diff --git a/lib/fsk4hf/cpolyfit.f90 b/lib/fsk4hf/cpolyfit.f90 new file mode 100644 index 000000000..ccc2bc317 --- /dev/null +++ b/lib/fsk4hf/cpolyfit.f90 @@ -0,0 +1,61 @@ +subroutine cpolyfit(c,pp,id,maxn,aa,bb,zz) + + parameter (KK=84) !Information bits (72 + CRC12) + parameter (ND=168) !Data symbols: LDPC (168,84), r=1/2 + parameter (NS=65) !Sync symbols (2 x 26 + Barker 13) + parameter (NR=3) !Ramp up/down + parameter (NN=NR+NS+ND) !Total symbols (236) + parameter (NSPS=16) !Samples per MSK symbol (16) + parameter (N2=2*NSPS) !Samples per OQPSK symbol (32) + parameter (N13=13*N2) !Samples in central sync vector (416) + parameter (NZ=NSPS*NN) !Samples in baseband waveform (3760) + parameter (NFFT1=4*NSPS,NH1=NFFT1/2) + + complex c(0:NZ-1) !Complex waveform + complex zz(NS+ND) !Complex symbol values (intermediate) + real x(NS),yi(NS),yq(NS) !For complex polyfit + real pp(2*NSPS) !Shaped pulse for OQPSK + real aa(20),bb(20) !Fitted polyco's + integer id(NS+ND) !NRZ values (+/-1) for Sync and Data + + ib=NSPS-1 + ib2=N2-1 + n=0 + do j=1,117 !First-pass demodulation + ia=ib+1 + ib=ia+N2-1 + zz(j)=sum(pp*c(ia:ib))/NSPS + if(abs(id(j)).eq.2) then !Save all sync symbols + n=n+1 + x(n)=float(ia+ib)/NZ - 1.0 + yi(n)=real(zz(j))*0.5*id(j) + yq(n)=aimag(zz(j))*0.5*id(j) + ! write(54,1225) n,x(n),yi(n),yq(n) + !1225 format(i5,3f12.4) + endif + if(j.le.116) then + zz(j+117)=sum(pp*c(ia+NSPS:ib+NSPS))/NSPS + endif + enddo + + aa=0. + bb=0. + nterms=0 + if(maxn.gt.0) then + ! Fit sync info with a complex polynomial + npts=n + mode=0 + chisqa0=1.e30 + chisqb0=1.e30 + nterms=maxn + ! do nterms=1,maxn + call polyfit4(x,yi,yi,npts,nterms,mode,aa,chisqa) + call polyfit4(x,yq,yq,npts,nterms,mode,bb,chisqb) +! if(chisqa/chisqa0.ge.0.98 .and. chisqb/chisqb0.ge.0.98) exit + chisqa0=chisqa + chisqb0=chisqb + ! enddo + endif + + return +end subroutine cpolyfit diff --git a/lib/fsk4hf/getfc1.f90 b/lib/fsk4hf/getfc1.f90 new file mode 100644 index 000000000..df6e9bc64 --- /dev/null +++ b/lib/fsk4hf/getfc1.f90 @@ -0,0 +1,59 @@ +subroutine getfc1(c,fc1) + + parameter (KK=84) !Information bits (72 + CRC12) + parameter (ND=168) !Data symbols: LDPC (168,84), r=1/2 + parameter (NS=65) !Sync symbols (2 x 26 + Barker 13) + parameter (NR=3) !Ramp up/down + parameter (NN=NR+NS+ND) !Total symbols (236) + parameter (NSPS=16) !Samples per MSK symbol (16) + parameter (N2=2*NSPS) !Samples per OQPSK symbol (32) + parameter (N13=13*N2) !Samples in central sync vector (416) + parameter (NZ=NSPS*NN) !Samples in baseband waveform (3760) + parameter (NFFT1=4*NSPS,NH1=NFFT1/2) + + complex