From 09686b99584ef6f642fe73475265fe8071efa0ac Mon Sep 17 00:00:00 2001 From: Joe Taylor Date: Fri, 31 Jul 2020 10:59:05 -0400 Subject: [PATCH] Add a simulator for experimental mode QRA66. --- CMakeLists.txt | 3 + lib/qra/qra66/qra66sim.f90 | 160 +++++++++++++++++++++++++++++++++++++ 2 files changed, 163 insertions(+) create mode 100644 lib/qra/qra66/qra66sim.f90 diff --git a/CMakeLists.txt b/CMakeLists.txt index 35ab08fc3..376401c46 100644 --- a/CMakeLists.txt +++ b/CMakeLists.txt @@ -1324,6 +1324,9 @@ target_link_libraries (sumsim wsjt_fort wsjt_cxx) add_executable (qra64sim lib/qra/qra64/qra64sim.f90 wsjtx.rc) target_link_libraries (qra64sim wsjt_fort wsjt_cxx) +add_executable (qra66sim lib/qra/qra66/qra66sim.f90 wsjtx.rc) +target_link_libraries (qra66sim wsjt_fort wsjt_cxx) + add_executable (jt49sim lib/jt49sim.f90 wsjtx.rc) target_link_libraries (jt49sim wsjt_fort wsjt_cxx) diff --git a/lib/qra/qra66/qra66sim.f90 b/lib/qra/qra66/qra66sim.f90 new file mode 100644 index 000000000..6043b3aed --- /dev/null +++ b/lib/qra/qra66/qra66sim.f90 @@ -0,0 +1,160 @@ +program qra66sim + +! Generate simulated QRA66 data for testing the decoder. + + use wavhdr + use packjt + parameter (NMAX=15*12000) !180,000 + parameter (NFFT=NMAX,NH=NFFT/2) + type(hdr) h !Header for .wav file + integer*2 iwave(NMAX) !Generated waveform + integer*4 itone(85) !Channel symbols (values 0-65) + real*4 xnoise(NMAX) !Generated random noise + real*4 dat(NMAX) !Generated real data + complex cdat(NMAX) !Generated complex waveform + complex cspread(0:NFFT-1) !Complex amplitude for Rayleigh fading + complex z + real*8 f0,dt,twopi,phi,dphi,baud,fsample,freq + character msg*22,fname*13,csubmode*1,arg*12 + character msgsent*22 + + nargs=iargc() + if(nargs.ne.6) then + print *, 'Usage: qra66sim "msg" A|B fDop DT Nfiles SNR' + print *, 'Example qra66sim "K1ABC W9XYZ EN37" A 0.2 0.0 1 -10' + go to 999 + endif + call getarg(1,msg) + call getarg(2,csubmode) + mode66=2**(ichar(csubmode)-ichar('A')) + call getarg(3,arg) + read(arg,*) fspread + call getarg(4,arg) + read(arg,*) xdt + call getarg(5,arg) + read(arg,*) nfiles + call getarg(6,arg) + read(arg,*) snrdb + + rms=100. + fsample=12000.d0 !Sample rate (Hz) + dt=1.d0/fsample !Sample interval (s) + twopi=8.d0*atan(1.d0) + npts=NMAX !Total samples in .wav file + nsps=1920 + baud=12000.d0/nsps !Keying rate = 6.25 baud + nsym=85 !Number of channel symbols + h=default_header(12000,npts) + ichk=66 !Flag sent to genqra64 + + write(*,1000) +1000 format('File Freq A|B S/N DT Dop Message'/60('-')) + + do ifile=1,nfiles !Loop over requested number of files + write(fname,1002) ifile !Output filename +1002 format('000000_',i6.6) + open(10,file=fname//'.wav',access='stream',status='unknown') + xnoise=0. + cdat=0. + if(snrdb.lt.90) then + do i=1,npts + xnoise(i)=gran() !Generate gaussian noise + enddo + endif + + f0=1500.0 + bandwidth_ratio=2500.0/6000.0 + sig=sqrt(2*bandwidth_ratio)*10.0**(0.05*snrdb) + if(snrdb.gt.90.0) sig=1.0 + call genqra64(msg,ichk,msgsent,itone,itype) + write(*,1020) ifile,f0,csubmode,xsnr,xdt,fspread,msgsent +1020 format(i4,f10.3,2x,a1,2x,f5.1,f6.2,f6.1,1x,a22) + phi=0.d0 + dphi=0.d0 + k=(xdt+0.5)*12000 !Start audio at t = xdt + 0.5 s + isym0=-99 + do i=1,npts !Add this signal into cdat() + isym=i/nsps + 1 + if(isym.gt.nsym) exit + if(isym.ne.isym0) then + freq=f0 + itone(isym)*baud*mode66 + dphi=twopi*freq*dt + isym0=isym + endif + phi=phi + dphi + if(phi.gt.twopi) phi=phi-twopi + xphi=phi + z=cmplx(cos(xphi),sin(xphi)) + k=k+1 + if(k.ge.1) cdat(k)=cdat(k) + sig*z + enddo + + if(fspread.ne.0) then !Apply specified Doppler spread + df=12000.0/nfft + cspread(0)=1.0 + cspread(NH)=0. + b=6.0 !Use truncated Lorenzian shape for fspread + do i=1,NH + f=i*df + x=b*f/fspread + z=0. + a=0. + if(x.lt.3.0) then !Cutoff beyond x=3 + a=sqrt(1.111/(1.0+x*x)-0.1) !Lorentzian amplitude + call random_number(r1) + phi1=twopi*r1 !Random phase + z=a*cmplx(cos(phi1),sin(phi1)) + endif + cspread(i)=z + z=0. + if(x.lt.3.0) then !Same thing for negative freqs + call random_number(r2) + phi2=twopi*r2 + z=a*cmplx(cos(phi2),sin(phi2)) + endif + cspread(NFFT-i)=z + enddo + +! do i=0,NFFT-1 +! f=i*df +! if(i.gt.NH) f=(i-nfft)*df +! s=real(cspread(i))**2 + aimag(cspread(i))**2 +! write(13,3000) i,f,s,cspread(i) +!3000 format(i5,f10.3,3f12.6) +! enddo +! s=real(cspread(0))**2 + aimag(cspread(0))**2 +! write(13,3000) 1024,0.0,s,cspread(0) + + call four2a(cspread,NFFT,1,1,1) !Transform to time domain + + sum=0. + do i=0,NFFT-1 + p=real(cspread(i))**2 + aimag(cspread(i))**2 + sum=sum+p + enddo + avep=sum/NFFT + fac=sqrt(1.0/avep) + cspread=fac*cspread !Normalize to constant avg power + cdat=cspread*cdat !Apply Rayleigh fading + +! do i=0,NFFT-1 +! p=real(cspread(i))**2 + aimag(cspread(i))**2 +! write(14,3010) i,p,cspread(i) +!3010 format(i8,3f12.6) +! enddo + endif + + dat=aimag(cdat) + xnoise !Add generated AWGN noise + 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) !Save the .wav file + close(10) + +! do i=1,NMAX +! write(15,3020) i/12000.0,iwave(i) +!3020 format(f10.6,i8) +! enddo + enddo + +999 end program qra66sim