diff --git a/CMakeLists.txt b/CMakeLists.txt index a058fa258..b70ce1e48 100644 --- a/CMakeLists.txt +++ b/CMakeLists.txt @@ -469,6 +469,7 @@ set (wsjt_FSRCS lib/geodist.f90 lib/getlags.f90 lib/getmet4.f90 + lib/ft2/gfsk_pulse.f90 lib/graycode.f90 lib/graycode65.f90 lib/grayline.f90 diff --git a/lib/fsk4hf/ft2d.f90 b/lib/fsk4hf/ft2d.f90 index c42bd38c4..e924366c6 100644 --- a/lib/fsk4hf/ft2d.f90 +++ b/lib/fsk4hf/ft2d.f90 @@ -93,7 +93,7 @@ program ft2d ibest=-1 sybest=-99. dfbest=-1. - do if=-15,+15 + do if=-30,+30 df=if a=0. a(1)=-df @@ -120,8 +120,6 @@ program ft2d enddo enddo -!dfbest=0.0 -!ibest=187 a=0. a(1)=-dfbest call twkfreq1(c2,NMAX/16,fs,a,cb) @@ -197,7 +195,6 @@ program ft2d call bpdecode128_90(llr2,apmask,max_iterations,message77,cw,nharderror,niterations) if(nharderror.ge.0) exit enddo - nhardmin=-1 if(sum(message77).eq.0) cycle if( nharderror.ge.0 ) then write(c77,'(77i1)') message77(1:77) @@ -212,8 +209,8 @@ program ft2d nsnr=nint(xsnr) freq=f0+dfbest 1210 format(a11,2i4,f6.2,f12.7,2x,a22,i3) - write(*,1212) datetime(8:11),nsnr,ibest/750.0,freq,message,'*',idf,nseq,ijitter,nharderror,nhardmin -1212 format(a4,i4,f5.1,f11.1,2x,a22,a1,i5,i5,i5,i5,i5) + write(*,1212) datetime(8:11),nsnr,ibest/750.0,freq,message,'*',nseq,nharderror +1212 format(a4,i4,f5.1,f11.1,2x,a22,a1,i5,i5) goto 888 endif enddo ! nseq diff --git a/lib/fsk4hf/ft2sim.f90 b/lib/fsk4hf/ft2sim.f90 index 6addbe8d8..5c0e07431 100644 --- a/lib/fsk4hf/ft2sim.f90 +++ b/lib/fsk4hf/ft2sim.f90 @@ -13,10 +13,12 @@ program ft2sim complex c0(0:NMAX-1) complex c(0:NMAX-1) real wave(NMAX) + real dphi(0:NMAX-1) + real pulse(480) 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.8) then @@ -42,12 +44,6 @@ program ft2sim call getarg(8,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) @@ -55,8 +51,8 @@ program ft2sim hmod=0.8 !Modulation index (0.5 is MSK, 1.0 is FSK) tt=NSPS*dt !Duration of symbols (s) baud=1.0/tt !Keying rate (baud) - bw=1.5*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 @@ -70,9 +66,8 @@ program ft2sim call genft2(msg37,0,msgsent37,itone,itype) write(*,*) write(*,'(a9,a37,3x,a7,i1,a1,i1)') '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:',f5.1) + 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' @@ -88,21 +83,41 @@ program ft2sim call sgran() +! The filtered frequency pulse + do i=1,480 + tt=(i-240.5)/160.0 + pulse(i)=gfsk_pulse(1.0,tt) + enddo + +! Define the instantaneous frequency waveform + dphi_peak=twopi*(hmod/2.0)/real(NSPS) + dphi=0.0 + do j=1,NN + ib=(j-1)*160 + ie=ib+480-1 + dphi(ib:ie)=dphi(ib:ie)+dphi_peak*pulse*(2*itone(j)-1) + enddo + + phi=0.0 + c0=0.0 + dphi=dphi+twopi*f0*dt + do j=0,NMAX-1 + c0(j)=cmplx(cos(phi),sin(phi)) + phi=mod(phi+dphi(j),twopi) + enddo + + c0(0:159)=c0(0:159)*(1.0-cos(twopi*(/(i,i=0,159)/)/320.0) )/2.0 + c0(145*160:145*160+159)=c0(145*160:145*160+159)*(1.0+cos(twopi*(/(i,i=0,159)/)/320.0 ))/2.0 + c0(146*160:)=0. + + k=nint((xdt+0.25)/dt) + c0=cshift(c0,-k) + ia=k + do ifile=1,nfiles - k=nint((xdt+0.25)/dt) - ia=k - phi=0.0 - c0=0.0 - do j=1,NN !Generate complex waveform - dphi=twopi*(f0*dt+(hmod/2.0)*(2*itone(j)-1)/real(NSPS)) - do i=1,NSPS - if(k.ge.0 .and. k.lt.NMAX) c0(k)=cmplx(cos(phi),sin(phi)) - k=k+1 - phi=mod(phi+dphi,twopi) - enddo - enddo - if(fspread.ne.0.0 .or. delay.ne.0.0) call watterson(c0,NMAX,NWAVE,fs,delay,fspread) - c=sig*c0 + c=c0 + if(fspread.ne.0.0 .or. delay.ne.0.0) call watterson(c,NMAX,NWAVE,fs,delay,fspread) + c=sig*c ib=k wave=real(c) diff --git a/lib/ft2/ft2_gfsk_iwave.f90 b/lib/ft2/ft2_gfsk_iwave.f90 new file mode 100644 index 000000000..2611eca09 --- /dev/null +++ b/lib/ft2/ft2_gfsk_iwave.f90 @@ -0,0 +1,88 @@ +subroutine ft2_gfsk_iwave(msg37,f0,snrdb,iwave) + +! Generate waveform for experimental "FT2" mode + + use packjt77 + include 'ft2_params.f90' !Set various constants + parameter (NWAVE=(NN+2)*NSPS) + character msg37*37,msgsent37*37 + real wave(NWAVE),xnoise(NWAVE) + real dphi(NWAVE) + real pulse(480) + + integer itone(NN) + integer*2 iwave(NWAVE) !Generated full-length waveform + logical first + data first/.true./ + save pulse + + twopi=8.0*atan(1.0) + fs=12000.0 !Sample rate (Hz) + dt=1.0/fs !Sample interval (s) + hmod=0.8 !Modulation index (MSK=0.5, FSK=1.0) + tt=NSPS*dt !Duration of symbols (s) + baud=1.0/tt !Keying rate (baud) + bw=1.5*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 + + if(first) then +! The filtered frequency pulse + do i=1,480 + tt=(i-240.5)/160.0 + pulse(i)=gfsk_pulse(1.0,tt) + enddo + dphi_peak=twopi*(hmod/2.0)/real(NSPS) + first=.false. + endif + +! Source-encode, then get itone(): + itype=1 + call genft2(msg37,0,msgsent37,itone,itype) + +! Create the instantaneous frequency waveform + dphi=0.0 + do j=1,NN + ib=(j-1)*160+1 + ie=ib+480-1 + dphi(ib:ie)=dphi(ib:ie)+dphi_peak*pulse*(2*itone(j)-1) + enddo + + phi=0.0 + wave=0.0 + sqrt2=sqrt(2.) + dphi=dphi+twopi*f0*dt + do j=1,NWAVE + wave(j)=sqrt2*sin(phi) + sqsig=sqsig + wave(j)**2 + phi=mod(phi+dphi(j),twopi) + enddo + wave(1:160)=wave(1:160)*(1.0-cos(twopi*(/(i,i=0,159)/)/320.0) )/2.0 + wave(145*160+1:146*160)=wave(145*160+1:146*160)*(1.0+cos(twopi*(/(i,i=0,159)/)/320.0 ))/2.0 + wave(146*160+1:)=0. + + if(snrdb.gt.90.0) then + iwave=nint((32767.0/sqrt(2.0))*wave) + return + endif + + sqnoise=1.e-30 + if(snrdb.lt.90) then + do i=1,NWAVE !Add gaussian noise at specified SNR + xnoise(i)=gran() !Noise has rms = 1.0 + enddo + endif + xnoise=xnoise*sqrt(0.5*fs/2500.0) + fac=30.0 + snr_amplitude=10.0**(0.05*snrdb) + wave=fac*(snr_amplitude*wave + xnoise) + datpk=maxval(abs(wave)) + print*,'A',snr_amplitude,datpk + + iwave=nint((30000.0/datpk)*wave) + + return +end subroutine ft2_gfsk_iwave diff --git a/lib/ft2/gfsk_pulse.f90 b/lib/ft2/gfsk_pulse.f90 new file mode 100644 index 000000000..99ab78e35 --- /dev/null +++ b/lib/ft2/gfsk_pulse.f90 @@ -0,0 +1,6 @@ +real function gfsk_pulse(b,t) + pi=4.*atan(1.0) + c=pi*sqrt(2.0/log(2.0)) + gfsk_pulse=0.5*(erf(c*b*(t+0.5))-erf(c*b*(t-0.5))) + return +end function gfsk_pulse