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Code cleanup for the sync64 routine. 

git-svn-id: svn+ssh://svn.code.sf.net/p/wsjt/wsjt/branches/wsjtx@6941 ab8295b8-cf94-4d9e-aec4-7959e3be5d79
This commit is contained in:
Joe Taylor 2016-07-22 21:04:50 +00:00
parent 71d94aa4c9
commit 6a8ed228e2
1 changed files with 35 additions and 37 deletions
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72
lib/sync64.f90
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@ -1,43 +1,45 @@
subroutine sync64(dd,nf1,nf2,maxf1,dtx,f0,kpk,snrdb,s3a)
parameter (NMAX=60*12000) !Max size of raw data at 12000 Hz
parameter (NSPS=2304) !Samples per symbol at 4000 Hz
parameter (NSPC=7*NSPS) !Samples per Costas array
real dd(NMAX) !Raw data
real x(672000) !Up to 56 s at 12000 Hz
real t(5)
real s3a(0:63,1:63)
real s0(0:NSPC-1)
real s1(0:NSPC-1)
real s2(0:NSPC-1)
real s3(0:NSPC-1)
real s0a(0:NSPC-1)
integer*8 count0,count1,clkfreq
integer icos7(0:6)
real s3a(0:63,1:63) !Synchronized symbol spectra
real s1(0:NSPC-1) !Power spectrum of Costas 1
real s2(0:NSPC-1) !Power spectrum of Costas 2
real s3(0:NSPC-1) !Power spectrum of Costas 3
real s0(0:NSPC-1) !Sum of s1+s2+s3
real s0a(0:NSPC-1) !Best synchromized spectrum
integer icos7(0:6) !Costas 7x7 tones
integer ipk0(1)
complex cc(0:NSPC-1)
complex c0(0:336000)
complex c1(0:NSPC-1)
complex c2(0:NSPC-1)
complex c3(0:NSPC-1)
complex cc(0:NSPC-1) !Costas waveform
complex c0(0:336000) !Complex spectrum of dd()
complex c1(0:NSPC-1) !Complex spectrum of Costas 1
complex c2(0:NSPC-1) !Complex spectrum of Costas 2
complex c3(0:NSPC-1) !Complex spectrum of Costas 3
logical first
equivalence (x,c0)
data icos7/2,5,6,0,4,1,3/ !Costas 7x7 pattern
data icos7/2,5,6,0,4,1,3/ !Costas 7x7 tone pattern
data first/.true./
save
twopi=8.0*atan(1.0)
dfgen=12000.0/6912.0
k=-1
phi=0.
do j=0,6
dphi=twopi*icos7(j)*dfgen/4000.0
do i=1,2304
phi=phi + dphi
if(phi.gt.twopi) phi=phi-twopi
k=k+1
cc(k)=cmplx(cos(phi),sin(phi))
if(first) then
twopi=8.0*atan(1.0)
dfgen=12000.0/6912.0
k=-1
phi=0.
do j=0,6 !Compute complex Costas waveform
dphi=twopi*icos7(j)*dfgen/4000.0
do i=1,2304
phi=phi + dphi
if(phi.gt.twopi) phi=phi-twopi
k=k+1
cc(k)=cmplx(cos(phi),sin(phi))
enddo
enddo
enddo
first=.false.
endif
npts0=54*12000
nfft1=672000
@ -45,11 +47,8 @@ subroutine sync64(dd,nf1,nf2,maxf1,dtx,f0,kpk,snrdb,s3a)
df1=12000.0/nfft1
fac=2.0/nfft1
x=fac*dd(1:nfft1)
call system_clock(count0,clkfreq)
call four2a(c0,nfft1,1,-1,0) !Forward r2c FFT
call four2a(c0,nfft2,1,1,1) !Inverse c2c FFT; c0 is analytic sig
call system_clock(count1,clkfreq)
t(1)=float(count1-count0)/float(clkfreq)
npts2=npts0/3 !Downsampled complex data length
nfft3=NSPC
nh3=nfft3/2
@ -66,7 +65,6 @@ subroutine sync64(dd,nf1,nf2,maxf1,dtx,f0,kpk,snrdb,s3a)
kb=maxf1
ipk=0
kpk=0
call system_clock(count0,clkfreq)
do iter=1,2
do j1=ja,jb,jstep
j2=j1 + 39*2304
@ -101,8 +99,6 @@ subroutine sync64(dd,nf1,nf2,maxf1,dtx,f0,kpk,snrdb,s3a)
ipk=ipk0(1)
f0=(ipk+ia-1)*df3
kpk=k
! write(16,3101) jpk,ipk,kpk,dtx,f0,snr
!3101 format(3i5,f8.3,f8.2,f10.1)
endif
enddo
enddo
@ -112,9 +108,11 @@ subroutine sync64(dd,nf1,nf2,maxf1,dtx,f0,kpk,snrdb,s3a)
! ka=kpk
! kb=kpk
enddo
call system_clock(count1,clkfreq)
t(2)=float(count1-count0)/float(clkfreq)
snrdb=10.0*log10(snr)-39.0
!###
! Now use tweak on the c0() array, then do nfft4=NSPS FFTs to get s3a(),
! the properly synchronized symbol spectra.
return
end subroutine sync64