From 9773afcb0af57cc38088b9114eb23a0e934d3ee4 Mon Sep 17 00:00:00 2001 From: Steven Franke Date: Thu, 26 May 2016 21:19:09 +0000 Subject: [PATCH] Routines for 72ms jtmsk messages. Nothing works yet. git-svn-id: svn+ssh://svn.code.sf.net/p/wsjt/wsjt/branches/wsjtx@6704 ab8295b8-cf94-4d9e-aec4-7959e3be5d79 --- lib/JTMSKsim144.f90 | 71 +++++++++++ lib/genmsk144.f90 | 196 +++++++++++++++++++++++++++++ lib/jtmsk_decode144.f90 | 125 +++++++++++++++++++ lib/syncmsk144.f90 | 270 ++++++++++++++++++++++++++++++++++++++++ 4 files changed, 662 insertions(+) create mode 100644 lib/JTMSKsim144.f90 create mode 100644 lib/genmsk144.f90 create mode 100644 lib/jtmsk_decode144.f90 create mode 100644 lib/syncmsk144.f90 diff --git a/lib/JTMSKsim144.f90 b/lib/JTMSKsim144.f90 new file mode 100644 index 000000000..9332eb7f0 --- /dev/null +++ b/lib/JTMSKsim144.f90 @@ -0,0 +1,71 @@ +program JTMSKsim + + use wavhdr + parameter (NMAX=15*12000) + real pings(0:NMAX-1) + real waveform(0:864-1) + character arg*8,msg*22,msgsent*22,fname*40 + character*3 rpt(0:7) + real wave(0:NMAX-1) !Simulated received waveform + real*8 dt,twopi,freq,phi,dphi0,dphi1,dphi + type(hdr) h !Header for .wav file + integer*2 iwave(0:NMAX-1) + integer itone(144) !Message bits + integer b11(11) !Barker-11 code + data b11/1,1,1,0,0,0,1,0,0,1,0/ + data rpt /'26 ','27 ','28 ','R26','R27','R28','RRR','73 '/ + + nargs=iargc() + if(nargs.ne.5) then + print*,'Usage: JTMSKsim message freq width snr nfiles' + print*,' ' + print*,'Examples: JTMSKsim "K1ABC W9XYZ EN37" 1500 0.12 2 1' + print*,' JTMSKsim " R26" 1500 0.01 1 3' + go to 999 + endif + call getarg(1,msg) + call getarg(2,arg) + read(arg,*) freq + call getarg(3,arg) + read(arg,*) width + call getarg(4,arg) + read(arg,*) snrdb + call getarg(5,arg) + read(arg,*) nfiles + sig=sqrt(2.0)*10.0**(0.05*snrdb) + twopi=8.d0*atan(1.d0) + h=default_header(12000,NMAX) + + ichk=0 + call genmsk(msg,ichk,msgsent,waveform,itype) !Check message type + if(itype.lt.1 .or. itype.gt.7) then + print*,'Illegal message' + go to 999 + endif + +! call makepings(pings,NMAX,width,sig) + pings=0.0 + pings(12345:24000)=sig + do ifile=1,nfiles !Loop over requested number of files + write(fname,1002) ifile !Output filename +1002 format('000000_',i4.4) + open(10,file=fname(1:11)//'.wav',access='stream',status='unknown') + + fac=sqrt(6000.0/2500.0) + j=-1 + do i=0,NMAX-1 + j=mod(j+1,864) + xx=gran() + wave(i)=pings(i)*waveform(j) + fac*xx + write(*,*) pings(i),fac,waveform(j),wave(j) + iwave(i)=30.0*wave(i) + enddo + + write(10) h,iwave !Save the .wav file + close(10) + +! call jtmsk_short(cwave,NMAX,msg) + + enddo + +999 end program JTMSKsim diff --git a/lib/genmsk144.f90 b/lib/genmsk144.f90 new file mode 100644 index 000000000..cf8884454 --- /dev/null +++ b/lib/genmsk144.f90 @@ -0,0 +1,196 @@ +subroutine genmsk144(msg0,ichk,msgsent,waveform,itype) + +!!!!!!!!!!!!!!!!!!!!! Experimental ldpc version +! b11 + 128bit code + 1 zero bit = 140 bits (70ms message duration) +! b13 + 128bit code + 2 slack + 1 zero bit = 144 bits (71ms message duration) +! +! Encode a JTMSK message +! Input: +! - msg0 requested message to be transmitted +! - ichk if ichk=1, return only msgsent +! if ichk.ge.10000, set imsg=ichk-10000 for short msg +! - msgsent message as it will be decoded +! - i4tone array of audio tone values, 0 or 1 +! - itype message type +! 