mirror of
https://github.com/saitohirga/WSJT-X.git
synced 2024-11-25 13:48:42 -05:00
a51c5c4251
As at ^/branches/wsjtx_exp@5271 git-svn-id: svn+ssh://svn.code.sf.net/p/wsjt/wsjt/branches/wsjtx@5272 ab8295b8-cf94-4d9e-aec4-7959e3be5d79
87 lines
2.2 KiB
Fortran
87 lines
2.2 KiB
Fortran
subroutine downsam9(id2,npts8,nsps8,newdat,nspsd,fpk,c2)
|
|
|
|
!Downsample from id2() into c2() so as to yield nspsd samples per symbol,
|
|
!mixing from fpk down to zero frequency. The downsample factor is 432.
|
|
|
|
use, intrinsic :: iso_c_binding
|
|
use FFTW3
|
|
|
|
include 'constants.f90'
|
|
integer(C_SIZE_T) NMAX1
|
|
parameter (NMAX1=653184)
|
|
parameter (NFFT1=653184,NFFT2=1512)
|
|
type(C_PTR) :: plan !Pointers plan for big FFT
|
|
integer*2 id2(0:8*npts8-1)
|
|
real*4, pointer :: x1(:)
|
|
complex c1(0:NFFT1/2)
|
|
complex c2(0:NFFT2-1)
|
|
real s(5000)
|
|
logical first
|
|
common/patience/npatience,nthreads
|
|
data first/.true./
|
|
save plan,first,c1,s,x1
|
|
|
|
df1=12000.0/NFFT1
|
|
npts=8*npts8
|
|
if(npts.gt.NFFT1) npts=NFFT1 !### Fix! ###
|
|
|
|
if(first) then
|
|
nflags=FFTW_ESTIMATE
|
|
if(npatience.eq.1) nflags=FFTW_ESTIMATE_PATIENT
|
|
if(npatience.eq.2) nflags=FFTW_MEASURE
|
|
if(npatience.eq.3) nflags=FFTW_PATIENT
|
|
if(npatience.eq.4) nflags=FFTW_EXHAUSTIVE
|
|
! Plan the FFTs just once
|
|
|
|
!$omp critical(fftw) ! serialize non thread-safe FFTW3 calls
|
|
plan=fftwf_alloc_real(NMAX1)
|
|
call c_f_pointer(plan,x1,[NMAX1])
|
|
x1(0:NMAX1-1) => x1 !remap bounds
|
|
call fftwf_plan_with_nthreads(nthreads)
|
|
plan=fftwf_plan_dft_r2c_1d(NFFT1,x1,c1,nflags)
|
|
call fftwf_plan_with_nthreads(1)
|
|
!$omp end critical(fftw)
|
|
|
|
first=.false.
|
|
endif
|
|
|
|
if(newdat.eq.1) then
|
|
x1(0:npts-1)=id2(0:npts-1)
|
|
x1(npts:NFFT1-1)=0. !Zero the rest of x1
|
|
call timer('FFTbig9 ',0)
|
|
call fftwf_execute_dft_r2c(plan,x1,c1)
|
|
call timer('FFTbig9 ',1)
|
|
|
|
nadd=int(1.0/df1)
|
|
s=0.
|
|
do i=1,5000
|
|
j=int((i-1)/df1)
|
|
do n=1,nadd
|
|
j=j+1
|
|
s(i)=s(i)+real(c1(j))**2 + aimag(c1(j))**2
|
|
enddo
|
|
enddo
|
|
newdat=0
|
|
endif
|
|
|
|
ndown=8*nsps8/nspsd !Downsample factor = 432
|
|
nh2=NFFT2/2
|
|
nf=nint(fpk)
|
|
i0=int(fpk/df1)
|
|
|
|
nw=100
|
|
ia=max(1,nf-nw)
|
|
ib=min(5000,nf+nw)
|
|
call pctile(s(ia),ib-ia+1,40,avenoise)
|
|
|
|
fac=sqrt(1.0/avenoise)
|
|
do i=0,NFFT2-1
|
|
j=i0+i
|
|
if(i.gt.nh2) j=j-NFFT2
|
|
c2(i)=fac*c1(j)
|
|
enddo
|
|
call four2a(c2,NFFT2,1,1,1) !FFT back to time domain
|
|
|
|
return
|
|
end subroutine downsam9
|