mirror of
https://github.com/saitohirga/WSJT-X.git
synced 2024-11-26 14:18:38 -05:00
197 lines
6.1 KiB
Fortran
197 lines
6.1 KiB
Fortran
program q65sim
|
|
|
|
! Generate simulated Q65 data for testing the decoder.
|
|
|
|
use wavhdr
|
|
use packjt
|
|
parameter (NMAX=300*12000) !Total samples in .wav file
|
|
type(hdr) h !Header for .wav file
|
|
integer*2 iwave(NMAX) !Generated waveform
|
|
integer itone(85) !Channel symbols (values 0-65)
|
|
integer y(63) !Codeword
|
|
real*4 xnoise(NMAX) !Generated random noise
|
|
real*4 dat(NMAX) !Generated real data
|
|
complex cdat(NMAX) !Generated complex waveform
|
|
complex cspread(0:NMAX-1) !Complex amplitude for Rayleigh fading
|
|
complex z
|
|
real*8 f0,dt,twopi,phi,dphi,baud,fsample,freq
|
|
character msg*37,fname*17,csubmode*1,arg*12
|
|
character msgsent*37
|
|
|
|
nargs=iargc()
|
|
if(nargs.ne.10) then
|
|
print*,'Usage: q65sim "msg" A-E freq fDop DT f1 Stp TRp Nfile SNR'
|
|
print*,'Example: q65sim "K1ABC W9XYZ EN37" A 1500 0.0 0.0 0.0 1 60 1 -26'
|
|
print*,' fDop = Doppler spread'
|
|
print*,' f1 = Drift or Doppler rate (Hz/min)'
|
|
print*,' Stp = Step size (Hz)'
|
|
print*,' Stp = 0 implies no Doppler tracking'
|
|
go to 999
|
|
endif
|
|
call getarg(1,msg)
|
|
call getarg(2,csubmode)
|
|
mode65=2**(ichar(csubmode)-ichar('A'))
|
|
call getarg(3,arg)
|
|
read(arg,*) f0
|
|
call getarg(4,arg)
|
|
read(arg,*) fspread
|
|
call getarg(5,arg)
|
|
read(arg,*) xdt
|
|
call getarg(6,arg)
|
|
read(arg,*) f1
|
|
call getarg(7,arg)
|
|
read(arg,*) nstp
|
|
call getarg(8,arg)
|
|
read(arg,*) ntrperiod
|
|
call getarg(9,arg)
|
|
read(arg,*) nfiles
|
|
call getarg(10,arg)
|
|
read(arg,*) snrdb
|
|
|
|
if(ntrperiod.eq.15) then
|
|
nsps=1800
|
|
else if(ntrperiod.eq.30) then
|
|
nsps=3600
|
|
else if(ntrperiod.eq.60) then
|
|
nsps=7200
|
|
else if(ntrperiod.eq.120) then
|
|
nsps=16000
|
|
else if(ntrperiod.eq.300) then
|
|
nsps=41472
|
|
else
|
|
print*,'Invalid TR period'
|
|
go to 999
|
|
endif
|
|
|
|
rms=100.
|
|
fsample=12000.d0 !Sample rate (Hz)
|
|
npts=fsample*ntrperiod !Total samples in .wav file
|
|
nfft=npts
|
|
nh=nfft/2
|
|
dt=1.d0/fsample !Sample interval (s)
|
|
twopi=8.d0*atan(1.d0)
|
|
nsym=85 !Number of channel symbols
|
|
mode65=2**(ichar(csubmode) - ichar('A'))
|
|
|
|
ichk=0
|
|
call genq65(msg,ichk,msgsent,itone,i3,n3)
|
|
|
|
j=0
|
|
do i=1,85
|
|
if(itone(i).gt.0) then
|
|
j=j+1
|
|
y(j)=itone(i)-1
|
|
endif
|
|
enddo
|
|
write(*,1001) y(1:13),y(1:13)
|
|
1001 format('Generated message'/'6-bit: ',13i3/'binary: ',13b6.6)
|
|
write(*,1002) y
|
|
1002 format(/'Codeword:'/(20i3))
|
|
write(*,1003) itone
|
|
1003 format(/'Channel symbols:'/(20i3))
|
|
|
|
baud=12000.d0/nsps !Keying rate (6.67 baud fot 15-s sequences)
|
|
h=default_header(12000,npts)
|
|
|
|
write(*,1004)
|
|
1004 format('File TR Freq Mode S/N Dop DT f1 Stp Message'/70('-'))
|
|
|
|
do ifile=1,nfiles !Loop over requested number of files
|
|
if(ntrperiod.lt.60) then
|
|
write(fname,1005) ifile !Output filename
|
|
1005 format('000000_',i6.6,'.wav')
|
|
else
|
|
write(fname,1106) ifile
|
|
1106 format('000000_',i4.4,'.wav')
|
|
endif
|
|
|
|
open(10,file=trim(fname),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
|
|
|
|
bandwidth_ratio=2500.0/6000.0
|
|
sig=sqrt(2*bandwidth_ratio)*10.0**(0.05*snrdb)
|
|
if(snrdb.gt.90.0) sig=1.0
|
|
write(*,1020) ifile,ntrperiod,f0,csubmode,snrdb,fspread,xdt,f1,nstp,trim(msgsent)
|
|
1020 format(i4,i6,f7.1,2x,a1,2x,f5.1,f6.2,2f6.1,i4,2x,a)
|
|
phi=0.d0
|
|
dphi=0.d0
|
|
k=(xdt+0.5)*12000 !Start audio at t=xdt+0.5 s (TR=15 and 30 s)
|
|
if(ntrperiod.ge.60) k=(xdt+1.0)*12000 !TR 60+ at t = xdt + 1.0 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_drift=f1*i*dt/60.0
|
|
if(nstp.ne.0) freq_drift=freq_drift - nstp*nint(freq_drift/nstp)
|
|
freq = f0 + freq_drift + itone(isym)*baud*mode65
|
|
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
|
|
phi1=twopi*rran() !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
|
|
phi2=twopi*rran()
|
|
z=a*cmplx(cos(phi2),sin(phi2))
|
|
endif
|
|
cspread(nfft-i)=z
|
|
enddo
|
|
|
|
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)
|
|
enddo
|
|
|
|
999 end program q65sim
|