Add routines necessary to generate simulated 'wspr4' wav files.

This commit is contained in:
Steven Franke 2020-04-14 10:34:00 -05:00
parent e82b9ffa38
commit c5e2593979
5 changed files with 302 additions and 0 deletions

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@ -610,6 +610,9 @@ set (wsjt_FSRCS
lib/fsk4hf/encode174_74.f90 lib/fsk4hf/encode174_74.f90
lib/fsk4hf/bpdecode174_74.f90 lib/fsk4hf/bpdecode174_74.f90
lib/fsk4hf/osd174_74.f90 lib/fsk4hf/osd174_74.f90
lib/fsk4hf/wspr4sim.f90
lib/fsk4hf/genwspr4.f90
lib/fsk4hf/gen_wspr4wave.f90
) )
# temporary workaround for a gfortran v7.3 ICE on Fedora 27 64-bit # temporary workaround for a gfortran v7.3 ICE on Fedora 27 64-bit
@ -1357,6 +1360,9 @@ target_link_libraries (ldpcsim174_91 wsjt_fort wsjt_cxx)
add_executable (ldpcsim174_74 lib/fsk4hf/ldpcsim174_74.f90 wsjtx.rc) add_executable (ldpcsim174_74 lib/fsk4hf/ldpcsim174_74.f90 wsjtx.rc)
target_link_libraries (ldpcsim174_74 wsjt_fort wsjt_cxx) target_link_libraries (ldpcsim174_74 wsjt_fort wsjt_cxx)
add_executable (wspr4sim lib/fsk4hf/wspr4sim.f90 wsjtx.rc)
target_link_libraries (wspr4sim wsjt_fort wsjt_cxx)
endif(WSJT_BUILD_UTILS) endif(WSJT_BUILD_UTILS)
# build the main application # build the main application

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@ -0,0 +1,68 @@
subroutine gen_wspr4wave(itone,nsym,nsps,fsample,f0,cwave,wave,icmplx,nwave)
real wave(nwave)
complex cwave(nwave)
real, allocatable, save :: pulse(:)
real, allocatable :: dphi(:)
integer itone(nsym)
logical first
data first/.true./
save pulse,first,twopi,dt,hmod
if(first) then
allocate( pulse(3*nsps*fsample) )
twopi=8.0*atan(1.0)
dt=1.0/fsample
hmod=1.0
! Compute the smoothed frequency-deviation pulse
do i=1,3*nsps
tt=(i-1.5*nsps)/real(nsps)
pulse(i)=gfsk_pulse(1.0,tt)
enddo
first=.false.
endif
! Compute the smoothed frequency waveform.
! Length = (nsym+2)*nsps samples, zero-padded
allocate( dphi(0:(nsym+2)*nsps-1) )
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.
if(icmplx.eq.1) cwave=0.
k=0
do j=0,(nsym+2)*nsps-1
k=k+1
if(icmplx.eq.0) then
wave(k)=sin(phi)
else
cwave(k)=cmplx(cos(phi),sin(phi))
endif
phi=mod(phi+dphi(j),twopi)
enddo
! Compute the ramp-up and ramp-down symbols
if(icmplx.eq.0) then
wave(1:nsps)=wave(1:nsps) * &
(1.0-cos(twopi*(/(i,i=0,nsps-1)/)/(2.0*nsps)))/2.0
k1=(nsym+1)*nsps+1
wave(k1:k1+nsps-1)=wave(k1:k1+nsps-1) * &
(1.0+cos(twopi*(/(i,i=0,nsps-1)/)/(2.0*nsps)))/2.0
else
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
endif
return
end subroutine gen_wspr4wave