c(0:NZ-1) !Complex waveform + complex c2(0:NFFT1-1) !Short spectra + real s(-NH1+1:NH1) !Coarse spectrum + + nspec=NZ/NFFT1 + fs=12000.0/72.0 + df1=fs/NFFT1 + s=0. + do k=1,nspec + ia=(k-1)*N2 + ib=ia+N2-1 + c2(0:N2-1)=c(ia:ib) + c2(N2:)=0. + call four2a(c2,NFFT1,1,-1,1) + do i=0,NFFT1-1 + j=i + if(j.gt.NH1) j=j-NFFT1 + s(j)=s(j) + real(c2(i))**2 + aimag(c2(i))**2 + enddo + enddo +! call smo121(s,NFFT1) + smax=0. + ipk=0 + fc1=0. + ia=nint(40.0/df1) + do i=-ia,ia + f=i*df1 + if(s(i).gt.smax) then + smax=s(i) + ipk=i + fc1=f + endif + ! write(51,3001) f,s(i),db(s(i)) +! 3001 format(f10.3,e12.3,f10.3) + enddo + +! The following is for testing SNR calibration: +! sp3n=(s(ipk-1)+s(ipk)+s(ipk+1)) !Sig + 3*noise +! base=(sum(s)-sp3n)/(NFFT1-3.0) !Noise per bin +! psig=sp3n-3*base !Sig only +! pnoise=(2500.0/df1)*base !Noise in 2500 Hz +! xsnrdb=db(psig/pnoise) + + + return +end subroutine getfc1 diff --git a/lib/fsk4hf/getfc2.f90 b/lib/fsk4hf/getfc2.f90 new file mode 100644 index 000000000..a261da239 --- /dev/null +++ b/lib/fsk4hf/getfc2.f90 @@ -0,0 +1,55 @@ +subroutine getfc2(c,fc1,fc2) + + parameter (KK=84) !Information bits (72 + CRC12) + parameter (ND=168) !Data symbols: LDPC (168,84), r=1/2 + parameter (NS=65) !Sync symbols (2 x 26 + Barker 13) + parameter (NR=3) !Ramp up/down + parameter (NN=NR+NS+ND) !Total symbols (236) + parameter (NSPS=16) !Samples per MSK symbol (16) + parameter (N2=2*NSPS) !Samples per OQPSK symbol (32) + parameter (N13=13*N2) !Samples in central sync vector (416) + parameter (NZ=NSPS*NN) !Samples in baseband waveform (3760) + parameter (NFFT1=4*NSPS,NH1=NFFT1/2) + + complex c(0:NZ-1) !Complex waveform + complex cs(0:NZ-1) !For computing spectrum + real a(5) + + fs=12000.0/72.0 + baud=fs/NSPS + a(1)=-fc1 + a(2:5)=0. + call twkfreq1(c,NZ,fs,a,cs) !Mix down by fc1 + +! Filter, square, then FFT to get refined carrier frequency fc2. + call four2a(cs,NZ,1,-1,1) !To freq domain + df=fs/NZ + ia=nint(0.75*baud/df) + cs(ia:NZ-1-ia)=0. !Save only freqs around fc1 + call four2a(cs,NZ,1,1,1) !Back to time domain + cs=cs/NZ + cs=cs*cs !Square the data + call four2a(cs,NZ,1,-1,1) !Compute squared spectrum + +! Find two peaks separated by baud + pmax=0. + fc2=0. + ic=nint(baud/df) + ja=nint(0.5*baud/df) + do j=-ja,ja + f2=j*df + ia=nint((f2-0.5*baud)/df) + if(ia.lt.0) ia=ia+NZ + ib=nint((f2+0.5*baud)/df) + p=real(cs(ia))**2 + aimag(cs(ia))**2 + & + real(cs(ib))**2 + aimag(cs(ib))**2 + if(p.gt.pmax) then + pmax=p + fc2=0.5*f2 + endif +! write(52,1200) f2,p,db(p) +!1200 format(f10.3,2f15.3) + enddo + + return +end subroutine getfc2 diff --git a/lib/fsk4hf/mskhfsim.f90 b/lib/fsk4hf/mskhfsim.f90 index 915ef4983..a929ee8c6 100644 --- a/lib/fsk4hf/mskhfsim.f90 +++ b/lib/fsk4hf/mskhfsim.f90 @@ -28,19 +28,16 @@ program msksim complex csync(0:NZ-1) !Sync symbols only, from cbb complex cb13(0:N13-1) !Barker 13 waveform complex c(0:NZ-1) !Complex waveform - complex cs(0:NZ-1) !For computing spectrum - complex c2(0:NFFT1-1) !Short spectra complex zz(NS+ND) !Complex symbol values (intermediate) - complex z,z0 - real s(-NH1+1:NH1) !Coarse spectrum + complex z real xnoise(0:NZ-1) !Generated random noise real ynoise(0:NZ-1) !Generated random noise - real x(NS),yi(NS),yq(NS) !For complex polyfit real rxdata(ND),llr(ND) !Soft symbols real pp(2*NSPS) !Shaped pulse for OQPSK real a(5) !For twkfreq1 real aa(20),bb(20) !Fitted polyco's integer id(NS+ND) !NRZ values (+/-1) for Sync and Data + integer ierror(NS+ND) integer icw(NN) integer*1 msgbits(KK),decoded(KK),apmask(ND),cw(ND) ! integer*1 codeword(ND) @@ -121,84 +118,12 @@ program msksim c=c + cmplx(xnoise,ynoise) !Add AWGN noise endif -!----------------------------------------------------------------- fc1 -! First attempt at finding carrier frequency, fc1: low-resolution power spectra - nspec=NZ/NFFT1 - df1=fs/NFFT1 - s=0. - do k=1,nspec - ia=(k-1)*N2 - ib=ia+N2-1 - c2(0:N2-1)=c(ia:ib) - c2(N2:)=0. - call four2a(c2,NFFT1,1,-1,1) - do i=0,NFFT1-1 - j=i - if(j.gt.NH1) j=j-NFFT1 - s(j)=s(j) + real(c2(i))**2 + aimag(c2(i))**2 - enddo - enddo -! call smo121(s,NFFT1) - smax=0. - ipk=0 - fc1=0. - ia=nint(40.0/df1) - do i=-ia,ia - f=i*df1 - if(s(i).gt.smax) then - smax=s(i) - ipk=i - fc1=f - endif -! write(51,3001) f,s(i),db(s(i)) -! 3001 format(f10.3,e12.3,f10.3) - enddo - -! The following is for testing SNR calibration: -! sp3n=(s(ipk-1)+s(ipk)+s(ipk+1)) !Sig + 3*noise -! base=(sum(s)-sp3n)/(NFFT1-3.0) !Noise per bin -! psig=sp3n-3*base !Sig only -! pnoise=(2500.0/df1)*base !Noise in 2500 Hz -! xsnrdb=db(psig/pnoise) - - a(1)=-fc1 - a(2:5)=0. - call twkfreq1(c,NZ,fs,a,cs) !Mix down by fc1 - -!----------------------------------------------------------------- fc2 -! Filter, square, then FFT to get refined carrier frequency fc2. - call four2a(cs,NZ,1,-1,1) !To freq domain - df=fs/NZ - ia=nint(0.75*baud/df) - cs(ia:NZ-1-ia)=0. !Save only freqs around fc1 - call four2a(cs,NZ,1,1,1) !Back to time domain - cs=cs/NZ - cs=cs*cs !Square the data - call four2a(cs,NZ,1,-1,1) !Compute squared spectrum - -! Find two peaks separated by baud - pmax=0. - fc2=0. - ic=nint(baud/df) - ja=nint(0.5*baud/df) - do j=-ja,ja - f2=j*df - ia=nint((f2-0.5*baud)/df) - if(ia.lt.0) ia=ia+NZ - ib=nint((f2+0.5*baud)/df) - p=real(cs(ia))**2 + aimag(cs(ia))**2 + & - real(cs(ib))**2 + aimag(cs(ib))**2 - if(p.gt.pmax) then - pmax=p - fc2=0.5*f2 - endif -! write(52,1200) f2,p,db(p) -!1200 format(f10.3,2f15.3) - enddo + call getfc1(c,fc1) !First approx for freq + call getfc2(c,fc1,fc2) !Refined freq sqf=sqf + (fc1+fc2-f0)**2 a(1)=-(fc1+fc2) a(2:5)=0. - call twkfreq1(c,NZ,fs,a,c) !Mix c down by fc1+fc2 + call twkfreq1(c,NZ,fs,a,c) !Mix c down by fc1+fc2 ! z=sum(c(1680:2095)*cb13)/208.0 !Get phase from Barker 13 vector ! z0=z/abs(z) @@ -217,104 +142,13 @@ program msksim !1220 format(i6,3f10.4) enddo xdt=jpk/fs + + call cpolyfit(c,pp,id,maxn,aa,bb,zz) + nterms=maxn -!------------------------------------------------------------------ cpolyfit - ib=NSPS-1 - ib2=N2-1 - n=0 - do j=1,117 !First-pass demodulation - ia=ib+1 - ib=ia+N2-1 - zz(j)=sum(pp*c(ia:ib))/NSPS - if(abs(id(j)).eq.2) then !Save all sync symbols - n=n+1 - x(n)=float(ia+ib)/NZ - 1.0 - yi(n)=real(zz(j))*0.5*id(j) - yq(n)=aimag(zz(j))*0.5*id(j) -! write(54,1225) n,x(n),yi(n),yq(n) -!1225 format(i5,3f12.4) - endif - if(j.le.116) then - zz(j+117)=sum(pp*c(ia+NSPS:ib+NSPS))/NSPS - endif - enddo - - aa=0. - bb=0. - nterms=0 - if(maxn.gt.0) then -! Fit sync info with a complex polynomial - npts=n - mode=0 - chisqa0=1.e30 - chisqb0=1.e30 - do nterms=1,maxn - call polyfit4(x,yi,yi,npts,nterms,mode,aa,chisqa) - call polyfit4(x,yq,yq,npts,nterms,mode,bb,chisqb) - if(chisqa/chisqa0.ge.0.98 .and. chisqb/chisqb0.ge.0.98) exit - chisqa0=chisqa - chisqb0=chisqb - enddo - endif - -!-------------------------------------------------------------- Soft Symbols - n=0 - do j=1,117 - xx=j*2.0/117.0 - 1.0 - yii=1. - yqq=0. - if(nterms.gt.0) then - yii=aa(1) - yqq=bb(1) - do i=2,nterms - yii=yii + aa(i)*xx**(i-1) - yqq=yqq + bb(i)*xx**(i-1) - enddo - endif - z0=cmplx(yii,yqq) - z=zz(j)*conjg(z0) - if(abs(id(j)).eq.2) then - if(real(z)*id(j).lt.0) then - nhardsync=nhardsync+1 - nhardsync0=nhardsync0+1 - endif -! write(55,2002) j,id(j)/2,xx,z*id(j)/2 !Sync bit -!2002 format(2i5,3f10.3) - else - p=real(z) !Data bit - n=n+1 - rxdata(n)=p - ierr=0 - if(id(j)*p.lt.0) ierr=1 - nhard0=nhard0+ierr - nhard=nhard+ierr -! write(56,2003) j,id(j),n,ierr,nhard,xx,p*id(j),z -!2003 format(5i6,4f10.3) - endif - enddo - - do j=118,233 - xx=(j-116.5)*2.0/117.0 - 1.0 - yii=1. - yqq=0. - if(nterms.gt.0) then - yii=aa(1) - yqq=bb(1) - do i=2,nterms - yii=yii + aa(i)*xx**(i-1) - yqq=yqq + bb(i)*xx**(i-1) - enddo - endif - z0=cmplx(yii,yqq) - z=zz(j)*conjg(z0) - p=aimag(z) - n=n+1 - rxdata(n)=p - ierr=0 - if(id(j)*p.lt.0) ierr=1 - nhard=nhard+ierr - enddo - + call msksoftsym(zz,aa,bb,id,nterms,ierror,rxdata) + +!