Re: [Discuss-gnuradio] question about the synchronization symbol used in ofdm example

​Hello Kun, Could you please verify whether the input to the FFT call are supposed to be shifted or not? Best, Aditya​ On Sun, Nov 2, 2014 at 10:44 AM, xianda wrote: > Hello all: > Thank you in advance.I have two questions about the symbol > used in ofdm example. > 1.

Re: [Discuss-gnuradio] Simple Frame Detection

Hello Daniel, Are you using OFDM? If so, read on, otherwise disregard the rest of the email. Please look at the Schmidl-Cox synchronization method (Robust Frequency and Timing Synchronization for OFDM). In a nutshell, the frame detection works like this: At the transmitter, the packet is created

Re: [Discuss-gnuradio] 3/4 and 5/6 Convolutional Codes

20 19 18 16 17 44 45 47 46 41 40 42 43 34 35 33 32 39 38 36 37 On Mon, Jan 6, 2014 at 7:25 PM, Aditya Dhananjay wrote: > Dear All, > > Does anyone have .fsm files for 3/4 and 5/6 rate convolutional codes? > > (Or alternatively, the state transition matrix and output matr

Re: [Discuss-gnuradio] Fwd: Questions on rx_ofdm example in GR 3.7.1

> > >> >> I've opened http://gnuradio.org/redmine/issues/611 and will try and >> figure this out. > > Hello Martin, I am still facing a problem here. (I have pulled the newest sources from GIT). First, let me describe the environment. I have connected the transmitter side to a channel model that i

Re: [Discuss-gnuradio] Fwd: Questions on rx_ofdm example in GR 3.7.1

> > Hello Martin, > > I am still facing a problem here. (I have pulled the newest sources from > GIT). First, let me describe the environment. I have connected the > transmitter side to a channel model that introduces frequency and timing > offsets (so that I have control over how dirty the channel

Re: [Discuss-gnuradio] Fwd: Questions on rx_ofdm example in GR 3.7.1

, Jan 15, 2014 at 4:34 PM, Aditya Dhananjay wrote: > > >> Hello Martin, >> >> I am still facing a problem here. (I have pulled the newest sources from >> GIT). First, let me describe the environment. I have connected the >> transmitter side to a channel model

Re: [Discuss-gnuradio] Fwd: Questions on rx_ofdm example in GR 3.7.1

, 2014 at 10:11 AM, Martin Braun wrote: > On Wed, Jan 15, 2014 at 07:55:45PM -0500, Aditya Dhananjay wrote: > > There is a variant of this issue that I discovered and would like to > point > > it out to the community. > > > > Synopsis: After the first time the head

Re: [Discuss-gnuradio] header_payload_demux_impl.cc - problem when using random bit stream (variable trigger location)

Hello David, I was facing the exact same issue, and the fix I use is identical to yours. I consume 4 symbols less than I need to, so the subsequent packet is not lost. Best, Aditya On Tue, Jan 21, 2014 at 11:14 AM, David Halls wrote: > Hi Martin, > > Making good progress with the relay but on

Re: [Discuss-gnuradio] Fwd: Questions on rx_ofdm example in GR 3.7.1

Oops, that was a typo. Sorry. I meant 200KHz. On Tue, Jan 21, 2014 at 12:17 PM, Martin Braun wrote: > On 01/21/2014 04:23 PM, Aditya Dhananjay wrote: > > Thanks for trying, Martin. > > > > My OFDM Specs are: > > > > FFT size = 64 > > CP length = 16 > &g

Re: [Discuss-gnuradio] header_payload_demux_impl.cc - problem when using random bit stream (variable trigger location)

> > > > Your solution will work, but you have to admit it's a hack. Who says my > payload is 3 or 4 symbols long? I'm currently working on the HPD, and > I'll figure out a way to get this in. > Absolutely; this is an unclean hack. > I guess not consuming the last symbol would be sufficient in mos

