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https://github.com/saitohirga/WSJT-X.git
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Significantly improved performance of msk40.
git-svn-id: svn+ssh://svn.code.sf.net/p/wsjt/wsjt/branches/wsjtx@6974 ab8295b8-cf94-4d9e-aec4-7959e3be5d79
This commit is contained in:
Steven Franke
parent
b449fd071c
commit
df4dd69bf4
@ -1,7 +1,7 @@
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subroutine detectmsk40(cbig,n,mycall,hiscall,lines,nmessages,nutc,ntol,t00)
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use timer_module, only: timer
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parameter (NSPM=240, NPTS=3*NSPM, MAXSTEPS=7500, NFFT=3*NSPM, MAXCAND=5)
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parameter (NSPM=240, NPTS=3*NSPM, MAXSTEPS=7500, NFFT=3*NSPM, MAXCAND=40)
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character*4 rpt(0:63)
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character*6 mycall,hiscall
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character*22 hashmsg,msgreceived
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@ -24,7 +24,9 @@ subroutine detectmsk40(cbig,n,mycall,hiscall,lines,nmessages,nutc,ntol,t00)
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integer nhashes(0:63)
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integer indices(MAXSTEPS)
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integer ipeaks(10)
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integer*1 cw(32)
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integer*1 decoded(16)
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integer*1 testcw(32)
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logical ismask(NFFT)
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real cbi(42),cbq(42)
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real detmet(-2:MAXSTEPS+3)
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@ -43,6 +45,8 @@ subroutine detectmsk40(cbig,n,mycall,hiscall,lines,nmessages,nutc,ntol,t00)
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data first/.true./
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data s8/0,1,1,1,0,0,1,0/
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data s8r/1,0,1,1,0,0,0,1/
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! codeword for the message <K9AN K1JT> RRR
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data testcw/0,1,0,0,0,1,0,1,0,0,1,1,1,1,0,1,0,1,1,1,1,1,0,0,0,0,0,0,1,1,1,0/
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save df,first,cb,cbr,fs,nhashes,pi,twopi,dt,s8,s8r,rcw,pp,nmatchedfilter,rpt
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if(first) then
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@ -150,8 +154,8 @@ subroutine detectmsk40(cbig,n,mycall,hiscall,lines,nmessages,nutc,ntol,t00)
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deltal=-real( (ctmp(ilpk-1)-ctmp(ilpk+1)) / (2*ctmp(ilpk)-ctmp(ilpk-1)-ctmp(ilpk+1)) )
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al=tonespec(ilpk)
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fdiff=(ihpk+deltah-ilpk-deltal)*df
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i2000=2000/df+1
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i4000=4000/df+1
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i2000=nint(2000/df)+1
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i4000=nint(4000/df)+1
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ferrh=(ihpk+deltah-i4000)*df/2.0
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ferrl=(ilpk+deltal-i2000)*df/2.0
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if( ah .ge. al ) then
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@ -223,18 +227,16 @@ subroutine detectmsk40(cbig,n,mycall,hiscall,lines,nmessages,nutc,ntol,t00)
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crmax=maxval(abs(ccr))
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!do i=1,NPTS
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!write(14,*) i,abs(ccr(i)),ddr(i)
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!write(15,*) i,abs(ccr(i)),ddr(i),abs(cdat(i))
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!enddo
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! Find 6 largest peaks
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do ipk=1,6
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iloc=maxloc(abs(ccr))
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ic1=iloc(1)
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iloc=maxloc(ddr)
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ic2=iloc(1)
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ic1=iloc(1)
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ipeaks(ipk)=ic1
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ccr(max(1,ic1-7):min(NPTS-40*6-41,ic1+7))=0.0
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ddr(max(1,ic1-7):min(NPTS-40*6-41,ic1+7))=0.0
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enddo
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!do i=1,6
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!write(*,*) i,ipeaks(i)
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@ -256,6 +258,7 @@ subroutine detectmsk40(cbig,n,mycall,hiscall,lines,nmessages,nutc,ntol,t00)
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ibb=iloc(1)
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bba=abs(bb(ibb))
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bbp=atan2(-imag(bb(ibb)),-real(bb(ibb)))/(2*twopi*6*dt)
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!write(*,*) abs(bb),bbp
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if( ibb .le. 3 ) ibb=ibb-1
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if( ibb .gt. 3 ) ibb=ibb-7
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@ -269,18 +272,17 @@ subroutine detectmsk40(cbig,n,mycall,hiscall,lines,nmessages,nutc,ntol,t00)
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if( ic .lt. 1 ) ic=ic+NSPM
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! Estimate fine frequency error.
