u/musicdenotation)\ **Replies:** 4\ **Last updated:** [April 23, 2014, 7:13pm UTC](https://www.ruby-forum.com/t/how-to-start-with-stream-tags/240595 "2014-04-23T19:13:59Z")
Dear List, I want to make time synchronization for implementation of two-way relaying network. Each node contain both RX chain and TX chain but they should not run simultaneously (half-duplex mode). Therefore, the T… --- ## [TX/RX caliberation utilities provided in UHD](https://www.ruby-forum.com/t/tx-rx-caliberation-utilities-provided-in-uhd/240587)
**Author:** [@Detlef\_R](https://www.ruby-forum.com/u/Detlef_R)\ **Replies:** 1\ **Last updated:** [April 23, 2014, 3:04pm UTC](https://www.ruby-forum.com/t/tx-rx-caliberation-utilities-provided-in-uhd/240587 "2014-04-23T15:04:20Z")
Hi I would be grateful if anyone could explain more about the TX/RX calibration utilities provided by UHD: uhd\_cal\_rx\_iq\_balance: uhd\_cal\_tx\_dc\_offset: uhd\_cal\_tx\_iq\_balance: a) I found them installed in one o… --- ## [How to reduce reconfiguration latency](https://www.ruby-forum.com/t/how-to-reduce-reconfiguration-latency/240610)
**Author:** [@musicdenotation](https://www.ruby-forum.com/u/musicdenotation)\ **Replies:** 1\ **Last updated:** [April 23, 2014, 2:51pm UTC](https://www.ruby-forum.com/t/how-to-reduce-reconfiguration-latency/240610 "2014-04-23T14:51:56Z")
I have a GNU radio based software that uses IQ modulation on the sending side and IQ demodulation on the receiving side. In my application, the transmitted signal could be scaled up to +/-5% in time domain. I don’t ha… --- ## ["Slicing" a complex signal](https://www.ruby-forum.com/t/slicing-a-complex-signal/240604)
**Author:** [@Detlef\_R](https://www.ruby-forum.com/u/Detlef_R)\ **Replies:** 1\ **Last updated:** [April 23, 2014, 12:59pm UTC](https://www.ruby-forum.com/t/slicing-a-complex-signal/240604 "2014-04-23T12:59:48Z")
I will try to explain this the best I can… but here is what I am looking to do: I have a digital signal that takes up 100kz of bandwidth. I want to “split” this signal and push both halves apart. The best way to exp… --- ## [GNU Radio Live SDR Environment 2014-0419 snapshot released](https://www.ruby-forum.com/t/gnu-radio-live-sdr-environment-2014-0419-snapshot-released/240556)
**Author:** [@musicdenotation](https://www.ruby-forum.com/u/musicdenotation)\ **Replies:** 3\ **Last updated:** [April 22, 2014, 8:23pm UTC](https://www.ruby-forum.com/t/gnu-radio-live-sdr-environment-2014-0419-snapshot-released/240556 "2014-04-22T20:23:47Z")
Discuss-gnuradio mailing list removed\_email\_address@domain.invalid https://lists.gnu.org/mailman/listinfo/discuss-gnuradio --- ## [Announcing NEWSDR at Boston University on Friday June 6](https://www.ruby-forum.com/t/announcing-newsdr-at-boston-university-on-friday-june-6/240585)
**Author:** [@musicdenotation](https://www.ruby-forum.com/u/musicdenotation)\ **Replies:** 0\ **Last updated:** [April 22, 2014, 4:17am UTC](https://www.ruby-forum.com/t/announcing-newsdr-at-boston-university-on-friday-june-6/240585 "2014-04-22T04:17:06Z")
Fourth-Annual \* \* New England Workshop on Software-Defined Radio \* NEWSDR 2014 \* … --- ## [Announcing NEWSDR at Boston University on Friday June 6](https://www.ruby-forum.com/t/announcing-newsdr-at-boston-university-on-friday-june-6/240586)
**Author:** [@Detlef\_R](https://www.ruby-forum.com/u/Detlef_R)\ **Replies:** 0\ **Last updated:** [April 22, 2014, 4:15am UTC](https://www.ruby-forum.com/t/announcing-newsdr-at-boston-university-on-friday-june-6/240586 "2014-04-22T04:15:55Z")
Fourth-Annual \*\* \*\* New England Workshop on Software-Defined Radio \*\* NEWSDR 2014 \*\* \*\* Friday, 6 June 2014, 8:30 AM - 5:30 PM … --- ## [Re: Build problems with pybombs](https://www.ruby-forum.com/t/re-build-problems-with-pybombs/240576)
**Author:** [@musicdenotation](https://www.ruby-forum.com/u/musicdenotation)\ **Replies:** 0\ **Last updated:** [April 21, 2014, 8:18pm UTC](https://www.ruby-forum.com/t/re-build-problems-with-pybombs/240576 "2014-04-21T20:18:27Z")
On Fri, Apr 18, 2014 at 5:07 PM, Mike W. address@hidden wrote: Yes indeed - I did an update. Is there any way to force it back to 1.54? Mike First, verify that you are actually using 1.55. To roll back, you shou… --- ## [Error trying to load FFT filter taps](https://www.ruby-forum.com/t/error-trying-to-load-fft-filter-taps/240542)
