Re: [Discuss-gnuradio] Tx Burst for Chirp signals
Hi, I want to simulate the radar delay by having real time receive, modulation and transmission of radar signal for ground testing purposes. Therefore, I need 2 TX channel and 1 RX, the first TX is to transmit out the signal to simulate a device transmitting to me elsewhere. Then the RX will take in this signal and do some DSP and then re-transmit back out to the device using the 2nd TX port in the USRP B210. The signal I am tasked to do is a radar signal and I have to transmit out one pulse width of the chirp and wait for certain amount of time before sending another pulse. Thank you in advanced! -Original Message- From: Müller, Marcus (CEL) [mailto:muel...@kit.edu] Sent: Friday, 11 May 2018 3:05 PM To: Yeo Jin Kuang Alvin (IA); discuss-gnuradio@gnu.org Subject: Re: [Discuss-gnuradio] Tx Burst for Chirp signals Could you be a little more specific, please, than "receive, digitize and re-transmit"? For what purpose? Why a chirp? Can you please give us the bigger picture, here? What's the thing you need to build? Best regards, Marcus On Fri, 2018-05-11 at 02:03 +, Yeo Jin Kuang Alvin (IA) wrote: > Hello, > > I am currently trying to work on the USRP B210 to act as a > transceiver. Basically, what I am tasked to do is to receive, > digitize, modulate and re-transmit. So what I am planning to do now > is to create a chirp signal in the USRP B210 and transmit back to > itself to the RX port. As a result, I have to send a pulse and stop > for a moment while it is receiving and then transmit again. > > Thank you in advanced! > > -Original Message- > From: Müller, Marcus (CEL) [mailto:muel...@kit.edu] > Sent: Thursday, 10 May 2018 9:09 PM > To: Yeo Jin Kuang Alvin (IA); discuss-gnuradio@gnu.org > Subject: Re: [Discuss-gnuradio] Tx Burst for Chirp signals > > sure, but it's not the way I'd recommend for perfectly periodic > transmissions and I'm almost certain this will just lead us further > down your XY problem: https://xyproblem.info > > Can you maybe explain in detail what you need chirps for, why you > need > them at this low repitition rate, what the purpose of all this is? We > might be better at helping you that way. > > thank you, > Marcus > > On Thu, 2018-05-10 at 09:58 +, Yeo Jin Kuang Alvin (IA) wrote: > > Hi, > > > > Thank you again. Are there any examples or guides I can refer to > > regarding the tx_time tags? Will this allow me to transmit every > > few > > seconds? > > > > Thank you in advanced! > > > > -Original Message- > > From: Müller, Marcus (CEL) [mailto:muel...@kit.edu] > > Sent: Thursday, 10 May 2018 5:34 PM > > To: Yeo Jin Kuang Alvin (IA); discuss-gnuradio@gnu.org > > Subject: Re: [Discuss-gnuradio] Tx Burst for Chirp signals > > > > Hi! > > > > So, you're continuously generating data to send, so it continuously > > sends data – it works as you've designed it. Maybe you want to > > somehow > > add "tx_time" tags every "packet length" samples? > > Also, make sure that one packet really contains one chirp. In your > > previous flow graph, that wasn't the case, so make sure the packet > > length corresponds to the number of samples per chirp. > > > > Best regards, > > Marcus > > > > On Thu, 2018-05-10 at 09:20 +, Yeo Jin Kuang Alvin (IA) wrote: > > > 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. St
Re: [Discuss-gnuradio] Tx Burst for Chirp signals
Could you be a little more specific, please, than "receive, digitize and re-transmit"? For what purpose? Why a chirp? Can you please give us the bigger picture, here? What's the thing you need to build? Best regards, Marcus On Fri, 2018-05-11 at 02:03 +, Yeo Jin Kuang Alvin (IA) wrote: > Hello, > > I am currently trying to work on the USRP B210 to act as a > transceiver. Basically, what I am tasked to do is to receive, > digitize, modulate and re-transmit. So what I am planning to do now > is to create a chirp signal in the USRP B210 and transmit back to > itself to the RX port. As a result, I have to send a pulse and stop > for a moment while it is receiving and then transmit again. > > Thank you in advanced! > > -Original Message- > From: Müller, Marcus (CEL) [mailto:muel...