That's a bit of a GNU Radio more than a USRP question, but nevertheless: You can't do that with the existing file_source. You'd need to extend the file_source's C++ or write your own block that does that cycling.
Best regards, Marcus On Wed, 2018-03-21 at 17:07 +0000, Benny Alexandar wrote: > Hi Marcus, > > Yes, I added a resampler to upsample by 250kHz and scaled the IQ > samples by dividing it with 2**16, since each IQ is of 16bit. > With this it started to work. > > Now, I want to keep changing the IQ file at run time. I have a lot of > IQ files in current folder, which I want to use for transmission > for certain time say after running one IQ file for 2 min, change the > IQ file, this should keep continuing. > > I had a look at the python code grc generated, and it basically > creates a class which initializes with the specified IQ file and > creates the connection > and runs. > > How do I change this python code so that it can loop over all IQ > files in the folder, any example python code available ? > > Please help me in setting it up. > > -ben > > > From: USRP-users <[email protected]> on behalf of > Marcus Müller via USRP-users <[email protected]> > Sent: Wednesday, March 21, 2018 2:10 AM > To: Marcus D. Leech; [email protected] > Subject: Re: [USRP-users] IQ transmission using grc > > Hi ben, > > also, no USRP can directly deal with a sampling rate as low as 48 kHz > – > you'll first have to resample to a rate that your USRP can deal with. > In case of the N210, these frequencies are integer fractions of 100 > MHz > i.e. 100 MHz / N, with the restriction that N be an integer 3 < n <= > 128 , an even integer 2 < n <= 256 or an integer multiple of 4 <= > 512. > > tx_samples_from_file can't resample – you should have been getting > UHD > warnings about impossible sampling rates; your IQ file has simply > been > played back at a higher rate. > > Best regards, > Marcus > > On Tue, 2018-03-20 at 12:58 -0400, Marcus D. Leech via USRP-users > wrote: > > On 03/20/2018 12:37 PM, Benny Alexandar via USRP-users wrote: > > > Hi, > > > > > > I have an IQ file sampled at 48kHz and want to transmit through > gnu > > > radio. The IQ samples are each 16bit, and stored interleaved in a > > > file > > > ie, IQIQIQIQ... I 16 bit and Q 16bit > > > > > > I tried creating a grc using iShort to Complex block and send to > > > USRP sink block (usrp n210), but the signal received is > distorted. > > > Do I need to convert the short values into float -1.0 to +1.0 > > > before transmission. Please help in resolving it. > > > > > > I want to use it only through grc and not to use > > > tx_samples_from_file which does the same. > > > > > > -ben > > > > > You'll need to scale your samples into {-1.0,1.0} > > > > > > > > _______________________________________________ > > USRP-users mailing list > > [email protected] > > http://lists.ettus.com/mailman/listinfo/usrp-users_lists.ettus.com > > _______________________________________________ > USRP-users mailing list > [email protected] > http://lists.ettus.com/mailman/listinfo/usrp-users_lists.ettus.com _______________________________________________ USRP-users mailing list [email protected] http://lists.ettus.com/mailman/listinfo/usrp-users_lists.ettus.com
