From 44b4c180f65d2a200ae3fce58bc766dbaaa079f4 Mon Sep 17 00:00:00 2001 From: Joe Taylor Date: Wed, 14 Jun 2017 20:21:01 +0000 Subject: [PATCH] First bare-bones decoder for FT8. git-svn-id: svn+ssh://svn.code.sf.net/p/wsjt/wsjt/branches/wsjtx@7716 ab8295b8-cf94-4d9e-aec4-7959e3be5d79 --- CMakeLists.txt | 10 ++++++++++ lib/fsk4hf/extractmessage174.f90 | 3 ++- lib/fsk4hf/ft8_params.f90 | 13 +++++++------ lib/fsk4hf/ft8sim.f90 | 24 ++++++++++++------------ lib/fsk4hf/genft8.f90 | 22 ++++++++++++---------- 5 files changed, 43 insertions(+), 29 deletions(-) diff --git a/CMakeLists.txt b/CMakeLists.txt index b423f66f7..c4d0710e7 100644 --- a/CMakeLists.txt +++ b/CMakeLists.txt @@ -326,6 +326,7 @@ set (wsjt_FSRCS lib/bpdecode144.f90 lib/fsk4hf/bpdecode120.f90 lib/fsk4hf/bpdecode168.f90 + lib/fsk4hf/bpdecode174.f90 lib/fsk4hf/bpdecode300.f90 lib/baddata.f90 lib/ccf2.f90 @@ -356,6 +357,7 @@ set (wsjt_FSRCS lib/encode_msk144.f90 lib/fsk4hf/encode120.f90 lib/fsk4hf/encode168.f90 + lib/fsk4hf/encode174.f90 lib/fsk4hf/encode300.f90 lib/entail.f90 lib/ephem.f90 @@ -363,6 +365,7 @@ set (wsjt_FSRCS lib/extract4.f90 lib/extractmessage144.f90 lib/fsk4hf/extractmessage168.f90 + lib/fsk4hf/extractmessage174.f90 lib/fano232.f90 lib/fast9.f90 lib/fast_decode.f90 @@ -387,6 +390,7 @@ set (wsjt_FSRCS lib/fqso_first.f90 lib/freqcal.f90 lib/fsk4hf/fsk4hf.f90 + lib/fsk4hf/ft8d.f90 lib/fsk4hf/ft8sim.f90 lib/gen4.f90 lib/gen65.f90 @@ -428,6 +432,7 @@ set (wsjt_FSRCS lib/ldpcsim144.f90 lib/fsk4hf/ldpcsim120.f90 lib/fsk4hf/ldpcsim168.f90 + lib/fsk4hf/ldpcsim174.f90 lib/fsk4hf/ldpcsim300.f90 lib/ldpcsim40.f90 lib/libration.f90 @@ -455,6 +460,7 @@ set (wsjt_FSRCS lib/mskrtd.f90 lib/fsk4hf/msksoftsym.f90 lib/fsk4hf/msksoftsymw.f90 + lib/fsk4hf/osd174.f90 lib/fsk4hf/osd300.f90 lib/pctile.f90 lib/peakdt9.f90 @@ -492,6 +498,7 @@ set (wsjt_FSRCS lib/sync4.f90 lib/sync64.f90 lib/sync65.f90 + lib/fsk4hf/sync8.f90 lib/sync9.f90 lib/sync9f.f90 lib/sync9w.f90 @@ -1149,6 +1156,9 @@ target_link_libraries (ldpcsim168 wsjt_fort wsjt_cxx) add_executable (fsk4hf lib/fsk4hf/fsk4hf.f90 wsjtx.rc) target_link_libraries (fsk4hf wsjt_fort wsjt_cxx) +add_executable (ft8d lib/fsk4hf/ft8d.f90 wsjtx.rc) +target_link_libraries (ft8d wsjt_fort wsjt_cxx) + add_executable (ft8sim lib/fsk4hf/ft8sim.f90 wsjtx.rc) target_link_libraries (ft8sim wsjt_fort wsjt_cxx) diff --git a/lib/fsk4hf/extractmessage174.f90 b/lib/fsk4hf/extractmessage174.f90 index 43823507a..1fc772c00 100644 --- a/lib/fsk4hf/extractmessage174.f90 +++ b/lib/fsk4hf/extractmessage174.f90 @@ -26,7 +26,8 @@ subroutine extractmessage174(decoded,msgreceived,ncrcflag,recent_calls,nrecent) i1Dec8BitBytes(11)=decoded(80)*128+decoded(81)*64+decoded(82)*2*32+decoded(83)*16 i1Dec8BitBytes(11)=i1Dec8BitBytes(11)+decoded(84)*8+decoded(85)*4+decoded(86)*2+decoded(87) - if( crc12_check(c_loc (i1Dec8BitBytes), 11) ) then +! if( crc12_check(c_loc (i1Dec8BitBytes), 11) ) then + if(.true.) then !### TEST ### ! CRC12 checks out --- unpack 72-bit message do ibyte=1,12 itmp=0 diff --git a/lib/fsk4hf/ft8_params.f90 b/lib/fsk4hf/ft8_params.f90 index 9978564e4..6643e7762 100644 --- a/lib/fsk4hf/ft8_params.f90 +++ b/lib/fsk4hf/ft8_params.f90 @@ -1,10 +1,11 @@ -! LDPC (168,84) code -parameter (KK=84) !Information bits (72 + CRC12) -parameter (ND=56) !Data symbols +! LDPC (174,87) code +parameter (KK=87) !Information bits (75 + CRC12) +parameter (ND=58) !Data symbols parameter (NS=21) !Sync symbols (3 @ Costas 7x7) -parameter (NN=NS+ND) !Total symbols (77) +parameter (NN=NS+ND) !Total symbols (79) parameter (NSPS=2048) !Samples per symbol at 12000 S/s parameter (N7=7*NSPS) !Samples in Costas 7x7 array (14,336) -parameter (NZ=NSPS*NN) !Samples in full 15 s waveform (157,696) +parameter (NZ=NSPS*NN) !Samples in full 15 s waveform (161,792) parameter (NMAX=15*12000) !Samples in iwave (180,000) -parameter (NFFT1=1*NSPS, NH1=NFFT1/2) !Length of FFTs for symbol spectra +parameter (NFFT1=2*NSPS, NH1=NFFT1/2) !Length of FFTs for symbol spectra +parameter (NHSYM=2*NMAX/NSPS-1) !Number of symbol spectra (half-symbol steps) diff --git a/lib/fsk4hf/ft8sim.f90 b/lib/fsk4hf/ft8sim.f90 index 20d7abb54..4991ce6c9 100644 --- a/lib/fsk4hf/ft8sim.f90 +++ b/lib/fsk4hf/ft8sim.f90 @@ -8,8 +8,8 @@ program ft8sim type(hdr) h !Header for .wav file character arg*12,fname*16 character msg*22,msgsent*22 - complex c0(0:NZ-1) - complex c(0:NZ-1) + complex c0(0:NMAX-1) + complex c(0:NMAX-1) integer itone(NN) integer*2 iwave(NMAX) !Generated full-length waveform @@ -42,7 +42,7 @@ program ft8sim bw=8*baud !Occupied bandwidth (Hz) txt=NZ*dt !Transmission length (s) bandwidth_ratio=2500.0/(fs/2.0) - sig=sqrt(bandwidth_ratio) * 10.0**(0.05*snrdb) + sig=sqrt(2*bandwidth_ratio) * 10.0**(0.05*snrdb) if(snrdb.gt.90.0) sig=1.0 txt=NN*NSPS/12000.0 @@ -53,7 +53,7 @@ program ft8sim phi=0.0 c0=0. - k=-1 + nint(xdt/dt) + k=-1 + nint((xdt+0.5)/dt) !Start audio at t=0.5 s do j=1,NN !Generate 8-FSK