But still in CCSDS case i am getting -0.3 only BER and not even saturating in FEC extended CC case(as per CCSDS Standard book it is dropping to 0 by 5dB)
On Sat, Aug 19, 2023 at 8:54 AM U L <jaredd...@gmail.com> wrote: > Hmm, this has gotten more complicated since your original post. Why? > > A good place to start might be the example GRC as referenced on this page > https://wiki.gnuradio.org/index.php?title=FEC_Extended_Decoder. You can > change the FEC definitions from LDPC to CC and add a BER block with a delay > b/w the input bytes and output bytes (bypass the char to float after the > decoder). Once that's working, you can replace the FEC encoder with a CCSDS > one. > > Jared. > > On Fri, Aug 18, 2023 at 9:05 PM Jiya Johnson <jiyajohnso...@gmail.com> > wrote: > >> I am getting need help pls look on the screenshot >> >> On Sat, Aug 19, 2023 at 8:23 AM Jiya Johnson <jiyajohnso...@gmail.com> >> wrote: >> >>> I will try and let you know >>> >>> On Sat, Aug 19, 2023, 8:08 AM U L <jaredd...@gmail.com> wrote: >>> >>>> Probably easier to use a vector source rather than text file. Vector >>>> source lets you specify the bytes exactly. So you could put in [ 0xdd, ] >>>> and be assured that byte will be output. >>>> >>>> On Fri, Aug 18, 2023 at 8:32 PM Jiya Johnson <jiyajohnso...@gmail.com> >>>> wrote: >>>> >>>>> What I tried is 11011101( by inputting a text file )it's hex version >>>>> came in the output with (3131303131313031) like that with encoding by left >>>>> shifting I got the value theoretically and decode I got dd (11011101) bt >>>>> this worked over windows not in ubuntu,this output I have done using >>>>> messag >>>>> debug option I am not aware whether it is the correct way. >>>>> >>>>> On Sat, Aug 19, 2023, 7:58 AM U L <jaredd...@gmail.com> wrote: >>>>> >>>>>> I don't understand what this means. How do you interpret it? >>>>>> Jared. >>>>>> >>>>>> >>>>>> On Fri, Aug 18, 2023 at 8:25 PM Jiya Johnson <jiyajohnso...@gmail.com> >>>>>> wrote: >>>>>> >>>>>>> >>>>>>> On Sat, Aug 19, 2023, 7:54 AM Jiya Johnson <jiyajohnso...@gmail.com> >>>>>>> wrote: >>>>>>> >>>>>>>> I have tried to do with a simple input 11011101 without noise and >>>>>>>> with noise noise also >>>>>>>> >>>>>>>> On Sat, Aug 19, 2023, 7:52 AM U L <jaredd...@gmail.com> wrote: >>>>>>>> >>>>>>>>> Some ideas: >>>>>>>>> >>>>>>>>> 1. Remove the noise completely. Also use a fixed, repeating input >>>>>>>>> vector rather than random bytes. Look at the actual error patterns >>>>>>>>> between >>>>>>>>> the input and output bits. Sometimes error patterns can clue you in. >>>>>>>>> 2. Check symbol polarity (i.e. 0=>-1, 1=>1, or 0=>1, 1=>-1) >>>>>>>>> 3. Try the more general (non-CCSDS) extended encoder with the same >>>>>>>>> params as the decoder. >>>>>>>>> 4. Esp if 3 works, compare the output of CCSDS with general >>>>>>>>> extended encoder. >>>>>>>>> >>>>>>>>> Good luck. >>>>>>>>> Jared. >>>>>>>>> >>>>>>>>> On Fri, Aug 18, 2023 at 8:04 PM Jiya Johnson < >>>>>>>>> jiyajohnso...@gmail.com> wrote: >>>>>>>>> >>>>>>>>>> Hi, >>>>>>>>>> Based on the given modifications still I am getting a -0.300 >>>>>>>>>> range of BER constantly from 0 to 15 dB range of SNR values.No >>>>>>>>>> variations >>>>>>>>>> are happening. >>>>>>>>>> >>>>>>>>>> How can I check the functionality of the block(encoder and >>>>>>>>>> decoder to check whether it's encoding and decoding properly)with a >>>>>>>>>> sample >>>>>>>>>> input. >>>>>>>>>> >>>>>>>>>> On Sun, Aug 13, 2023, 8:11 PM U L <jaredd...@gmail.com> wrote: >>>>>>>>>> >>>>>>>>>>> One other thing I noticed is that the encode CCSDS, decode, >>>>>>>>>>> CCSDS, and BER blocks all operate on packed bytes. (See e.g. >>>>>>>>>>> https://wiki.gnuradio.org/index.php?title=Encode_CCSDS_27). To >>>>>>>>>>> do this you would change your random source to output from 0 to 256 >>>>>>>>>>> byte >>>>>>>>>>> values. Also, considering the output of the decoder block are >>>>>>>>>>> packed bytes >>>>>>>>>>> you should probably skip the byte->float and binary slicer after >>>>>>>>>>> your >>>>>>>>>>> decoder and just input it's output directly into the BER block. >>>>>>>>>>> Finally, >>>>>>>>>>> looking at the >>>>>>>>>>> https://wiki.gnuradio.org/index.php?title=Decode_CCSDS_27 page >>>>>>>>>>> it seems the delay out of the decoder is 4 bytes, so you could add >>>>>>>>>>> a delay >>>>>>>>>>> of 4 between your source and BER block to align the two streams. >>>>>>>>>>> >>>>>>>>>>> Jared. >>>>>>>>>>> >>>>>>>>>>> On Sat, Aug 12, 2023 at 9:58 PM U L <jaredd...@gmail.com> wrote: >>>>>>>>>>> >>>>>>>>>>>> One thing I think might be an issue is that you have no delay >>>>>>>>>>>> between your source reference and your BER block. Usually the FEC >>>>>>>>>>>> decoders >>>>>>>>>>>> (and possibly the encoder?) may output blocks of 0s before they >>>>>>>>>>>> output the >>>>>>>>>>>> samples that correspond to your inputs. I don't know much about >>>>>>>>>>>> those FEC >>>>>>>>>>>> blocks specifically, but maybe the docs have some info on their >>>>>>>>>>>> delays. You >>>>>>>>>>>> can just insert a delay block b/w your random source and the ber >>>>>>>>>>>> block to >>>>>>>>>>>> align the input and output bits. >>>>>>>>>>>> >>>>>>>>>>>> Hope that helps, >>>>>>>>>>>> Jared. >>>>>>>>>>>> >>>>>>>>>>>> On Sat, Aug 12, 2023 at 4:28 AM Jiya Johnson < >>>>>>>>>>>> jiyajohnso...@gmail.com> wrote: >>>>>>>>>>>> >>>>>>>>>>>>> >>>>>>>>>>>>> [image: image.png] >>>>>>>>>>>>> Dear community >>>>>>>>>>>>> Need help for BER plot using the above flowgraph its always >>>>>>>>>>>>> coming 10^-1.17 and whenever I tried to change the noise voltage >>>>>>>>>>>>> the values >>>>>>>>>>>>> are not changing. >>>>>>>>>>>>> Please find the attached GRC file for your reference. >>>>>>>>>>>>> >>>>>>>>>>>>> *Regards, JIYA JOHNSON* >>>>>>>>>>>>> >>>>>>>>>>>>>
BER_FEC EXTENDED.pdf
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BER_CCSDS-fec extended.pdf
Description: Adobe PDF document
