Update wsprcpm simulator and decoder.

git-svn-id: svn+ssh://svn.code.sf.net/p/wsjt/wsjt/branches/wsjtx@8603 ab8295b8-cf94-4d9e-aec4-7959e3be5d79
This commit is contained in:
Steven Franke 2018-04-03 14:55:55 +00:00
parent 396aab7274
commit 1f9d73963b
5 changed files with 286 additions and 333 deletions

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@ -15,20 +15,23 @@ subroutine genwsprcpm(msg,msgsent,itone)
integer icw(ND) integer icw(ND)
integer id(NS+ND) integer id(NS+ND)
integer jd(NS+ND) integer jd(NS+ND)
integer ipreamble(32) !Long sync vector integer ipreamble(16) !Freq estimation preamble
integer isync(32) !Long sync vector integer isync(200) !Long sync vector
integer itone(NN) integer itone(NN)
integer*8 n8 data ipreamble/1,1,1,1,0,0,0,0,0,0,0,0,1,1,1,1/
data ipreamble/1,1,1,1,1,1,1,1,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,1,1,1,1,1,1,1,1/
data first/.true./ data first/.true./
data iuniqueword0/z'30C9E8AD'/ data iuniqueword0/z'30C9E8AD'/
save first,isync,ipreamble save first,isync,ipreamble
if(first) then if(first) then
write(sbits,'(b32.32)') iuniqueword0 write(sbits,'(b32.32)') iuniqueword0
read(sbits,'(32i1)') isync read(sbits,'(32i1)') isync(1:32)
ipreamble=2*ipreamble-1 read(sbits,'(32i1)') isync(33:64)
isync=2*isync-1 read(sbits,'(32i1)') isync(65:96)
read(sbits,'(32i1)') isync(97:128)
read(sbits,'(32i1)') isync(129:160)
read(sbits,'(32i1)') isync(161:192)
read(sbits,'(8i1)') isync(193:200)
first=.false. first=.false.
endif endif
@ -52,17 +55,16 @@ write(*,'(a6,b16.16)') 'icrc: ',icrc
write(*,'(50i1,1x,14i1,1x,4i1)') msgbits write(*,'(50i1,1x,14i1,1x,4i1)') msgbits
call encode204(msgbits,codeword) !Encode the test message call encode204(msgbits,codeword) !Encode the test message
icw=2*codeword - 1 !NRZ codeword
! Message structure: ! Message structure:
! s32 d200 p32 ! d100 p16 d100
itone(1:32)=isync itone(1:100)=isync(1:100)+2*codeword(1:100)
itone(33:232)=icw itone(101:116)=ipreamble+1
itone(233:264)=ipreamble itone(117:216)=isync(101:200)+2*codeword(101:200)
itone=2*itone-3
! do i=1,264 do i=1,216
! write(*,*) i,itone(i) write(*,*) i,itone(i)
! enddo enddo
return return
end subroutine genwsprcpm end subroutine genwsprcpm

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@ -1,11 +1,11 @@
parameter (KK=64) !Information bits (50 + CRC14) ? parameter (KK=64) !Information bits (50 + CRC14) ?
parameter (ND=200) !Data symbols: LDPC (204,68), r=1/3, don't send last 4 bits parameter (ND=200) !Data symbols: LDPC (204,68), r=1/3, don't send last 4 bits
parameter (NS=64) !Sync symbols (2x32) parameter (NS=16) !Sync symbols (16)
parameter (NN=NS+ND) !Total symbols (264) parameter (NN=NS+ND) !Total symbols (216)
parameter (NSPS0=5300) !Samples per symbol at 12000 S/s parameter (NSPS0=6400) !Samples per symbol at 12000 S/s
parameter (NDOWN=53) !Downsample to 100 samples per symbol... parameter (NDOWN=32) !Downsample to 200 sa/symbol (375 Hz) for candidate selection
parameter (NSPS=NSPS0/NDOWN) !Samples per symbol parameter (NSPS=NSPS0/NDOWN) !Samples per symbol
parameter (NZ=NSPS*NN) !Samples in baseband waveform parameter (NZ=NSPS*NN) !Samples in baseband waveform

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@ -1,4 +1,4 @@
subroutine wsprcpm_wav(baud,xdt,h1,h2,f0,itone,snrdb,iwave) subroutine wsprcpm_wav(baud,xdt,h,f0,itone,snrdb,iwave)
! Generate iwave() from itone(). ! Generate iwave() from itone().