Re: [Discuss-gnuradio] Fwd: Questions on rx_ofdm example in GR 3.7.1

> > > > > For the record: The default is 8 bits CRC, so there's a 1/256th chance a > packet will fail and pass. But then there's also the payload CRC, which > has 32 bits. Unlikely they'll both pass. > I agree. While false positives in the header CRC so happen from time to time, I've never noticed

Re: [Discuss-gnuradio] header_payload_demux_impl.cc - problem when using random bit stream (variable trigger location)

On Tue, Jan 21, 2014 at 1:03 PM, David Halls wrote: > Ah, I see. You want to isolate the effect of the channel. I believe it > will be difficult, if not impossible, to remove the slight jitter of the > trigger, even in very high SNR - perhaps others can comment/help? > Yes, that is correct. It is

Re: [Discuss-gnuradio] header_payload_demux_impl.cc - problem when using random bit stream (variable trigger location)

> > Aditya - am I to understand that you want to have perfect timing sync? > Correct. This is because I want to study how the channel changes across OFDM subcarriers (caused due to multi-path). Having rotations in the channel across subcarriers caused by trigger timing offsets is what I want to el

Re: [Discuss-gnuradio] header_payload_demux_impl.cc - problem when using random bit stream (variable trigger location)

> > > Dear Martin, Thanks for the ideas. > > Two ideas: > - You could remove the sync block and sync your rx/tx paths with other > means (e.g. MIMO connector, it depends on your hardware). This makes the > sync influence independent of the noise. > Good idea, I will try it out once I get the ca

Re: [Discuss-gnuradio] Detailed Analysis

I am looking to do some detailed analysis of my recorded data. I have been > trying to look at the data in GNURadio using the FFT Plot, but I am having > a hard time discerning things. Specifically, I am trying to see if a signal > persists over a period of time. I am going to try and look at thing

Re: [Discuss-gnuradio] Detailed Analysis

On Wed, Jan 22, 2014 at 7:26 PM, Paul B. Huter wrote: > Aditya: > > I am looking at sections of my data, one-M at a time - that is, from 0 MHz > to 1 MHz, 1 MHz to 2 MHz, etc. So, for example, when I look at 0-to-1 MHz, > I am using an FFT set to FFT-size of 1000. My data is about 13 seconds > lon

[Discuss-gnuradio] Question about Frequency Selective Fading Model

Dear All, I have an OFDM TX block connected to an OFDM RX block through a 'Frequency Selective Fading Model' block, implemented in GRC. The parameters used in the model are: Num sinusoids (for sum of sinusoids): 8 Max Doppler: 0 LOS Model: NLOS PDP Delays: (0, 1.6, 2.8) PDP Magnitudes: (0.4, 0.4,

Re: [Discuss-gnuradio] how to use FFT without grc block

Hi Nasi, And the problem is in that input part. It is not clear what is inbuf... > I create gr_complex vector and want to input it into fft. It does not work > in any way. There are alot of questions are still open. > You can look at fft.cc and fft_vcc_fftw.cc. It is quite clear how the FFTW li

Re: [Discuss-gnuradio] OFDM Packet lost

Hi Piotr, I was facing the same issue, and the issue is caused by Schmidl-Cox sometimes detecting the packet boundaries a little late. This cannot really be helped, as channel noise may force the correlator to detect a peak/plateau later than it should. I have found a couple of ways to overcome th

[Discuss-gnuradio] Buffer too small for min_noutput_items (ofdm_carrier_allocator_cvc)

Dear All, I am running OFDM TX-RX in GRC. The parameters used are very similar to those in the TXRX example, with a few differences: - FFT size changed to 1024 - Pilots aren't placed on fixed subcarriers on every symbol index. Every third symbol index has pilots. - I've updated sync_word1, sync_w

Re: [Discuss-gnuradio] Buffer too small for min_noutput_items (ofdm_carrier_allocator_cvc)

cking to all. best, aditya On Wed, Jan 29, 2014 at 12:19 PM, Aditya Dhananjay wrote: > Dear All, > > I am running OFDM TX-RX in GRC. The parameters used are very similar to > those in the TXRX example, with a few differences: > > - FFT size changed to 1024 > - Pil

Re: [Discuss-gnuradio] Buffer too small for min_noutput_items (ofdm_carrier_allocator_cvc)

