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Add and update test programs. 

git-svn-id: svn+ssh://svn.code.sf.net/p/wsjt/wsjt/branches/wsjtx@7650 ab8295b8-cf94-4d9e-aec4-7959e3be5d79
This commit is contained in:
Joe Taylor 2017-04-24 16:16:18 +00:00
parent 52fedc02c5
commit f41c206318
8 changed files with 648 additions and 1 deletions
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9
CMakeLists.txt
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@ -335,6 +335,7 @@ set (wsjt_FSRCS
lib/chkss2.f90
lib/coord.f90
lib/fsk4hf/cpolyfit.f90
lib/fsk4hf/cpolyfitw.f90
lib/db.f90
lib/decode4.f90
lib/decode65a.f90
@ -392,8 +393,11 @@ set (wsjt_FSRCS
lib/genmsk144.f90
lib/genmsk40.f90
lib/fsk4hf/genmskhf.f90
lib/fsk4hf/genwsprlf.f90
lib/fsk4hf/getfc1.f90
lib/fsk4hf/getfc2.f90
lib/fsk4hf/getfc1w.f90
lib/fsk4hf/getfc2w.f90
lib/genqra64.f90
lib/genwspr.f90
lib/geodist.f90
@ -443,6 +447,7 @@ set (wsjt_FSRCS
lib/fsk4hf/mskhfsim.f90
lib/mskrtd.f90
lib/fsk4hf/msksoftsym.f90
lib/fsk4hf/msksoftsymw.f90
lib/pctile.f90
lib/peakdt9.f90
lib/peakup.f90
@ -496,6 +501,7 @@ set (wsjt_FSRCS
lib/xcor.f90
lib/xcor4.f90
lib/wqencode.f90
lib/fsk4hf/wsprlfsim.f90
lib/wspr_downsample.f90
lib/zplot9.f90
)
@ -1125,6 +1131,9 @@ target_link_libraries (ldpcsim168 wsjt_fort wsjt_cxx)
add_executable (fsk4hf lib/fsk4hf/fsk4hf.f90 wsjtx.rc)
target_link_libraries (fsk4hf wsjt_fort wsjt_cxx)
add_executable (wsprlfsim lib/fsk4hf/wsprlfsim.f90 wsjtx.rc)
target_link_libraries (wsprlfsim wsjt_fort wsjt_cxx)
add_executable (mskhfsim lib/fsk4hf/mskhfsim.f90 wsjtx.rc)
target_link_libraries (mskhfsim wsjt_fort wsjt_cxx)

76
lib/fsk4hf/cpolyfitw.f90 Normal file
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@ -0,0 +1,76 @@
subroutine cpolyfitw(c,pp,id,maxn,aa,bb,zz,nhardsync)
parameter (KK=60) !Information bits (50 + CRC10)
parameter (ND=300) !Data symbols: LDPC (300,60), r=1/5
parameter (NS=109) !Sync symbols (2 x 48 + Barker 13)
parameter (NR=3) !Ramp up/down
parameter (NN=NR+NS+ND) !Total symbols (412)
parameter (NSPS=16) !Samples per MSK symbol (16)
parameter (N2=2*NSPS) !Samples per OQPSK symbol (32)
parameter (N13=13*N2) !Samples in central sync vector (416)
parameter (NZ=NSPS*NN) !Samples in baseband waveform (6592)
parameter (NFFT1=4*NSPS,NH1=NFFT1/2)
complex c(0:NZ-1) !Complex waveform
complex zz(NS+ND) !Complex symbol values (intermediate)
complex z,z0
real x(NS),yi(NS),yq(NS) !For complex polyfit
real pp(2*NSPS) !Shaped pulse for OQPSK
real aa(20),bb(20) !Fitted polyco's
integer id(NS+ND) !NRZ values (+/-1) for Sync and Data
ib=NSPS-1
ib2=N2-1
n=0
do j=1,205 !First-pass demodulation
ia=ib+1
ib=ia+N2-1
zz(j)=sum(pp*c(ia:ib))/NSPS
if(abs(id(j)).eq.2) then !Save all sync symbols
n=n+1
x(n)=float(ia+ib)/NZ - 1.0
yi(n)=real(zz(j))*0.5*id(j)
yq(n)=aimag(zz(j))*0.5*id(j)
! write(54,1225) n,x(n),yi(n),yq(n)
!1225 format(i5,3f12.4)
endif
if(j.le.204) then
zz(j+205)=sum(pp*c(ia+NSPS:ib+NSPS))/NSPS
endif
enddo
aa=0.
