WSJT-X/lib/analytic.f90
Steven Franke e4c5811ac3 Changes needed to accommodate channel equalization implemented in the new msk144signalquality.f90. Warning - msk144signalquality writes to the executable directory.
git-svn-id: svn+ssh://svn.code.sf.net/p/wsjt/wsjt/branches/wsjtx@7412 ab8295b8-cf94-4d9e-aec4-7959e3be5d79
2016-12-20 03:01:43 +00:00

58 lines
1.8 KiB
Fortran

subroutine analytic(d,npts,nfft,c,a,equalize)
! Convert real data to analytic signal
parameter (NFFTMAX=1024*1024)
real d(npts)
complex h(NFFTMAX/2)
real*8 a(5),alast(5),fp
real ac(5),a0(5)
complex c(NFFTMAX)
logical*1 equalize
data nfft0/0/
data alast/0.0,0.0,0.0,0.0,0.0/
data ac/1.0,0.05532,0.11438,0.12918,0.09274/ ! amp coeffs for TS2000
data a0/0.0,0.0,-0.952,0.768,-0.565/ ! baseline phase coeffs for TS2000
save nfft0,h,alast,a0,ac
! disable baseline phase correction for commit - should look for a file with coeffs
a0(1:5)=0.0
df=12000.0/nfft
nh=nfft/2
if( nfft.ne.nfft0 .or. any(alast .ne. a) ) then
t=1.0/2000.0
beta=0.1
pi=4.0*atan(1.0)
do i=1,nh+1
ff=(i-1)*df
f=ff-1500.0
fp=f/1000.0
h(i)=cmplx(1.0,0.0)
if( equalize ) then
phase0=a0(1)+fp*(a0(2)+fp*(a0(3)+fp*(a0(4)+fp*a0(5))))
phase=a(1)+fp*(a(2)+fp*(a(3)+fp*(a(4)+fp*a(5))))
! amp=ac(1)+fp*(ac(2)+fp*(ac(3)+fp*(ac(4)+fp*ac(5))))
amp=1.0 ! no amplitude correction for now
h(i)=amp*cmplx(cos(phase),sin(phase))*cmplx(cos(phase0),sin(phase0))
endif
if(abs(f).gt.(1-beta)/(2*t) .and. abs(f).le.(1+beta)/(2*t)) then
h(i)=h(i)*0.5*(1+cos((pi*t/beta )*(abs(f)-(1-beta)/(2*t))))
endif
enddo
nfft0=nfft
endif
fac=2.0/nfft
c(1:npts)=fac*d(1:npts)
c(npts+1:nfft)=0.
call four2a(c,nfft,1,-1,1) !Forward c2c FFT
c(1:nh+1)=h(1:nh+1)*c(1:nh+1)
c(1)=0.5*c(1) !Half of DC term
c(nh+2:nfft)=0. !Zero the negative frequencies
call four2a(c,nfft,1,1,1) !Inverse c2c FFT
alast=a
return
end subroutine analytic