Re: [Discuss-gnuradio] OFDM example from gr-digital with UHD

On 22.07.2015 16:49, Jose Perez wrote: > Thanks again Marcus. > > Now I am using the "Head" block... I don't know which number I have to put > in "Num Items" to get out my file with no repeated information. > I can understand this number to a Sin/Cosine function or a random source > that I can li

Re: [Discuss-gnuradio] OFDM example from gr-digital with UHD

Jose, If you set your file source to "repeat" it will produce an infinite amount of samples, just like a sine would. If you know you want to produce 10,000 packets (and see how many are received), you only need to 96*10,000 samples. Hence, you'll use the head block after the file source and set

Re: [Discuss-gnuradio] OFDM example from gr-digital with UHD

Jose, If you set your file source to "repeat" it will produce an infinite amount of samples, just like a sine would. If you know you want to produce 10,000 packets (and see how many are received), you only need to 96*10,000 samples. Hence, you'll use the head block after the file source and set

Re: [Discuss-gnuradio] OFDM example from gr-digital with UHD

Thanks again Marcus. Now I am using the "Head" block... I don't know which number I have to put in "Num Items" to get out my file with no repeated information. I can understand this number to a Sin/Cosine function or a random source that I can limit how many samples I want ... but for a file I do

Re: [Discuss-gnuradio] OFDM example from gr-digital with UHD

As I mentioned, use the "head" block. BR, Marcus On 16.07.2015 14:33, Jose Perez wrote: Marcus and Martin, you are helping me to much! Sorry for this guys. I just have this forum to ask because my partners here don't know nothing about GNU Radio. So, I have the number of packets that I received

Re: [Discuss-gnuradio] OFDM example from gr-digital with UHD

Marcus and Martin, you are helping me to much! Sorry for this guys. I just have this forum to ask because my partners here don't know nothing about GNU Radio. So, I have the number of packets that I received but how I know how many packets my original file have? (I have: packet_len Value: 96 and m

Re: [Discuss-gnuradio] OFDM example from gr-digital with UHD

On 15.07.2015 07:23, Jose Perez wrote: > Hi Marcus! > > Yes, Percentage of successful packets would be great for me. But I don't > have idea how blocks I need use in the flowgraph to obtain a number for > this. Run the ofdm_loopback example, and you'll see the receiver block outputs a sequence nu

Re: [Discuss-gnuradio] OFDM example from gr-digital with UHD

Well, that depends, but couldn't you simply save the successfully decoded packets to a file (assuming that no broken packages pass the checksums) and divide that file's size by the payload size of a packet? You'd limit the amount of payload being sent using the good ol' head block. Best regards

Re: [Discuss-gnuradio] OFDM example from gr-digital with UHD

Hi Marcus! Yes, Percentage of successful packets would be great for me. But I don't have idea how blocks I need use in the flowgraph to obtain a number for this. -- View this message in context: http://gnuradio.4.n7.nabble.com/OFDM-example-from-gr-digital-with-UHD-tp54446p54816.html Sent from

Re: [Discuss-gnuradio] OFDM example from gr-digital with UHD

Kind of what Martin hinted at: Percentage of successful packets? Net throughput? On 15.07.2015 02:10, Jose Perez wrote: Ok, Martin. But do you have any suggest to measure how good is the transmission/reception? Thaks. Cheers, José -- View this message in context: http://gnuradio.4.n7.nabble

Re: [Discuss-gnuradio] OFDM example from gr-digital with UHD

Ok, Martin. But do you have any suggest to measure how good is the transmission/reception? Thaks. Cheers, José -- View this message in context: http://gnuradio.4.n7.nabble.com/OFDM-example-from-gr-digital-with-UHD-tp54446p54790.html Sent from the GnuRadio mailing list archive at Nabble.com. _

Re: [Discuss-gnuradio] OFDM example from gr-digital with UHD

On 13.07.2015 17:49, Jose Perez wrote: > Another question... to use the block "Error Rate" to calculate the > BER of the system, I just need put the File Source block in the > Reference in Error Rate block and the output of Repack Bits block on > RX side? That won't be as helpful as you might thin

Re: [Discuss-gnuradio] OFDM example from gr-digital with UHD

Thanks for all, Martin and Marcus! I changed the Random Source block to a File Source block and put a File Sink block on the receiver side ... It is working well ;) (I am transmitting a .txt file) Another question... to use the block "Error Rate" to calculate the BER of the system, I just need p

