# GNU Radio **URL:** https://www.ruby-forum.com/c/gnu-radio/15.md?page=87 [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:** 88 --- ## [Fwd: New Defects reported by Coverity Scan for GNURadio](https://www.ruby-forum.com/t/fwd-new-defects-reported-by-coverity-scan-for-gnuradio/239536)
**Author:** [@Detlef\_R](https://www.ruby-forum.com/u/Detlef_R)\ **Replies:** 2\ **Last updated:** [March 4, 2014, 1:20pm UTC](https://www.ruby-forum.com/t/fwd-new-defects-reported-by-coverity-scan-for-gnuradio/239536 "2014-03-04T13:20:44Z")
The latest Coverity scan showed these new items. We should probably double check them. The Null dereference is likely related to the order in which some class methods get called. The compare against zero of an unsigne… --- ## [Blocks with message input and output only](https://www.ruby-forum.com/t/blocks-with-message-input-and-output-only/239539)
**Author:** [@musicdenotation](https://www.ruby-forum.com/u/musicdenotation)\ **Replies:** 1\ **Last updated:** [March 4, 2014, 1:24am UTC](https://www.ruby-forum.com/t/blocks-with-message-input-and-output-only/239539 "2014-03-04T01:24:18Z")
Hi Guys, How to write blocks that have only message input and outputs only? I have derived from gr:block, and in most cases it seems to work, but if I put together a test that has no streams, then the whole graph stop… --- ## [Re: Unable to stop the flow graph after calling stop()](https://www.ruby-forum.com/t/re-unable-to-stop-the-flow-graph-after-calling-stop/239518)
**Author:** [@musicdenotation](https://www.ruby-forum.com/u/musicdenotation)\ **Replies:** 6\ **Last updated:** [March 3, 2014, 2:12pm UTC](https://www.ruby-forum.com/t/re-unable-to-stop-the-flow-graph-after-calling-stop/239518 "2014-03-03T14:12:48Z")
Dear Sir, Thank you very much. What if, we want to stop the flow graph in the constructor of a block? In work() we can just return -1. But in constructor, what value should be returned, also -1 ? Regards, Activeca… --- ## [Modifying gr-air-modes to work with Nutaq's Zepto/Pico](https://www.ruby-forum.com/t/modifying-gr-air-modes-to-work-with-nutaqs-zepto-pico/239484)
**Author:** [@musicdenotation](https://www.ruby-forum.com/u/musicdenotation)\ **Replies:** 1\ **Last updated:** [March 3, 2014, 1:31pm UTC](https://www.ruby-forum.com/t/modifying-gr-air-modes-to-work-with-nutaqs-zepto-pico/239484 "2014-03-03T13:31:33Z")
Hello, I’m currently working on a project where I need to install gr-air-modes on a Zepto then a Pico from Nutaq. The problem is that gr-air-modes is working with UHD/Osmocom. I wondered if somebody had any ideas abo… --- ## [GSoC2014 Turbo Equalizer](https://www.ruby-forum.com/t/gsoc2014-turbo-equalizer/239412)
**Author:** [@Detlef\_R](https://www.ruby-forum.com/u/Detlef_R)\ **Replies:** 3\ **Last updated:** [March 3, 2014, 8:44am UTC](https://www.ruby-forum.com/t/gsoc2014-turbo-equalizer/239412 "2014-03-03T08:44:57Z")
Hi everyone, I am a student at Communications Engineering Lab (CEL) at Karlsruhe Institute of Technology. I major in “communication systems” and I am currently doing my masterthesis on “Parallel log-map decoders for … --- ## [Not getting constellation output](https://www.ruby-forum.com/t/not-getting-constellation-output/239517)
