From 58de27e65ca1fb7f222a77f9d348dff02f9197e7 Mon Sep 17 00:00:00 2001 From: Steven Franke Date: Tue, 2 Aug 2016 02:30:33 +0000 Subject: [PATCH] Bump up sigma at low SNRs to suppress noise decodes. git-svn-id: svn+ssh://svn.code.sf.net/p/wsjt/wsjt/branches/wsjtx@6983 ab8295b8-cf94-4d9e-aec4-7959e3be5d79 --- lib/detectmsk40.f90 | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) diff --git a/lib/detectmsk40.f90 b/lib/detectmsk40.f90 index 9f26ffa77..6de164075 100644 --- a/lib/detectmsk40.f90 +++ b/lib/detectmsk40.f90 @@ -214,6 +214,7 @@ subroutine detectmsk40(cbig,n,pchk_file,mycall,hiscall,lines,nmessages, & cdat=cbig(imid-NPTS/2+1:imid+NPTS/2) ferr=ferrs(ip) nsnr=nint(snrs(ip)) + xsnr=snrs(ip) if( nsnr .lt. -5 ) nsnr=-5 if( nsnr .gt. 25 ) nsnr=25 @@ -362,6 +363,7 @@ subroutine detectmsk40(cbig,n,pchk_file,mycall,hiscall,lines,nmessages, & softbits=softbits/ssig sigma=0.75 + if( xsnr .lt. -4.0 ) sigma=1.1 lratio(1:32)=exp(2.0*softbits(9:40)/(sigma*sigma)) max_iterations=5 @@ -389,7 +391,7 @@ subroutine detectmsk40(cbig,n,pchk_file,mycall,hiscall,lines,nmessages, & nrxhash=(imsg-nrxrpt)/64 if( nhammd .le. 5 .and. cord .lt. 1.7 .and. nrxhash .eq. nhashes(nrxrpt) ) then fest=1500+ferr+ferr2+deltaf -!write(14,'(i6.6,11i6,f7.1)') nutc,ip,ipk,id,idf,iav,ipha,niterations,nbadsync,nrxrpt,ncalls,nhammd,cord +!write(14,'(i6.6,11i6,f7.1,f7.1)') nutc,ip,ipk,id,idf,iav,ipha,niterations,nbadsync,nrxrpt,ncalls,nhammd,cord,xsnr nhashflag=1 msgreceived=' ' nmessages=1