From 9de51ebfa3d9a48661c99aacf3b1eb1b6969f039 Mon Sep 17 00:00:00 2001
From: Joe Taylor <joe@princeton.edu>
Date: Wed, 12 Jun 2019 11:31:35 -0400
Subject: [PATCH] Rename and tweak rtty_spec.f90.

---
 CMakeLists.txt    |  3 ++
 lib/rtty_spec.f90 | 86 +++++++++++++++++++++++++++++++++++++++++++++++
 2 files changed, 89 insertions(+)
 create mode 100644 lib/rtty_spec.f90

diff --git a/CMakeLists.txt b/CMakeLists.txt
index 4b425a6e4..0c10ff8d8 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -1274,6 +1274,9 @@ target_link_libraries (jt49sim wsjt_fort wsjt_cxx)
 add_executable (allsim lib/allsim.f90 wsjtx.rc)
 target_link_libraries (allsim wsjt_fort wsjt_cxx)
 
+add_executable (rtty_spec lib/rtty_spec.f90 wsjtx.rc)
+target_link_libraries (rtty_spec wsjt_fort wsjt_cxx)
+
 add_executable (jt65code lib/jt65code.f90 wsjtx.rc)
 target_link_libraries (jt65code wsjt_fort wsjt_cxx)
 
diff --git a/lib/rtty_spec.f90 b/lib/rtty_spec.f90
new file mode 100644
index 000000000..704e5ce53
--- /dev/null
+++ b/lib/rtty_spec.f90
@@ -0,0 +1,86 @@
+program rtty_spec
+
+! Generate simulated data for standard RTTY and WSJT-X modes FT8, FT4
+
+  use wavhdr
+  use packjt
+  parameter (NMAX=15*12000)
+  type(hdr) h
+  complex cwave(NMAX)
+  real wave(NMAX)
+  real*4 dat(NMAX)             !Generated waveform
+  integer*2 iwave(NMAX)        !Generated waveform
+  integer itone(680)           !Channel symbols (values 0-1, 0-3, 0-7)
+  integer*1 msgbits(77)
+  character*37 msg37,msgsent37
+  character*8 arg
+
+  nargs=iargc()
+  if(nargs.ne.1) then
+     print*,'Usage:   rtty_spec <snr>'
+     go to 999
+  endif
+  call getarg(1,arg)
+  read(arg,*) snrdb                  !S/N in dB (2500 hz reference BW)
+
+  rmsdb=25.
+  rms=10.0**(0.05*rmsdb)
+  sig=10.0**(0.05*snrdb)
+  npts=NMAX
+
+  do i=1,NMAX                   !Generate gaussian noise
+     dat(i)=gran()
+  enddo
+
+! Add the RTTY signal
+  fsample=12000.0                   !Sample rate (Hz)
+  dt=1.0/fsample                    !Sample interval (s)
+  twopi=8.0*atan(1.0)
+  phi=0.
+  dphi=0.
+  j0=-1
+  do i=6001,NMAX-6000
+     j=nint(i*dt/0.022)
+     if(j.ne.j0) then
+        f0=1415.0
+        call random_number(rr)
+        if(rr.gt.0.5) f0=1585.0
+        dphi=twopi*f0*dt
+        j0=j
+     endif
+     phi=phi+dphi
+     if(phi.gt.twopi) phi=phi-twopi
+     dat(i)=dat(i) + sig*sin(phi)
+  enddo
+
+! Add the FT8 signal
+  i3=0
+  n3=0
+  msg37='WB9XYZ KA2ABC FN42'
+  call genft8(msg37,i3,n3,msgsent37,msgbits,itone)
+  nsym=79
+  nsps=1920
+  bt=2.0
+  f0=3000.0
+  icmplx=0
+  nwave=nsym*nsps
+  call gen_ft8wave(itone,nsym,nsps,bt,fsample,f0,cwave,wave,icmplx,nwave)
+  dat(6001:6000+nwave)=dat(6001:6000+nwave) + sig*wave(1:nwave)
+
+! Add the FT4 signal
+  ichk=0
+  call genft4(msg37,ichk,msgsent37,msgbits,itone)
+  nsym=103
+  nsps=576
+  f0=3500.0
+  icmplx=0
+  nwave=(nsym+2)*nsps
+  call gen_ft4wave(itone,nsym,nsps,fsample,f0,cwave,wave,icmplx,nwave)
+  dat(6001:6000+nwave)=dat(6001:6000+nwave) + sig*wave(1:nwave)
+  h=default_header(12000,NMAX)
+  iwave=nint(rms*dat)
+  open(10,file='000000_000001.wav',access='stream',status='unknown')
+  write(10) h,iwave
+  close(10)
+
+999 end program rtty_spec