**Author:** [@musicdenotation](https://www.ruby-forum.com/u/musicdenotation)\ **Replies:** 4\ **Last updated:** [April 20, 2014, 6:39pm UTC](https://www.ruby-forum.com/t/error-trying-to-load-fft-filter-taps/240542 "2014-04-20T18:39:41Z")
Am getting the following error when trying to run a GRC flowgraph that loads FFT filter taps from an external file. The type filter parameter is set to complex-\>complex (complex taps). The flow graph has imported num… --- ## [Dvb-t project with two USRPN200 devices failure](https://www.ruby-forum.com/t/dvb-t-project-with-two-usrpn200-devices-failure/240161)
**Author:** [@musicdenotation](https://www.ruby-forum.com/u/musicdenotation)\ **Replies:** 10\ **Last updated:** [April 20, 2014, 5:41pm UTC](https://www.ruby-forum.com/t/dvb-t-project-with-two-usrpn200-devices-failure/240161 "2014-04-20T17:41:17Z")
Hi all, I am using ubuntu 13.04, GNURADIO 3.7. I cannot transmit or receive using two (USRPN200 + XCRV2450 d.board+VERT2450 antennas) devices for DVB-T project. Here is the dvb-t project: GitHub - BogdanDIA/gr-dvbt:… --- ## [Processing block with conditional number of output items](https://www.ruby-forum.com/t/processing-block-with-conditional-number-of-output-items/237574)
**Author:** [@musicdenotation](https://www.ruby-forum.com/u/musicdenotation)\ **Replies:** 1\ **Last updated:** [April 20, 2014, 1:42pm UTC](https://www.ruby-forum.com/t/processing-block-with-conditional-number-of-output-items/237574 "2014-04-20T13:42:35Z")
Hello all, I’m a grad student writing my first GNU Radio processing block, and I’m a little stuck. I’m not sure how to tell GNU Radio the input output relationship of my block. The block takes 2 inputs. One is an … --- ## [Forecast(), set\_history() or set\_output\_multiple()](https://www.ruby-forum.com/t/forecast-set-history-or-set-output-multiple/240545)
**Author:** [@Detlef\_R](https://www.ruby-forum.com/u/Detlef_R)\ **Replies:** 0\ **Last updated:** [April 19, 2014, 8:50pm UTC](https://www.ruby-forum.com/t/forecast-set-history-or-set-output-multiple/240545 "2014-04-19T20:50:38Z")
Hi everybody, I’m working on building a block which processes samples in chunks: if the energy of each chunk is greater than a given threshold, the chunk is reported in output. Moreover for each chunk reported in outp… --- ## [Error trying to load taps into FFT filter](https://www.ruby-forum.com/t/error-trying-to-load-taps-into-fft-filter/240541)
**Author:** [@Detlef\_R](https://www.ruby-forum.com/u/Detlef_R)\ **Replies:** 0\ **Last updated:** [April 19, 2014, 7:03pm UTC](https://www.ruby-forum.com/t/error-trying-to-load-taps-into-fft-filter/240541 "2014-04-19T19:03:14Z")
Am getting the following error when trying to run a GRC flowgraph that loads FFT filter taps from an external file. The type filter parameter is set to complex-\>complex (complex taps). The flow graph has imported nump… --- ## [Continue the Installation](https://www.ruby-forum.com/t/continue-the-installation/240536)
**Author:** [@Detlef\_R](https://www.ruby-forum.com/u/Detlef_R)\ **Replies:** 1\ **Last updated:** [April 19, 2014, 6:43pm UTC](https://www.ruby-forum.com/t/continue-the-installation/240536 "2014-04-19T18:43:10Z")
I am installing GNURADIO from this link http://blogs.bu.edu/mhirsch/2012/07/installing-gnu-radio-in-ubuntu-12-04-x64/comment-page-1/ http://blogs.bu.edu/mhirsch/2012/07/installing-gnu-radio-in-ubuntu-12-04-x64/comment-… --- ## [Error trying to load taps into FFT filter](https://www.ruby-forum.com/t/error-trying-to-load-taps-into-fft-filter/240540)