1 = standard message "Call_1 Call_2 Grid/Rpt" +! 2 = type 1 prefix +! 3 = type 1 suffix +! 4 = type 2 prefix +! 5 = type 2 suffix +! 6 = free text (up to 13 characters) +! 7 = short message " Rpt" + + use iso_c_binding, only: c_loc,c_size_t + use packjt + use hashing + character*85 pchk_file,gen_file + character*22 msg0 + character*22 message !Message to be generated + character*22 msgsent !Message as it will be received + integer*4 i4Msg6BitWords(13) !72-bit message as 6-bit words + integer*4 i4tone(144) ! + integer*1, target:: i1Msg8BitBytes(10) !80 bits represented in 10 bytes + integer*1 codeword(128) !Encoded bits before re-ordering + integer*1 msgbits(80) !72-bit message + 8-bit hash + integer*1 reorderedcodeword(128) !Odd bits first, then even + integer*1 bitseq(144) !Tone #s, data and sync (values 0-1) + integer*1 i1hash(4) + integer*1 b7(7) + integer*1 b8(8) + integer*1 b11(11) + integer*1 b13(13) + real*8 pp(12) + real*8 xi(864),xq(864),pi,twopi,phi,dphi + real waveform(864) + data b7/1,1,1,0,0,1,0/ + data b8/0,1,1,1,0,0,1,0/ + data b11/1,1,1,0,0,0,1,0,0,1,0/ !Barker 11 code + data b13/1,1,1,1,1,0,0,1,1,0,1,0,1/ !Barker 13 code + equivalence (ihash,i1hash) + logical first + data first/.true./ + save + + if( first ) then + print*,"Initializing ldpc" + first=.false. + nsym=128 + pchk_file="peg-128-80-reg3.pchk" + gen_file="peg-128-80-reg3.gen" + call init_ldpc(trim(pchk_file)//char(0),trim(gen_file)//char(0)) + pi=4.*atan(1.0) + twopi=8.*atan(1.0) + do i=1,12 + pp(i)=sin( (i-1)*pi/12 ) + enddo + endif + + if(msg0(1:1).eq.'@') then !Generate a fixed tone + read(msg0(2:5),*,end=1,err=1) nfreq !at specified frequency + go to 2 +1 nfreq=1000 +2 i4tone(1)=nfreq + else + message=msg0 + do i=1,22 + if(ichar(message(i:i)).eq.0) then + message(i:)=' ' + exit + endif + enddo + + do i=1,22 !Strip leading blanks + if(message(1:1).ne.' ') exit + message=message(i+1:) + enddo + + if(message(1:1).eq.'<') then + call genmsk_short(message,msgsent,ichk,i4tone,itype) + if(itype.lt.0) go to 999 + i4tone(36)=-35 + go to 999 + endif + + call packmsg(message,i4Msg6BitWords,itype) !Pack into 12 6-bit bytes + call unpackmsg(i4Msg6BitWords,msgsent) !Unpack to get msgsent + if(ichk.eq.1) go to 999 + i4=0 + ik=0 + im=0 + do i=1,12 + nn=i4Msg6BitWords(i) + do j=1, 6 + ik=ik+1 + i4=i4+i4+iand(1,ishft(nn,j-6)) + i4=iand(i4,255) + if(ik.eq.8) then + im=im+1 +! if(i4.gt.127) i4=i4-256 + i1Msg8BitBytes(im)=i4 + ik=0 + endif + enddo + enddo + + ihash=nhash(c_loc(i1Msg8BitBytes),int(9,c_size_t),146) + ihash=2*iand(ihash,32767) !Generate