@ -23,23 +23,10 @@ subroutine wsprcpm_wav(baud,xdt,h1,h2,f0,itone,snrdb,iwave)
sig=1.0 sig=1.0
endif endif
dphi01=twopi*(f0-(h1/2.0d0)*baud)*dt
dphi11=twopi*(f0+(h1/2.0d0)*baud)*dt
dphi02=twopi*(f0-(h2/2.0d0)*baud)*dt
dphi12=twopi*(f0+(h2/2.0d0)*baud)*dt
phi=0.d0 phi=0.d0
k=nint(xdt/dt) k=nint(xdt/dt)
do j=1,NN do j=1,NN
if( mod(j,2).eq.0 ) then dphi=twopi*(f0+itone(j)*(h/2.0d0)*baud)*dt
dphi0=dphi01
dphi1=dphi11
else
dphi0=dphi02
dphi1=dphi12
endif
dphi=dphi0
if(itone(j).eq.1) dphi=dphi1
if(k.eq.0) phi=-dphi
do i=1,NSPS0 do i=1,NSPS0
k=k+1 k=k+1
phi=phi+dphi phi=phi+dphi

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@ -4,136 +4,89 @@ program wsprcpmd
! WSPRCPM is a WSPR-like mode based on full-response CPM. ! WSPRCPM is a WSPR-like mode based on full-response CPM.
! !
! Modulation Capabilities include:
! support for multi-h cpm with two modulation indexes: [h1,h2].
! h1,h2 (modulation index) are variable; h1=h2=0.5 is MSK, h1=h2=1.0 is standard
! fsk intended for noncoherent demodulation.
! demodulator uses noncoherent sequence detection with variable window size.
! symbol demodulation is done symbol-by-symbol - each symbol is
! estimated using a data frame comprising N symbol intervals, where N can
! be 1, 3, 5, 7, 9, 11. The central symbol is estimated and then the window
! is stepped forward by one symbol.
! soft symbols are decoded by log-domain belief propagation followed by ordered-
! statistics decoding.
!
! Currently configured to use (204,68) r=1/3 LDPC code, regular column weight 3. ! Currently configured to use (204,68) r=1/3 LDPC code, regular column weight 3.
! 50 data bits + 14 bit CRC + 4 "0" bits. The 4 "0" bits are unused bits that ! 50 data bits + 14 bit CRC + 4 "0" bits. The 4 "0" bits are unused bits that
! are not transmitted. At the decoder, these bits are treated as "AP" bits. ! are not transmitted. At the decoder, these bits are treated as "AP" bits.
! This shortens the code to (200,64) r=0.32, slightly decreasing the code rate. ! This shortens the code to (200,64) r=0.32, slightly decreasing the code rate.
! !
! Frame format is: ! Frame format is:
! s32 d200 p32 (264) channel symbols ! d100 p32 d100 (232) channel symbols
! !
use crc use crc
include 'wsprcpm_params.f90' include 'wsprcpm_params.f90'
parameter(NMAX=120*12000) parameter(NMAX=120*12000)
character arg*8,message*22,cbits*50,infile*80,fname*16,datetime*11 character arg*8,message*22,cbits*50,infile*80,fname*16,datetime*11
character*22 decodes(100)
character*120 data_dir character*120 data_dir
character*32 uwbits character*32 uwbits
character*68 dmsg character*68 dmsg
complex csync(0:32*100-1) !Sync symbols only, from cbb complex c2(0:120*12000/32-1) !Complex waveform
complex cpreamble(0:32*100-1) !Sync symbols only, from cbb complex cframe(0:216*200-1) !Complex waveform
complex cp2(0:32*100-1) complex cd(0:216*10-1) !Complex waveform
complex ctwks(0:32*100-1) complex c1(0:9,0:1),c0(0:9,0:1)
complex ctwkp(0:32*100-1) complex ccor(0:1,216)
complex c2(0:120*12000/53-1) !Complex waveform complex csum,cterm
complex ctmp(0:4*32*100-1)
complex cframe(0:264*100-1) !Complex waveform
complex cd(0:264*100-1) !Complex waveform
complex c1(0:9,1:2),c0(0:9,1:2)
complex ccor(0:1,264)
complex csum,cp(0:1,1:2),cterm
complex ccohs(0:31)
complex ccohp(0:31)
real*8 fMHz real*8 fMHz
real rxdata(ND),llr(204) !Soft symbols real rxdata(ND),llr(204) !Soft symbols
