Tom - maybe you can correct me if I'm wrong, here? I think you are asking about the changes Tom made to the general loop formula, the details of which you can find here:
http://www.trondeau.com/blog/2011/8/13/control-loop-gain-values.html Cheers, Ben On Thu, Feb 2, 2012 at 7:14 AM, shashank gaur <shashankg...@ieee.org> wrote: > Hello > > First of all Thank you very much for your support > I was able to run the program on two different USRP and it was successful. > > But still I have some new problems. Actually I am doing my masters project > on gnuradio and usrp. > I am trying to make a BPSK transmitter and receiver(Attached GRC Files), > then use it further in my project. My mentor suggested to use MPSK Receiver > for the receiver part but I am not sure about Loop Bandwidth and Theta as > the solution my mentor gave is for the old version of gnuradio. Can you > help me with understanding these parameters? > Right now when I start my receiver program on a usrp the number plot > varies around 0.5 (which I guess is normal when there is no transmission) > but when I start transmitter the value goes high to 0.6 or 0.7 (It should > be lower than 0.3). > I am using following parameters for the same > > M = 2 for BPSK > > Theta = 0 (I was not sure about this so I put it 0) > > Loop Bandwidth= ????? (I dont knw what to put here) > > Min Freq = -0.05 > > Max Freq = 0.05 > > Mu = 0.5 > > Gain Mu = 0.001 > > Omega = 8 > > Gain Omega = 0.000001 > > Omega Relative Limit = 0.0001 > Also I tried to use Costas loop and Clock Recovery MM with same parameters > but they are also not working. > It would be great help if anyone can help me understand these parameters. > > Shashank Gaur > > > > On Fri, Jan 27, 2012 at 9:38 PM, shashank gaur <shashankg...@ieee.org>wrote: > >> Hello all >> Thank you very much for such prompt response. >> >> @Marcus: I understand the problem now and will try to implement the Rx >> and Tx on different USRP on Monday. The weeekend has already started here >> in France. >> @Andrew: I will also get back with exact result of the commands but what >> I remember for uhd_find_devices the result was the device address that is >> 4d9de875 and in uhd_usrp_probe it detected all the available RX and Tx (it >> has Flex900). >> Apologies for the delay but cannot access the usrp before Monday. The >> mentor doesnt allow me to have usrp at home. Hope you understand >> Thanks again for your time >> >> shashank gaur >> >> On Fri, Jan 27, 2012 at 9:18 PM, Marcus D. Leech <mle...@ripnet.com>wrote: >> >>> ** >>> On 27/01/12 03:00 PM, Andrew Davis wrote: >>> >>> Type " uhd_find_devices " into console, then " uhd_usrp_probe " then >>> give us the results, and the code for the program you're trying to run. >>> >>> On Fri, Jan 27, 2012 at 9:39 AM, shashank gaur <shashankg...@ieee.org>wrote: >>> >>>> Hello >>>> >>>> I am simply trying to build a transmitter and receiver for bpsk >>>> modulation and demodulation using mpsk receiver at receiving end. I am >>>> using USRP1 (Flex900 Daughter boards) with Gnuradio Companion 3.5.0rc0 on >>>> Ubuntu 10.10. >>>> >>>> When I run either (trransmitter or receiver) of any grc applications >>>> first the grc executes it successfully and when I run other the grc gives >>>> following error. >>>> linux; GNU C++ version 4.4.5; Boost_104200; UHD_003.003.001-8ff8f20 >>>> >>>> Traceback (most recent call last): >>>> File "/home/sunny/Examples/top_block.py", line 105, in <module> >>>> tb = top_block() >>>> File "/home/sunny/Examples/top_block.py", line 40, in __init__ >>>> num_channels=1, >>>> File >>>> "/usr/local/lib/python2.6/dist-packages/gnuradio/uhd/__init__.py", line 93, >>>> in constructor_interceptor >>>> return old_constructor(*args, **kwargs) >>>> File >>>> "/usr/local/lib/python2.6/dist-packages/gnuradio/uhd/uhd_swig.py", line >>>> 2003, in usrp_sink >>>> return _uhd_swig.usrp_sink(*args, **kwargs) >>>> RuntimeError: LookupError: KeyError: No devices found for -----> >>>> Device Address: >>>> serial: 4d9de875 >>>> >>>> >>>> I think it has something to do with USRP UHD Source/Sink block >>>> parameters. >>>> Either the grc is not able to recognize the daughter board or there is >>>> problem with hardware. may be I am wrong. >>>> Please help me to recognize the error. >>>> Thank you very much for your time >>>> Shashank Gaur >>>> >>>> _______________________________________________ >>>> Discuss-gnuradio mailing list >>>> Discuss-gnuradio@gnu.org >>>> https://lists.gnu.org/mailman/listinfo/discuss-gnuradio >>>> >>>> >>> >>> _______________________________________________ >>> Discuss-gnuradio mailing >>> listDiscuss-gnuradio@gnu.orghttps://lists.gnu.org/mailman/listinfo/discuss-gnuradio >>> >>> Just so we're clear here. If you're trying to run your RX and TX as two >>> separate processes, against the >>> same USRP1, that won't work. You'll need to have two independant >>> USRP1s, or collapse your RX and >>> TX into a single combined program--only one process can have a >>> "handle" against each USRP1 at a time. >>> >>> >>> >>> >>> -- >>> Principal Investigator >>> Shirleys Bay Radio Astronomy Consortiumhttp://www.sbrac.org >>> >>> >>> _______________________________________________ >>> 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 > >
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