locked LDPC #Modes Coding Process draft doc. #modes


Andy Talbot
 

Thanks for comments from a couple of people, that and a bit of extensive re-reading myself, several errors have been found and corrected.   The latest version,  with a  correction to the way the parity generation is described, has been done just now.   The document keeps the same file name, but anyone interested in this process is advised to download the latest version.   http://g4jnt.com/WSJT-X_LdpcModesCodingProcess_DRAFT.pdf

Andy  G4JNT


Reino Talarmo
 
Edited


 

Hi!

Interesting opinion as I have had no problem with the country display in any version of wsjt-x. You must have some setting not properly set. Of course it is difficult to give an advice without knowing exactly all your relates settings and whether the wsjtx_log.adi file is in the proper directory. Clearly it is not a question of program version, but something else.
I assume that e.g. you have first closed the program before installing the previous version and most probably you have also restarted your PC.

73, Reino OH3mA


Andy Talbot
 

I just check the symbol pattern generated against that output from 'code'.exe
There isn't an FT4CODE.EXE in the normal distribution, but it does exist in the distribution users build for themselves (I don't do this), but someone sent me a compiled version and my FT4 generation does check out



Erik Icket
 

Hi Andy,

I am willing to try an implementation in Java following your guide. I have already a working WSPR encoder in Java, which can produce the channel symbols and the subsequent audio waveform.

I suppose testing the implementation and your documented steps is done with the *code.exe WSJT-X executables and verifying the intermediate results. Or do you have any better idea / examples to verify the implementation steps ?

73's Erik
ON4PB

 


Andy Talbot
 

The Document has been updated to include FT4 - although as there appears to be be no FT4CODE utility, it has not bene possible to verify coding process by rewriting into PowerBasic and checking.  http://g4jnt.com/WSJT-X_LdpcModesCodingProcess_DRAFT.pdf



On Tue, 7 Dec 2021 at 16:25, Andy Talbot <andy.g4jnt@...> wrote:
I've written a description of the coding process for the LDPC modes FST4/FST4W, FT8 and MSK144 based on a study of the source code, converting this into code generating routines in an alternative programming language to make sure it gives the same symbol sets

Can someone who understands the innards in depth take a look at this and see if I've made any glaring foobs in there.

My routines work (plain text and telemetry mode only) but something may have got missed while doing the write-up.


Andy Talbot
 

I've written a description of the coding process for the LDPC modes FST4/FST4W, FT8 and MSK144 based on a study of the source code, converting this into code generating routines in an alternative programming language to make sure it gives the same symbol sets

Can someone who understands the innards in depth take a look at this and see if I've made any glaring foobs in there.

My routines work (plain text and telemetry mode only) but something may have got missed while doing the write-up.