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* >>>>> >>>>>