**Author:** [@musicdenotation](https://www.ruby-forum.com/u/musicdenotation)\ **Replies:** 0\ **Last updated:** [March 3, 2014, 6:51am UTC](https://www.ruby-forum.com/t/not-getting-constellation-output/239517 "2014-03-03T06:51:50Z")
1).I am not finding QT GUI Constellation block/ QT GUI Frequency sink blocks s in my GNU Radio 3.6.5. How to integrate those blocks in to my GNU Radio?. 2).When I tried to execute the enclosed GRC file, I am not findi… --- ## [Build error](https://www.ruby-forum.com/t/build-error/239515)
**Author:** [@Detlef\_R](https://www.ruby-forum.com/u/Detlef_R)\ **Replies:** 2\ **Last updated:** [March 3, 2014, 3:36am UTC](https://www.ruby-forum.com/t/build-error/239515 "2014-03-03T03:36:41Z")
hi, when i install a new block ,try “make”,i got these errors: CMakeFiles/test-scramble.dir/test\_scramble.cc.o: In function boost::filesystem::operator/(boost::filesystem::path const&, boost::filesystem::path const&)'… --- ## [Clarification regarding Sample width in USRP](https://www.ruby-forum.com/t/clarification-regarding-sample-width-in-usrp/239507)
**Author:** [@Detlef\_R](https://www.ruby-forum.com/u/Detlef_R)\ **Replies:** 3\ **Last updated:** [March 2, 2014, 6:05am UTC](https://www.ruby-forum.com/t/clarification-regarding-sample-width-in-usrp/239507 "2014-03-02T06:05:58Z")
Hello Everyone, From little bit of googling I understood that there are different sample width possible in USRP. If my understanding is correct, we can use 16/8 bit sample width. But my usrp block in GNU Radio lists… --- ## [Re: RuntimeError: audio\_oss\_sink](https://www.ruby-forum.com/t/re-runtimeerror-audio-oss-sink/239491)
**Author:** [@musicdenotation](https://www.ruby-forum.com/u/musicdenotation)\ **Replies:** 1\ **Last updated:** [March 1, 2014, 3:46pm UTC](https://www.ruby-forum.com/t/re-runtimeerror-audio-oss-sink/239491 "2014-03-01T15:46:25Z")
missing dependency for audio support for Ubuntu Hi Tom op25 is more or less out of business without GR audio support - is there a way to add something in the gr-op25 pybombs recipe to specify that audio should be… --- ## [Dvb-t2 + gnuradio](https://www.ruby-forum.com/t/dvb-t2-gnuradio/239493)
**Author:** [@Detlef\_R](https://www.ruby-forum.com/u/Detlef_R)\ **Replies:** 1\ **Last updated:** [March 1, 2014, 12:55pm UTC](https://www.ruby-forum.com/t/dvb-t2-gnuradio/239493 "2014-03-01T12:55:13Z")
Hi all, Do you know any project related to DVB-T2 (TV) standard? --- ## [How to measure a throughput in the given scenario?](https://www.ruby-forum.com/t/how-to-measure-a-throughput-in-the-given-scenario/239495)
**Author:** [@musicdenotation](https://www.ruby-forum.com/u/musicdenotation)\ **Replies:** 0\ **Last updated:** [March 1, 2014, 11:55am UTC](https://www.ruby-forum.com/t/how-to-measure-a-throughput-in-the-given-scenario/239495 "2014-03-01T11:55:46Z")
Hi Everyone, I am going to start with the general network settings: Number of Computer : 01 Number of USRPs: 03 (i.e. Source node, Relay node, and Destination node) USRPs and the computer are connected through an un… --- ## [Calculate frequency offset from phase offset](https://www.ruby-forum.com/t/calculate-frequency-offset-from-phase-offset/239492)
**Author:** [@musicdenotation](https://www.ruby-forum.com/u/musicdenotation)\ **Replies:** 0\ **Last updated:** [March 1, 2014, 4:49am UTC](https://www.ruby-forum.com/t/calculate-frequency-offset-from-phase-offset/239492 "2014-03-01T04:49:14Z")
Hi guys, I’m reading the code of Airprobe and I found this function. double gsm\_receiver\_cf::compute\_freq\_offset(const gr\_complex \* input, unsigned first\_sample, unsigned last\_sample) { double phase\_sum = 0; unsign… --- ## [Piped Video Streaming Crash](https://www.ruby-forum.com/t/piped-video-streaming-crash/239486)