real sbits(264),sbits1(264),sbits3(264) real sbits(216),sbits1(216),sbits3(216)
real ps(0:8191),psbest(0:8191) real ps(0:8191),psbest(0:8191)
real candidates(100,2)
integer iuniqueword0 integer iuniqueword0
integer isync(32) !Unique word integer isync(200) !Unique word
integer ipreamble(32) !Preamble vector integer isync2(216)
integer ipreamble(16) !Preamble vector
integer ihdr(11) integer ihdr(11)
integer*2 iwave(NMAX) !Generated full-length waveform integer*2 iwave(NMAX) !Generated full-length waveform
integer*1,target :: idat(9) integer*1,target :: idat(9)
integer*1 decoded(68),apmask(204),cw(204) integer*1 decoded(68),apmask(204),cw(204)
integer*1 hbits(264),hbits1(264),hbits3(264) integer*1 hbits(216),hbits1(216),hbits3(216)
data ipreamble/1,1,1,1,1,1,1,1,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,1,1,1,1,1,1,1,1/ data ipreamble/1,1,1,1,0,0,0,0,0,0,0,0,1,1,1,1/
data iuniqueword0/z'30C9E8AD'/ data iuniqueword0/z'30C9E8AD'/
write(uwbits,'(b32.32)') iuniqueword0 write(uwbits,'(b32.32)') iuniqueword0
read(uwbits,'(32i1)') isync read(uwbits,'(32i1)') isync(1:32)
ipreamble=2*ipreamble-1 read(uwbits,'(32i1)') isync(33:64)
isync=2*isync-1 read(uwbits,'(32i1)') isync(65:96)
read(uwbits,'(32i1)') isync(97:128)
read(uwbits,'(32i1)') isync(129:160)
read(uwbits,'(32i1)') isync(161:192)
read(uwbits,'(8i1)') isync(193:200)
fs=12000.0/NDOWN !Sample rate fs=12000.0/NDOWN !Sample rate
dt=1.0/fs !Sample interval (s) dt=1.0/fs !Sample interval (s)
tt=NSPS*dt !Duration of "itone" symbols (s) tt=NSPS*dt !Duration of "itone" symbols (s)
baud=1.0/tt !Keying rate for "itone" symbols (baud) baud=1.0/tt !Keying rate for "itone" symbols (baud)
txt=NZ*dt !Transmission length (s) txt=NZ*dt !Transmission length (s)
h1=0.80 !h=0.8 seems to be optimum for AWGN sensitivity (not for fading) h=1.00 !h=0.8 seems to be optimum for AWGN sensitivity (not for fading)
h2=0.80
twopi=8.0*atan(1.0) twopi=8.0*atan(1.0)
dphi11=twopi*baud*(h1/2.0)*dt
dphi01=-twopi*baud*(h1/2.0)*dt
dphi12=twopi*baud*(h2/2.0)*dt
dphi02=-twopi*baud*(h2/2.0)*dt
k=0
phi=0.0
do i=1,32
if( mod(i,2) .eq. 0 ) then
dphi1=dphi11
dphi0=dphi01
else
dphi1=dphi12
dphi0=dphi02
endif
dphi=dphi0
if( isync(i) .eq. 1 ) dphi=dphi1
do j=1,100
phi=mod(phi+dphi,twopi)
csync(k)=cmplx(cos(phi),sin(phi))
k=k+1
enddo
enddo
k=0 isync2(1:100)=isync(1:100)
phi=0.0 isync2(101:104)=0 ! This is *not* backwards.
do i=1,32 isync2(105:112)=1
if( mod(i,2) .eq. 0 ) then isync2(113:116)=0
dphi1=dphi11 isync2(117:216)=isync(101:200)
dphi0=dphi01
else
dphi1=dphi12
dphi0=dphi02
endif
dphi=dphi0
if( ipreamble(i) .eq. 1 ) dphi=dphi1
do j=1,100
phi=mod(phi+dphi,twopi)
cpreamble(k)=cmplx(cos(phi),sin(phi))
k=k+1
enddo
enddo
dphi1=twopi*baud*(h1/2.0)*dt*10 ! dt*10 is samp interval after downsample ! data sync tone
dphi2=twopi*baud*(h2/2.0)*dt*10 ! dt*10 is samp interval after downsample ! 0 0 0
cp(1,1)=cmplx(cos(dphi1*10),sin(dphi1*10)) ! 0 1 1
cp(0,1)=conjg(cp(1,1)) ! 1 0 2
cp(1,2)=cmplx(cos(dphi2*10),sin(dphi2*10)) ! 1 1 3
cp(0,2)=conjg(cp(1,2)) dphi=twopi*baud*(h/2.0)*dt*20 ! dt*10 is samp interval after downsample
do j=1,2 do j=0,1
if( j.eq.1 ) then if(j.eq.0) then
dphi=dphi1 dphi0=-3*dphi
dphi1=+1*dphi
else else
dphi=dphi2 dphi0=-1*dphi
dphi1=+3*dphi
endif endif
phi0=0.0 phi0=0.0
phi1=0.0 phi1=0.0
do i=0,9 do i=0,9
c1(i,j)=cmplx(cos(phi1),sin(phi1)) c1(i,j)=cmplx(cos(phi1),sin(phi1))