> > >> We recently discussed this problem, I think it was the January dev call. > Currently, we don't want to fix this, as it would require too many changes > to our architecture. If a streamed PDU is too large for tagged stream > blocks, you'll just have to use message passing. That makes perfec

[Discuss-gnuradio] Possible bug with PATH/gr-channels/lib/cfo_model_impl.h

Dear All, I suspect there is a bug in cfo_model_impl.h, where calling set_std_dev to set the std_dev back to 0 causes undesirable effects. How to reproduce the bug: a) Standard OFDM TX-RX example in GRC. Connect the TX block to the RX block through this channel model block. b) Use a variable sl

Re: [Discuss-gnuradio] Possible bug with PATH/gr-channels/lib/cfo_model_impl.h

> > Nope, not a bug. You're reducing the standard deviation, but the > actual CFO value is not this value but is adjusted based on it. > > I think more of what you are looking for is a direct way to set the > value of the CFO (or something like a reset() function). > Hi Tom, thanks for the clarif

Re: [Discuss-gnuradio] psk mod and channel model

Hi Marco, Could you please attach your GRC file? Thanks, Aditya On Sat, Feb 8, 2014 at 6:32 AM, Marco Bosco wrote: > Hi! > > I am trying to do a simple simulation in GRC: > > Signal source --> Packet encoder --> PSK mod --> Channel model --> PSK > demod --> Packet decoder --> Scope sink > > T

Re: [Discuss-gnuradio] .so: undefined symbol: _ZN2gr6blocks12count_bits16E

You could also try "sudo ldconfig". It looks like the linker can't find some required symbols. Happy hacking! On Mon, Feb 10, 2014 at 12:59 PM, Nick Foster wrote: > Usually a "make clean" will solve this. > > --n > > > On Mon, Feb 10, 2014 at 9:57 AM, raf raf wrote: > >> Hi all gnuradio users

Re: [Discuss-gnuradio] LPF in FM receiver

> > In the FM receiver: Why a LPF is used instead of a BPF in order to select > the Radio channel that we want to hear? That is the only part I don't > understand. > > Hello Pablo, Let's say you are trying to receive an FM signal centered around 100MHz. In other words, the signal of interest is fr

Re: [Discuss-gnuradio] LPF in FM receiver

receivers are designed the way they are. On Tue, Feb 11, 2014 at 11:31 AM, Aditya Dhananjay wrote: > > >> In the FM receiver: Why a LPF is used instead of a BPF in order to select >> the Radio channel that we want to hear? That is the only part I don't >> understand. >&

Re: [Discuss-gnuradio] Different sensing results with same hypothesis

On Wed, Feb 19, 2014 at 6:26 AM, Lebowski80 wrote: > Hello everyone, > > Before to explain my problem I give some technical information about my > hardaware. I'm using USRPs v1 and the boards integrated are XCVR2450 > Transceivers. > > I'm using the script usrp_spectrum_sense.py in a USRP to dete

Re: [Discuss-gnuradio] Different sensing results with same hypothesis

I don't think there is any AGC on USRP hardware... > > Hi Dan, You are correct; I stand corrected. The XVCR2450 does not have an AGC. best, aditya ___ Discuss-gnuradio mailing list Discuss-gnuradio@gnu.org https://lists.gnu.org/mailman/listinfo/discuss-

Re: [Discuss-gnuradio] QPSK over air

Hi Mark, The problem is that GNU Radio does not have equalizers that can perform sufficiently well for constellations such as 64-QAM. As far as I know, the only one present is a simple decision feedback equalizer. I'm working on implementing a few equalizers: a) 2D Triangulation, and b) Whittaker

Re: [Discuss-gnuradio] Loopback flowgraph

Remove the printf. Put in "tag debug" blocks at different points in your flowgraph to see what's going on. On Wed, Feb 26, 2014 at 8:34 AM, raf raf wrote: > Hello all GnuRadio users, > > I wanted to have a flowgraph without an USRP source and USRP sink, only by > using the software blocks. The