the 8-bit hash + i1Msg8BitBytes(10)=i1hash(1) !CRC to byte 10 + + mbit=0 + do i=1, 10 + i1=i1Msg8BitBytes(i) + do ibit=1,8 + mbit=mbit+1 + msgbits(mbit)=iand(1,ishft(i1,ibit-8)) + enddo + enddo + + call ldpc_encode(msgbits,codeword) + + j=0 + do i=1,nsym/2 !Reorder the encoded bits + j=j+1 + reorderedcodeword(j)=codeword(2*i-1) + reorderedcodeword(j+nsym/2)=codeword(2*i) + enddo + +!Create 144-bit channel vector: +!8-bit sync word + 48 bits + 8-bit sync word + 80 bits + bitseq=0 + bitseq(1:8)=b8 + bitseq(9:56)=reorderedcodeword(1:48) + bitseq(57:64)=b8 + bitseq(65:144)=reorderedcodeword(49:128) + bitseq=2*bitseq-1 + + xq(1:6)=bitseq(1)*pp(7:12) !first bit is mapped to 1st half-symbol on q + do i=1,71 + is=(i-1)*12+7 + xq(is:is+11)=bitseq(2*i+1)*pp + enddo + xq(864-5:864)=bitseq(1)*pp(1:6) !first half of last zero bit on q channel + do i=1,72 + is=(i-1)*12+1 + xi(is:is+11)=bitseq(2*i)*pp + enddo + + dphi=2*pi*1500/12000.0; + phi=0.0 + do i=1,864 + waveform(i)=imag(complex(xi(i),xq(i))*complex(cos(phi),sin(phi))) + phi=mod(phi+dphi,twopi) + enddo + +! Map bits to I and Q (in anticipation of coherent demodulation), +! If bit indices run from 1 to 140. +! I bits are 1,3,5,...139 +! Q bits are 2,4,6,...140 +! Sample the offset qpsk waveform at 140 sampling instants to determine tones. +! Send low tone if I and Q have different sign, send high tone if I and Q have same sign. +! Modulator will take care of ensuring phase continuity. +! i4tone=0 +! iq=140 +! it=1 +! do ii=1,139,2 +! do inner=1,2 +! if( bitseq(ii) .eq. bitseq(iq) ) then +! i4tone(it)=1 +! endif +! print*,it,ii,iq,bitseq(ii),bitseq(iq),bitseq(it),i4tone(it) +! if( mod(it,2) .eq. 1 ) then +! iq=mod(iq+2,140) +! if( iq .eq. 0 ) iq=140 +! endif +! it=it+1 +! enddo +! enddo + endif + +!i4tone(1:11)=b11 +! print*,"transmitted tones" +! do i=1,140 +! print*,i,i4tone(i) +! enddo + +999 return +end subroutine genmsk diff --git a/lib/jtmsk_decode144.f90 b/lib/jtmsk_decode144.f90 new file mode 100644 index 000000000..650c0d60a --- /dev/null +++ b/lib/jtmsk_decode144.f90 @@ -0,0 +1,125 @@ +subroutine jtmsk_decode(id2,narg,line) + +! Decoder for JTMSK mode + + parameter (NMAX=30*12000) + parameter (NFFTMAX=512*1024) + parameter (NSPM=840) !Samples per JTMSK long message + integer*2 id2(0:NMAX) !Raw i*2 data, up to T/R = 30 s + integer hist(0:32868) + real d(0:NMAX) !Raw r*4 data + real ty(NMAX/512) !Ping times + real yellow(NMAX/512) + complex c(NFFTMAX) !Complex (analytic) data + complex cdat(24000) !Short segments, up to 2 s + complex cdat2(24000) + integer narg(0:14) !Arguments passed from calling pgm + character*22 msg,msg0 !Decoded message + character*80 line(100) !Decodes passed back to caller + equivalence (hist,d) + +! Parameters from GUI are in narg(): + nutc=narg(0) !UTC + npts=min(narg(1),NMAX) !Number of samples in id2 (12000 Hz) + newdat=narg(3) !1==> new data, compute symbol spectra + minsync=narg(4) !Lower sync limit + npick=narg(5) + t0=0.001*narg(6) + t1=0.001*narg(7) + maxlines=narg(8) !Max # of decodes to return to caller + nmode=narg(9) + nrxfreq=narg(10) !Target Rx audio frequency (Hz) + ntol=narg(11) !Search range, +/- ntol (Hz) + nhashcalls=narg(12) + naggressive=narg(14) + nsnr0=-99 + nline=0 + line(1:100)(1:1)=char(0) + msg0=' ' + msg=msg0 + + hist=0 + do i=0,npts-1 + n=abs(id2(i)) + hist(n)=hist(n)+1 + enddo + ns=0 + do n=0,32768 + ns=ns+hist(n) + if(ns.gt.npts/2) exit + enddo + fac=1.0/(1.5*n) + d(0:npts-1)=fac*id2(0:npts-1) +! rms=sqrt(dot_product(d(0:npts-1),d(0:npts-1))/npts) +!### Would it be better to set median rms to 1.0 ? +! d(0:npts-1)=d(0:npts-1)/rms !Normalize so that rms=1.0 + call mskdt(d,npts,ty,yellow,nyel) + print*,nyel + do i=1,nyel + print*,i,ty(i),yellow(i) + enddo + + nyel=min(nyel,5) + + n=log(float(npts))/log(2.0) + 1.0 + nfft=min(2**n,1024*1024) + call analytic(d,npts,nfft,c) !Convert to analytic signal and filter + + nbefore=NSPM + nafter=4*NSPM +! Process ping list (sorted by S/N) from top down. +! do n=1,nyel + do n=1,1 + ia=ty(n)*12000.0 - nbefore + if(ia.lt.1) ia=1 + ib=ia + nafter + if(ib.gt.NFFTMAX) ib=NFFTMAX + iz=ib-ia+1 + cdat2(1:iz)=c(ia:ib) !Select nlen complex samples + ja=ia/NSPM + 1 + jb=ib/NSPM + t0=ia/12000.0 +! do itry=1,21 + do itry=1,1 + idf1=(itry/2) * 50 + if(mod(itry,2).eq.1) idf1=-idf1 + if(abs(idf1).gt.ntol) exit + fpk=idf1 + nrxfreq + call tweak1(cdat2,iz,1500.0-fpk,cdat) + call syncmsk(cdat,iz,jpk,ipk,idf,rmax,snr,metric,msg) + if(metric.eq.-9999) cycle !No output if no significant sync + if(msg(1:1).eq.' ') call jtmsk_short(cdat,iz,narg,tbest,idfpk,msg) + if(msg(1:1).eq.'<' .and. naggressive.eq.0 .and. & + narg(13)/8.ne.narg(12)) msg=' ' + if(msg(1:1).ne.' ') then + if(msg.ne.msg0) then + nline=nline+1 + nsnr0=-99 + endif + freq=fpk+idf + t0=(ia+jpk)/12000.0 + y=10.0**(0.1*(yellow(n)-1.5)) + nsnr=max(-5,nint(db(y))) + if(nsnr.gt.nsnr0 .and. nline.gt.0) then + call rectify_msk(cdat2(jpk:jpk+NSPM-1),msg,narg(13),freq2) + freq=freq2 + if(msg(1:1).eq.'<') freq=freq2+idfpk +!### Check freq values !!! + write(line(nline),1020) nutc,nsnr,t0,nint(freq),msg +1020 format(i6.6,i4,f5.1,i5,' & ',a22) + nsnr0=nsnr + go to 900 + endif + msg0=msg + if(nline.ge.maxlines) go to 900 + endif + enddo +! print*,'c',nutc,n,nint(yellow(n)-4.0),freq,freq2 + enddo + +900 continue +! print*,'d',nutc,n,nint(yellow(n)-4.0),freq,freq2 + if(line(1)(1:6).eq.' ') line(1)(1:1)=char(0) + + return +end subroutine jtmsk_decode diff --git a/lib/syncmsk144.f90 b/lib/syncmsk144.f90 new file mode 100644 index 000000000..9458b5edc --- /dev/null +++ b/lib/syncmsk144.f90 @@ -0,0 +1,270 @@ +subroutine syncmsk(cdat,npts,jpk,ipk,idf,rmax,snr,metric,decoded) + +! Attempt synchronization, and if successful decode using Viterbi algorithm. + + use iso_c_binding, only: c_loc,c_size_t + use packjt + use hashing + use timer_module, only: timer + + parameter (NSPM=840,NSAVE=2000) + character*85 pchk_file,gen_file + complex cdat(npts) !Analytic signal + complex cb(72) !Complex waveform for bit-reversed B11 + complex cd(0:11,0:3) + complex c(0:NSPM-1) !Complex data for one message length + complex c2(0:NSPM-1) + complex cb3(1:NSPM,3) + real r(12000) + real rdat(12000) + real ss1(12000) + real symbol(140) + real rdata(140) + real rd2(128) + real rsave(NSAVE) + real xp(29) + real pp(12) !Half-sine pulse shape + real cbi(72),cbq(72) + complex z,z0,z1,z2,z3,cfac + integer*1 e1(128) + integer*1, target :: d8(13) + integer*1 i1hash(4) + integer*1 i1 + integer*4 i4Msg6BitWords(12) !72-bit message as 6-bit words + integer mettab(0:255,0:1) !Metric table for BPSK modulation + integer ipksave(NSAVE) + integer jpksave(NSAVE) + integer indx(NSAVE) + integer b11(11) !Barker-11 code + character*22 decoded + character*72 c72 + logical first + equivalence (i1,i4) + equivalence (ihash,i1hash) + data first/.true./ + data b11/1,1,1,0,0,0,1,0,0,1,0/ + save first,cb,cd,pi,twopi,dt,f0,f1,mettab + + phi=0. + if(first) then + pchk_file="peg-128-80-reg3.pchk" + gen_file="peg-128-80-reg3.gen" + call init_ldpc(trim(pchk_file)//char(0),trim(gen_file)//char(0)) + + pi=4.0*atan(1.0) + do i=1,12 + angle=(i-1)*pi/12.0 + pp(i)=sin(angle) + enddo + + cbi(1:12)=(2*b11(11)-1)*pp + cbi(13:24)=(2*b11(9)-1)*pp + cbi(25:36)=(2*b11(7)-1)*pp + cbi(37:48)=(2*b11(5)-1)*pp + cbi(49:60)=(2*b11(3)-1)*pp + cbi(61:72)=(2*b11(1)-1)*pp + cbq(1:6)=0.0 + cbq(7:18)=(2*b11(10)-1)*pp + cbq(19:30)=(2*b11(8)-1)*pp + cbq(31:42)=(2*b11(6)-1)*pp + cbq(43:54)=(2*b11(4)-1)*pp + cbq(55:66)=(2*b11(2)-1)*pp + cbq(67:72)=0.0 + print*,"cb" + do i=1,72 + print*,i,cbi(i),cbq(i) + cb(i)=complex(cbi(i),cbq(i)) + enddo + + first=.false. + endif + + nfft=NSPM + jz=npts-nfft + decoded=" " + ipk=0 + jpk=0 + metric=-9999 + r=0. + open(unit=78,file="blah.txt") + call timer('sync1 ',0) + do j=1,jz !Find the Barker-11 sync vectors + z=0. + ss=0. + do i=1, 72 + ss=ss + real(cdat(j+i-1))**2 + aimag(cdat(j+i-1))**2 + z=z + cdat(j+i-1)*conjg(cb(i)) !Signal matching Barker 11 + enddo + ss=sqrt(ss/72.0)*72.0 + r(j)=abs(z)/ss !Goodness-of-fit to Barker 11 + ss1(j)=ss + write(78,*) j,r(j),ss1(j) + enddo + + z=0 + dt=1.0/12000.0 + do j=7,jz + z=z+(cdat(j)*conjg(cdat(j-6)))**2 + enddo + fff=(atan2(aimag(z),real(z))-pi)/(4*pi*6*dt) + print*,"Frequency error ",fff + call timer('sync1 ',1) + + call timer('sync2 ',0) + jz=npts-nfft + rmax=0. +! n1=35, n2=69, n3=94 + k=0 + do j=1,jz !Find best full-message sync + if(ss1(j).lt.85.0) cycle + r1=r(j) + r(j+282) + r(j+768) ! 6*(12+n1) 6*(24+n1+n2) + r2=r(j) + r(j+486) + r(j+1122) ! 6*(12+n2) 6*(24+n2+n3) + r3=r(j) + r(j+636) + r(j+918) ! 