bb=0.
nterms=0
chisqa=0.
chisqb=0.
if(maxn.gt.0) then
npts=n
mode=0
nterms=maxn
call polyfit4(x,yi,yi,npts,nterms,mode,aa,chisqa)
call polyfit4(x,yq,yq,npts,nterms,mode,bb,chisqb)
endif
nhardsync=0
do j=1,205
if(abs(id(j)).ne.2) cycle
xx=j*2.0/205.0 - 1.0
yii=1.
yqq=0.
if(nterms.gt.0) then
yii=aa(1)
yqq=bb(1)
do i=2,nterms
yii=yii + aa(i)*xx**(i-1)
yqq=yqq + bb(i)*xx**(i-1)
enddo
endif
z0=cmplx(yii,yqq)
z=zz(j)*conjg(z0)
p=real(z)
if(p*id(j).lt.0) nhardsync=nhardsync+1
enddo
return
end subroutine cpolyfitw

129
lib/fsk4hf/genwsprlf.f90 Normal file
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@ -0,0 +1,129 @@
subroutine genwsprlf(msgbits,id,icw,cbb,csync)
!Encode a WSPR-LF message, produce baseband waveform and sync vector.
parameter (KK=60) !Information bits (50 + CRC10)
parameter (ND=300) !Data symbols: LDPC (300,60), r=1/5
parameter (NS=109) !Sync symbols (2 x 48 + Barker 13)
parameter (NR=3) !Ramp up/down (2 x half-length symbols)
parameter (NN=NR+NS+ND) !Total symbols (410)
parameter (NSPS=16) !Samples per MSK symbol (16)
parameter (N2=2*NSPS) !Samples per OQPSK symbol (32)
parameter (N13=13*N2) !Samples in central sync vector (416)
parameter (NZ=NSPS*NN) !Samples in baseband waveform (6560)
parameter (NFFT1=4*NSPS,NH1=NFFT1/2)
complex cbb(0:NZ-1)
complex csync(0:NZ-1)
real x(0:NZ-1)
real y(0:NZ-1)
real pp(N2)
logical first
integer*1 msgbits(KK),codeword(ND)
integer icw(ND)
integer id(NS+ND)
integer isync(48) !Long sync vector
integer ib13(13) !Barker 13 code
integer*8 n8
data ib13/1,1,1,1,1,-1,-1,1,1,-1,1,-1,1/
data first/.true./
save first,isync,twopi,pp
if(first) then
n8=z'cbf089223a51'
do i=1,48
isync(i)=-1
if(iand(n8,1).eq.1) isync(i)=1
n8=n8/2
enddo
twopi=8.0*atan(1.0)
do i=1,N2 !Half-sine shaped pulse
pp(i)=sin(0.5*(i-1)*twopi/N2)
enddo
first=.false.
endif
call encode300(msgbits,codeword) !Encode the test message
icw=2*codeword - 1
! Message structure: R1 48*(S1+D1) S13 48*(D1+S1) R1
! Generate QPSK without any offset; then shift the y array to get OQPSK.
