program ft8sim ! Generate simulated data for a 15-second HF/6m mode using 8-FSK. ! Output is saved to a *.wav file. use wavhdr include 'ft8_params.f90' !Set various constants type(hdr) h !Header for .wav file character arg*12,fname*17,sorm*1 character msg*22,msgsent*22 character*6 mygrid6 logical bcontest complex c0(0:NMAX-1) complex c(0:NMAX-1) integer itone(NN) integer*1 msgbits(KK) integer*2 iwave(NMAX) !Generated full-length waveform data mygrid6/'EM48 '/ ! Get command-line argument(s) nargs=iargc() if(nargs.ne.8) then print*,'Usage: ft8sim "message" s|m f0 DT fdop del nfiles snr' print*,'Example: ft8sim "K1ABC W9XYZ EN37" m 1500.0 0.0 0.1 1.0 10 -18' print*,'s|m: "s" for single signal at 1500 Hz, "m" for 25 signals' print*,'f0 is ignored when sorm = m' print*,'Make nfiles negative to invoke 72-bit contest mode.' go to 999 endif call getarg(1,msg) !Message to be transmitted call getarg(2,sorm) !s for single signal, m for multiple sigs if(sorm.eq."s") then print*,"Generating single signal at 1500 Hz." nsig=1 elseif( sorm.eq."m") then print*,"Generating 25 signals per file." nsig=25 else print*,"sorm parameter must be s (single) or m (multiple)." goto 999 endif call getarg(3,arg) read(arg,*) f0 !Frequency (only used for single-signal) call getarg(4,arg) read(arg,*) xdt !Time offset from nominal (s) call getarg(5,arg) read(arg,*) fspread !Watterson frequency spread (Hz) call getarg(6,arg) read(arg,*) delay !Watterson delay (ms) call getarg(7,arg) read(arg,*) nfiles !Number of files call getarg(8,arg) read(arg,*) snrdb !SNR_2500 bcontest=nfiles.lt.0 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() call genft8(msg,mygrid6,bcontest,msgsent,msgbits,itone) write(*,1000) f0,xdt,txt,snrdb,bw,msgsent 1000 format('f0:',f9.3,' DT:',f6.2,' TxT:',f6.1,' SNR:',f6.1, & ' BW:',f4.1,2x,a22) write(*,'(28i1,1x,28i1)') msgbits(1:56) write(*,'(16i1)') msgbits(57:72) write(*,'(3i1)') msgbits(73:75) write(*,'(12i1)') msgbits(76:87) ! call sgran() do ifile=1,nfiles c=0. do isig=1,nsig c0=0. if(nsig.eq.25) then f0=(isig+2)*100.0 endif k=-1 + nint((xdt+0.5+0.01*gran())/dt) ! k=-1 + nint((xdt+0.5)/dt) phi=0.0 do j=1,NN !Generate complex waveform dphi=twopi*(f0+itone(j)*baud)*dt do i=1,NSPS k=k+1 phi=mod(phi+dphi,twopi) if(k.ge.0 .and. k.lt.NMAX) c0(k)=cmplx(cos(phi),sin(phi)) enddo enddo if(fspread.ne.0.0 .or. delay.ne.0.0) call watterson(c0,NMAX,fs,delay,fspread) c=c+sig*c0 enddo if(snrdb.lt.90) then do i=0,NMAX-1 !Add gaussian noise at specified SNR xnoise=gran() ynoise=gran() c(i)=c(i) + cmplx(xnoise,ynoise) enddo endif fac=32767.0 rms=100.0 if(snrdb.ge.90.0) iwave(1:NMAX)=nint(fac*real(c)) if(snrdb.lt.90.0) iwave(1:NMAX)=nint(rms*real(c)) 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