c0(i,j)=cmplx(cos(phi0),sin(phi0)) c0(i,j)=cmplx(cos(phi0),sin(phi0))
phi1=mod(phi1+dphi,twopi) phi1=mod(phi1+dphi1,twopi)
phi0=mod(phi0-dphi,twopi) phi0=mod(phi0+dphi0,twopi)
enddo enddo
enddo enddo
@ -156,14 +109,14 @@ program wsprcpmd
iarg=iarg+2 iarg=iarg+2
endif endif
ncoh=1 ncoh=1
npdi=32 npdi=16
if(arg(1:2).eq.'-c') then if(arg(1:2).eq.'-c') then
call getarg(iarg+1,arg) call getarg(iarg+1,arg)
read(arg,*) ncoh read(arg,*) ncoh
iarg=iarg+2 iarg=iarg+2
npdi=32/ncoh npdi=16/ncoh
endif endif
write(*,*) 'ncoh: ',ncoh,' npdi: ',npdi ! write(*,*) 'ncoh: ',ncoh,' npdi: ',npdi
open(13,file=trim(data_dir)//'/ALL_WSPR.TXT',status='unknown', & open(13,file=trim(data_dir)//'/ALL_WSPR.TXT',status='unknown', &
position='append') position='append')
@ -197,123 +150,43 @@ program wsprcpmd
fa=-100.0 fa=-100.0
fb=100.0 fb=100.0
fs=12000.0/53.0 fs=12000.0/32.0
npts=120*12000/53 npts=120*12000.0/32.0
nsync=32 nsync=16
call getcandidate2(c2,npts,fs,fa,fb,ncand,candidates) !First approx for freq
call getcandidate2(c2,npts,fs,fa,fb,fc1,xsnr) !First approx for freq ndecodes=0
do icand=1,ncand
fcest=fc1 fc0=candidates(icand,1)
do iii=1,2 xsnr=candidates(icand,2)
izero=226 xmax=-1e32
dphi=twopi*fcest*dt do i=-5,5
ctwks=cmplx(0.0,0.0) ft=fc0+i*0.2
ctwkp=cmplx(0.0,0.0) call noncoherent_frame_sync(c2,ft,isync2,is,xf1)
phi=0 if(xf1.gt.xmax) then
do i=0,nsync*NSPS-1 xmax=xf1
phi=mod(phi+dphi,twopi) fc1=ft
ctwks(i)=csync(i)*cmplx(cos(phi),sin(phi)) is0=is
ctwkp(i)=cpreamble(i)*cmplx(cos(phi),sin(phi))
enddo
imax=100
xcmax=-1e32
do it = -imax,imax
its=izero+it
ccohs=0.0
do k=0,npdi-1
is=k*ncoh*nsps
ccohs(k)=sum(c2(its+is:its+is+ncoh*nsps-1)*conjg(ctwks(is:is+ncoh*nsps-1)))
ccohs(k)=ccohs(k)/(ncoh*nsps)
enddo
! term1=sum(abs(ccohs(0:npdi-1))**2)
itp=izero+it+232*100
ccohp=0.0
do k=0,npdi-1
is=k*ncoh*nsps
ccohp(k)=sum(c2(itp+is:itp+is+ncoh*nsps-1)*conjg(ctwkp(is:is+ncoh*nsps-1)))
ccohp(k)=ccohp(k)/(ncoh*nsps)
enddo
csum=0.0
terms=0.0
do n=1,npdi-1
do k=n,npdi-1
csum=csum+ccohs(k)*conjg(ccohs(k-n))
enddo
terms=terms+abs(csum)
enddo
csum=0.0
termp=0.0
do n=1,npdi-1
do k=n,npdi-1
csum=csum+ccohp(k)*conjg(ccohp(k-n))
enddo
termp=termp+abs(csum)
enddo
!write(23,*) it,terms,termp
xmetric=sqrt(terms*termp)
if( xmetric .gt. xcmax ) then
xcmax=xmetric
ibestt=it
endif endif
enddo enddo
call coherent_preamble_fsync(c2,ipreamble,nsync,NSPS,is0,fc1,fcest,xp1)
call noncoherent_frame_sync(c2,fcest,isync2,istart,xf2)
write(*,'(i5,i5,i5,4(f11.5,2x))') ifile,iii,istart,fc0,fc1,fcest
istart=izero+ibestt do ijitter=0,4
if(iii .eq. 2) goto 887 io=-10*(ijitter/2+1)
if(mod(ijitter,2).eq.0) io=10*(ijitter/2)
ctmp=0.0 ib=max(0,istart+io)
ctmp(0:32*100-1)=c2(istart+232*100:istart+264*100-1)*conjg(ctwkp) cframe=c2(ib:ib+216*200-1)
call four2a(ctmp,4*32*100,1,-1,1) !c2c FFT to freq domain
xmax=0.0
ctmp=cshift(ctmp,-200)
do i=150,250
xa=abs(ctmp(i))
if(xa.gt.xmax) then
ishift=i
xmax=xa
endif
enddo
dfp=1/(4*5300.0/12000.0*32)
delta=(ishift-200)*dfp
! need to add bounds protection
xm1=abs(ctmp(ishift-1))
x0=abs(ctmp(ishift))
xp1=abs(ctmp(ishift+1))
xint=(log(xm1)-log(xp1))/(log(xm1)+log(xp1)-2*log(x0))
delta2=delta+xint*dfp/2.0
fcest=fcest+delta2
enddo
887 write(*,'(i4,i5,5(2x,f9.5))') ifile,istart,xcmax,fc1,fcest
xdt=(istart-226)/100.0
if(abs(xdt).le.0.1) ngood=ngood+1
xs1=xs1+xdt
xs2=xs2+xdt**2
fr1=fr1+fc1
fr2=fr2+fc1**2
nav=nav+1
!**************
! fcest=0.0
! istart=226