! Do the I channel first: results in array x
n=0
k=0
ia=0
ib=NSPS-1
x(ia:ib)=0. !Ramp up (half-symbol; shape TBD)
do j=1,48 !Insert group of 48*(S1+D1)
ia=ib+1
ib=ia+N2-1
n=n+1
id(n)=2*isync(j)
x(ia:ib)=isync(j)*pp !Insert Sync bit
ia=ib+1
ib=ia+N2-1
k=k+1
n=n+1
id(n)=icw(k)
x(ia:ib)=id(n)*pp !Insert data bit
enddo
do j=1,13 !Insert Barker 13 code
ia=ib+1
ib=ia+N2-1
n=n+1
id(n)=2*ib13(j)
x(ia:ib)=ib13(j)*pp
enddo
do j=1,48 !Insert group of 48*(S1+D1)
ia=ib+1
ib=ia+N2-1
k=k+1
n=n+1
id(n)=icw(k)
x(ia:ib)=id(n)*pp !Insert data bit
ia=ib+1
ib=ia+N2-1
n=n+1
id(n)=2*isync(j)
x(ia:ib)=isync(j)*pp !Insert Sync bit
enddo
ia=ib+1
ib=ia+NSPS-1
x(ia:ib)=0. !Ramp down (half-symbol; shape TBD)
! Now do the Q channel: results in array y
ia=0
ib=NSPS-1
y(ia:ib)=0. !Ramp up (half-symbol; shape TBD)
do j=1,204
ia=ib+1
ib=ia+N2-1
k=k+1
n=n+1
id(n)=icw(k)
y(ia:ib)=id(n)*pp
enddo
ia=ib+1
ib=ia+NSPS-1
y(ia:ib)=0. !Ramp down (half-symbol; shape TBD)
y=cshift(y,-NSPS) !Shift Q array to get OQPSK
cbb=cmplx(x,y) !Complex baseband waveform
ib=NSPS-1
ib2=NSPS-1+64*N2
do j=1,48 !Zero all data symbols in x
ia=ib+1+N2
ib=ia+N2-1
x(ia:ib)=0.
ia2=ib2+1+N2
ib2=ia2+N2-1
x(ia2:ib2)=0.
enddo
csync=x
return
end subroutine genwsprlf

57
lib/fsk4hf/getfc1w.f90 Normal file
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@ -0,0 +1,57 @@
subroutine getfc1w(c,fs,fc1)
parameter (KK=60) !Information bits (50 + CRC10)
parameter (ND=300) !Data symbols: LDPC (300,60), r=1/5
parameter (NS=109) !Sync symbols (2 x 48 + Barker 13)
parameter (NR=3) !Ramp up/down
parameter (NN=NR+NS+ND) !Total symbols (412)
parameter (NSPS=16) !Samples per MSK symbol (16)
parameter (N2=2*NSPS) !Samples per OQPSK symbol (32)
parameter (N13=13*N2) !Samples in central sync vector (416)
parameter (NZ=NSPS*NN) !Samples in baseband waveform (6592)
parameter (NFFT1=4*NSPS,NH1=NFFT1/2)
complex c(0:NZ-1) !Complex waveform
complex c2(0:NFFT1-1) !Short spectra
real s(-NH1+1:NH1) !Coarse spectrum
nspec=NZ/NFFT1
df1=fs/NFFT1
s=0.
do k=1,nspec
ia=(k-1)*N2
ib=ia+N2-1
c2(0:N2-1)=c(ia:ib)
c2(N2:)=0.
call four2a(c2,NFFT1,1,-1,1)
do i=0,NFFT1-1
j=i
if(j.gt.NH1) j=j-NFFT1
s(j)=s(j) + real(c2(i))**2 + aimag(c2(i))**2
enddo
enddo
! call smo121(s,NFFT1)
smax=0.
ipk=0
fc1=0.
