From f447fe49e19465e3fe2413e1bcb303a93a0be8b7 Mon Sep 17 00:00:00 2001 From: Steve Franke Date: Thu, 17 Jan 2019 15:25:06 -0600 Subject: [PATCH] Fix some indexing problems. Create subroutine ft2_gfsk_iwave.f90 for use with ft2.exe. Needs testing. --- CMakeLists.txt | 1 + lib/fsk4hf/ft2sim.f90 | 11 +---- lib/ft2/ft2_gfsk_iwave.f90 | 88 ++++++++++++++++++++++++++++++++++++++ lib/ft2/gfsk_pulse.f90 | 6 +++ 4 files changed, 97 insertions(+), 9 deletions(-) create mode 100644 lib/ft2/ft2_gfsk_iwave.f90 create mode 100644 lib/ft2/gfsk_pulse.f90 diff --git a/CMakeLists.txt b/CMakeLists.txt index ef0bac291..e33ffe408 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/ft2sim.f90 b/lib/fsk4hf/ft2sim.f90 index 49d53c728..5c0e07431 100644 --- a/lib/fsk4hf/ft2sim.f90 +++ b/lib/fsk4hf/ft2sim.f90 @@ -1,10 +1,3 @@ -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 - program ft2sim ! Generate simulated signals for experimental "FT2" mode @@ -114,8 +107,8 @@ program ft2sim enddo c0(0:159)=c0(0:159)*(1.0-cos(twopi*(/(i,i=0,159)/)/320.0) )/2.0 - c0(144*160:144*160+159)=c0(144*160:144*160+159)*(1.0+cos(twopi*(/(i,i=0,159)/)/320.0 ))/2.0 - c0(145*160:)=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) 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