do ijitter=0,2
io=ijitter
if(ijitter.eq.2) io=-1
cframe=c2(istart+io:istart+io+264*100-1)
call downsample2(cframe,fcest,cd) call downsample2(cframe,fcest,cd)
dts=10*dt s2=sum(cd*conjg(cd))/(10*216)
s2=sum(cd*conjg(cd))/(10*264)
cd=cd/sqrt(s2) cd=cd/sqrt(s2)
do nseq=1,7 do nseq=1,7
if( nseq.eq.1 ) then ! noncoherent single-symbol detection if( nseq.eq.1 ) then ! noncoherent single-symbol detection
sbits1=0.0 sbits1=0.0
do ibit=1,264 do ibit=1,216
if( mod(ibit,2).eq.0 ) j=1 j=isync2(ibit)
if( mod(ibit,2).eq.1 ) j=2
ib=(ibit-1)*10 ib=(ibit-1)*10
ccor(1,ibit)=sum(cd(ib:ib+9)*conjg(c1(0:9,j))) ccor(1,ibit)=sum(cd(ib:ib+9)*conjg(c1(0:9,j)))
ccor(0,ibit)=sum(cd(ib:ib+9)*conjg(c0(0:9,j))) ccor(0,ibit)=sum(cd(ib:ib+9)*conjg(c0(0:9,j)))
@ -334,19 +207,17 @@ do ijitter=0,2
if( nseq.eq. 6 ) nbit=11 if( nseq.eq. 6 ) nbit=11
if( nseq.eq. 7 ) nbit=13 if( nseq.eq. 7 ) nbit=13
numseq=2**(nbit) numseq=2**(nbit)
do ibit=nbit/2+1,264-nbit/2 do ibit=nbit/2+1,216-nbit/2
ps=0.0 ps=0.0
pmax=0.0 pmax=0.0
do iseq=0,numseq-1 do iseq=0,numseq-1
csum=0.0 csum=0.0
cterm=cmplx(1.0,0.0) cterm=1.0
k=1 k=1
do i=nbit-1,0,-1 do i=nbit-1,0,-1
ibb=iand(iseq/(2**i),1) ibb=iand(iseq/(2**i),1)
csum=csum+ccor(ibb,ibit-(nbit/2+1)+k)*cterm csum=csum+ccor(ibb,ibit-(nbit/2+1)+k)*cterm
if( mod(ibit-(nbit/2+1)+k,2) .eq. 0 ) j=1 cterm=-cterm
if( mod(ibit-(nbit/2+1)+k,2) .eq. 1 ) j=2
cterm=cterm*conjg(cp(ibb,j))
k=k+1 k=k+1
enddo enddo
ps(iseq)=abs(csum) ps(iseq)=abs(csum)
@ -366,7 +237,8 @@ do ijitter=0,2
sbits=sbits3 sbits=sbits3
hbits=hbits3 hbits=hbits3
endif endif
rxdata(1:200)=sbits(33:232) rxdata(1:100)=sbits(1:100)
rxdata(101:200)=sbits(117:216);
rxav=sum(rxdata(1:200))/200.0 rxav=sum(rxdata(1:200))/200.0
rx2av=sum(rxdata(1:200)*rxdata(1:200))/200.0 rx2av=sum(rxdata(1:200)*rxdata(1:200))/200.0
rxsig=sqrt(rx2av-rxav*rxav) rxsig=sqrt(rx2av-rxav*rxav)
@ -401,6 +273,13 @@ do ijitter=0,2
1202 format(8b8,b4) 1202 format(8b8,b4)
idat(7)=ishft(idat(7),6) idat(7)=ishft(idat(7),6)
call wqdecode(idat,message,itype) call wqdecode(idat,message,itype)
idupe=0
do i=1,ndecodes
if(decodes(i).eq.message) idupe=1
enddo
if(idupe.eq.1) goto 888
ndecodes=ndecodes+1
decodes(ndecodes)=message
nsnr=nint(xsnr) nsnr=nint(xsnr)
freq=fMHz + 1.d-6*(fc1+fbest) freq=fMHz + 1.d-6*(fc1+fbest)
nfdot=0 nfdot=0
@ -413,23 +292,138 @@ do ijitter=0,2
enddo ! nseq enddo ! nseq
enddo !jitter enddo !jitter
888 continue 888 continue
enddo !candidate list
enddo !files enddo !files
avshift=xs1/nav
varshift=xs2/nav
stdshift=sqrt(varshift-avshift**2)
avfr=fr1/nav
varfr=fr2/nav
stdfr=sqrt(varfr-avfr**2)
write(*,*) 'ngood: ',ngood
write(*,'(a7,f7.3,f7.3)') 'shift: ',avshift,stdshift
write(*,*) 'freq: ',avfr,stdfr
write(*,1120) write(*,1120)
1120 format("<DecodeFinished>") 1120 format("<DecodeFinished>")
999 end program wsprcpmd 999 end program wsprcpmd
subroutine coherent_preamble_fsync(c2,ipreamble,nsync,nsps,istart,fc0,fc1,xmax)
complex c2(0:120*12000/32-1)
complex cpreamble(0:16*200-1)
complex ctmp1(0:4*16*200-1)
complex ctwkp(0:16*200-1)
complex ccohp(0:15)
integer ipreamble(nsync)
logical first/.true./
save dt,first,h,twopi,cpreamble
if(first) then
baud=12000.0/6400.0
dt=32.0/12000.0
h=1.00
twopi=8.0*atan(1.0)
k=0
phi=0.0
dphi=twopi*baud*0.5*h*dt
do i=1,16
dp=dphi
if(ipreamble(i).eq.0) dp=-dphi
do j=1,200
cpreamble(k)=cmplx(cos(phi),sin(phi))
phi=mod(phi+dp,twopi)
k=k+1
enddo
enddo
first=.false.