Re: [Discuss-gnuradio] Message API questions

On Wed, Feb 26, 2014 at 8:45 AM, Nowlan, Sean wrote: > I have a few questions regarding messages in GR. > > > > 1) 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 didn't have m

Re: [Discuss-gnuradio] The GMSK demodulation

> > > As I have known, GSM uses GMSK modulation which BT = 0.3 and it > uses Viterbi algorithm for demodulation. And I took a look at the code of > GMSK demod code in GNU Radio, it use quadrature_demod but not Viterbi as > demodulation method. So which one is better in doing demodulating GMSK? > >

Re: [Discuss-gnuradio] GSoC 2014 project "Wireless Networks In-the-Loop" and "Channel Sounder"

Hi Achuth, Channel sounding with USRP radios and GNU Radio has been done by some folks at Rutgers and AT&T Labs. http://arxiv.org/pdf/1211.4940v1.pdf It might be a good idea to contact Nazmul Islam (CCed) about this project. Good luck. best, aditya On Mon, Mar 3, 2014 at 3:05 PM, achuth pv

Re: [Discuss-gnuradio] rx_ofdm Does Not Work Past Synchronizer

Hi Jon, Disclaimer: I haven't run your code, but based on eyeballing the png file: It looks like your "delay" block is not configured properly. The delay should be fft_len + cp_len which is 80 (instead of 72). Best, Aditya On Tue, Mar 18, 2014 at 7:25 PM, Jonathan Fox <31...@cardinalmail.cua.

Re: [Discuss-gnuradio] rx_ofdm Does Not Work Past Synchronizer

And if you are running over the air, try setting the TX and RX sampling rate to have the same value. In any case, I would first run in loopback mode (as shown in your png file) and save the over-the-air transmissions for later. On Tue, Mar 18, 2014 at 7:51 PM, Aditya Dhananjay wrote: > Hi

Re: [Discuss-gnuradio] OFDM link simulation

Hi Sara, Please look at the OFDM TX/RX examples in GNU Radio Companion. It's already there for you. :) best, aditya On Tue, Mar 18, 2014 at 8:44 PM, Sara Chérif wrote: > I want to simulate an OFDM link to carry 214 bytes per Ethernet packet & > implement it using 2 laptops running GNU & 2 US

Re: [Discuss-gnuradio] uhd_rx_cfile: getting constant O-overflows using the USRP B200 with debian

Hello Ingmar, Can you please repeat the experiment with lower sampling rates (say, 10 Mhz)? Thanks. best, aditya On Wed, Mar 19, 2014 at 8:42 AM, Ingmar Splitt < ingmar.spl...@eas.iis.fraunhofer.de> wrote: > Hi developers, > > I have a fresh gnu radio installed with pybombs for my usrp B200.

Re: [Discuss-gnuradio] uhd_rx_cfile: getting constant O-overflows using the USRP B200 with debian

t; 4 53 6 > > 2 27 3 > > > > Do you have a hint for me for fixing this problem? > > > > regards, > > Ingmar > > > > *Von:* Aditya Dhananjay [mailto:adi...@cs.nyu.edu] > *Gesendet:* Mittwoch, 19. März 2014 16:

Re: [Discuss-gnuradio] VOLK - vector multiplication

I had the same question. Thanks! :) On Thu, Mar 20, 2014 at 10:07 AM, Tom Rondeau wrote: > On Thu, Mar 20, 2014 at 7:05 AM, Nasi wrote: > > Hi all, > > > > I am using ubuntu 13.04, GNUradio 3.7. > > I have a question related to VOLK library. > > > > When I create a vector, lets say: > > > > ve

Re: [Discuss-gnuradio] Question regarding frequency offset correction

On Mon, Jul 14, 2014 at 12:14 PM, Perper wrote: > Hi all, > > In many applications very good synchronization of carrier and sampling > frequencies is required. > Available sources of signal not always have good clock reference. One of > the examples is cheap RTL SDR receiver based on a DVB-T dong