**Author:** [@Detlef\_R](https://www.ruby-forum.com/u/Detlef_R)\ **Replies:** 0\ **Last updated:** [February 28, 2014, 6:26pm UTC](https://www.ruby-forum.com/t/piped-video-streaming-crash/239486 "2014-02-28T18:26:31Z")
Hi Marcus Hopefully your seeing this, for some reason that other threadhttp://lists.gnu.org/archive/html/discuss-gnuradio/2014-02/msg00351.htmlis no long in my mail inbox or trash… My problem was: VLC - Named Pipe 1… --- ## [Converting from #ifndef/#define include guards to #pragma once globally](https://www.ruby-forum.com/t/converting-from-ifndef-define-include-guards-to-pragma-once-globally/239355)
**Author:** [@musicdenotation](https://www.ruby-forum.com/u/musicdenotation)\ **Replies:** 10\ **Last updated:** [February 28, 2014, 11:00am UTC](https://www.ruby-forum.com/t/converting-from-ifndef-define-include-guards-to-pragma-once-globally/239355 "2014-02-28T11:00:57Z")
\-----BEGIN PGP SIGNED MESSAGE----- Hash: SHA1 Hello community, after finding a minor mistake in a header include file this week, I’ve wanted to make sure that the GR header files have proper, non-conflicting include… --- ## [Message port names](https://www.ruby-forum.com/t/message-port-names/239394)
**Author:** [@Detlef\_R](https://www.ruby-forum.com/u/Detlef_R)\ **Replies:** 5\ **Last updated:** [February 28, 2014, 9:20am UTC](https://www.ruby-forum.com/t/message-port-names/239394 "2014-02-28T09:20:55Z")
Quick question: can a message port name be any valid PMT type? Or does it have to be a string converted to a symbol? Thanks, Sean --- ## [Block is requesting more input data than it can provide](https://www.ruby-forum.com/t/block-is-requesting-more-input-data-than-it-can-provide/239469)
**Author:** [@Detlef\_R](https://www.ruby-forum.com/u/Detlef_R)\ **Replies:** 1\ **Last updated:** [February 28, 2014, 9:17am UTC](https://www.ruby-forum.com/t/block-is-requesting-more-input-data-than-it-can-provide/239469 "2014-02-28T09:17:58Z")
Hi - I’m having some trouble configuring a flowgraph. In my flowgraph, there are two paths for data. In one path, the data goes through a gnuradio block that is lightweight enough to process the data in real-time. … --- ## [Gnu radio installation fail](https://www.ruby-forum.com/t/gnu-radio-installation-fail/239472)
**Author:** [@Detlef\_R](https://www.ruby-forum.com/u/Detlef_R)\ **Replies:** 0\ **Last updated:** [February 28, 2014, 4:59am UTC](https://www.ruby-forum.com/t/gnu-radio-installation-fail/239472 "2014-02-28T04:59:06Z")
Dear GNU Radio Users, I have been facing the gnu radio installation problem for quite some time , The following errors are shown in the terminal when i try to install it using the commands: 1)git clone gnuradio.git -… --- ## [RuntimeError: audio\_oss\_sink](https://www.ruby-forum.com/t/runtimeerror-audio-oss-sink/239456)
**Author:** [@Detlef\_R](https://www.ruby-forum.com/u/Detlef_R)\ **Replies:** 1\ **Last updated:** [February 27, 2014, 9:03pm UTC](https://www.ruby-forum.com/t/runtimeerror-audio-oss-sink/239456 "2014-02-27T21:03:41Z")
Hi Alex, I ran into the same problem with pybombs on Ubuntu. It seems there is a missing dependency for audio support for Ubuntu based distros. The missing package is libasound2-dev. I never figured out how to rebuild … --- ## [CDMA with 40MHz BandWidth](https://www.ruby-forum.com/t/cdma-with-40mhz-bandwidth/239465)
