WSJT-X/libm65/setupmsk.f90
Joe Taylor 3ba268cf14 Functioning JTMSK decoder, within stand-alone program msk.
git-svn-id: svn+ssh://svn.code.sf.net/p/wsjt/wsjt/branches/jtms3@2519 ab8295b8-cf94-4d9e-aec4-7959e3be5d79
2012-07-17 19:31:01 +00:00

52 lines
1.2 KiB
Fortran

subroutine setupmsk(cw,cwb)
! Calculate the JTMS character waveforms.
complex cw(168,0:63)
complex cwb(168)
integer nb(7)
! real*8 twopi,dt,f0,f1
character cc*64
! 1 2 3 4 5 6
! 0123456789012345678901234567890123456789012345678901234567890123
data cc/'0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZ./?- _ @'/
nsps=24
twopi=8.d0*atan(1.d0)
dt=1.d0/48000.d0 !Sample interval
f0=1000.d0
f1=2000.d0
dphi0=twopi*dt*f0
dphi1=twopi*dt*f1
do i=0,63
k=0
m=0
do n=5,0,-1 !Each character gets 6+1 bits
k=k+1
nb(k)=iand(1,ishft(i,-n))
m=m+nb(k)
enddo
k=k+1
nb(k)=iand(m,1) !Insert parity bit
phi=0.
j=0
do k=1,7 !Generate the waveform
if(nb(k).eq.0) then
dphi=dphi0
else
dphi=dphi1
endif
do ii=1,nsps
j=j+1
phi=phi+dphi
cw(j,i)=cmplx(cos(phi),sin(phi))
enddo
enddo
enddo
cwb=cw(1:168,57)
return
end subroutine setupmsk