**Author:** [@musicdenotation](https://www.ruby-forum.com/u/musicdenotation)\ **Replies:** 0\ **Last updated:** [April 19, 2014, 6:37pm UTC](https://www.ruby-forum.com/t/error-trying-to-load-taps-into-fft-filter/240540 "2014-04-19T18:37:16Z")
Am getting the following error when trying to run a GRC flowgraph that loads FFT filter taps from an external file. The type filter parameter is set to complex-\>complex (complex taps). The flow graph has imported nump… --- ## [FIR filters and set\_history()](https://www.ruby-forum.com/t/fir-filters-and-set-history/128261)
**Author:** [@george\_n](https://www.ruby-forum.com/u/george_n)\ **Replies:** 9\ **Last updated:** [April 19, 2014, 2:32pm UTC](https://www.ruby-forum.com/t/fir-filters-and-set-history/128261 "2014-04-19T14:32:45Z")
Hi all, Sorry that this e-mail is long, but I’m trying to be as detailed as possible for those reading it to understand, otherwise it will take a couple e-mail exchanges. I’m attempting to build a filter using the fi… --- ## [Build problems with pybombs](https://www.ruby-forum.com/t/build-problems-with-pybombs/240534)
**Author:** [@musicdenotation](https://www.ruby-forum.com/u/musicdenotation)\ **Replies:** 7\ **Last updated:** [April 18, 2014, 11:08pm UTC](https://www.ruby-forum.com/t/build-problems-with-pybombs/240534 "2014-04-18T23:08:46Z")
Yet more difficulties. Having found a work around for the Usb issue with the B200, I was then unable to get any of the audio examples to run again due to /dev/dsp not being present and gnuradio insisting on using oss.… --- ## [Build issues](https://www.ruby-forum.com/t/build-issues/240533)
**Author:** [@Detlef\_R](https://www.ruby-forum.com/u/Detlef_R)\ **Replies:** 0\ **Last updated:** [April 18, 2014, 10:45pm UTC](https://www.ruby-forum.com/t/build-issues/240533 "2014-04-18T22:45:44Z")
Yet more difficulties. Having found a work around for the Usb issue with the B200, I was then unable to get any of the audio examples to run again due to /dev/dsp not being present and gnuradio insisting on using oss.… --- ## [How to implement TDM on USRP1 and GNU Radio](https://www.ruby-forum.com/t/how-to-implement-tdm-on-usrp1-and-gnu-radio/240525)
**Author:** [@Detlef\_R](https://www.ruby-forum.com/u/Detlef_R)\ **Replies:** 0\ **Last updated:** [April 18, 2014, 11:00am UTC](https://www.ruby-forum.com/t/how-to-implement-tdm-on-usrp1-and-gnu-radio/240525 "2014-04-18T11:00:51Z")
Hello everyone, I’m working on implementation of two-way relaying model using GNU Radio (with GNU Radio Companion as interface) and 3 USRP1s (each has one RFX2400 daughterboard and one VERT2450 antena). The relay nod… --- ## [Signal Power in OFDM](https://www.ruby-forum.com/t/signal-power-in-ofdm/240523)
**Author:** [@musicdenotation](https://www.ruby-forum.com/u/musicdenotation)\ **Replies:** 0\ **Last updated:** [April 18, 2014, 4:10am UTC](https://www.ruby-forum.com/t/signal-power-in-ofdm/240523 "2014-04-18T04:10:40Z")
Hello I have written a OFDM transmission reception chain in MATLAB. I would like to calculate the signal power and compare it with the MOS(Minimal operational Sensitivity). I am using the following equation: P = 10lo… --- ## [April Developer Call Video online](https://www.ruby-forum.com/t/april-developer-call-video-online/240518)
**Author:** [@Detlef\_R](https://www.ruby-forum.com/u/Detlef_R)\ **Replies:** 0\ **Last updated:** [April 17, 2014, 10:20pm UTC](https://www.ruby-forum.com/t/april-developer-call-video-online/240518 "2014-04-17T22:20:36Z")
Enjoy, Philip --- ## [How to Access Received Data for Use In Changing RX Parameters](https://www.ruby-forum.com/t/how-to-access-received-data-for-use-in-changing-rx-parameters/240506)
**Author:** [@Detlef\_R](https://www.ruby-forum.com/u/Detlef_R)\ **Replies:** 1\ **Last updated:** [April 17, 2014, 7:41pm UTC](https://www.ruby-forum.com/t/how-to-access-received-data-for-use-in-changing-rx-parameters/240506 "2014-04-17T19:41:57Z")
Hey List, I have two scripts I am running, the ofdm\_v1\_tx\_freq\_test.py and the RX version of it (see flow graph images and attached transmitter Python script). I am transmitting a sinusoid using OFDM modulation over t… --- ## [Re: help on exception on using the uhd.dll i think](https://www.ruby-forum.com/t/re-help-on-exception-on-using-the-uhd-dll-i-think/240514)
