program jt4sim ! Generate simulated data for testing the JT4 decoder use wavhdr use packjt use jt4 parameter (NMAX=60*12000) type(hdr) h integer*2 iwave(NMAX) !Generated waveform real*4 dat(NMAX) real*4 r(2) real*8 f0,f,dt,twopi,phi,dphi0,dphi,baud,fspread,fsample,freq,sps character message*22,msgsent*22,arg*8,fname*11,submode*1 integer*4 itone(206) !Channel symbols (values 0-8) nargs=iargc() if(nargs.ne.5) then print*,'Usage: jt4sim "message" [A-G] fspread SNR nfiles' print*,'Example: jt4sim "CQ K1ABC FN42" F 200 -17 1' go to 999 endif call getarg(1,message) call fmtmsg(message,iz) call getarg(2,arg) read(arg,*) submode mode4=ichar(submode) - ichar('A') + 1 call getarg(3,arg) read(arg,*) fspread !Frequency spread (Hz) call getarg(4,arg) read(arg,*) snrdb !S/N in dB (2500 hz reference BW) call getarg(5,arg) read(arg,*) nfiles !Number of files rmsdb=25. rms=10.0**(0.05*rmsdb) fsample=12000.d0 !Sample rate (Hz) dt=1.d0/fsample !Sample interval (s) twopi=8.d0*atan(1.d0) npts=60*12000 sps=12000.d0/4.375d0 !2742.857... f0=1000.d0 !Frequency of lowest tone (Hz) freq=f0 !Silence compiler warning dphi=0.0 !Silence compiler warning call init_random_seed() ! seed Fortran RANDOM_NUMBER generator call sgran() ! see C rand generator (used in gran) h=default_header(12000,npts) if(message(1:3).eq.'sin') read(message(4:),*) sinfreq write(*,1000) 1000 format('File S/N Message'/ & '--------------------------------') call gen4(message,0,msgsent,itone,itype) !Encode message into tone #s ! write(*,1030) itone !1030 format(/'Channel symbols'/(30i2)) do ifile=1,nfiles !Loop over all files nmin=(ifile-1)*2 ihr=nmin/60 imin=mod(nmin,60) write(fname,1002) ihr,imin !Create output filename 1002 format('000000_',2i2.2) open(10,file=fname//'.wav',access='stream',status='unknown') if(snrdb.lt.90) then do i=1,npts dat(i)=gran() enddo else dat(1:npts)=0. endif snrdbx=snrdb sig=10.0**(0.05*snrdbx) if(snrdb.gt.90.0) sig=1.0 write(*,1020) ifile,snrdbx,msgsent 1020 format(i3,f7.1,2x,a22) phi=0. baud=12000.d0/sps isym0=0 k0=12000 do k=k0+1,npts isym=1.d0 + (k-k0)/sps if(isym.gt.206) exit if(isym.ne.isym0) then freq=f0 + itone(isym)*baud*nch(mode4) if(message(1:3).eq.'sin') freq=sinfreq dphi0=twopi*freq*dt dphi=dphi0 isym0=isym endif if(fspread.gt.0.d0 .and. mod(k,120).eq.0) then call random_number(r) f=freq + 0.5*fspread*(r(1)+r(2)-1.0) dphi=twopi*f*dt endif phi=phi + dphi if(phi.gt.twopi) phi=phi-twopi xphi=phi dat(k)=dat(k) + sig*sin(xphi) enddo fac=32767.0 if(snrdb.ge.90.0) iwave(1:npts)=nint(fac*dat(1:npts)) if(snrdb.lt.90.0) iwave(1:npts)=nint(rms*dat(1:npts)) write(10) h,iwave(1:npts) close(10) enddo 999 end program jt4sim