ia=nint(10.0/df1)
do i=-ia,ia
f=i*df1
if(s(i).gt.smax) then
smax=s(i)
ipk=i
fc1=f
endif
! write(51,3001) f,s(i),db(s(i))
! 3001 format(f10.3,e12.3,f10.3)
enddo
! The following is for testing SNR calibration:
! sp3n=(s(ipk-1)+s(ipk)+s(ipk+1)) !Sig + 3*noise
! base=(sum(s)-sp3n)/(NFFT1-3.0) !Noise per bin
! psig=sp3n-3*base !Sig only
! pnoise=(2500.0/df1)*base !Noise in 2500 Hz
! xsnrdb=db(psig/pnoise)
return
end subroutine getfc1w

73
lib/fsk4hf/getfc2w.f90 Normal file
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@ -0,0 +1,73 @@
subroutine getfc2w(c,csync,fs,fc1,fc2,fc3)
parameter (KK=60) !Information bits (50 + CRC10)
parameter (ND=300) !Data symbols: LDPC (300,60), r=1/5
parameter (NS=109) !Sync symbols (2 x 48 + Barker 13)
parameter (NR=3) !Ramp up/down
parameter (NN=NR+NS+ND) !Total symbols (412)
parameter (NSPS=16) !Samples per MSK symbol (16)
parameter (N2=2*NSPS) !Samples per OQPSK symbol (32)
parameter (N13=13*N2) !Samples in central sync vector (416)
parameter (NZ=NSPS*NN) !Samples in baseband waveform (6592)
parameter (NFFT1=4*NSPS,NH1=NFFT1/2)
complex c(0:NZ-1) !Complex waveform
complex cs(0:NZ-1) !For computing spectrum
complex csync(0:NZ-1) !Sync symbols only, from cbb
real a(5)
df=fs/NZ
baud=fs/NSPS
a(1)=-fc1
a(2:5)=0.
call twkfreq1(c,NZ,fs,a,cs) !Mix down by fc1
! Filter, square, then FFT to get refined carrier frequency fc2.
call four2a(cs,NZ,1,-1,1) !To freq domain
ia=nint(0.75*baud/df)
cs(ia:NZ-1-ia)=0. !Save only freqs around fc1
call four2a(cs,NZ,1,1,1) !Back to time domain
cs=cs/NZ
cs=cs*cs !Square the data
call four2a(cs,NZ,1,-1,1) !Compute squared spectrum
! Find two peaks separated by baud
pmax=0.
fc2=0.
ic=nint(baud/df)
ja=nint(0.5*baud/df)
do j=-ja,ja
f2=j*df
ia=nint((f2-0.5*baud)/df)
if(ia.lt.0) ia=ia+NZ
ib=nint((f2+0.5*baud)/df)
p=real(cs(ia))**2 + aimag(cs(ia))**2 + &
real(cs(ib))**2 + aimag(cs(ib))**2
if(p.gt.pmax) then
pmax=p
fc2=0.5*f2
endif
! write(52,1200) f2,p,db(p)
!1200 format(f10.3,2f15.3)
enddo
a(1)=-fc1
a(2:5)=0.
call twkfreq1(c,NZ,fs,a,cs) !Mix down by fc1
cs=cs*conjg(csync)
call four2a(cs,NZ,1,-1,1) !To freq domain
pmax=0.
do i=0,NZ-1
f=i*df
if(i.gt.NZ/2) f=(i-NZ)*df
p=real(cs(i))**2 + aimag(cs(i))**2
! write(51,3001) f,p,db(p)
!3001 format(f10.3,e12.3,f10.3)
if(p.gt.pmax) then
pmax=p
fc3=f
endif
enddo
return
end subroutine getfc2w

85
lib/fsk4hf/msksoftsymw.f90 Normal file
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@ -0,0 +1,85 @@
subroutine msksoftsymw(zz,aa,bb,id,nterms,ierror,rxdata,nhard0,nhardsync0)
parameter (KK=60) !Information bits (50 + CRC10)
parameter (ND=300) !Data symbols: LDPC (300,60), r=1/5
parameter (NS=109) !Sync symbols (2 x 48 + Barker 13)
parameter (NR=3) !Ramp up/down
parameter (NN=NR+NS+ND) !Total symbols (412)
parameter (NSPS=16) !Samples per MSK symbol (16)
parameter (N2=2*NSPS) !Samples per OQPSK symbol (32)
parameter (N13=13*N2) !Samples in central sync vector (416)
parameter (NZ=NSPS*NN) !Samples in baseband waveform (6592)
parameter (NFFT1=4*NSPS,NH1=NFFT1/2)
complex zz(NS+ND) !Complex symbol values (intermediate)
complex z,z0
real rxdata(ND) !Soft symbols
real aa(20),bb(20) !Fitted polyco's
integer id(NS+ND) !NRZ values (+/-1) for Sync and Data
integer ierror(NS+ND)
n=0
ierror=0
ierr=0
do j=1,205
xx=j*2.0/205.0 - 1.0
yii=1.
