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Discussion and technical support related to USRP, UHD, RFNoC
View all threadsRe: [USRP-users] Support with setting usrp sampling rate to 150MSPS
Hello Koyel,
This is a fundamental problem that increasing sample rate takes more
processing power to handle but provides more bandwidth of spectrum. How
wide is the signal you need to process? The general recommendation is that
you sample at 1.25 times your bandwidth. This provides 20% more spectrum
than is necessary, but means that your signal is minimally affected by the
digital filters used in the decimation in the FPGA. This is part of how the
160 MHz bandwidth of the UBX is derived from the 200 MHz sampling rate of
an X310 (what is inside the 2954R).
The default FPGA image is limited to integer decimation rates as described
in the manual.
http://files.ettus.com/manual/page_general.html#general_sampleratenotes
GSM 1800 covers 170 MHz so even with the full sampling rate the outermost
edges will be attenuated by both the analog filters and the digital
filters. If you only want to look at the uplink or downlink individually
then you can observe the 75 MHz bandwidth with 100 MS/s and easily meet the
recommended maximum of 80% occupied bandwidth.
For non-integer decimation rates such as 200e6/150e6 = 4/3 you would have
to implement a rational resampler as a custom RFNoC block to support that
decimation rate, certainly possible but additional work.
Regards,
Derek
On Wed, Aug 23, 2017 at 7:17 AM, Koyel Das koyel.das@vehere.com wrote:
Hi,
Many thanks for your reply. Yes 200 MSps works.
But taking 200 MSps will increase the amount of data considerably and
increase the processing time and very less amount of data is decoded from
large amount of input samples compared to lower sampling frequencies. What
is the solution to these problems?
Regards,
Koyel
On Tue, Aug 22, 2017 at 9:14 PM, Snehasish Kar snehasish.cse@live.com
wrote:
Ok I will try that.
BR
Snehasish
On 22-Aug-2017, at 8:51 PM, Derek Kozel derek.kozel@ettus.com wrote:
Try 200MS/s. The FPGA can only decimate integer amounts from the ADC
rate, which is 200MS/s.
On Tue, Aug 22, 2017 at 5:15 PM, Snehasish Kar via USRP-users <
usrp-users@lists.ettus.com> wrote:
Hello
I am trying to receive gsm 1800 band using NI USRP 2954R, but when I am
trying to set the sampling rate of uhd_source in gnuradio to 150 MSPS, it's
giving an error message saying hardware does not support sampling rate
above 100MSPS.
Please help!
BR
Snehasish
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USRP-users@lists.ettus.com
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--
Koyel Das
Senior Product Engineer
Vehere | Proactive Communications Intelligence & Cyber Defence
M: +919051132173 <+91%2090511%2032173> | T: +91 33 24008400
<+91%2033%202400%208400> | F: +91 33 247988100 | W: www.vehere.com
Vehere is the proud recipient of the Fastest Growing Technology Company
Awards in India & Asia since 2012!
The content of this e-mail is confidential and intended solely for the use
of the addressee. The text of this email (including any attachments) may
contain information, which is proprietary and/or confidential or privileged
in nature belonging to Vehere Interactive Pvt Ltd and/or its associates/
group companies/ subsidiaries. If you are not the addressee, or the person
responsible for delivering it to the addressee, any disclosure, copying,
distribution or any action taken or omitted to be taken in reliance on it
is prohibited and may be unlawful. If you have received this e-mail in
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is given as to completeness and accuracy of the content of the email. The
recipient further acknowledges that the views contained in the email
message are those of the sender and may not necessarily reflect those of
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please check and scan for virus. WARNING: Computer viruses can be
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for any damage caused by any virus transmitted by this email.
Hi,
I am capturing 75 MHz using 100 MSps sample rate as well as using 200 MSps sample rate but I am not getting the near-end bands with 100 MSps while I am getting those with 200 MSps. What I have done is capture the data and then pass it through a polyphase channelizer to give me 200 K bandwidth channels and then I am upsampling that data to 1 MSps or 2 Msps and passing through gr-gsm receiver. With 200 MSps I am getting correct data whereas with 100 MSps I am not. But according to usrp specs my sampling rate as 1.25*75 MHz should be enough but that is not happening. Please help.
Regards,
Snehasish
From: Derek Kozel derek.kozel@ettus.com
Sent: Wednesday, August 23, 2017 12:15:11 PM
To: Koyel Das
Cc: Snehasish Kar; usrp-users@lists.ettus.com
Subject: Re: [USRP-users] Support with setting usrp sampling rate to 150MSPS
Hello Koyel,
This is a fundamental problem that increasing sample rate takes more processing power to handle but provides more bandwidth of spectrum. How wide is the signal you need to process? The general recommendation is that you sample at 1.25 times your bandwidth. This provides 20% more spectrum than is necessary, but means that your signal is minimally affected by the digital filters used in the decimation in the FPGA. This is part of how the 160 MHz bandwidth of the UBX is derived from the 200 MHz sampling rate of an X310 (what is inside the 2954R).