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cca=sum(cdat(ic:ic+41)*conjg(cb))
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cca=sum(cdat(ic:ic+41)*conjg(cbr))
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if( ic+40*6+41 .le. NPTS ) then
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ccb=sum(cdat(ic+40*6:ic+40*6+41)*conjg(cb))
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ccb=sum(cdat(ic+40*6:ic+40*6+41)*conjg(cbr))
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cfac=ccb*conjg(cca)
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ferr2=atan2(imag(cfac),real(cfac))/(twopi*40*6*dt)
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else
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ccb=sum(cdat(ic-40*6:ic-40*6+41)*conjg(cb))
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ccb=sum(cdat(ic-40*6:ic-40*6+41)*conjg(cbr))
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cfac=cca*conjg(ccb)
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ferr2=atan2(imag(cfac),real(cfac))/(twopi*40*6*dt)
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endif
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do idf=0,6 ! frequency jitter
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if( idf .eq. 0 ) then
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deltaf=0.0
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@ -308,7 +310,7 @@ subroutine detectmsk40(cbig,n,mycall,hiscall,lines,nmessages,nutc,ntol,t00)
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endif
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! Estimate final frequency error and carrier phase.
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cca=sum(c(1:1+41)*conjg(cb))
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cca=sum(c(1:1+41)*conjg(cbr))
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phase0=atan2(imag(cca),real(cca))
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do ipha=1,3
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@ -342,34 +344,41 @@ subroutine detectmsk40(cbig,n,mycall,hiscall,lines,nmessages,nutc,ntol,t00)
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nbadsync1=(8-sum( (2*hardbits(1:8)-1)*s8r ) )/2
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nbadsync=nbadsync1
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if( nbadsync .gt. 3 ) cycle
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! nerr=0
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! do i=1,32
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! if( testcw(i) .ne. hardbits(i+8) ) nerr=nerr+1
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! enddo
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! normalize the softsymbols before submitting to decoder
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sav=sum(softbits)/40
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s2av=sum(softbits*softbits)/40
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ssig=sqrt(s2av-sav*sav)
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softbits=softbits/ssig
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sigma=0.65
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sigma=0.75
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lratio(1:32)=exp(2.0*softbits(9:40)/(sigma*sigma))
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max_iterations=5
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max_dither=1
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niterations=0
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call ldpc_decode(lratio,decoded,max_iterations,niterations,max_dither,ndither)
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ncalls=ncalls+1
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nhashflag=0
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if( niterations .ge. 0 ) then
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call ldpc_encode(decoded,cw)
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nhammd=0
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do i=1,32
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if( cw(i) .ne. hardbits(i+8) ) nhammd=nhammd+1
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enddo
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imsg=0
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do i=1,16
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imsg=ishft(imsg,1)+iand(1 , decoded(17-i))
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imsg=ishft(imsg,1)+iand(1,decoded(17-i))
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enddo
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nrxrpt=iand(imsg,63)
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nrxhash=(imsg-nrxrpt)/64
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if( nrxhash .eq. nhashes(nrxrpt) ) then
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fest=1500+ferr+ferr2+deltaf
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!write(14,'(i6.6,10i5,2f7.1)') nutc,ip,ipk,id,idf,iav,ipha,niterations,nbadsync,nrxrpt,ncalls,ferr,ferr2
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write(14,'(i6.6,11i5)') nutc,ip,ipk,id,idf,iav,ipha,niterations,nbadsync,nrxrpt,ncalls,nhammd
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nhashflag=1
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msgreceived=' '
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nmessages=1
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@ -78,7 +78,7 @@ subroutine genmsk40(msg,msgsent,ichk,itone,itype)
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itone=0
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do i=1, 20
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itone(2*i-1)=(bitseq(2*i)*bitseq(2*i-1)+1)/2;
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itone(2*i)=-(bitseq(2*i)*bitseq(mod(2*i,32)+1)-1)/2;
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itone(2*i)=-(bitseq(2*i)*bitseq(mod(2*i,40)+1)-1)/2;
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enddo
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! Flip polarity
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