Re: [Discuss-gnuradio] references using in ofdm_equalizer_simpledfe

On Thu, Sep 4, 2014 at 9:04 AM, Tiankun Hu wrote: > Hi Martin, > Could you tell me the reference paper that you used in > ofdm_equalizer_simpledfe? ​Hello Tiankun, A decision feedback equalizer (DFE) works like this: The equalizer keeps track of the channel estimate on every subcarrier​ i. Ca

Re: [Discuss-gnuradio] references using in ofdm_equalizer_simpledfe

On Thu, Sep 4, 2014 at 11:29 AM, Tiankun Hu wrote: > Hi Aditya, > What's use of pilot symbols in "ofdm_equalizer_simpledfe" ? > I just found pilot symbols update their carrier's channel state, but > didn't find what's the use of these pilot channel state, seems them has no > relate with data symb

Re: [Discuss-gnuradio] 回复： references using in ofdm_equalizer_simpledfe

> Hi Aditya, >> Thanks your time! >> But how to use pilotes symbol's channel state to update data symbol's? >> "ofdm_equalizer_simpledfe" is so simple, so it didn't realize that, >> right? >> Is there any example or paper can be for reference? &

Re: [Discuss-gnuradio] build-gnuradio did not install gnuradio-runtime

On Tue, Sep 17, 2013 at 10:13 AM, Tom Rondeau wrote: > On Tue, Sep 17, 2013 at 3:43 AM, Dincer Beken wrote: > > Hi all, > > > > so I have installed Bastian's Gnu Radio and could build the files. I > have not changed the FindGnuradioRuntime.cmake, because when I ran the > cmake with Bastian's Pr

[Discuss-gnuradio] Working example of rx_ofdm and rx_ofdm with Gnuradio Companion

Hello All, Reviving an older discussion (from what I gather from the list archives). Does anyone have a working example of rx_ofdm.grc and tx_ofdm.grc? Or in the minimum, a working example of rx_ofdm.grc that plays with benchmark_tx, and/or a working example of tx_ofdm.grc that plays with benchma

Re: [Discuss-gnuradio] Working example of rx_ofdm and rx_ofdm with Gnuradio Companion

T hanks! On Thu, Sep 19, 2013 at 1:13 AM, Martin Braun (CEL) wrote: > Hi Aditya, > > there's a ticket on this (see our issue tracker) and I'm on it. > > tx_ofdm.grc should work, though. > > MB > > > On Wed, Sep 18, 2013 at 01:13:11PM -040

Re: [Discuss-gnuradio] Fwd: Gnuradio disabled components

Could you please post the entire output from cmake? Thanks On Thu, Sep 19, 2013 at 7:26 PM, Mauricio Olivera wrote: > Hi all, > > I have recently installed GNU radio 3.7.1 in Manjaro (Distro based in > Arch). > While building some components where disable. > I am interested in having some of t

Re: [Discuss-gnuradio] Fwd: Gnuradio disabled components

box.com/s/md5v8pr0iyllm8f/gnuradio_inst > > Many thanks. > > > 2013/9/19 Aditya Dhananjay > >> Could you please post the entire output from cmake? >> >> Thanks >> >> >> On Thu, Sep 19, 2013 at 7:26 PM, Mauricio Olivera < >> m.olivera.go..

Re: [Discuss-gnuradio] Fwd: Gnuradio disabled components

Oops, sorry, I missed those details in your previous email. On Thu, Sep 19, 2013 at 8:10 PM, Aditya Dhananjay wrote: > Have you installed all the dependencies? Which Linux are you running? > > > http://gnuradio.org/redmine/projects/gnuradio/wiki/UbuntuInstall#Install-Dependencie

Re: [Discuss-gnuradio] build-gnuradio did not install gnuradio-runtime

On Tue, Sep 17, 2013 at 12:18 PM, Dincer Beken wrote: > Hi, > > so i installed a Fedora 19 with build-gnuradio -m. (Yes I used the > official GnuRadio :(( ). > > I ran a cmake .. with Bastians new cmake files (both for gr-foo & > gr-ieee802-15-4). > > It did not work. So it really does not work w

