WSJT-X/lib/fst4
Steven Franke 11b7aa9429
Implements decoding of FST4W messages as (240,50) crc-less codewords.
By cascading the full 24-bit crc generator matrix with the (240,74) LDPC code generator, create a (240,50) generator that is used to decode with approximately 1 dB better sensitivity than the (240,64) with 14-bit CRC approach that is normally used. This approach treats the CRC bits as additional parity bits and provides no means for identifying incorrect codewords. All codewords on the list generated by the OSD algorithm have CRCs that match the CRC of the message payload. Codewords are validated by unpacking the message and comparing the unpacked message with the list of stored callsign/grid pairs stored in the fst4w_calls.txt file.
2021-01-04 14:59:56 +00:00
..
bpdecode240_101.f90 Rename fst240 to fst4 in Fortran routines. 2020-07-23 12:48:50 -05:00
decode240_74.f90 Implements decoding of FST4W messages as (240,50) crc-less codewords. 2021-01-04 14:59:56 +00:00
decode240_101.f90 Tweaks to update the diagnostics that are written to fort.21. 2020-08-29 19:55:22 +01:00
encode240_74.f90 Rename fst240 to fst4 in Fortran routines. 2020-07-23 12:48:50 -05:00
encode240_101.f90 Rename fst240 to fst4 in Fortran routines. 2020-07-23 12:48:50 -05:00
fastosd240_74.f90 Implements decoding of FST4W messages as (240,50) crc-less codewords. 2021-01-04 14:59:56 +00:00
fst4_baseline.f90 Use 3rd order polynomial fit to estimate the noise baseline. The 2020-08-29 19:55:23 +01:00
fst4_params.f90 Rename fst240 to fst4 in Fortran routines. 2020-07-23 12:48:50 -05:00
fst4sim.f90 Rename fst240 to fst4 in Fortran routines. 2020-07-23 12:48:50 -05:00
gen_fst4wave.f90 Rename fst240 to fst4 in Fortran routines. 2020-07-23 12:48:50 -05:00
genfst4.f90 A few more cosmetic 240 -> 4 changes 2020-07-23 19:13:05 +01:00
get_crc24.f90 Rename fst240 to fst4 in Fortran routines. 2020-07-23 12:48:50 -05:00
get_fst4_bitmetrics2.f90 Fix SNR calculation for B,C,D submodes. 2020-08-29 19:49:46 +01:00
get_fst4_bitmetrics.f90 Remove some unused variables. 2020-09-14 13:07:07 -05:00
ldpc_240_74_generator.f90 Rename fst240 to fst4 in Fortran routines. 2020-07-23 12:48:50 -05:00
ldpc_240_74_parity.f90 Rename fst240 to fst4 in Fortran routines. 2020-07-23 12:48:50 -05:00
ldpc_240_101_generator.f90 Rename fst240 to fst4 in Fortran routines. 2020-07-23 12:48:50 -05:00
ldpc_240_101_parity.f90 Rename fst240 to fst4 in Fortran routines. 2020-07-23 12:48:50 -05:00
ldpcsim240_74.f90 Implements decoding of FST4W messages as (240,50) crc-less codewords. 2021-01-04 14:59:56 +00:00
ldpcsim240_101.f90 Rename fst240 to fst4 in Fortran routines. 2020-07-23 12:48:50 -05:00
osd240_74.f90 Rename fst240 to fst4 in Fortran routines. 2020-07-23 12:48:50 -05:00
osd240_101.f90 Rename fst240 to fst4 in Fortran routines. 2020-07-23 12:48:50 -05:00