Re: [Discuss-gnuradio] OFDM example from gr-digital with UHD

On 30.06.2015 12:12, Jose Perez wrote: > > So ... Is it possible to see the Constellation points like QPSK in this > flowgraph? > Sorry for so many questions! On TX, you can plot the complex symbols before they go into the carrier allocator. On the receive side, you can do the same after the carr

Re: [Discuss-gnuradio] OFDM example from gr-digital with UHD

Jose, we're talking about this flow graph, right? http://gnuradio.4.n7.nabble.com/file/n54534/ofdm_tx.png In this flow graph, you're trying to find the individual symbols in time domain; that's not possible, they only exist clearly distinguishable in frequency. That is why there is an DFT (in thi

Re: [Discuss-gnuradio] OFDM example from gr-digital with UHD

So ... Is it possible to see the Constellation points like QPSK in this flowgraph? Sorry for so many questions! Thanks Martin! -- View this message in context: http://gnuradio.4.n7.nabble.com/OFDM-example-from-gr-digital-with-UHD-tp54446p54537.html Sent from the GnuRadio mailing list archive

Re: [Discuss-gnuradio] OFDM example from gr-digital with UHD

On 30.06.2015 11:06, Jose Perez wrote: > I am plotting the signal after the Multiply Const Block ... the signal that I > will transmitt with USRP. > Isn't correct? > If what you want to plot is your constellation, then no, it's not. This is all modulated, pulse shaped and all. Cheers, M __

Re: [Discuss-gnuradio] OFDM example from gr-digital with UHD

I am plotting the signal after the Multiply Const Block ... the signal that I will transmitt with USRP. Isn't correct? -- View this message in context: http://gnuradio.4.n7.nabble.com/OFDM-example-from-gr-digital-with-UHD-tp54446p5453

Re: [Discuss-gnuradio] OFDM example from gr-digital with UHD

On 30.06.2015 10:41, Jose Perez wrote: > Hi Marcus, > > Thanks so much for the answer. But like in the screenshots of Gabriele, the > blocks OFDM Transmitter e OFDM Receiver are off. And I can't visualize four > symbols (QPSK) or 2 symbols (BPSK) in the output of QT Constellation just a > big one

Re: [Discuss-gnuradio] OFDM example from gr-digital with UHD

Hi Marcus, Thanks so much for the answer. But like in the screenshots of Gabriele, the blocks OFDM Transmitter e OFDM Receiver are off. And I can't visualize four symbols (QPSK) or 2 symbols (BPSK) in the output of QT Constellation just a big one (see the screenshot), is this correct? Thanks agai

Re: [Discuss-gnuradio] OFDM example from gr-digital with UHD

Hi Jose, > And I have another question (if Marcus can help) ... what is the modulation > in this example (QPSK, QAM)? You can set that yourself in the OFDM Transmitter Block, separately for header and payload. > Sorry for my bad english Your English is really fine, don't worry. If we don't underst

Re: [Discuss-gnuradio] OFDM example from gr-digital with UHD

Hi, Gabriele, do you have news about this? I am trying to do the same. And I have another question (if Marcus can help) ... what is the modulation in this example (QPSK, QAM)? Sorry for my bad english Thanks -- View this message in context: http://gnuradio.4.n7.nabble.com/OFDM-example-fr

Re: [Discuss-gnuradio] OFDM example from gr-digital with UHD

Hi Gabriele, if there is no output, chances are the receiver side packet detector doesn't see any valid packets. Make sure tx and rx parameters match, and adjust the RX gain. Make sure no under/overflows happen. There's quite a lot of things that can go wrong in a real-world transceiver, but these

Re: [Discuss-gnuradio] OFDM example from gr-digital with UHD

Thanks Marcus and Martin. I finally increased the sample rate up to 1 Msps and decreased the amplitude multiplier. Now I can see a clear ofdm spectrum with no distortion at all. Did some of you tried file transmission from one end to the other? I did it for GMSK before. Now when it comes ofdm and

Re: [Discuss-gnuradio] OFDM example from gr-digital with UHD

On 25.06.2015 06:07, Marcus Müller wrote: > Hi Gabriele, > > have you tried adding more gain on the TX side? ...or less gain? > Also, you will need to increase sampling rate. Right now, you're using > 100kHz, which is 1/1000 of the master clock rate of the N200. If I'm not > mistaken, the maximu

Re: [Discuss-gnuradio] OFDM example from gr-digital with UHD

Hi Gabriele, have you tried adding more gain on the TX side? Also, you will need to increase sampling rate. Right now, you're using 100kHz, which is 1/1000 of the master clock rate of the N200. If I'm not mistaken, the maximum decimation for the N200 is 512, and hence the minimum rate would be 100