2020-07-31 10:59:05 -04:00
|
|
|
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
|
|
|
|
|
nsym=85 !Number of channel symbols
|
2020-07-31 11:16:03 -04:00
|
|
|
if(csubmode.eq.'B') then
|
|
|
|
|
nsps=960
|
|
|
|
|
nsym=169
|
|
|
|
|
endif
|
|
|
|
|
baud=12000.d0/nsps !Keying rate = 6.25 baud
|
2020-07-31 10:59:05 -04:00
|
|
|
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
|
2020-07-31 11:16:03 -04:00
|
|
|
if(csubmode.eq.'B' .and. isym.gt.84) isym=isym-84
|
2020-07-31 10:59:05 -04:00
|
|
|
if(isym.ne.isym0) then
|
2020-07-31 11:16:03 -04:00
|
|
|
freq=f0 + itone(isym)*baud
|
2020-07-31 10:59:05 -04:00
|
|
|
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
|
