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Fix several flaws in the waveforms generated by ft4sim_mult.

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This commit is contained in:
Joe Taylor 2019-01-31 11:37:54 -05:00
parent 9f909b6b1b
commit 7ae1210266
1 changed files with 11 additions and 8 deletions
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19
lib/ft4/ft4sim_mult.f90
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@ -71,33 +71,35 @@ program ft4sim_mult
call pack77(msg37,i3,n3,c77)
call genft4(msg37,0,msgsent37,itone)
! Compute the smoothed frequency waveform
! Compute the smoothed frequency waveform.
! Length = (NN+2)*NSPS samples, zero-padded to NMAX
dphi_peak=twopi*hmod/real(NSPS)
dphi=0.0
do j=1,NN
ib=(j-1)*NSPS
ie=ib+3*NSPS-1
dphi(ib:ie)=dphi(ib:ie)+dphi_peak*pulse*itone(j)
dphi(ib:ie) = dphi(ib:ie) + dphi_peak*pulse*itone(j)
enddo
! Calculate and insert the audio waveform
phi=0.0
dphi=dphi+twopi*f0*dt
dphi = dphi + twopi*f0*dt !Shift frequency up by f0
tmp=0.
k0=nint((xdt+0.043)/dt)
k0=nint(xdt/dt)
k=k0-1
do j=0,NMAX-1
k=k+1
tmp(k)=sin(phi)
phi=mod(phi+dphi(j),twopi)
enddo
k1=k
k1=k0+(NN+1)*NSPS
! Compute the ramp-up and ramp-down symbols
tmp(k0-NSPS:k0-1)=tmp(k0-NSPS:k0-1) * &
tmp(k0:k0+NSPS-1)=tmp(k0:k0+NSPS-1) * &
(1.0-cos(twopi*(/(i,i=0,NSPS-1)/)/(2.0*NSPS)))/2.0
tmp(k1+1:k1+NSPS)=tmp(k1+1:k1+NSPS) * &
tmp(k1:k1+NSPS-1)=tmp(k1:k1+NSPS-1) * &
(1.0+cos(twopi*(/(i,i=0,NSPS-1)/)/(2.0*NSPS)))/2.0
tmp(k1+NSPS:)=0.
! Insert this signal into wave() array
sig=sqrt(2*bandwidth_ratio) * 10.0**(0.05*isnr)
@ -107,7 +109,8 @@ program ft4sim_mult
enddo ! isig
100 backspace 10
do i=1,NMAX !Add gaussian noise at specified SNR
do i=1,NZZ !Add gaussian noise at specified SNR
xnoise=gran()
wave(i)=wave(i) + xnoise
enddo