Hi, Thanks Marcus! Corrected it and thanks for the info!
1) I would like to transmit burst signals of the chirp generated from the flowgraph attached. I tried using the “stream to Tagged stream” way, but when I ran the GNU Radio Companion, it’s being transmitted continuously. Nothing seems to be happening. Am I doing something wrong and is there a better way for burst transmission? Does anyone know this? Thanks in advanced! -----Original Message----- From: Müller, Marcus (CEL) [mailto:muel...@kit.edu] Sent: Thursday, 10 May 2018 5:06 PM To: Yeo Jin Kuang Alvin (IA); discuss-gnuradio@gnu.org Subject: Re: [Discuss-gnuradio] Tx Burst for Chirp signals Hi! your receiver low pass filter is incorrectly parameterized, probably (sampling rate isn't 32 MS/s). And so is the rest of your flow graph – your USRP is using a sampling rate of 2 MS/s, but you act as if it's running at 32 MS/s. Start with 2 MS/s and make it work with that – then later scale up (the processing load of 32 MS/s is harder than you probably think). Remember that GNU Radio is pure DSP, so all the axis labels on your visualizations are just that – labels, interpreting relative frequencies (i.e. frequencies divided by the sampling rate) by multiplying them with the value you entered in bandwidth. The "physical meaning" of your signal is defined by the sampling rate of your physical device. Thus, you want to use the same sampling rate everywhere in your flow graph. These things mean! something. Best regards, Marcus On Thu, 2018-05-10 at 08:31 +0000, Yeo Jin Kuang Alvin (IA) wrote: > Hi everyone, > > There are two questions that I would like to ask. > > 1) I would like to transmit burst signals of the chirp generated > from the flowgraph attached. I tried using the “stream to Tagged > stream” way, but when I ran the GNU Radio Companion, it’s being > transmitted continuously. Nothing seems to be happening. Am I doing > something wrong and is there a better way for burst transmission? > > 2) I noticed something with the sampling rates of the blocks. > When I use the same sampling rate for all the blocks, I get underflow > “UUU”. However, when I changed all the block’s sampling rate to 32MHz > and leave the USRP Sink and Source to 2MHz, no underflow is seen but > there is still overflow (seen in the attached screenshot). > > What is the difference between the USRP’s sampling rate compared to > the other block’s sampling rate? > > Thank you in advanced! > _______________________________________________ > Discuss-gnuradio mailing list > Discuss-gnuradio@gnu.org > https://lists.gnu.org/mailman/listinfo/discuss-gnuradio _______________________________________________ Discuss-gnuradio mailing list Discuss-gnuradio@gnu.org https://lists.gnu.org/mailman/listinfo/discuss-gnuradio