mirror of
https://github.com/saitohirga/WSJT-X.git
synced 2024-11-19 10:32:02 -05:00
f3d62edb2e
git-svn-id: svn+ssh://svn.code.sf.net/p/wsjt/wsjt/branches/wsjtx@6962 ab8295b8-cf94-4d9e-aec4-7959e3be5d79
45 lines
1.3 KiB
Fortran
45 lines
1.3 KiB
Fortran
subroutine spec64(c0,npts2,mode64,jpk,s3a)
|
|
|
|
parameter (NSPS=2304) !Samples per symbol at 4000 Hz
|
|
complex c0(0:360000) !Complex spectrum of dd()
|
|
complex cs(0:NSPS-1) !Complex symbol spectrum
|
|
real s3a(0:63,1:63) !Synchronized symbol spectra
|
|
|
|
nfft4=221184
|
|
c0(npts2:)=0.
|
|
call four2a(c0,nfft4,1,-1,1) !Forward c2c
|
|
ndown=16/mode64
|
|
nfft5=nfft4/ndown
|
|
npts3=npts2/ndown
|
|
call four2a(c0,nfft5,1,1,1) !Inverse c2c, downsampled
|
|
|
|
nfft6=nsps/ndown
|
|
fsample=4000.0/ndown
|
|
df=fsample/nfft6
|
|
jpkd=nint(float(jpk)/ndown)
|
|
do j=1,63
|
|
jj=j+7 !Skip first Costas array
|
|
if(j.ge.32) jj=j+14 !Skip middle Costas array
|
|
ja=jpkd + (jj-1)*nfft6
|
|
jb=ja+nfft6-1
|
|
cs(0:nfft6-1)=1.3e-8*c0(ja:jb)
|
|
call four2a(cs,nfft6,1,-1,1)
|
|
ia=-mode64/2 - mode64
|
|
do ii=0,63
|
|
ia=ia+mode64
|
|
ib=ia+mode64-1
|
|
s=0.
|
|
do i=ia,ib
|
|
if(i.ge.0) then
|
|
s=s + real(cs(i))**2 + aimag(cs(i))**2
|
|
else
|
|
s=s + real(cs(nfft6+i))**2 + aimag(cs(nfft6+i))**2
|
|
endif
|
|
enddo
|
|
s3a(ii,j)=s/mode64
|
|
enddo
|
|
enddo
|
|
|
|
return
|
|
end subroutine spec64
|