[Discuss-gnuradio] Endianness in OFDM Implementation

Hello All, I have a question about the implementation of the mapping from an incoming bit-stream to generate an output of frequency-domain OFDM symbols (ofdm_mapper_bcv_impl.cc). Let's say that the incoming bit-stream is '0x00', '0x36', '0x00', '0x36', '0xff', '0x3f', '0x37', '0x27' '0x37'. Conve

Re: [Discuss-gnuradio] Endianness in OFDM Implementation

Hello All, > > I have a question about the implementation of the mapping from an incoming > bit-stream to generate an output of frequency-domain OFDM symbols > (ofdm_mapper_bcv_impl.cc). > > Let's say that the incoming bit-stream is '0x00', '0x36', '0x00', '0x36', > '0xff', '0x3f', '0x37', '0x27' '

Re: [Discuss-gnuradio] I/Q samples and Analytic Signals

Perhaps, Chapter 2 of "Digital Communications" by John Proakis? best, aditya On Mon, Sep 30, 2013 at 10:26 AM, Lucas Ingles wrote: > Hello to all, > > I am using GNU Radio to study digital communications systems. > I have been working on the basic FM receiver with RTL-SDR for a while. > > I wa

Re: [Discuss-gnuradio] Summary of desires for GRC, just discuss on the #ghuradio channel

On Wed, Oct 2, 2013 at 3:16 PM, Ethan Trewhitt wrote: > On Wed, Oct 2, 2013 at 3:03 PM, Marcus Leech wrote: > > Just a quick summary of the "things people would like" to see in GRC: > > > >o off-page connectors -- for managing large flow-graphs > >o better-handling of GRC-produced hier-bl

Re: [Discuss-gnuradio] GNURADIO.org down???

> > >> It's still working for me. > http://www.downforeveryoneorjustme.com/gnuradio.org > Down for me. I see the advert for domains priced right. ___ Discuss-gnuradio mailing list Discuss-gnuradio@gnu.org https://lists.gnu.org/mailman/listinfo/discuss-g

Re: [Discuss-gnuradio] recv and send frame size

On Tue, Oct 15, 2013 at 7:00 AM, Baier wrote: > Hi all, > > is there any possibilty to increase the send frame size ans recv frame > size of the USRP from the host? > Thanks > AB > What are you using to transmit and receive? Are you using the benchmark_tx and benchmark_rx files? (I assume that f

[Discuss-gnuradio] Repeatability of delivery ratios using benchmark_tx/rx

Hi All, I have two USRP N210 devices connected by an attenuator cable. I set up the following experiments. -- BEGIN EXPERIMENT 1 Step 1) Use benchmark_tx on one of the USRPs and send 100 packets. At the receiver, I simply record the incoming samples and save them into a file called samples1.dat.

Re: [Discuss-gnuradio] Repeatability of delivery ratios using benchmark_tx/rx

On Wed, Oct 16, 2013 at 10:22 PM, Aditya Dhananjay wrote: > Hi All, > > I have two USRP N210 devices connected by an attenuator cable. I set up > the following experiments. > > -- BEGIN EXPERIMENT 1 > > Step 1) Use benchmark_tx on one of the USRPs and send 100 packets. At

Re: [Discuss-gnuradio] Repeatability of delivery ratios using benchmark_tx/rx

On Wed, Oct 16, 2013 at 10:29 PM, Aditya Dhananjay wrote: > > > On Wed, Oct 16, 2013 at 10:22 PM, Aditya Dhananjay wrote: > >> Hi All, >> >> I have two USRP N210 devices connected by an attenuator cable. I set up >> the following experiments. >>

Re: [Discuss-gnuradio] Sampling with multiple USRP N210s with one host computer

On Thu, Oct 31, 2013 at 4:54 PM, rmsrms1987 wrote: > Hi Everyone, > > I recently discovered that Ettus offer a way of synchronizing up the eight > USRPs with the following clock distribution system: > > https://www.ettus.com/product/details/OctoClock-G >

Re: [Discuss-gnuradio] Why the Qam modulation cannot work well in ofdm benchmark example?