waveform from itone dphi=twopi*(f0+itone(j)*baud)*dt if(k.eq.0) phi=-dphi @@ -62,11 +62,11 @@ program ft8sim phi=phi+dphi if(phi.gt.twopi) phi=phi-twopi xphi=phi - if(k.ge.0 .and. k.lt.NZ) c0(k)=cmplx(cos(xphi),sin(xphi)) + if(k.ge.0 .and. k.lt.NMAX) c0(k)=cmplx(cos(xphi),sin(xphi)) enddo enddo - call sgran() +! call sgran() do ifile=1,nfiles c=c0 if( fspread .ne. 0.0 .or. delay .ne. 0.0 ) then @@ -83,8 +83,8 @@ program ft8sim fac=32767.0 rms=100.0 - if(snrdb.ge.90.0) iwave(1:NZ)=nint(fac*real(c)) - if(snrdb.lt.90.0) iwave(1:NZ)=nint(rms*real(c)) + if(snrdb.ge.90.0) iwave(1:NMAX)=nint(fac*real(c)) + if(snrdb.lt.90.0) iwave(1:NMAX)=nint(rms*real(c)) iwave(NZ+1:)=0 h=default_header(12000,NMAX) @@ -95,10 +95,10 @@ program ft8sim close(10) write(*,1110) ifile,xdt,f0,snrdb,fname 1110 format(i4,f7.2,f8.2,f7.1,2x,a16) - do i=0,NZ-1 - write(13,3001) i,i/12000.0,c(i),iwave(i+1) -3001 format(i8,f12.6,2f12.3,i8) - enddo +! do i=0,NZ-1 +! write(13,3001) i,i/12000.0,c(i),iwave(i+1) +!3001 format(i8,f12.6,2f12.3,i8) +! enddo enddo 999 end program ft8sim diff --git a/lib/fsk4hf/genft8.f90 b/lib/fsk4hf/genft8.f90 index df4b760e0..046087351 100644 --- a/lib/fsk4hf/genft8.f90 +++ b/lib/fsk4hf/genft8.f90 @@ -8,8 +8,8 @@ subroutine genft8(msg,msgsent,itone) include 'ft8_params.f90' character*22 msg,msgsent - character*84 cbits - integer*4 i4Msg6BitWords(12) !72-bit message as 6-bit words + character*87 cbits + integer*4 i4Msg6BitWords(12) !72-bit message as 6-bit words integer*1 msgbits(KK),codeword(3*ND) integer itone(NN) integer icos7(0:6) @@ -17,24 +17,26 @@ subroutine genft8(msg,msgsent,itone) call packmsg(msg,i4Msg6BitWords,itype) !Pack into 12 6-bit bytes call unpackmsg(i4Msg6BitWords,msgsent) !Unpack to get msgsent - icrc=0 !### temporary ### + i3bit=0 !### temporary ### + icrc12=0 !### temporary ### - write(cbits,1000) i4Msg6BitWords,icrc -1000 format(12b6.6,b12.12) + write(cbits,1000) i4Msg6BitWords,i3bit,icrc12 +1000 format(12b6.6,b3.3,b12.12) read(cbits,1002) msgbits -1002 format(84i1) +1002 format(87i1) + print*,cbits - call encode168(msgbits,codeword) !Encode the test message + call encode174(msgbits,codeword) !Encode the test message -! Message structure: S7 D28 S7 D28 S7 +! Message structure: S7 D29 S7 D29 S7 itone(1:7)=icos7 - itone(35+1:35+7)=icos7 + itone(36+1:36+7)=icos7 itone(NN-6:NN)=icos7 k=7 do j=1,ND i=3*j -2 k=k+1 - if(j.eq.29) k=k+7 + if(j.eq.30) k=k+7 itone(k)=codeword(i)*4 + codeword(i+1)*2 + codeword(i+2) enddo