@kit.edu] > Sent: Thursday, 10 May 2018 9:09 PM > To: Yeo Jin Kuang Alvin (IA); discuss-gnuradio@gnu.org > Subject: Re: [Discuss-gnuradio] Tx Burst for Chirp signals > > sure, but it's not the way I'd recommend for perfectly periodic > transmissions and I'm almost certain this will just lead us further > down your XY problem: https://xyproblem.info > > Can you maybe explain in detail what you need chirps for, why you > need > them at this low repitition rate, what the purpose of all this is? We > might be better at helping you that way. > > thank you, > Marcus > > On Thu, 2018-05-10 at 09:58 +, Yeo Jin Kuang Alvin (IA) wrote: > > Hi, > > > > Thank you again. Are there any examples or guides I can refer to > > regarding the tx_time tags? Will this allow me to transmit every > > few > > seconds? > > > > Thank you in advanced! > > > > -Original Message- > > From: Müller, Marcus (CEL) [mailto:muel...@kit.edu] > > Sent: Thursday, 10 May 2018 5:34 PM > > To: Yeo Jin Kuang Alvin (IA); discuss-gnuradio@gnu.org > > Subject: Re: [Discuss-gnuradio] Tx Burst for Chirp signals > > > > Hi! > > > > So, you're continuously generating data to send, so it continuously > > sends data – it works as you've designed it. Maybe you want to > > somehow > > add "tx_time" tags every "packet length" samples? > > Also, make sure that one packet really contains one chirp. In your > > previous flow graph, that wasn't the case, so make sure the packet > > length corresponds to the number of samples per chirp. > > > > Best regards, > > Marcus > > > > On Thu, 2018-05-10 at 09:20 +, Yeo Jin Kuang Alvin (IA) wrote: > > > 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. > > > > > &
Re: [Discuss-gnuradio] Tx Burst for Chirp signals
Hello, I am currently trying to work on the USRP B210 to act as a transceiver. Basically, what I am tasked to do is to receive, digitize, modulate and re-transmit. So what I am planning to do now is to create a chirp signal in the USRP B210 and transmit back to itself to the RX port. As a result, I have to send a pulse and stop for a moment while it is receiving and then transmit again. Thank you in advanced! -Original Message- From: Müller, Marcus (CEL) [mailto:muel...@kit.edu] Sent: Thursday, 10 May 2018 9:09 PM To: Yeo Jin Kuang Alvin (IA); discuss-gnuradio@gnu.org Subject: Re: [Discuss-gnuradio] Tx Burst for Chirp signals sure, but it's not the way I'd recommend for perfectly periodic transmissions and I'm almost certain this will just lead us further down your XY problem: https://xyproblem.info Can you maybe explain in detail what you need chirps for, why you need them at this low repitition rate, what the purpose of all this is? We might be better at helping you that way. thank you, Marcus On Thu, 2018-05-10 at 09:58 +, Yeo Jin Kuang Alvin (IA) wrote: > Hi, > > Thank you again. Are there any examples or guides I can refer to > regarding the tx_time tags? Will this allow me to transmit every few > seconds? > > Thank you in advanced! > > -Original Message- > From: Müller, Marcus (CEL) [mailto:muel...@kit.edu] > Sent: Thursday, 10 May 2018 5:34 PM > To: Yeo Jin Kuang Alvin (IA); discuss-gnuradio@gnu.org > Subject: Re: [Discuss-gnuradio] Tx Burst for Chirp signals > > Hi! > > So, you're continuously generating data to send, so it continuously > sends data – it works as you've designed it. Maybe you want to > somehow > add "tx_time" tags every "packet length" samples? > Also, make sure that one packet really contains one chirp. In your > previous flow graph, that wasn't the case, so make sure the packet > length corresponds to the number of samples per chirp. > > Best regards, > Marcus > > On Thu, 2018-05-10 at 09:20 +, Yeo Jin Kuang Alvin (IA) wrote: > > 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 +, 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 &
