gr-uhd: Switching DSP frequency of *RX* over stream tags in TX (USRP Sink)

2020-03-03 Thread Lukas Haase
Hi, I need to (synchronously) switch the DUC/DDC frequency at certain sample intervals. I previously used the message ports for that and created timed commands. This worked nicely for the RX (USRP Source) and with analog retuning. However, it turned out that this does not work for the transmitt

Wire shark output question

2020-03-03 Thread sampath ranga
Dear all, I am currently working on IEEE802.15.4 protocol with GNU Radio and different SDR. I am using Dr. Basti's code for testing. Its successful. But i am having few questions to ask. I see two connections to Wireshark from PHY layer "rxout" pin and also from pdu out of MAC layer. When i dis

Re: DVB-T receiver problem (OFDM symbol acquisition)

2020-03-03 Thread Ralf Gorholt
Hi Ron, when I adapt the parameters of my flow graph I get exactly the same result with your file as you do. Kind regards, Ralf Am 03.03.2020 um 02:22 schrieb Ron Economos: Yes, changing back to uint16_t is correct. But something is not correct with your file. When you read from a file, samp

Re: Channel estimation OFDM saving taps

2020-03-03 Thread CEL
Hi Vinicius, you can directly feed the output of the OFDM channel estimation block into a simple general block that you write yourself[1] – even in Python – and make that block * either save the contents of the relevant tags to a file or * output a vector of (inverse) channel coefficients take

Re: DVB-T receiver problem (OFDM symbol acquisition)

2020-03-03 Thread Ralf Gorholt
Hi Federico, I think I have sent my previous email a bit too fast. After having looked at the code of the OFDM Synchronization block it seems to me that this block is specific to ISDB-T. This would mean that I cannot use it for DVB-T because of incompatibilities between ISDB-T and DVB-T (e.g. ca

Re: Weird behaviour of the analog signal source (was: Re: How ensure consistency with timing signals)

2020-03-03 Thread Sylvain Munaut
Hi, > I am by no means an expert on this but just for my understanding I would be > curious: > > 1.) I still do not understand why for 1 Hz at 5MSps I can get a period that's > "500578.5" on average. The frequency error is a whopping 0.1158%! > ((5005789.5-500)/500*100). Huge. That's b

Re: Weird behaviour of the analog signal source (was: Re: How ensure consistency with timing signals)

2020-03-03 Thread Lukas Haase
Hi Sylvain, Thank you very much for your answer. Much appreciated! > Von: "Sylvain Munaut" <246...@gmail.com> > > Hi, > > > How can (or better: *should*) a fully digital signal source have phase > > noise? > > Limited precision arithmetic > > > > Also, for 1Hz at 5MSps I always get either 500578

Channel estimation OFDM saving taps

2020-03-03 Thread Vinicius Mesquita
Hello. Thank you in advance for the help... I already searched the mailing list and could not find it how to properly see/save the channel taps from the OFDM Channel Estimation block. I saw that is in a tag, but how can I save it? What I'd love to find is a way to see the channel estimation with

Re: Inject "tx_time" tags in a stream

2020-03-03 Thread jnunez
Hi Derek, Thank you very much for your detailed response. I thought that tag's insertion could be done directly from GRC. I hoped that there would be some library to insert these tags in a stream. The truth is that I don't have enough knowledge to write my own block. On the other hand, I

Aw: Re: DVB-T receiver problem (OFDM symbol acquisition)

2020-03-03 Thread Ralf Gorholt
Thank you very much, Federico.   If I understand correctly, this block replaces the OFDM symbol acquisition block. I will have a look at the examples and try it.   Best regards,   Ralf, DL5EU     Gesendet: Dienstag, 03. März 2020 um 13:05 Uhr Von: "Federico 'Larroca' La Rocca" An: "Ralf Go

Re: DVB-T receiver problem (OFDM symbol acquisition)

2020-03-03 Thread Federico 'Larroca' La Rocca
Hi Ralf, It should be right after the channel. It performs symbol acquisition, FFT and channel equalization (as well as sampling corrections and coarse and fine frequency corrections). Please see the examples folder in gr-isdbt (for instance rx_demo.grc which also includes the gr-dtv blocks disable

Re: Weird behaviour of the analog signal source (was: Re: How ensure consistency with timing signals)

2020-03-03 Thread Sylvain Munaut
Hi, > How can (or better: *should*) a fully digital signal source have phase noise? Limited precision arithmetic > Also, for 1Hz at 5MSps I always get either 5005789 or 5005790 samples > (instead of 500) ... this is fairly deterministic. That's because the signal source works with phase i