The default FPGA image is limited to integer decimation rates as described in the manual.
http://files.ettus.com/manual/page_general.html#general_sampleratenotes
GSM 1800 covers 170 MHz so even with the full sampling rate the outermost edges will be attenuated by both the analog filters and the digital filters. If you only want to look at the uplink or downlink individually then you can observe the 75 MHz bandwidth with 100 MS/s and easily meet the recommended maximum of 80% occupied bandwidth.
For non-integer decimation rates such as 200e6/150e6 = 4/3 you would have to implement a rational resampler as a custom RFNoC block to support that decimation rate, certainly possible but additional work.
Regards,
Derek
On Wed, Aug 23, 2017 at 7:17 AM, Koyel Das <koyel.das@vehere.commailto:koyel.das@vehere.com> wrote:
Hi,
Many thanks for your reply. Yes 200 MSps works.
But taking 200 MSps will increase the amount of data considerably and increase the processing time and very less amount of data is decoded from large amount of input samples compared to lower sampling frequencies. What is the solution to these problems?
Regards,
Koyel
On Tue, Aug 22, 2017 at 9:14 PM, Snehasish Kar <snehasish.cse@live.commailto:snehasish.cse@live.com> wrote:
Ok I will try that.
BR
Snehasish
On 22-Aug-2017, at 8:51 PM, Derek Kozel <derek.kozel@ettus.commailto:derek.kozel@ettus.com> wrote:
Try 200MS/s. The FPGA can only decimate integer amounts from the ADC rate, which is 200MS/s.
On Tue, Aug 22, 2017 at 5:15 PM, Snehasish Kar via USRP-users <usrp-users@lists.ettus.commailto:usrp-users@lists.ettus.com> wrote:
Hello
I am trying to receive gsm 1800 band using NI USRP 2954R, but when I am trying to set the sampling rate of uhd_source in gnuradio to 150 MSPS, it's giving an error message saying hardware does not support sampling rate above 100MSPS.
Please help!
BR
Snehasish
USRP-users mailing list
USRP-users@lists.ettus.commailto:USRP-users@lists.ettus.com
http://lists.ettus.com/mailman/listinfo/usrp-users_lists.ettus.com
--
Koyel Das
Senior Product Engineer
Vehere | Proactive Communications Intelligence & Cyber Defence
M: +919051132173tel:+91%2090511%2032173 | T: +91 33 24008400tel:+91%2033%202400%208400 | F: +91 33 247988100 | W: www.vehere.comhttp://www.vehere.com
Vehere is the proud recipient of the Fastest Growing Technology Company Awards in India & Asia since 2012!
The content of this e-mail is confidential and intended solely for the use of the addressee. The text of this email (including any attachments) may contain information, which is proprietary and/or confidential or privileged in nature belonging to Vehere Interactive Pvt Ltd and/or its associates/ group companies/ subsidiaries. If you are not the addressee, or the person responsible for delivering it to the addressee, any disclosure, copying, distribution or any action taken or omitted to be taken in reliance on it is prohibited and may be unlawful. If you have received this e-mail in error, please notify the sender and remove this communication entirely from your system. The recipient acknowledges that no guarantee or any warranty is given as to completeness and accuracy of the content of the email. The recipient further acknowledges that the views contained in the email message are those of the sender and may not necessarily reflect those of Vehere Interactive Pvt Ltd. Before opening and accessing the attachment please check and scan for virus. WARNING: Computer viruses can be transmitted via email. The recipient should check this email and any attachments for the presence of viruses. The company accepts no liability for any damage caused by any virus transmitted by this email.
Hi Snehasish,
knowing the roll-off of the halfband filters in the USRP, this is rather
surprising. So, my best guess is that there's might be a problem with
your software, but I can't really assess that.
Best regards,
Marcus
On 09/13/2017 12:41 PM, Snehasish Kar via USRP-users wrote:
I have noticed that IQ will stream from unpopulated daughtercard
slots... Is this expected?
Hi,
I am capturing 75 MHz using 100 MSps sample rate as well as using 200
MSps sample rate but I am not getting the near-end bands with 100 MSps
while I am getting those with 200 MSps. What I have done is capture
the data and then pass it through a polyphase channelizer to give me
200 K bandwidth channels and then I am upsampling that data to 1 MSps
or 2 Msps and passing through gr-gsm receiver. With 200 MSps I am
getting correct data whereas with 100 MSps I am not. But according to
usrp specs my sampling rate as 1.25*75 MHz should be enough but that
is not happening. Please help.