**Author:** [@musicdenotation](https://www.ruby-forum.com/u/musicdenotation)\ **Replies:** 0\ **Last updated:** [February 27, 2014, 7:10pm UTC](https://www.ruby-forum.com/t/cdma-with-40mhz-bandwidth/239465 "2014-02-27T19:10:25Z")
Does anyone know if GNU Radio and any other vendor has any applications that support a spread spectrum system (CDMA) with a 40 MHz bandwidth which is to be used to pass, in real-time, bi-directional video? It could be… --- ## [Async message flow control](https://www.ruby-forum.com/t/async-message-flow-control/239450)
**Author:** [@musicdenotation](https://www.ruby-forum.com/u/musicdenotation)\ **Replies:** 1\ **Last updated:** [February 27, 2014, 3:38pm UTC](https://www.ruby-forum.com/t/async-message-flow-control/239450 "2014-02-27T15:38:07Z")
How does one achieve flow control with the new style message passing API? I have a use case in which I’m generating packets in one flowgraph and pushing them through a pdu\_to\_tagged\_stream (P2TS) block to be modulated… --- ## [OOT Decimation Module dropping data samples](https://www.ruby-forum.com/t/oot-decimation-module-dropping-data-samples/239430)
**Author:** [@Detlef\_R](https://www.ruby-forum.com/u/Detlef_R)\ **Replies:** 4\ **Last updated:** [February 27, 2014, 2:11pm UTC](https://www.ruby-forum.com/t/oot-decimation-module-dropping-data-samples/239430 "2014-02-27T14:11:17Z")
I am seeing some odd behavior with an OOT decimation block. What I am seeing is chunks of data are being dropped down to noise for random calls of the work function in my OOT. To observe this happening, I tee’d off … --- ## [Mode S // DME // Classical SSR](https://www.ruby-forum.com/t/mode-s-dme-classical-ssr/186302)
**Author:** [@arjackson](https://www.ruby-forum.com/u/arjackson)\ **Replies:** 1\ **Last updated:** [February 27, 2014, 6:37am UTC](https://www.ruby-forum.com/t/mode-s-dme-classical-ssr/186302 "2014-02-27T06:37:00Z")
I found a copy of Eric C.'s gr-air src It is quite similiar to what I am doing. Using a 1090 MHz receiver, Digital Storage Scope and LINUX perl. Things I am doing DME detection SSR detection and decode - to either M… --- ## [RuntimeError: audio\_oss\_sink](https://www.ruby-forum.com/t/runtimeerror-audio-oss-sink/239452)
**Author:** [@musicdenotation](https://www.ruby-forum.com/u/musicdenotation)\ **Replies:** 1\ **Last updated:** [February 26, 2014, 10:55pm UTC](https://www.ruby-forum.com/t/runtimeerror-audio-oss-sink/239452 "2014-02-26T22:55:30Z")
I just installed gnuradio using pybombs, and the install appeared to complete with no errors. When trying to run dial\_tone.py, I receive the following error: audio\_oss\_sink: /dev/dsp: No such file or directory Traceb… --- ## [Message API questions](https://www.ruby-forum.com/t/message-api-questions/239444)
**Author:** [@musicdenotation](https://www.ruby-forum.com/u/musicdenotation)\ **Replies:** 3\ **Last updated:** [February 26, 2014, 3:50pm UTC](https://www.ruby-forum.com/t/message-api-questions/239444 "2014-02-26T15:50:33Z")
I have a few questions regarding messages in GR. Is it possible to mix-and-match the old style message sink/source blocks with the new style message passing API? Any guidance on how to make the connections? I di… --- ## [Loopback flowgraph](https://www.ruby-forum.com/t/loopback-flowgraph/239443)
