WSJT-X/lib/JTMSKsim.f90
Joe Taylor b228025156 Correct the Tx message length and adjust reported SNR for short JTMSK messages.
Commit some things omitted last time.   


git-svn-id: svn+ssh://svn.code.sf.net/p/wsjt/wsjt/branches/wsjtx@6420 ab8295b8-cf94-4d9e-aec4-7959e3be5d79
2016-01-22 17:06:57 +00:00

94 lines
2.6 KiB
Fortran

program JTMSKsim
use wavhdr
parameter (NMAX=15*12000)
real pings(0:NMAX-1)
character arg*8,msg*22,msgsent*22,fname*40
character*3 rpt(0:7)
complex cmsg(0:1404-1) !Waveform of message (once)
complex cwave(0:NMAX-1) !Simulated received waveform
real*8 dt,twopi,freq,phi,dphi0,dphi1,dphi
type(hdr) h !Header for .wav file
integer*2 iwave(0:NMAX-1)
integer itone(234) !Message bits
integer b11(11) !Barker-11 code
data b11/1,1,1,0,0,0,1,0,0,1,0/
data rpt /'26 ','27 ','28 ','R26','R27','R28','RRR','73 '/
nargs=iargc()
if(nargs.ne.5) then
print*,'Usage: JTMSKsim message freq width snr nfiles'
print*,' '
print*,'Examples: JTMSKsim "K1ABC W9XYZ EN37" 1500 0.12 2 1'
print*,' JTMSKsim "<K1ABC W9XYZ> R26" 1500 0.01 1 3'
go to 999
endif
call getarg(1,msg)
call getarg(2,arg)
read(arg,*) freq
call getarg(3,arg)
read(arg,*) width
call getarg(4,arg)
read(arg,*) snrdb
call getarg(5,arg)
read(arg,*) nfiles
sig=10.0**(0.05*snrdb)
twopi=8.d0*atan(1.d0)
h=default_header(12000,NMAX)
ichk=0
call genmsk(msg,ichk,msgsent,itone,itype) !Check message type
if(itype.lt.1 .or. itype.gt.7) then
print*,'Illegal message'
go to 999
endif
dt=1.d0/12000.d0 !Sample interval
dphi0=twopi*(freq-500.d0)*dt !Phase increment, lower tone
dphi1=twopi*(freq+500.d0)*dt !Phase increment, upper tone
nsym=234
if(itype.eq.7) nsym=35
nspm=6*nsym !Samples per message
k=-1
phi=0.d0
do j=1,nsym
dphi=dphi0
if(itone(j).eq.1) dphi=dphi1
do i=1,6
k=k+1
phi=phi + dphi
if(phi.gt.twopi) phi=phi-twopi
xphi=phi
cmsg(k)=cmplx(cos(xphi),sin(xphi))
enddo
enddo
call makepings(pings,NMAX,width,sig)
do ifile=1,nfiles !Loop over requested number of files
write(fname,1002) ifile !Output filename
1002 format('000000_',i4.4)
open(10,file=fname(1:11)//'.wav',access='stream',status='unknown')
fac=sqrt(6000.0/2500.0)
j=-1
do i=0,NMAX-1
j=j+1
if(j.ge.6*nsym) j=j-6*nsym
xx=0.707*gran()
yy=0.707*gran()
cwave(i)=pings(i)*cmsg(j) + fac*cmplx(xx,yy)
iwave(i)=30.0*real(cwave(i))
! write(88,3003) i,i/12000.d0,cwave(i)
!3003 format(i8,f12.6,2f10.3)
enddo
write(10) h,iwave !Save the .wav file
close(10)
! call jtmsk_short(cwave,NMAX,msg)
enddo
999 end program JTMSKsim