Re: [Discuss-gnuradio] Tx Burst for Chirp signals
sure, but it's not the way I'd recommend for perfectly periodic transmissions and I'm almost certain this will just lead us further down your XY problem: https://xyproblem.info Can you maybe explain in detail what you need chirps for, why you need them at this low repitition rate, what the purpose of all this is? We might be better at helping you that way. thank you, Marcus On Thu, 2018-05-10 at 09:58 +, Yeo Jin Kuang Alvin (IA) wrote: > Hi, > > Thank you again. Are there any examples or guides I can refer to > regarding the tx_time tags? Will this allow me to transmit every few > seconds? > > Thank you in advanced! > > -Original Message- > From: Müller, Marcus (CEL) [mailto:muel...@kit.edu] > Sent: Thursday, 10 May 2018 5:34 PM > To: Yeo Jin Kuang Alvin (IA); discuss-gnuradio@gnu.org > Subject: Re: [Discuss-gnuradio] Tx Burst for Chirp signals > > Hi! > > So, you're continuously generating data to send, so it continuously > sends data – it works as you've designed it. Maybe you want to > somehow > add "tx_time" tags every "packet length" samples? > Also, make sure that one packet really contains one chirp. In your > previous flow graph, that wasn't the case, so make sure the packet > length corresponds to the number of samples per chirp. > > Best regards, > Marcus > > On Thu, 2018-05-10 at 09:20 +, Yeo Jin Kuang Alvin (IA) wrote: > > 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 +, 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 smime.p7s Description: S/MIME cryptographic signature ___ Discuss-gnuradio mailing list Discuss-gnuradio@gnu.org https://lists.gnu.org/mailman/listinfo/discuss-gnuradio
Re: [Discuss-gnuradio] Tx Burst for Chirp signals
Hi, Thank you again. Are there any examples or guides I can refer to regarding the tx_time tags? Will this allow me to transmit every few seconds? Thank you in advanced! -Original Message- From: Müller, Marcus (CEL) [mailto:muel...@kit.edu] Sent: Thursday, 10 May 2018 5:34 PM To: Yeo Jin Kuang Alvin (IA); discuss-gnuradio@gnu.org Subject: Re: [Discuss-gnuradio] Tx Burst for Chirp signals Hi! So, you're continuously generating data to send, so it continuously sends data – it works as you've designed it. Maybe you want to somehow add "tx_time" tags every "packet length" samples? Also, make sure that one packet really contains one chirp. In your previous flow graph, that wasn't the case, so make sure the packet length corresponds to the number of samples per chirp. Best regards, Marcus On Thu, 2018-05-10 at 09:20 +, Yeo Jin Kuang Alvin (IA) wrote: > 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 +, 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
Re: [Discuss-gnuradio] Tx Burst for Chirp signals
Hi! So, you're continuously generating data to send, so it continuously sends data – it works as you've designed it. Maybe you want to somehow add "tx_time" tags every "packet length" samples? Also, make sure that one packet really contains one chirp. In your previous flow graph, that wasn't the case, so make sure the packet length corresponds to the number of samples per chirp. Best regards, Marcus On Thu, 2018-05-10 at 09:20 +, Yeo Jin Kuang Alvin (IA) wrote: > 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 +, 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 smime.p7s Description: S/MIME cryptographic signature ___ Discuss-gnuradio mailing list Discuss-gnuradio@gnu.org https://lists.gnu.org/mailman/listinfo/discuss-gnuradio
Re: [Discuss-gnuradio] Tx Burst for Chirp signals
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 +, 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
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 +, 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 smime.p7s Description: S/MIME cryptographic signature ___ Discuss-gnuradio mailing list Discuss-gnuradio@gnu.org https://lists.gnu.org/mailman/listinfo/discuss-gnuradio
