program ft8sim ! Generate simulated "type 2" ft8 files ! Output is saved to a *.wav file. use wavhdr use packjt77 include 'ft8_params.f90' !Set various constants parameter (NWAVE=NN*NSPS) type(hdr) h !Header for .wav file character arg*12,fname*17 character msg37*37,msgsent37*37,msg40*40 character c77*77 complex c0(0:NMAX-1) complex c(0:NMAX-1) real wave(NMAX) integer itone(NN) integer*1 msgbits(77) integer*2 iwave(NMAX) !Generated full-length waveform ! Get command-line argument(s) nargs=iargc() if(nargs.ne.8) then print*,'Usage: ft8sim "message" f0 DT fdop del width nfiles snr' print*,'Examples: ft8sim "K1ABC W9XYZ EN37" 1500.0 0.0 0.1 1.0 0 10 -18' print*,' ft8sim "WA9XYZ/R KA1ABC/R FN42" 1500.0 0.0 0.1 1.0 0 10 -18' print*,' ft8sim "K1ABC RR73; W9XYZ -11" 300 0 0 0 25 1 -10' go to 999 endif call getarg(1,msg37) !Message to be transmitted call getarg(2,arg) read(arg,*) f0 !Frequency (only used for single-signal) call getarg(3,arg) read(arg,*) xdt !Time offset from nominal (s) call getarg(4,arg) read(arg,*) fspread !Watterson frequency spread (Hz) call getarg(5,arg) read(arg,*) delay !Watterson delay (ms) call getarg(6,arg) read(arg,*) width !Filter transition width (Hz) call getarg(7,arg) read(arg,*) nfiles !Number of files call getarg(8,arg) read(arg,*) snrdb !SNR_2500 nsig=1 if(f0.lt.100.0) then nsig=f0 f0=1500 endif nfiles=abs(nfiles) twopi=8.0*atan(1.0) fs=12000.0 !Sample rate (Hz) dt=1.0/fs !Sample interval (s) tt=NSPS*dt !Duration of symbols (s) baud=1.0/tt !Keying rate (baud) bw=8*baud !Occupied bandwidth (Hz) txt=NZ*dt !Transmission length (s) bandwidth_ratio=2500.0/(fs/2.0) sig=sqrt(2*bandwidth_ratio) * 10.0**(0.05*snrdb) if(snrdb.gt.90.0) sig=1.0 txt=NN*NSPS/12000.0 ! Source-encode, then get itone() i3=-1 n3=-1 call pack77(msg37,i3,n3,c77) call genft8(msg37,i3,n3,msgsent37,msgbits,itone) write(*,*) write(*,'(a23,a37,3x,a7,i1,a1,i1)') 'New Style FT8 Message: ',msgsent37,'i3.n3: ',i3,'.',n3 write(*,1000) f0,xdt,txt,snrdb,bw 1000 format('f0:',f9.3,' DT:',f6.2,' TxT:',f6.1,' SNR:',f6.1, & ' BW:',f4.1) write(*,*) if(i3.eq.1) then write(*,*) ' mycall hiscall hisgrid' write(*,'(28i1,1x,i1,1x,28i1,1x,i1,1x,i1,1x,15i1,1x,3i1)') msgbits(1:77) else write(*,'(a14)') 'Message bits: ' write(*,'(77i1)') msgbits endif write(*,*) write(*,'(a17)') 'Channel symbols: ' write(*,'(79i1)') itone write(*,*) call sgran() msg0=msg do ifile=1,nfiles k=nint((xdt+0.5)/dt) ia=k phi=0.0 c0=0.0 do j=1,NN !Generate complex waveform dphi=twopi*(f0*dt+itone(j)/real(NSPS)) do i=1,NSPS if(k.ge.0 .and. k.lt.NMAX) c0(k)=cmplx(cos(phi),sin(phi)) k=k+1 phi=mod(phi+dphi,twopi) enddo enddo if(fspread.ne.0.0 .or. delay.ne.0.0) call watterson(c0,NMAX,NWAVE,fs,delay,fspread) c=sig*c0 ib=k wave=real(c) peak=maxval(abs(wave(ia:ib))) rms=sqrt(dot_product(wave(ia:ib),wave(ia:ib))/NWAVE) nslots=1 if(width.gt.0.0) call filt8(f0,nslots,width,wave) if(snrdb.lt.90) then do i=1,NMAX !Add gaussian noise at specified SNR xnoise=gran() wave(i)=wave(i) + xnoise enddo endif fac=32767.0 rms=100.0 if(snrdb.ge.90.0) iwave(1:NMAX)=nint(fac*wave) if(snrdb.lt.90.0) iwave(1:NMAX)=nint(rms*wave) h=default_header(12000,NMAX) write(fname,1102) ifile 1102 format('000000_',i6.6,'.wav') open(10,file=fname,status='unknown',access='stream') write(10) h,iwave !Save to *.wav file close(10) write(*,1110) ifile,xdt,f0,snrdb,fname 1110 format(i4,f7.2,f8.2,f7.1,2x,a17) enddo 999 end program ft8sim