Hello Ben, Shantharam, my colleague, installed the latest UHD image. Now I don't see the 1 MHz frequency offset any more. The benchmark_rx program is also receiving packets correctly from the benchmark_tx code.
Thanks a lot for your help. We really appreciate your effort. Nazmul On Thu, Feb 9, 2012 at 12:44 PM, Ben Hilburn <b...@ettus.com> wrote: > Nazmul - > > Your version of UHD is from November 22nd. Will you try updating your UHD > install? > > I'm not sure how you installed, or how familiar you are with git / Linux > - here is a quick command list, assuming you used Git to checkout the code > to begin with, and it is in a directory called uhd.git/ > > $ cd uhd.git > $ git checkout master > $ git remote update; git pull > $ rm -rf build > $ mkdir build; cd build > $ cmake ../ && make > > Let us know how it goes! > > Cheers, > Ben > > On Wed, Feb 8, 2012 at 8:52 PM, Nazmul Islam > <mnis...@winlab.rutgers.edu>wrote: > >> Thanks for the reply, Jason. The uhd_usrp_probe --version command gave >> the following result: >> >> linux; GNU C++ version 4.4.5; Boost_104200; UHD_003.004.000-71810ad >> >> 003.004.000-71810ad >> >> Do I have to download the latest UHD image? The image that I am using >> right now was downloaded by one of my colleagues and I think that he did it >> recently. >> >> Also, I tried running the benchmark_tx and benchmark_rx codes with a 1 >> MHz frequency offset input, i.e., I gave the following commands: >> >> ./benchmark_tx.py -f 2.4G -r 1M -m gmsk -a "addr = 192.168.10.2" >> >> ./benchmark_tx.py -f 2.401G -r 1M -m gmsk -a "addr = 192.168.10.2" >> >> Since the uhd_fft.py and the my lab spectrum analyzer show a 1 MHz >> frequency offset, I assumed that the above commands would work. >> Unfortunately, this did not help either! >> >> Suggestions will be very appreciated. >> >> Thanks, >> >> Nazmul >> >> >> >> >> On Wed, Feb 8, 2012 at 7:37 PM, Jason Abele <ja...@ettus.com> wrote: >> >>> On Wed, Feb 08, 2012 at 06:39:24PM -0500, Nazmul Islam wrote: >>> > Hello, >>> > >>> > I am running the benchmark_tx.py codes and looking at the spectrum of >>> the >>> > signals using uhd_fft.py. I am using the latest image of GNU radio >>> > (GNUradio 3.5) and I have XCVR2450 daughterboards. I ran the >>> > benchmark_tx.py code in three transmitter nodes and surprisingly, all >>> of >>> > them are transmitting with 1 MHz frequency offset! I have attached two >>> > screenshots with the email (I hope that they go through). I give the >>> > following input parameters to run the benchmark_tx code. >>> > >>> > ./benchmark_tx.py -f 2.4G -r 1M -m gmsk -M 10 -a "addr = 192.168.10.2" >>> > >>> > Both uhd_fft.py and the spectrum analyzer of my laboratory show that >>> the >>> > received signal is centered at 2.401 GHz. I varied the frequency to >>> 2.45 >>> > GHz, 2.41 GHz, but this 1 MHz frequency shift persists. >>> > >>> > When I run the benchmark_rx.py code at the receiver nodes, they don't >>> > receive/detect any packets (due to the frequency offset, I guess). I >>> even >>> > tried to run the transmitter at 2.4 GHz and the receiver at 2.401 GHz. >>> > However, that did not help either! >>> > >>> > I will try to modify the control loop gain parameters using Tom's blogs >>> > suggestions and see if that helps. However, I am really surprised to >>> see >>> > how all three different transmitter nodes can transmit with almost >>> exactly >>> > 1 MHz frequency offset. Any suggestion will be appreciated. >>> > >>> >>> Can you tell us which version of UHD you are using? >>> (uhd_usrp_probe --version) >>> >>> We have heard reports of such an issue and my best guess is that it was >>> related to an accidental swap of I and Q in the XCVR2450 transmitter >>> code. This went in after the 3.3.2 release and is fixed on latest UHD >>> master since 837437c65ce36d418cceb3df5b093f9497b3af5f >>> >>> Jason >>> >> >> >> >> -- >> Muhammad Nazmul Islam >> >> Graduate Student >> Electrical & Computer Engineering >> Wireless Information & Networking Laboratory >> Rutgers, USA. >> >> >> _______________________________________________ >> Discuss-gnuradio mailing list >> Discuss-gnuradio@gnu.org >> https://lists.gnu.org/mailman/listinfo/discuss-gnuradio >> >> > -- Muhammad Nazmul Islam Graduate Student Electrical & Computer Engineering Wireless Information & Networking Laboratory Rutgers, USA.
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