6*(12+n3) 6*(24+n3+n1) + if(r1.gt.rmax) then + rmax=r1 + jpk=j + ipk=1 + endif + if(r2.gt.rmax) then + rmax=r2 + jpk=j + ipk=2 + endif + if(r3.gt.rmax) then + rmax=r3 + jpk=j + ipk=3 + endif + rrmax=max(r1,r2,r3) + if(rrmax.gt.1.9) then + k=min(k+1,NSAVE) + if(r1.eq.rrmax) ipksave(k)=1 + if(r2.eq.rrmax) ipksave(k)=2 + if(r3.eq.rrmax) ipksave(k)=3 + jpksave(k)=j + rsave(k)=rrmax + endif + enddo + call timer('sync2 ',1) + kmax=k + + call indexx(rsave,kmax,indx) + + call timer('sync3 ',0) + do kk=1,kmax + k=indx(kmax+1-kk) + ipk=ipksave(k) + jpk=jpksave(k) + rmax=rsave(k) + + c=conjg(cb3(1:NSPM,ipk))*cdat(jpk:jpk+nfft-1) + smax=0. + dfx=0. + idfbest=0 + do itry=1,25 + idf=itry/2 + if(mod(itry,2).eq.0) idf=-idf + idf=4*idf + twk=idf + call tweak1(c,NSPM,-twk,c2) + z=sum(c2) + if(abs(z).gt.smax) then + dfx=twk + smax=abs(z) + phi=atan2(aimag(z),real(z)) !Carrier phase offset + idfbest=idf + endif + enddo + idf=idfbest + call tweak1(cdat,npts,-dfx,cdat) + cfac=cmplx(cos(phi),-sin(phi)) + cdat=cfac*cdat + + sig=0. + ref=0. + rdat(1:npts)=cdat + iz=11 + do k=1,234 !Compute soft symbols + j=jpk+6*(k-1) + + z0=2.0*dot_product(cdat(j:j+iz),cd(0:iz,0)) + z1=2.0*dot_product(cdat(j:j+iz),cd(0:iz,1)) + z2=2.0*dot_product(cdat(j:j+iz),cd(0:iz,2)) + z3=2.0*dot_product(cdat(j:j+iz),cd(0:iz,3)) + +!### Maybe these should be weighted by yellow() ? + if(j+1404+iz.lt.npts) then + z0=z0 + dot_product(cdat(j+1404:j+1404+iz),cd(0:iz,0)) + z1=z1 + dot_product(cdat(j+1404:j+1404+iz),cd(0:iz,1)) + z2=z2 + dot_product(cdat(j+1404:j+1404+iz),cd(0:iz,2)) + z3=z3 + dot_product(cdat(j+1404:j+1404+iz),cd(0:iz,3)) + endif + + if(j-1404.ge.1) then + z0=z0 + dot_product(cdat(j-1404:j-1404+iz),cd(0:iz,0)) + z1=z1 + dot_product(cdat(j-1404:j-1404+iz),cd(0:iz,1)) + z2=z2 + dot_product(cdat(j-1404:j-1404+iz),cd(0:iz,2)) + z3=z3 + dot_product(cdat(j-1404:j-1404+iz),cd(0:iz,3)) + endif + + sym=max(abs(real(z2)),abs(real(z3))) - max(abs(real(z0)),abs(real(z1))) + + if(sym.lt.0.0) then + phi=atan2(aimag(z0),real(z0)) + sig=sig + real(z0)**2 + ref=ref + aimag(z0)**2 + else + phi=atan2(aimag(z1),real(z1)) + sig=sig + real(z1)**2 + ref=ref + aimag(z1)**2 + endif + n=k + if(ipk.eq.2) n=k+47 + if(ipk.eq.3) n=k+128 + if(n.gt.234) n=n-234 + ibit=0 + if(sym.ge.0) ibit=1 + symbol(n)=sym + enddo + snr=db(sig/ref-1.0) + +! rdata(1:35)=symbol(12:46) +! rdata(36:104)=symbol(59:127) +! rdata(105:198)=symbol(140:233) + +! Re-order the symbols and make them i*1 + j=0 + do i=1,99 + i4=128+rdata(i) !### Should be nint() ??? ### + if(i4.gt.255) i4=255 + if(i4.lt.0) i4=0 + j=j+1 + e1(j)=i1 + rd2(j)=rdata(i) + i4=128+rdata(i+99) + if(i4.gt.255) i4=255 + if(i4.lt.0) i4=0 + j=j+1 + e1(j)=i1 + rd2(j)=rdata(i+99) + enddo + +! Decode the message + nb1=87 + call vit213(e1,nb1,mettab,d8,metric) + ihash=nhash(c_loc(d8),int(9,c_size_t),146) + ihash=2*iand(ihash,32767) + decoded=' ' + if(d8(10).eq.i1hash(2) .and. d8(11).eq.i1hash(1)) then + write(c72,1012) d8(1:9) +1012 format(9b8.8) + read(c72,1014) i4Msg6BitWords +1014 format(12b6.6) + call unpackmsg(i4Msg6BitWords,decoded) !Unpack to get msgsent + endif + if(decoded.ne.' ') exit + enddo + call timer('sync3 ',1) + + return +end subroutine syncmsk