subroutine rectify_msk(c,msg,freq2) parameter (NSPM=1404) complex c(0:NSPM-1) !Received data complex cmsg(0:NSPM-1) !Message waveform complex c1(0:NSPM-1) !Rectified signal complex c2(0:NSPM-1) !Integral of rectified signal complex c3(0:2*NSPM-1) !FFT of rectified signal complex cfac,z character*22 msg,msgsent integer i4tone(234) ichk=0 call genmsk(msg,ichk,msgsent,i4tone,itype) !Get tone sequence for msg twopi=8.0*atan(1.0) dt=1.0/12000.0 f0=1000.0 f1=2000.0 phi=0. dphi=0. k=-1 c2=0. do j=1,234 !Generate Tx waveform for msg if(i4tone(j).eq.0) dphi=twopi*f0*dt if(i4tone(j).eq.1) dphi=twopi*f1*dt do i=1,6 k=k+1 phi=phi+dphi cmsg(k)=cmplx(cos(phi),sin(phi)) c1(k)=conjg(cmsg(k))*c(k) if(k.ge.1) c2(k)=c2(k-1) + c1(k) enddo enddo c2(0)=c2(1) pha=atan2(aimag(c2(NSPM-1)),real(c2(NSPM-1))) cfac=cmplx(cos(pha),-sin(pha)) c1=cfac*c1 c2=cfac*c2 ! sq=0. ! do k=0,NSPM-1 ! pha=atan2(aimag(c2(k)),real(c2(k))) ! write(61,3001) k,c1(k),c2(k),pha !3001 format(i6,7f12.3) ! sq=sq + aimag(c1(k))**2 ! enddo ! z=c2(5) ! do j=1,234 ! k=j*6 - 1 ! if(j.ge.2) z=c2(k)-c2(k-6) ! pha=atan2(aimag(z),real(z)) ! write(62,3001) j,z,pha ! enddo nfft=2*NSPM c3(0:NSPM-1)=c2 c3(NSPM:nfft-1)=0. df=12000.0/nfft call four2a(c3,nfft,1,-1,1) smax=0. do i=0,nfft-1 f=i*df if(i.gt.nfft/2) f=f-12000.0 s=1.e-10*(real(c3(i))**2 + aimag(c3(i))**2) if(s.gt.smax) then smax=s freq2=1500.0 + f endif ! write(63,3002) f,s,db(s),c3(i) !3002 format(f10.1,f12.3,f10.2,2f12.1) enddo return end subroutine rectify_msk