endif
dphi=twopi*fc0*dt
ctwkp=cmplx(0.0,0.0)
phi=0
do i=0,nsync*nsps-1
ctwkp(i)=cpreamble(i)*cmplx(cos(phi),sin(phi))
phi=mod(phi+dphi,twopi)
enddo
ipstart=istart+100*200
ctmp1=0.0
ctmp1(0:16*200-1)=c2(ipstart:ipstart+16*200-1)*conjg(ctwkp)
call four2a(ctmp1,4*16*200,1,-1,1) !c2c FFT to freq domain
xmax=0.0
ctmp1=cshift(ctmp1,-200)
dfp=1/(4*6400.0/12000.0*16)
do i=150,250
xa=abs(ctmp1(i))
if(xa.gt.xmax) then
ishift=i
xmax=xa
endif
enddo
delta=(ishift-200)*dfp
xm1=abs(ctmp1(ishift-1))
x0=abs(ctmp1(ishift))
xp1=abs(ctmp1(ishift+1))
xint=(log(xm1)-log(xp1))/(log(xm1)+log(xp1)-2*log(x0))
delta2=delta+xint*dfp/2.0
fc1=fc0+delta2
return
end subroutine coherent_preamble_fsync
subroutine noncoherent_frame_sync(c2,fc,isync2,istart,ssmax)
complex c2(0:120*12000/32-1)
complex ct0(0:199),ct1(0:199),ct2(0:199),ct3(0:199)
integer isync2(216)
twopi=8.0*atan(1.0)
h=1.0
dt=32.0/12000.0
baud=12000.0/6400.0
imax=370 ! defines dt search range (375 samples/s)
ssmax=-1e32
izero=375
do it = -imax,imax,10
! noncoherent wspr-type dt estimation
dp0=twopi*(fc-1.5*h*baud)*dt
dp1=twopi*(fc-0.5*h*baud)*dt
dp2=twopi*(fc+0.5*h*baud)*dt
dp3=twopi*(fc+1.5*h*baud)*dt
th0=0.0
th1=0.0
th2=0.0
th3=0.0
do i=0,199
ct0(i)=cmplx(cos(th0),sin(th0))
ct1(i)=cmplx(cos(th1),sin(th1))
ct2(i)=cmplx(cos(th2),sin(th2))
ct3(i)=cmplx(cos(th3),sin(th3))
th0=mod(th0+dp0,twopi)
th1=mod(th1+dp1,twopi)
th2=mod(th2+dp2,twopi)
th3=mod(th3+dp3,twopi)
enddo
ss=0.0
totp=0.0
do is=1,216
i0=izero+it+(is-1)*200
p0=abs(sum(c2(i0:i0+199)*conjg(ct0)))
p1=abs(sum(c2(i0:i0+199)*conjg(ct1)))
p2=abs(sum(c2(i0:i0+199)*conjg(ct2)))
p3=abs(sum(c2(i0:i0+199)*conjg(ct3)))
p0=sqrt(p0)
p1=sqrt(p1)
p2=sqrt(p2)
p3=sqrt(p3)
totp=totp+p0+p1+p2+p3
! cmet=(p1+p3)-(p0+p2)
cmet=max(p1,p3)-max(p0,p2) ! This works better near threshold SNR
if(isync2(is).eq.0) ss=ss-cmet
if(isync2(is).eq.1) ss=ss+cmet
enddo
ss=ss/totp
if(ss.gt.ssmax) then
ioffset=it
ssmax=ss
endif
enddo
istart=izero+ioffset
return
end subroutine noncoherent_frame_sync
subroutine getmetric2(ib,ps,ns,xmet) subroutine getmetric2(ib,ps,ns,xmet)
real ps(0:ns-1) real ps(0:ns-1)
xm1=0 xm1=0
@ -443,10 +437,10 @@ subroutine getmetric2(ib,ps,ns,xmet)
end subroutine getmetric2 end subroutine getmetric2
subroutine downsample2(ci,f0,co) subroutine downsample2(ci,f0,co)
parameter(NI=264*100,NH=NI/2,NO=NI/10) ! downsample from 100 samples per symbol to 10 parameter(NI=216*200,NH=NI/2,NO=NI/20) ! downsample from 200 samples per symbol to 10
