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Add routines needed to test FT8 with GFSK pulses.

This commit is contained in:
Steve Franke 2019-02-21 15:48:02 -06:00
parent a98e1d7f37
commit 1acb5d5d99
3 changed files with 197 additions and 0 deletions
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5
CMakeLists.txt
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@ -456,6 +456,7 @@ set (wsjt_FSRCS
lib/ft8.f90
lib/ft8dec.f90
lib/ft8/ft8sim.f90
lib/ft8/ft8sim_gfsk.f90
lib/gen4.f90
lib/gen65.f90
lib/gen9.f90
@ -465,6 +466,7 @@ set (wsjt_FSRCS
lib/genmsk40.f90
lib/ft4/genft4.f90
lib/ft4/gen_ft4wave.f90
lib/ft8/gen_ft8wave.f90
lib/genqra64.f90
lib/ft8/genft8refsig.f90
lib/genwspr.f90
@ -1265,6 +1267,9 @@ target_link_libraries (ft8 wsjt_fort wsjt_cxx)
add_executable (ft8sim lib/ft8/ft8sim.f90 wsjtx.rc)
target_link_libraries (ft8sim wsjt_fort wsjt_cxx)
add_executable (ft8sim_gfsk lib/ft8/ft8sim_gfsk.f90 wsjtx.rc)
target_link_libraries (ft8sim_gfsk wsjt_fort wsjt_cxx)
add_executable (msk144sim lib/msk144sim.f90 wsjtx.rc)
target_link_libraries (msk144sim wsjt_fort wsjt_cxx)

129
lib/ft8/ft8sim_gfsk.f90 Normal file
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@ -0,0 +1,129 @@
program ft8sim_gfsk
! Generate simulated "type 2" ft8 files
! Output is saved to a *.wav file.
use wavhdr
use packjt77
include 'ft8_params.f90' !Set various constants
parameter (NWAVE=(NN+2)*NSPS)
type(hdr) h !Header for .wav file
character arg*12,fname*17
character msg37*37,msgsent37*37
character c77*77
complex c0(0:NMAX-1)
complex c(0:NMAX-1)
complex cwave(0:NWAVE-1)
real wave(NMAX)
integer itone(NN)
integer*1 msgbits(77)
integer*2 iwave(NMAX) !Generated full-length waveform
! Get command-line argument(s)
nargs=iargc()
if(nargs.ne.7) then
print*,'Usage: ft8sim "message" f0 DT fdop del nfiles snr'
print*,'Examples: ft8sim "K1ABC W9XYZ EN37" 1500.0 0.0 0.1 1.0 10 -18'
print*,' ft8sim "WA9XYZ/R KA1ABC/R FN42" 1500.0 0.0 0.1 1.0 10 -18'
print*,' ft8sim "K1ABC RR73; W9XYZ <KH1/KH7Z> -11" 300 0 0 0 25 1 -10'
go to 999
endif
call getarg(1,msg37) !Message to be transmitted
call getarg(2,arg)
read(arg,*) f0 !Frequency (only used for single-signal)
call getarg(3,arg)
read(arg,*) xdt !Time offset from nominal (s)
call getarg(4,arg)
read(arg,*) fspread !Watterson frequency spread (Hz)
call getarg(5,arg)
read(arg,*) delay !Watterson delay (ms)
call getarg(6,arg)
read(arg,*) nfiles !Number of files
call getarg(7,arg)
read(arg,*) snrdb !SNR_2500
nsig=1
if(f0.lt.100.0) then
nsig=f0
f0=1500
endif
nfiles=abs(nfiles)
twopi=8.0*atan(1.0)
fs=12000.0 !Sample rate (Hz)
dt=1.0/fs !Sample interval (s)
tt=NSPS*dt !Duration of symbols (s)
baud=1.0/tt !Keying rate (baud)
bw=8*baud !Occupied bandwidth (Hz)
txt=NZ*dt !Transmission length (s)
bandwidth_ratio=2500.0/(fs/2.0)
sig=sqrt(2*bandwidth_ratio) * 10.0**(0.05*snrdb)
if(snrdb.gt.90.0) sig=1.0
txt=NN*NSPS/12000.0
! Source-encode, then get itone()
i3=-1
n3=-1
call pack77(msg37,i3,n3,c77)
call genft8(msg37,i3,n3,msgsent37,msgbits,itone)
call gen_ft8wave(itone,NN,NSPS,fs,f0,cwave,NWAVE)
write(*,*)
write(*,'(a23,a37,3x,a7,i1,a1,i1)') 'New Style FT8 Message: ',msgsent37,'i3.n3: ',i3,'.',n3
write(*,1000) f0,xdt,txt,snrdb,bw
1000 format('f0:',f9.3,' DT:',f6.2,' TxT:',f6.1,' SNR:',f6.1, &
' BW:',f4.1)
write(*,*)
if(i3.eq.1) then
write(*,*) ' mycall hiscall hisgrid'
write(*,'(28i1,1x,i1,1x,28i1,1x,i1,1x,i1,1x,15i1,1x,3i1)') msgbits(1:77)
else
write(*,'(a14)') 'Message bits: '
write(*,'(77i1)') msgbits
endif
write(*,*)
write(*,'(a17)') 'Channel symbols: '
write(*,'(79i1)') itone
write(*,*)
call sgran()
msg0=msg
do ifile=1,nfiles
c0=0.
c0(0:NWAVE-1)=cwave
c0=cshift(c0,-nint((xdt+0.5)/dt))
if(fspread.ne.0.0 .or. delay.ne.0.0) call watterson(c0,NMAX,NWAVE,fs,delay,fspread)
c=sig*c0
wave=imag(c)
peak=maxval(abs(wave))
nslots=1
if(snrdb.lt.90) then
do i=1,NMAX !Add gaussian noise at specified SNR
xnoise=gran()
wave(i)=wave(i) + xnoise
enddo
endif
gain=100.0
if(snrdb.lt.90.0) then
wave=gain*wave
else
datpk=maxval(abs(wave))
fac=32766.9/datpk
wave=fac*wave
endif
if(any(abs(wave).gt.32767.0)) print*,"Warning - data will be clipped."
iwave=nint(wave)
h=default_header(12000,NMAX)
write(fname,1102) ifile
1102 format('000000_',i6.6,'.wav')
open(10,file=fname,status='unknown',access='stream')
write(10) h,iwave !Save to *.wav file
close(10)
write(*,1110) ifile,xdt,f0,snrdb,fname
1110 format(i4,f7.2,f8.2,f7.1,2x,a17)
enddo
999 end program ft8sim_gfsk

63
lib/ft8/gen_ft8wave.f90 Normal file
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@ -0,0 +1,63 @@
subroutine gen_ft8wave(itone,nsym,nsps,fsample,f0,cwave,nwave)
!
! generate ft8 waveform using Gaussian-filtered frequency pulses.
!
parameter(MAX_SECONDS=20)
real wave(nwave)
complex cwave(nwave)
real pulse(5760)
real dphi(0:(nsym+2)*nint(fsample)-1)
integer itone(nsym)
logical first
data first/.true./
save pulse,first,twopi,dt,hmod
if(nsave .gt. MAX_SECONDS*nint(fsample)) then
print*,"gen_ft8wave: ERROR - waveform length too large."
endif
if(first) then
twopi=8.0*atan(1.0)
dt=1.0/fsample
hmod=1.0
bt=1.0
! Compute the frequency-smoothing pulse
do i=1,3*nsps
tt=(i-1.5*nsps)/real(nsps)
pulse(i)=gfsk_pulse(bt,tt)
enddo
first=.false.
endif
! Compute the smoothed frequency waveform.
! Length = (nsym+2)*nsps samples, zero-padded
dphi_peak=twopi*hmod/real(nsps)
dphi=0.0
do j=1,nsym
ib=(j-1)*nsps
ie=ib+3*nsps-1
dphi(ib:ie) = dphi(ib:ie) + dphi_peak*pulse(1:3*nsps)*itone(j)
enddo
! Calculate and insert the audio waveform
phi=0.0
dphi = dphi + twopi*f0*dt !Shift frequency up by f0
wave=0.
k=0
do j=0,nwave-1
k=k+1
wave(k)=sin(phi)
cwave(k)=cmplx(cos(phi),sin(phi))
phi=mod(phi+dphi(j),twopi)
enddo
! Compute the ramp-up and ramp-down symbols
cwave(1:nsps)=cwave(1:nsps) * &
(1.0-cos(twopi*(/(i,i=0,nsps-1)/)/(2.0*nsps)))/2.0
k1=(nsym+1)*nsps+1
cwave(k1:k1+nsps-1)=cwave(k1:k1+nsps-1) * &
(1.0+cos(twopi*(/(i,i=0,nsps-1)/)/(2.0*nsps)))/2.0
return
end subroutine gen_ft8wave