**Author:** [@musicdenotation](https://www.ruby-forum.com/u/musicdenotation)\ **Replies:** 2\ **Last updated:** [February 26, 2014, 2:49pm UTC](https://www.ruby-forum.com/t/loopback-flowgraph/239443 "2014-02-26T14:49:55Z")
Hello all GnuRadio users, I wanted to have a flowgraph without an USRP source and USRP sink, only by using the software blocks. The objective is to transmit and receive the BPSK modulated packets. I attached a thread… --- ## [Link FFTW3 in OOT module](https://www.ruby-forum.com/t/link-fftw3-in-oot-module/239442)
**Author:** [@Detlef\_R](https://www.ruby-forum.com/u/Detlef_R)\ **Replies:** 1\ **Last updated:** [February 26, 2014, 2:45pm UTC](https://www.ruby-forum.com/t/link-fftw3-in-oot-module/239442 "2014-02-26T14:45:47Z")
Dear all I try to link the FFTW3 lib to my OOT module but always get the error: Linking CXX executable test-mymodule libgnuradio-mymodule.so: undefined reference to fftw\_plan\_dft\_1d' libgnuradio-mymodule.so: undefined… --- ## [Bypassing CIC and half-band filter on N2x0](https://www.ruby-forum.com/t/bypassing-cic-and-half-band-filter-on-n2x0/239427)
**Author:** [@Detlef\_R](https://www.ruby-forum.com/u/Detlef_R)\ **Replies:** 2\ **Last updated:** [February 26, 2014, 2:03pm UTC](https://www.ruby-forum.com/t/bypassing-cic-and-half-band-filter-on-n2x0/239427 "2014-02-26T14:03:24Z")
Is there any way to bypass the CIC and the HBF on the USRP N200 to just stream decimated (no integration) real samples off the 100 MHz ADC? I’d like to eg., record every 25th sample arriving on the ADC. I’d like to av… --- ## [GSoC2014 Turbo Equalizer](https://www.ruby-forum.com/t/gsoc2014-turbo-equalizer/239419)
**Author:** [@musicdenotation](https://www.ruby-forum.com/u/musicdenotation)\ **Replies:** 5\ **Last updated:** [February 26, 2014, 9:39am UTC](https://www.ruby-forum.com/t/gsoc2014-turbo-equalizer/239419 "2014-02-26T09:39:39Z")
Just FYI, the gr-trellis has implementations of all these components you suggested. One interesting project is to take the core algorithms of gr-trellis (Viterbi and SISO) and make them threaded for multi-core (eg, b… --- ## [QT waterfall sink manual intensity](https://www.ruby-forum.com/t/qt-waterfall-sink-manual-intensity/239401)
**Author:** [@musicdenotation](https://www.ruby-forum.com/u/musicdenotation)\ **Replies:** 2\ **Last updated:** [February 26, 2014, 4:38am UTC](https://www.ruby-forum.com/t/qt-waterfall-sink-manual-intensity/239401 "2014-02-26T04:38:24Z")
Is there way to manually scale the intensity of the QT waterfall sink, in other words, set the dynamic range and reference level like the WX sink? Adjusting the time axis with the scroll wheel alters the intensity axi… --- ## [QPSK over air](https://www.ruby-forum.com/t/qpsk-over-air/239425)
**Author:** [@musicdenotation](https://www.ruby-forum.com/u/musicdenotation)\ **Replies:** 6\ **Last updated:** [February 26, 2014, 1:24am UTC](https://www.ruby-forum.com/t/qpsk-over-air/239425 "2014-02-26T01:24:45Z")
I’m looking for an example of a higher-order modulation implemented successfully in GNU Radio with an SDR frontend. I’ve seen bpsk, GMSK, etc. implemented over a wireless channel, but I’ve only seen simulations of hig… [Previous page](https://www.ruby-forum.com/c/gnu-radio/15.md?page=86) [Next page](https://www.ruby-forum.com/c/gnu-radio/15.md?page=88)