complex ci(0:NI-1),ct(0:NI-1) complex ci(0:NI-1),ct(0:NI-1)
complex co(0:NO-1) complex co(0:NO-1)
fs=12000.0/53.0 fs=12000.0/32.0
df=fs/NI df=fs/NI
ct=ci ct=ci
call four2a(ct,NI,1,-1,1) !c2c FFT to freq domain call four2a(ct,NI,1,-1,1) !c2c FFT to freq domain
@ -454,14 +448,10 @@ subroutine downsample2(ci,f0,co)
ct=cshift(ct,i0) ct=cshift(ct,i0)
co=0.0 co=0.0
co(0)=ct(0) co(0)=ct(0)
! b=3.4*0.875/0.715 b=8.0
! b=2.6*0.5625/0.715
b=12.0
do i=1,NO/2 do i=1,NO/2
arg=(i*df/b)**2 arg=(i*df/b)**2
filt=exp(-arg) filt=exp(-arg)
! filt=0.0
! if( i*df .le. b ) filt=1.0
co(i)=ct(i)*filt co(i)=ct(i)*filt
co(NO-i)=ct(NI-i)*filt co(NO-i)=ct(NI-i)*filt
enddo enddo
@ -470,72 +460,62 @@ subroutine downsample2(ci,f0,co)
return return
end subroutine downsample2 end subroutine downsample2
subroutine getcandidate2(c,npts,fs,fa,fb,fc1,xsnr) subroutine getcandidate2(c,npts,fs,fa,fb,ncand,candidates)
parameter(NDAT=100,NFFT1=8*NDAT,NH1=NFFT1/2) parameter(NDAT=200,NFFT1=120*12000/32,NH1=NFFT1/2,NFFT2=120*12000/320,NH2=NFFT2/2)
complex c(0:npts-1) !Complex waveform complex c(0:npts-1) !Complex waveform
complex cc(0:NFFT1-1)
complex csfil(0:NFFT2-1)
complex cwork(0:NFFT2-1)
real bigspec(0:NFFT2-1)
complex c2(0:NFFT1-1) !Short spectra complex c2(0:NFFT1-1) !Short spectra
real s(-NH1+1:NH1) !Coarse spectrum real s(-NH1+1:NH1) !Coarse spectrum
real ss(-NH1+1:NH1) !Smoothed coarse spectrum real ss(-NH1+1:NH1) !Smoothed coarse spectrum
real w(0:NFFT1-1) real candidates(100,2)
real pi integer indx(NFFT2-1)
logical first logical first
data first/.true./ data first/.true./
save first,w save first,w,df,csfil
if(first) then if(first) then
pi=4.0*atan(1.0) df=10*fs/NFFT1
do i=0,NFFT1-1 csfil=cmplx(0.0,0.0)
w(i)=sin(pi*i/(NDAT-1))**2 do i=0,NFFT2-1
csfil(i)=exp(-((i-NH2)/20.0)**2)
enddo enddo
csfil=cshift(csfil,NH2)
call four2a(csfil,NFFT2,1,-1,1)
first=.false. first=.false.
endif endif
nspec=int((npts-NFFT1)/NDAT)+1 cc=cmplx(0.0,0.0)
df1=fs/NFFT1 cc(0:npts-1)=c;
s=0. call four2a(cc,NFFT1,1,-1,1)
do k=1,nspec cc=abs(cc)**2
ia=(k-1)*NDAT call four2a(cc,NFFT1,1,-1,1)
ib=ia+NFFT1-1 cwork(0:NH2)=cc(0:NH2)*conjg(csfil(0:NH2))
c2(0:NFFT1-1)=c(ia:ib)*w cwork(NH2+1:NFFT2-1)=cc(NFFT1-NH2+1:NFFT1-1)*conjg(csfil(NH2+1:NFFT2-1))
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
do i=-NH1+1+4,NH1-4
ss(i)=sum(s(i-4:i+4))/9.0
enddo
! do i=-NH1+1+8,NH1-8
! ss(i)=sum(ss(i-4:i+4))/9.0
! enddo
do i=-20,20
write(52,*) i*df1,ss(i)
enddo
smax=0.
ipk=0
fc1=0.
