Re: [Discuss-gnuradio] Saving the I/Q samples of multiple synchronized USRPs

2016-07-20 Thread avinash kalyanaraman
at the beginning. The file size difference is really > just because due to the nature of general purpose hardware and GNU Radio's > scheduling, there's no guarantee all blocks have written the same amount of > data when you kill the flow graph. > > Am 18. Juli 2016 17

Re: [Discuss-gnuradio] Saving the I/Q samples of multiple synchronized USRPs

2016-07-18 Thread avinash kalyanaraman
? Thanks! On Fri, Jul 15, 2016 at 5:30 PM, Martin Braun wrote: > This'll work. However, the uhd_rx_cfile utility that comes with GNU > Radio will do that for you. > > Cheers, > M > > On 07/15/2016 11:33 AM, avinash kalyanaraman wrote: > > Hi all, > > >

Re: [Discuss-gnuradio] Low transmission rate on tx_ofdm causes underflow

2016-06-24 Thread avinash kalyanaraman
I wasn't getting anything through. My USRP Sink block had an empty TSB tag name property. I didn't have a TSB tag name = packet_len property. I started getting data across after adding that. On Fri, Jun 24, 2016 at 2:12 PM, Martin Braun wrote: > On 06/23/2016 02:42 PM, avinash

[Discuss-gnuradio] Low transmission rate on tx_ofdm causes underflow

2016-06-23 Thread avinash kalyanaraman
Hi All, I am doing an OFDM transmission with tx_ofdm.grc and receiving it with rx_ofdm.grc. I am using two USRP N210s for this. I edited the tx_ofdm to set the transmission rate to generate 96-byted packets every 10ms via : message strobe-> random pdu generator->pdu to tagged stream. However, n

Re: [Discuss-gnuradio] Re channel state information on rx_ofdm.grc

2016-06-20 Thread avinash kalyanaraman
OFDM question: > > You take the DFT of the input signal. Hence, the bins of the DFT are > f_nyquist/l_fft spaced. > > Best regards, > > Marcus > On 17.06.2016 17:57, avinash kalyanaraman wrote: > > Thanks Marcus - that helps. > > Could you please let me know wha

[Discuss-gnuradio] Control the transmission rate of TX_OFDM.grc

2016-06-20 Thread avinash kalyanaraman
Hi All, I am doing an OFDM transmission with tx_ofdm.grc and receiving it with rx_ofdm.grc. I am using the Random Source of the tx_ofdm unmodified. I want to be able to control the packet transmission rate - for e.g. 10 packets every 100ms. How can I modify the grc to be able to do this ? Thanks!

Re: [Discuss-gnuradio] Re channel state information on rx_ofdm.grc

2016-06-17 Thread avinash kalyanaraman
Thanks Marcus - that helps. Could you please let me know what's the bandwidth of each sub-carrier? How can I calculate that and reconfigure the same? On Sat, Jun 18, 2016 at 12:50 AM, Marcus Müller wrote: > Hi Avinash, > > On 06/16/2016 03:29 PM, avinash kalyanaraman wrote: &

Re: [Discuss-gnuradio] Re channel state information on rx_ofdm.grc

2016-06-16 Thread avinash kalyanaraman
Hi Marcus, Thanks for the email. I connected the debug tag to OFDM Channel Estimation and noted that the ofdm_sync_chan_taps key has 64 complex values. Could you please confirm the following two things ? i) These 64 complex values (a + ib) represent the 64 sub-carriers and I can get the amplitude

[Discuss-gnuradio] Re channel state information on rx_ofdm.grc

2016-06-15 Thread avinash kalyanaraman
Hello all, Could you please let me know how I can get channel-frequency response (like channel state information (CSI) ) for an OFDM transmission? I am looking at rx_ofdm.grc to capture the phase and amplitude at each of the 64 sub-carriers. Would connecting the OFDM Channel Estimation Block of t