yqq=0.
if(nterms.gt.0) then
yii=aa(1)
yqq=bb(1)
do i=2,nterms
yii=yii + aa(i)*xx**(i-1)
yqq=yqq + bb(i)*xx**(i-1)
enddo
endif
z0=cmplx(yii,yqq)
z=zz(j)*conjg(z0)
p=real(z)
if(abs(id(j)).eq.2) then
if(real(z)*id(j).lt.0) then !Sync bit
nhardsync0=nhardsync0+1
ierror(j)=2
endif
else
n=n+1 !Data bit
rxdata(n)=p
ierr=0
if(id(j)*p.lt.0) then
ierr=1
ierror(j)=1
endif
nhard0=nhard0+ierr
endif
! write(41,3301) j,id(j),ierror(j),ierr,p*id(j)
!3301 format(4i6,f10.3)
enddo
do j=206,409
xx=(j-204.5)*2.0/205.0 - 1.0
yii=1.
yqq=0.
if(nterms.gt.0) then
yii=aa(1)
yqq=bb(1)
do i=2,nterms
yii=yii + aa(i)*xx**(i-1)
yqq=yqq + bb(i)*xx**(i-1)
enddo
endif
z0=cmplx(yii,yqq)
z=zz(j)*conjg(z0)
p=aimag(z)
n=n+1
rxdata(n)=p
ierr=0
if(id(j)*p.lt.0) then
ierr=1
ierror(j)=1
endif
nhard0=nhard0+ierr
! write(41,3301) j,id(j),ierror(j),ierr,p*id(j)
enddo
return
end subroutine msksoftsymw

2
lib/fsk4hf/watterson.f90
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@ -1,6 +1,6 @@
subroutine watterson(c,nz,fs,delay,fspread)
parameter (NZMAX=3776)
parameter (NZMAX=6592)
complex c(0:nz-1)
complex c2(0:NZMAX-1)
complex cs1(0:NZMAX-1)

218
lib/fsk4hf/wsprlfsim.f90 Normal file
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@ -0,0 +1,218 @@
program wsprlfsim
! Simulate characteristics of a potential "WSPR-LF" mode using LDPC (300,60)
! code, OQPSK modulation, and 5 minute T/R sequences.
! Reception and Demodulation algorithm:
! 1. Compute coarse spectrum; find fc1 = approx carrier freq
! 2. Mix from fc1 to 0; LPF at +/- 0.75*R
! 3. Square, FFT; find peaks near -R/2 and +R/2 to get fc2
! 4. Mix from fc2 to 0
! 5. Fit cb13 (central part of csync) to c -> lag, phase
! 6. Fit complex ploynomial for channel equalization
! 7. Get soft bits from equalized data
parameter (KK=60) !Information bits (50 + CRC10)
parameter (ND=300) !Data symbols: LDPC (300,60), r=1/5
parameter (NS=109) !Sync symbols (2 x 48 + Barker 13)
parameter (NR=3) !Ramp up/down
parameter (NN=NR+NS+ND) !Total symbols (412)
parameter (NSPS=16) !Samples per MSK symbol (16)
parameter (N2=2*NSPS) !Samples per OQPSK symbol (32)
parameter (N13=13*N2) !Samples in central sync vector (416)
parameter (NZ=NSPS*NN) !Samples in baseband waveform (6592)
parameter (NFFT1=4*NSPS,NH1=NFFT1/2)
! Q: Would it be better for central Sync array to use both I and Q channels?
