WSJT-X/lib/ft8/foxgen.f90

113 lines
2.4 KiB
Fortran
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subroutine foxgen()
parameter (NN=79,KK=87,NSPS=4*1920)
parameter (NWAVE=NN*NSPS,NFFT=614400,NH=NFFT/2)
character*32 cmsg
character*22 msg,msgsent
logical bcontest
integer itone(NN)
integer*1 msgbits(KK)
integer*8 count0,count1,clkfreq
real x(NFFT),y(NFFT)
real*8 dt,twopi,f0,fstep,dfreq,phi,dphi
complex cx(0:NH),cy(0:NH)
common/foxcom/wave(NWAVE),nslots,cmsg(5)
equivalence (x,cx),(y,cy)
call system_clock(count0,clkfreq)
bcontest=.false.
i3bit=0
fstep=60.d0
dfreq=6.25d0
dt=1.d0/48000.d0
twopi=8.d0*atan(1.d0)
wave=0.
do n=1,nslots
i3bit=0
print*,n,i3bit,cmsg(n)
msg=cmsg(n)(1:22)
call genft8(msg," ",bcontest,i3bit,msgsent,msgbits,itone)
f0=1500.d0 + fstep*(n-1)
phi=0.d0
k=0
do j=1,NN
f=f0 + dfreq*itone(j)
dphi=twopi*f*dt
do ii=1,NSPS
k=k+1
phi=phi+dphi
xphi=phi
wave(k)=wave(k)+sin(xphi)
enddo
enddo
call system_clock(count1,clkfreq)
enddo
sqx=0.
do i=1,NWAVE
sqx=sqx + wave(i)*wave(i)
enddo
sigmax=sqrt(sqx/NWAVE)
wave=wave/sigmax !Force rms=1.0
do i=1,NWAVE
wave(i)=h1(wave(i)) !Compress the waveform
enddo
fac=1.0/maxval(abs(wave)) !Set maxval = 1.0
wave=fac*wave
if(NWAVE.ne.-99) go to 100 !### Omit filtering, for now ###
x(1:k)=wave
x(k+1:)=0.
call four2a(x,nfft,1,-1,0)
nadd=64
k=0
df=48000.0/NFFT
rewind(29)
do i=1,NH/nadd - 1
sx=0.
! sy=0.
do j=1,nadd
k=k+1
sx=sx + real(cx(k))**2 + aimag(cx(k))**2
! sy=sy + real(cy(k))**2 + aimag(cy(k))**2
enddo
freq=df*(k-nadd/2+0.5)
write(29,1022) freq,sx,sy,db(sx)-90.0,db(sy)-90.0
1022 format(f10.3,2e12.3,2f10.3)
if(freq.gt.3000.0) exit
enddo
flush(29)
100 call system_clock(count1,clkfreq)
! time=float(count1-count0)/float(clkfreq) !Cumulative execution time
! write(*,3010) time
!3010 format('Time:',f10.6)
return
end subroutine foxgen
real function h1(x)
! sigma=1.0/sqrt(2.0)
sigma=1.0
xlim=sigma/sqrt(6.0)
ax=abs(x)
sgnx=1.0
if(x.lt.0) sgnx=-1.0
if(ax.le.xlim) then
h1=x
else
z=exp(1.0/6.0 - (ax/sigma)**2)
h1=sgnx*sqrt(6.0)*sigma*(2.0/3.0 - 0.5*z)
endif
return
end function h1