**Author:** [@musicdenotation](https://www.ruby-forum.com/u/musicdenotation)\ **Replies:** 1\ **Last updated:** [April 17, 2014, 6:31pm UTC](https://www.ruby-forum.com/t/re-help-on-exception-on-using-the-uhd-dll-i-think/240514 "2014-04-17T18:31:43Z")
Well, The exception happens on this line: uhd::device\_addrs\_t device\_addrs = uhd::device::find(vm\[“args”\].asstd::string()); the exception is: First-chance exception at 0x0f62763b in uhd\_find\_devices.exe: 0xC0000005… --- ## [Developer Call today at 1700 UTC](https://www.ruby-forum.com/t/developer-call-today-at-1700-utc/240513)
**Author:** [@Detlef\_R](https://www.ruby-forum.com/u/Detlef_R)\ **Replies:** 0\ **Last updated:** [April 17, 2014, 5:12pm UTC](https://www.ruby-forum.com/t/developer-call-today-at-1700-utc/240513 "2014-04-17T17:12:03Z")
I’ll be starting the hangout promptly at 1700 UTC. (That’s 1 PM EDT) I am 99.9% certain I will start the hangout by inviting one person, then posting a link in the #gnuradio irc channel. This worked an hour ago, so I … --- ## [Digital voice encryption block](https://www.ruby-forum.com/t/digital-voice-encryption-block/240504)
**Author:** [@Detlef\_R](https://www.ruby-forum.com/u/Detlef_R)\ **Replies:** 5\ **Last updated:** [April 17, 2014, 4:51pm UTC](https://www.ruby-forum.com/t/digital-voice-encryption-block/240504 "2014-04-17T16:51:59Z")
Hi all, I want to simulate a voice transmission system in GNURadio Companion (GRC) before I build a real one. My system configuration is as follows. TX: mic → encoder → encryption → modulator → RF Rx: speaker ← dec… --- ## [Help on exception on using the uhd.dll i think](https://www.ruby-forum.com/t/help-on-exception-on-using-the-uhd-dll-i-think/240507)
**Author:** [@musicdenotation](https://www.ruby-forum.com/u/musicdenotation)\ **Replies:** 1\ **Last updated:** [April 17, 2014, 4:22pm UTC](https://www.ruby-forum.com/t/help-on-exception-on-using-the-uhd-dll-i-think/240507 "2014-04-17T16:22:28Z")
Hey, In order to start my on application code using the uhd code, I tried creating a new blank project ,and did all The necessary includes, and library include in the linker an compiler and so on… As a starter I co… --- ## [Ctest -V segfault, coredump reveals nothing](https://www.ruby-forum.com/t/ctest-v-segfault-coredump-reveals-nothing/240496)
**Author:** [@musicdenotation](https://www.ruby-forum.com/u/musicdenotation)\ **Replies:** 4\ **Last updated:** [April 17, 2014, 3:51am UTC](https://www.ruby-forum.com/t/ctest-v-segfault-coredump-reveals-nothing/240496 "2014-04-17T03:51:25Z")
Hi All, I have a gnuradio block which I am testing through a C++ QA function. I call the handler function directly in C++ QA test function, and everything runs. My test function is structured as follows: I create… --- ## [Pad source&&Wifi physical layer input/output](https://www.ruby-forum.com/t/pad-source-wifi-physical-layer-input-output/240476)
**Author:** [@musicdenotation](https://www.ruby-forum.com/u/musicdenotation)\ **Replies:** 4\ **Last updated:** [April 17, 2014, 12:09am UTC](https://www.ruby-forum.com/t/pad-source-wifi-physical-layer-input-output/240476 "2014-04-17T00:09:34Z")
Hi,GR I run Bloessl’s “802.11 OFDM physical layer” GRC program. The input and output block are “Pad source” block. What is the funcion of “Pad source”,how to use “Pad source”? If I want to use “File source” block to … --- ## [Cheetah - Not Found error during GNU Radio installation on Fedora 20](https://www.ruby-forum.com/t/cheetah-not-found-error-during-gnu-radio-installation-on-fedora-20/240478)
**Author:** [@Detlef\_R](https://www.ruby-forum.com/u/Detlef_R)\ **Replies:** 1\ **Last updated:** [April 16, 2014, 5:57pm UTC](https://www.ruby-forum.com/t/cheetah-not-found-error-during-gnu-radio-installation-on-fedora-20/240478 "2014-04-16T17:57:17Z")
I am trying to install GNU Radio on Fedora 20. I get Cheetah not found error, even when the installed cheetah version is more than what is required (currently cheetah version is 2.4.4 on my PC). Initially I tried ins… [Previous page](https://www.ruby-forum.com/c/gnu-radio/15.md?page=76) [Next page](https://www.ruby-forum.com/c/gnu-radio/15.md?page=78)