character*8 arg
complex cbb(0:NZ-1) !Complex baseband waveform
complex csync(0:NZ-1) !Sync symbols only, from cbb
complex cb13(0:N13-1) !Barker 13 waveform
complex c(0:NZ-1) !Complex waveform
complex c0(0:NZ-1) !Complex waveform
complex zz(NS+ND) !Complex symbol values (intermediate)
complex z
real xnoise(0:NZ-1) !Generated random noise
real ynoise(0:NZ-1) !Generated random noise
real rxdata(ND),llr(ND) !Soft symbols
real pp(2*NSPS) !Shaped pulse for OQPSK
real a(5) !For twkfreq1
real aa(20),bb(20) !Fitted polyco's
integer id(NS+ND) !NRZ values (+/-1) for Sync and Data
integer ierror(NS+ND)
integer icw(NN)
integer*1 msgbits(KK),decoded(KK),apmask(ND),cw(ND)
! integer*1 codeword(ND)
data msgbits/0,0,1,0,0,1,1,1,1,0,0,1,0,0,0,0,0,0,0,0,1,0,0,0,1,1,0,0,0,1, &
1,1,1,0,1,1,1,1,1,1,1,0,0,1,0,0,1,1,0,1,1,0,1,0,1,1,0,0,1,1/
nargs=iargc()
if(nargs.ne.6) then
print*,'Usage: wsprlfsim f0(Hz) delay(ms) fspread(Hz) maxn iters snr(dB)'
print*,'Example: wsprlfsim 0 0 0 5 10 -20'
print*,'Set snr=0 to cycle through a range'
go to 999
endif
call getarg(1,arg)
read(arg,*) f0 !Generated carrier frequency
call getarg(2,arg)
read(arg,*) delay !Delta_t (ms) for Watterson model
call getarg(3,arg)
read(arg,*) fspread !Fspread (Hz) for Watterson model
call getarg(4,arg)
read(arg,*) maxn !Max nterms for polyfit
call getarg(5,arg)
read(arg,*) iters !Iterations at each SNR
call getarg(6,arg)
read(arg,*) snrdb !Specified SNR_2500
twopi=8.0*atan(1.0)
fs=12000.0/540.0 !Sample rate = 22.2222... Hz
dt=1.0/fs !Sample interval (s)
tt=NSPS*dt !Duration of "itone" symbols (s)
ts=2*NSPS*dt !Duration of OQPSK symbols (s)
baud=1.0/tt !Keying rate for "itone" symbols (baud)
txt=NZ*dt !Transmission length (s)
bandwidth_ratio=2500.0/(fs/2.0)
write(*,1000) f0,delay,fspread,maxn,iters,baud,3*baud,txt
1000 format('f0:',f5.1,' Delay:',f4.1,' fSpread:',f5.2,' maxn:',i3, &
' Iters:',i6/'Baud:',f7.3,' BW:',f5.1,' TxT:',f5.1,f5.2/)
write(*,1004)
1004 format(/' SNR sync data ser ber fer fsigma tsigma'/60('-'))
do i=1,N2 !Half-sine pulse shape
pp(i)=sin(0.5*(i-1)*twopi/(2*NSPS))
enddo
call genwsprlf(msgbits,id,icw,cbb,csync)!Generate baseband waveform and csync
cb13=csync(3088:3503) !Copy the Barker 13 waveform
a=0.
a(1)=f0
call twkfreq1(cbb,NZ,fs,a,cbb) !Mix to specified frequency
! write(*,3101) id
!3101 format(20i3)
isna=-20
isnb=-40
if(snrdb.ne.0.0) then
isna=nint(snrdb)
isnb=isna
endif
do isnr=isna,isnb,-1 !Loop over SNR range
if(isna.ne.isnb) snrdb=isnr
sig=sqrt(bandwidth_ratio) * 10.0**(0.05*snrdb)
if(snrdb.gt.90.0) sig=1.0
nhard=0
nhardsync=0
nfe=0
sqf=0.
sqt=0.
