From 8e6b4ac9bcd7f8603a82e85ddff09d0f700cb9fd Mon Sep 17 00:00:00 2001
From: Steven Franke <s.j.franke@icloud.com>
Date: Fri, 27 May 2016 20:46:48 +0000
Subject: [PATCH] genmsk144 now generates the tone indices need by
 Modulator.cpp.

git-svn-id: svn+ssh://svn.code.sf.net/p/wsjt/wsjt/branches/wsjtx@6708 ab8295b8-cf94-4d9e-aec4-7959e3be5d79
---
 lib/JTMSKsim144.f90 | 24 ++++++++++++++++---
 lib/genmsk144.f90   | 56 ++++++++++++++++++---------------------------
 2 files changed, 43 insertions(+), 37 deletions(-)

diff --git a/lib/JTMSKsim144.f90 b/lib/JTMSKsim144.f90
index 25affab2b..303899667 100644
--- a/lib/JTMSKsim144.f90
+++ b/lib/JTMSKsim144.f90
@@ -33,11 +33,29 @@ program JTMSKsim
   call getarg(5,arg)
   read(arg,*) nfiles
   sig=sqrt(2.0)*10.0**(0.05*snrdb)
-  twopi=8.d0*atan(1.d0)
   h=default_header(12000,NMAX)
 
   ichk=0
-  call genmsk(msg,ichk,msgsent,waveform,itype)   !this is genmsk144
+  call genmsk144(msg,ichk,msgsent,itone,itype) 
+  twopi=8.d0*atan(1.d0)
+  
+  dphi0=twopi*1000/12000.0
+  dphi1=twopi*2000/12000.0
+  phi=0.0
+  indx=0
+  do i=1,144
+    if( itone(i) .eq. 0 ) then
+      dphi=dphi0
+    else
+      dphi=dphi1
+    endif
+    do j=1,6  
+      waveform(indx)=cos(phi);
+      indx=indx+1
+      phi=mod(phi+dphi,twopi)
+    enddo 
+  enddo
+ 
   if(itype.lt.1 .or. itype.gt.7) then
      print*,'Illegal message'
      go to 999
@@ -57,7 +75,7 @@ program JTMSKsim
         j=mod(j+1,864)
         xx=gran()
         wave(i)=pings(i)*waveform(j) + fac*xx
-        write(*,*) pings(i),fac,waveform(j),wave(j)
+!        write(*,*) pings(i),fac,waveform(j),wave(j)
         iwave(i)=30.0*wave(i)
      enddo
 
diff --git a/lib/genmsk144.f90 b/lib/genmsk144.f90
index c66336254..e19b1632e 100644
--- a/lib/genmsk144.f90
+++ b/lib/genmsk144.f90
@@ -1,4 +1,4 @@
-subroutine genmsk144(msg0,ichk,msgsent,waveform,itype)
+subroutine genmsk144(msg0,ichk,msgsent,i4tone,itype)
 
 !!!!!!!!!!!!!!!!!! Experimental small blocklength ldpc version
 ! s8 + 48bits + s8 + 40 bits = 144 bits (72ms message duration)
@@ -153,43 +153,31 @@ subroutine genmsk144(msg0,ichk,msgsent,waveform,itype)
        xi(is:is+11)=bitseq(2*i)*pp
      enddo
 
-     dphi=2*pi*1500/12000.0;
-     phi=0.0
-     do i=1,864
-       waveform(i)=imag(complex(xi(i),xq(i))*complex(cos(phi),sin(phi)))
-       phi=mod(phi+dphi,twopi)
-     enddo
-
-! Map bits to I and Q (in anticipation of coherent demodulation), 
-! If bit indices run from 1 to 140.
-! I bits are 1,3,5,...139
-! Q bits are 2,4,6,...140
-! Sample the offset qpsk waveform at 140 sampling instants to determine tones.
-! Send low tone if I and Q have different sign, send high tone if I and Q have same sign.
-! Modulator will take care of ensuring phase continuity.
-!     i4tone=0 
-!     iq=140
-!     it=1
-!     do ii=1,139,2
-!       do inner=1,2
-!         if( bitseq(ii) .eq. bitseq(iq) ) then
-!           i4tone(it)=1
-!         endif
-!         print*,it,ii,iq,bitseq(ii),bitseq(iq),bitseq(it),i4tone(it)
-!         if( mod(it,2) .eq. 1 ) then
-!           iq=mod(iq+2,140)
-!           if( iq .eq. 0 ) iq=140
-!         endif
-!         it=it+1
-!       enddo
+!     dphi=2*pi*1500/12000.0;
+!     phi=0.0
+!     do i=1,864
+!       waveform(i)=imag(complex(xi(i),xq(i))*complex(cos(phi),sin(phi)))
+!       phi=mod(phi+dphi,twopi)
 !     enddo
+
+! Map I and Q  to tones. 
+    i4tone=0 
+    iq=144
+    it=1
+    do i=1,72
+      i4tone(2*i-1)=(bitseq(2*i)*bitseq(2*i-1)+1)/2;
+      i4tone(2*i)=-(bitseq(2*i)*bitseq(mod(2*i,144)+1)-1)/2;
+    enddo
   endif
 
-!i4tone(1:11)=b11
+! Had to flip the polarity - not sure if this will be needed when we are 
+! sending the tone to  Modulator.cpp.
+  i4tone=-i4tone+1
+
 !  print*,"transmitted tones"
-!  do i=1,140
-!    print*,i,i4tone(i)
+!  do i=1,144
+!    print*,i,bitseq(i),i4tone(i)
 !  enddo
 
 999 return
-end subroutine genmsk
+end subroutine genmsk144