97
lib/fsk4hf/genwspr4.f90 Normal file
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@ -0,0 +1,97 @@
subroutine genwspr4(msg0,ichk,msgsent,msgbits,i4tone)
! Encode an FT4 message
! Input:
! - msg0 requested message to be transmitted
! - ichk if ichk=1, return only msgsent
! - msgsent message as it will be decoded
! - i4tone array of audio tone values, {0,1,2,3}
! Frame structure:
! s16 + 87symbols + 2 ramp up/down = 105 total channel symbols
! r1 + s4 + d29 + s4 + d29 + s4 + d29 + s4 + r1
! Message duration: TxT = 105*13312/12000 = 116.48 s
! use iso_c_binding, only: c_loc,c_size_t
use packjt77
include 'wspr4_params.f90'
character*37 msg0
character*37 message !Message to be generated
character*37 msgsent !Message as it will be received
character*77 c77
character*24 c24
integer*4 i4tone(NN),itmp(ND)
integer*1 codeword(2*ND)
integer*1 msgbits(74),rvec(77)
integer icos4a(4),icos4b(4),icos4c(4),icos4d(4)
integer*4 ncrc24
logical unpk77_success
data icos4a/0,1,3,2/
data icos4b/1,0,2,3/
data icos4c/2,3,1,0/
data icos4d/3,2,0,1/
data rvec/0,1,0,0,1,0,1,0,0,1,0,1,1,1,1,0,1,0,0,0,1,0,0,1,1,0,1,1,0, &
1,0,0,1,0,1,1,0,0,0,0,1,0,0,0,1,0,1,0,0,1,1,1,1,0,0,1,0,1, &
0,1,0,1,0,1,1,0,1,1,1,1,1,0,0,0,1,0,1/
message=msg0
do i=1, 37
if(ichar(message(i:i)).eq.0) then
message(i:37)=' '
exit
endif
enddo
do i=1,37 !Strip leading blanks
if(message(1:1).ne.' ') exit
message=message(i+1:)
enddo
i3=-1
n3=-1
call pack77(message,i3,n3,c77)
call unpack77(c77,0,msgsent,unpk77_success) !Unpack to get msgsent
msgbits=0
read(c77,'(50i1)') msgbits(1:50)
call get_crc24(msgbits,ncrc24)
write(c24,'(b24.24)') ncrc24
read(c24,'(24i1)') msgbits(51:74)
if(ichk.eq.1) go to 999
read(c77,'(74i1)',err=1) msgbits
if(unpk77_success) go to 2
1 msgbits=0
itone=0
msgsent='*** bad message *** '
go to 999
entry get_wspr4_tones_from_74bits(msgbits,i4tone)
2 msgbits=mod(msgbits+rvec(1:74),2)
call encode174_74(msgbits,codeword)
! Grayscale mapping:
! bits tone
! 00 0
! 01 1
! 11 2
! 10 3
do i=1,ND
is=codeword(2*i)+2*codeword(2*i-1)
if(is.le.1) itmp(i)=is
if(is.eq.2) itmp(i)=3
if(is.eq.3) itmp(i)=2
enddo
i4tone(1:4)=icos4a
i4tone(5:33)=itmp(1:29)
i4tone(34:37)=icos4b
i4tone(38:66)=itmp(30:58)
i4tone(67:70)=icos4c
i4tone(71:99)=itmp(59:87)
i4tone(100:103)=icos4d
999 return
end subroutine genwspr4

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@ -0,0 +1,16 @@
! WSPR4
! LDPC(174,74)/CRC24 code, four 4x4 Costas arrays for sync, ramp-up and ramp-down symbols
parameter (KK=50) !Information bits (50 + CRC24)
parameter (ND=87) !Data symbols
parameter (NS=16) !Sync symbols
parameter (NN=NS+ND) !Sync and data symbols (103)
parameter (NN2=NS+ND+2) !Total channel symbols (105)
parameter (NSPS=13312) !Samples per symbol at 12000 S/s
parameter (NZ=NSPS*NN) !Sync and Data samples (1,397,136)
parameter (NZ2=NSPS*NN2) !Total samples in shaped waveform (1,397,760)
parameter (NMAX=408*3456) !Samples in iwave (1,410,048)
parameter (NFFT1=4*NSPS, NH1=NFFT1/2) !Length of FFTs for symbol spectra
parameter (NSTEP=NSPS) !Coarse time-sync step size
parameter (NHSYM=(NMAX-NFFT1)/NSTEP) !Number of symbol spectra (1/4-sym steps)
parameter (NDOWN=32) !Downsample factor

115
lib/fsk4hf/wspr4sim.f90 Normal file
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@ -0,0 +1,115 @@
program wspr4sim
! Generate simulated signals for experimental "wspr4" mode
use wavhdr
use packjt77
include 'wspr4_params.f90' !Set various constants
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)
real wave(NMAX)
integer itone(NN)
integer*1 msgbits(74)
integer*2 iwave(NMAX) !Generated full-length waveform
! Get command-line argument(s)
nargs=iargc()
if(nargs.ne.7) then
print*,'Usage: wspr4sim "message" f0 DT fdop del nfiles snr'
print*,'Examples: wspr4sim "K9AN EN50 37" 1500 0.0 0.1 1.0 10 -15'
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
nfiles=abs(nfiles)
twopi=8.0*atan(1.0)
fs=12000.0 !Sample rate (Hz)
dt=1.0/fs !Sample interval (s)
hmod=1.0 !Modulation index (0.5 is MSK, 1.0 is FSK)
tt=NSPS*dt !Duration of symbols (s)
baud=1.0/tt !Keying rate (baud)
txt=NZ2*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
call genwspr4(msg37,0,msgsent37,msgbits,itone)
write(*,*)
write(*,'(a9,a37,3x,a7,i1,a1,i1)') 'Message: ',msgsent37,'i3.n3: ',i3,'.',n3
write(*,1000) f0,xdt,txt,snrdb
1000 format('f0:',f9.3,' DT:',f6.2,' TxT:',f6.1,' SNR:',f6.1)
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(*,'(76i1)') itone
write(*,*)
call sgran()
fsample=12000.0
icmplx=1
call gen_wspr4wave(itone,NN,NSPS,fsample,f0,c0,wave,icmplx,NMAX)
k=nint((xdt+0.5)/dt)-NSPS
c0=cshift(c0,-k)
if(k.gt.0) c0(0:k-1)=0.0
if(k.lt.0) c0(NMAX+k:NMAX-1)=0.0
do ifile=1,nfiles
c=c0
if(fspread.ne.0.0 .or. delay.ne.0.0) call watterson(c,NMAX,NZ,fs,delay,fspread)
c=sig*c
wave=real(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 wspr4sim