do iter=1,iters !Loop over requested iterations
c=cbb
if(delay.ne.0.0 .or. fspread.ne.0.0) then
call watterson(c,NZ,fs,delay,fspread)
endif
c=sig*c !Scale to requested SNR
if(snrdb.lt.90) then
do i=0,NZ-1 !Generate gaussian noise
xnoise(i)=gran()
ynoise(i)=gran()
enddo
c=c + cmplx(xnoise,ynoise) !Add AWGN noise
endif
call getfc1w(c,fs,fc1) !First approx for freq
call getfc2w(c,csync,fs,fc1,fc2,fc3) !Refined freq
sqf=sqf + (fc1+fc2-f0)**2
!NB: Measured performance is about equally good using fc2 or fc3 here:
a(1)=-(fc1+fc2)
a(2:5)=0.
call twkfreq1(c,NZ,fs,a,c) !Mix c down by fc1+fc2
! The following may not be necessary?
! z=sum(c(3088:3503)*cb13)/208.0 !Get phase from Barker 13 vector
! z0=z/abs(z)
! c=c*conjg(z0)
!---------------------------------------------------------------- DT
! Not presently used:
amax=0.
jpk=0
iaa=0
ibb=NZ-1
do j=-20*NSPS,20*NSPS !Get jpk
! z=sum(c(3088+j:3503+j)*conjg(cb13))/208.0
ia=j
ib=NZ-1+j
if(ia.lt.0) then
ia=0
iaa=-j
else
iaa=0
endif
if(ib.gt.NZ-1) then
ib=NZ-1
ibb=NZ-1-j
endif
z=sum(c(ia:ib)*conjg(csync(iaa:ibb)))
if(abs(z).gt.amax) then
amax=abs(z)
jpk=j
endif
enddo
xdt=jpk/fs
sqt=sqt + xdt**2
!-----------------------------------------------------------------
nterms=maxn
c0=c
do itry=1,20
idf=itry/2
if(mod(itry,2).eq.0) idf=-idf
nhard0=0
nhardsync0=0
ifer=1
a(1)=idf*0.00085
a(2:5)=0.
call twkfreq1(c0,NZ,fs,a,c) !Mix c0 into c
call cpolyfitw(c,pp,id,maxn,aa,bb,zz,nhs)
call msksoftsymw(zz,aa,bb,id,nterms,ierror,rxdata,nhard0,nhardsync0)
if(nhardsync0.gt.35) cycle
rxav=sum(rxdata)/ND
rx2av=sum(rxdata*rxdata)/ND
rxsig=sqrt(rx2av-rxav*rxav)
rxdata=rxdata/rxsig
ss=0.84
llr=2.0*rxdata/(ss*ss)
apmask=0
max_iterations=40
ifer=0
call bpdecode300(llr,apmask,max_iterations,decoded,niterations,cw)
nbadcrc=0
if(niterations.ge.0) call chkcrc10(decoded,nbadcrc)
if(niterations.lt.0 .or. count(msgbits.ne.decoded).gt.0 .or. &
nbadcrc.ne.0) ifer=1
if(ifer.eq.0) exit
enddo !Freq dither loop
nhard=nhard+nhard0
nhardsync=nhardsync+nhardsync0
nfe=nfe+ifer
if(nhardsync0+nhard0+niterations+ifer.gt.0) write(42,1045) snrdb, &
nhardsync0,nhard0,niterations,ifer,xdt
1045 format(f6.1,4i6,f8.2)
enddo
fsigma=sqrt(sqf/iters)
tsigma=sqrt(sqt/iters)
ser=float(nhardsync)/(NS*iters)
ber=float(nhard)/(ND*iters)
fer=float(nfe)/iters
write(*,1050) snrdb,nhardsync,nhard,ser,ber,fer,fsigma,tsigma
1050 format(f6.1,2i7,2f8.4,f7.3,2f8.2)
enddo
write(*,1060) NS*iters,ND*iters
1060 format(60('-')/6x,2i7)
999 end program wsprlfsim