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* >>>>>>>>>>>> >>>>>>>>>>>>