Regards,
Snehasish
From: Derek Kozel derek.kozel@ettus.com
Sent: Wednesday, August 23, 2017 12:15:11 PM
To: Koyel Das
Cc: Snehasish Kar; usrp-users@lists.ettus.com
Subject: Re: [USRP-users] Support with setting usrp sampling rate to
150MSPS
Hello Koyel,
This is a fundamental problem that increasing sample rate takes more
processing power to handle but provides more bandwidth of spectrum.
How wide is the signal you need to process? The general recommendation
is that you sample at 1.25 times your bandwidth. This provides 20%
more spectrum than is necessary, but means that your signal is
minimally affected by the digital filters used in the decimation in
the FPGA. This is part of how the 160 MHz bandwidth of the UBX is
derived from the 200 MHz sampling rate of an X310 (what is inside the
2954R).
The default FPGA image is limited to integer decimation rates as
described in the manual.
http://files.ettus.com/manual/page_general.html#general_sampleratenotes
GSM 1800 covers 170 MHz so even with the full sampling rate the
outermost edges will be attenuated by both the analog filters and the
digital filters. If you only want to look at the uplink or downlink
individually then you can observe the 75 MHz bandwidth with 100 MS/s
and easily meet the recommended maximum of 80% occupied bandwidth.
For non-integer decimation rates such as 200e6/150e6 = 4/3 you would
have to implement a rational resampler as a custom RFNoC block to
support that decimation rate, certainly possible but additional work.
Regards,
Derek
On Wed, Aug 23, 2017 at 7:17 AM, Koyel Das <koyel.das@vehere.com
mailto:koyel.das@vehere.com> wrote:
Hi,
Many thanks for your reply. Yes 200 MSps works.
But taking 200 MSps will increase the amount of data considerably
and increase the processing time and very less amount of data is
decoded from large amount of input samples compared to lower
sampling frequencies. What is the solution to these problems?
Regards,
Koyel
On Tue, Aug 22, 2017 at 9:14 PM, Snehasish Kar
<snehasish.cse@live.com <mailto:snehasish.cse@live.com>> wrote:
Ok I will try that.
BR
Snehasish
On 22-Aug-2017, at 8:51 PM, Derek Kozel <derek.kozel@ettus.com
<mailto:derek.kozel@ettus.com>> wrote:
Try 200MS/s. The FPGA can only decimate integer amounts from
the ADC rate, which is 200MS/s.
On Tue, Aug 22, 2017 at 5:15 PM, Snehasish Kar via USRP-users
<usrp-users@lists.ettus.com
<mailto:usrp-users@lists.ettus.com>> wrote:
Hello
I am trying to receive gsm 1800 band using NI USRP 2954R,
but when I am trying to set the sampling rate of
uhd_source in gnuradio to 150 MSPS, it's giving an error
message saying hardware does not support sampling rate
above 100MSPS.
Please help!
BR
Snehasish
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--
Koyel Das
Senior Product Engineer
Vehere | Proactive Communications Intelligence & Cyber Defence
M: +919051132173 <tel:+91%2090511%2032173> | T: +91 33 24008400
<tel:+91%2033%202400%208400> | F: +91 33 247988100 | W:
www.vehere.com <http://www.vehere.com>
Vehere is the proud recipient of the Fastest Growing Technology
Company Awards in India & Asia since 2012!
The content of this e-mail is confidential and intended solely for
the use of the addressee. The text of this email (including any
attachments) may contain information, which is proprietary and/or
confidential or privileged in nature belonging to Vehere
Interactive Pvt Ltd and/or its associates/ group companies/
subsidiaries. If you are not the addressee, or the person
responsible for delivering it to the addressee, any disclosure,
copying, distribution or any action taken or omitted to be taken
in reliance on it is prohibited and may be unlawful. If you have
received this e-mail in error, please notify the sender and remove
this communication entirely from your system. The recipient
acknowledges that no guarantee or any warranty is given as to
completeness and accuracy of the content of the email. The
recipient further acknowledges that the views contained in the
email message are those of the sender and may not necessarily
reflect those of Vehere Interactive Pvt Ltd. Before opening and
accessing the attachment please check and scan for virus. WARNING:
Computer viruses can be transmitted via email. The recipient
should check this email and any attachments for the presence of
viruses. The company accepts no liability for any damage caused by
any virus transmitted by this email.
USRP-users mailing list
USRP-users@lists.ettus.com
http://lists.ettus.com/mailman/listinfo/usrp-users_lists.ettus.com