ia=nint(fa/df1)
ib=nint(fb/df1)
do i=ia,ib
f=i*df1
if(ss(i).gt.smax) then
smax=ss(i)
ipk=i
fc1=f
endif
enddo
xint=(log(ss(ipk-1))-log(ss(ipk+1)))/(log(ss(ipk-1))+log(ss(ipk+1))-2*log(ss(ipk))) call four2a(cwork,NFFT2,1,+1,1)
fc1=fc1+xint*df1/2.0 bigspec=cshift(real(cwork),-NH2)
! The following is for testing SNR calibration: il=NH2+fa/df
sp3n=sum(s(ipk-5:ipk+5)) ih=NH2+fb/df
base=(sum(s)-sp3n)/(NFFT1-11.0) nnl=ih-il+1
psig=sp3n-11*base call indexx(bigspec(il:il+nnl-1),nnl,indx)
pnoise=(2500.0/df1)*base xn=bigspec(il-1+indx(nint(0.3*nnl)))
xsnr=db(psig/pnoise) bigspec=bigspec/xn
ncand=0
do i=il,ih
if((bigspec(i).gt.bigspec(i-1)).and. &
(bigspec(i).gt.bigspec(i+1)).and. &
(bigspec(i).gt.1.15).and.ncand.lt.100) then
ncand=ncand+1
candidates(ncand,1)=df*(i-NH2)
candidates(ncand,2)=10*log10(bigspec(i))-30.0
endif
enddo
! do i=1,ncand
! write(*,*) i,candidates(i,1),candidates(i,2)
! enddo
return return
end subroutine getcandidate2 end subroutine getcandidate2
@ -545,9 +525,9 @@ subroutine wsprcpm_downsample(iwave,c)
! Output: Complex data in c(), sampled at 400 Hz ! Output: Complex data in c(), sampled at 400 Hz
include 'wsprcpm_params.f90' include 'wsprcpm_params.f90'
parameter (NMAX=120*12000,NFFT2=NMAX/53) parameter (NMAX=120*12000,NFFT2=NMAX/32)
integer*2 iwave(NMAX) integer*2 iwave(NMAX)
complex c(0:NZ-1) complex c(0:NMAX/32-1)
complex c1(0:NFFT2-1) complex c1(0:NFFT2-1)
complex cx(0:NMAX/2) complex cx(0:NMAX/2)
real x(NMAX) real x(NMAX)
@ -564,8 +544,7 @@ subroutine wsprcpm_downsample(iwave,c)
enddo enddo
c1=c1/NFFT2 c1=c1/NFFT2
call four2a(c1,NFFT2,1,1,1) !c2c FFT back to time domain call four2a(c1,NFFT2,1,1,1) !c2c FFT back to time domain
c=c1(0:NZ-1) c=c1(0:NMAX/32-1)
return return
end subroutine wsprcpm_downsample end subroutine wsprcpm_downsample

View File

@ -42,7 +42,6 @@ program wsprcpmsim
fs=12000.0/NDOWN ! fs=12000.0/NDOWN !
dt=1.0/fs !Sample interval (s) dt=1.0/fs !Sample interval (s)
tt=NSPS*dt !Duration of "itone" symbols (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) baud=1.0/tt !Keying rate for "itone" symbols (baud)
txt=NZ*dt !Transmission length (s) txt=NZ*dt !Transmission length (s)
bandwidth_ratio=2500.0/(fs/2.0) bandwidth_ratio=2500.0/(fs/2.0)
@ -55,25 +54,11 @@ program wsprcpmsim
1000 format('f0:',f9.3,' DT:',f6.2,' txt:',f6.1,' SNR:',f6.1, & 1000 format('f0:',f9.3,' DT:',f6.2,' txt:',f6.1,' SNR:',f6.1, &
' fspread:',f6.1,' delay:',f6.1,' nfiles:',i3,2x,a22) ' fspread:',f6.1,' delay:',f6.1,' nfiles:',i3,2x,a22)
h1=0.80 h=1.00
h2=0.80
dphi11=twopi*(f0+(h1/2.0)*baud)*dt
dphi01=twopi*(f0-(h1/2.0)*baud)*dt
dphi12=twopi*(f0+(h2/2.0)*baud)*dt
dphi02=twopi*(f0-(h2/2.0)*baud)*dt
phi=0.0
c0=0. c0=0.
k=-1 + nint(xdt/dt) k=-1 + nint(xdt/dt)
do j=1,NN do j=1,NN
if( mod(j,2) .eq. 0 ) then dp=twopi*(f0+itone(j)*(h/2.0)*baud)*dt
dphi1=dphi11
dphi0=dphi01
else
dphi1=dphi12
dphi0=dphi02
endif
dp=dphi1
if(itone(j).eq.-1) dp=dphi0
do i=1,NSPS do i=1,NSPS
k=k+1 k=k+1
phi=mod(phi+dp,twopi) phi=mod(phi+dp,twopi)
@ -109,7 +94,7 @@ program wsprcpmsim
!write(57,*) i,real(c(i)),imag(c(i)) !write(57,*) i,real(c(i)),imag(c(i))
!enddo !enddo
else else
call wsprcpm_wav(baud,xdt,h1,h2,f0,itone,snrdb,iwave) call wsprcpm_wav(baud,xdt,h,f0,itone,snrdb,iwave)
hwav=default_header(12000,NMAX) hwav=default_header(12000,NMAX)
write(fname,1102) ifile write(fname,1102) ifile
1102 format('000000_',i4.4,'.wav') 1102 format('000000_',i4.4,'.wav')