On Sun, Nov 3, 2013 at 5:09 AM, Martin Braun (CEL) wrote: > On Fri, Nov 01, 2013 at 07:23:33PM -0700, Yingjie Chen wrote: > > Recently, I have conducted a project based on ofdm benchmark. However, > when I > > use the high modulation rate like qam16 and qam64, the packet error rate > > increase si

[Discuss-gnuradio] GRC | Block to Variable

Hello! In GRC, is it possible to store the latest output of a block into a variable? Let's say I have a block "A" that is outputting floats. I want to save the latest output of block "A" into a variable "var" such that a block "B" can read "var" asynchronously if it needs to. Thanks! Aditya

Re: [Discuss-gnuradio] GRC | Block to Variable

Update: I had tried to use "Function Probe" to accomplish this task, but couldn't get it to work. After the latest pull from the git repo, it works! Best, Aditya On Wed, Nov 6, 2013 at 2:54 PM, Aditya Dhananjay wrote: > Hello! > > In GRC, is it possible to store the

Re: [Discuss-gnuradio] Fwd: Questions on rx_ofdm example in GR 3.7.1

> > > > With this fix, now I see a new error: > > INFO: Detected an invalid packet at item 0 > INFO: Parser returned #f > thread[thread-per-block[18]: ]: Buffer > too small for min_noutput_items > > I'll look into this, but just in case this is familiar to anyone... > I face the same problem. I c

Re: [Discuss-gnuradio] Fwd: Questions on rx_ofdm example in GR 3.7.1

On Thu, Nov 7, 2013 at 7:57 AM, Martin Braun (CEL) wrote: > On Wed, Nov 06, 2013 at 06:27:40PM -0500, Aditya Dhananjay wrote: > > I created an OFDM TX/RX flowgraph (mostly copying stuff out from the GNU > Radio > > reference GRC implementation), where the TX goes out to a US

Re: [Discuss-gnuradio] How to detect collision when two packets are transmitted simultaneously from two transmitters.

Hi Sumedha, 1. You could perhaps look at the average power received over that time slot. If there is a collision, the receive power would ostensibly be higher. 2. Traditionally, a collision implied that nothing could be done, and the data was lost (unless one transmitter overwhelmed the other tra

Re: [Discuss-gnuradio] How to detect collision when two packets are transmitted simultaneously from two transmitters.

> > 1. I tried checking for the average power but that doesn't work. Even with > two transmitters transmitting at the same time the energy detected by the > receiver doesn't change much. It remains in the same order. > It is expected behavior to be in the same order. Try looking at the received po

Re: [Discuss-gnuradio] How to detect collision when two packets are transmitted simultaneously from two transmitters.

> > > Fundamentally a very hard problem. > Yes, this is a very hard problem. Sumedha, you are implementing a TDMA scheme right? In a correctly implemented TDMA, there shouldn't be any collisions between transmitters that are using your TDMA protocol. If you are using a probabilistic TDMA (like S

Re: [Discuss-gnuradio] How to collect the complex data of a dpsk modulator in a text file

> I am experimenting with the one of the flowgraph examples > "uhd_tx_dpsk.grc". I am able to > see the complex number output in WX GUI NUMBER SINK block but I want to > collect this > output in a text file. If I use a "FILE SINK" block, it shows some symbols > but nothing in the > form of x+jy. Ki

Re: [Discuss-gnuradio] Fwd: Questions on rx_ofdm example in GR 3.7.1

> > > I've opened http://gnuradio.org/redmine/issues/611 and will try and > figure this out. > Thanks, Martin. ___ Discuss-gnuradio mailing list Discuss-gnuradio@gnu.org https://lists.gnu.org/mailman/listinfo/discuss-gnuradio

Re: [Discuss-gnuradio] HELP! - Problem with radio application deploy

Tom, that was a very useful explanation. Thanks! On Tue, Nov 19, 2013 at 7:29 PM, Tom Rondeau wrote: > On Tue, Nov 19, 2013 at 7:19 PM, Paul B. Huter > wrote: > > I recall that that was what you had mentioned yesterday, but could you > > explain why setting it to 15M will allow me to grab 30M?