---------------------------------------------------------------- Decode rxav=sum(rxdata)/ND rx2av=sum(rxdata*rxdata)/ND rxsig=sqrt(rx2av-rxav*rxav) @@ -330,11 +164,18 @@ program msksim if(niterations.lt.0 .or. count(msgbits.ne.decoded).gt.0 .or. & nbadcrc.ne.0) ifer=1 nfe=nfe+ifer - write(58,1045) snrdb,nhard0,nhardsync0,niterations,nbadcrc,ifer, & - nterms,fc1+fc2-f0,xdt - if(ifer.eq.1) write(59,1045) snrdb,nhard0,nhardsync0,niterations, & - nbadcrc,ifer,nterms,fc1+fc2-f0,xdt -1045 format(f6.1,6i5,2f8.3) +! write(58,1045) snrdb,nhard0,nhardsync0,niterations,nbadcrc,ifer, & +! nterms,fc1+fc2-f0,xdt +! if(ifer.eq.1) write(59,1045) snrdb,nhard0,nhardsync0,niterations, & +! nbadcrc,ifer,nterms,fc1+fc2-f0,xdt +!1045 format(f6.1,6i5,2f8.3) +! if(ifer.gt.0) then +! write(63,1046) iter,nhard0,nhardsync0 +!1046 format(/3i6) +! write(63,1047) ierror(1:117) +! write(63,1047) ierror(118:233) +!1047 format(70i1) +! endif enddo fsigma=sqrt(sqf/iters) ber=float(nhard)/((NS+ND)*iters) @@ -345,3 +186,8 @@ program msksim enddo 999 end program msksim + + include 'getfc1.f90' + include 'getfc2.f90' + include 'cpolyfit.f90' + include 'msksoftsym.f90' diff --git a/lib/fsk4hf/msksoftsym.f90 b/lib/fsk4hf/msksoftsym.f90 new file mode 100644 index 000000000..fa1d965bf --- /dev/null +++ b/lib/fsk4hf/msksoftsym.f90 @@ -0,0 +1,84 @@ +subroutine msksoftsym(zz,aa,bb,id,nterms,ierror,rxdata) + + parameter (KK=84) !Information bits (72 + CRC12) + parameter (ND=168) !Data symbols: LDPC (168,84), r=1/2 + parameter (NS=65) !Sync symbols (2 x 26 + Barker 13) + parameter (NR=3) !Ramp up/down + parameter (NN=NR+NS+ND) !Total symbols (236) + parameter (NSPS=16) !Samples per MSK symbol (16) + parameter (N2=2*NSPS) !Samples per OQPSK symbol (32) + parameter (N13=13*N2) !Samples in central sync vector (416) + parameter (NZ=NSPS*NN) !Samples in baseband waveform (3760) + parameter (NFFT1=4*NSPS,NH1=NFFT1/2) + + complex zz(NS+ND) !Complex symbol values (intermediate) + complex z,z0 + real rxdata(ND) !Soft symbols + real aa(20),bb(20) !Fitted polyco's + integer id(NS+ND) !NRZ values (+/-1) for Sync and Data + integer ierror(NS+ND) + + n=0 + ierror=0 + do j=1,117 + xx=j*2.0/117.0 - 1.0 + yii=1. + yqq=0. + if(nterms.gt.0) then + yii=aa(1) + yqq=bb(1) + do i=2,nterms + yii=yii + aa(i)*xx**(i-1) + yqq=yqq + bb(i)*xx**(i-1) + enddo + endif + z0=cmplx(yii,yqq) + z=zz(j)*conjg(z0) + p=real(z) + if(abs(id(j)).eq.2) then + if(real(z)*id(j).lt.0) then !Sync bit + nhardsync=nhardsync+1 + nhardsync0=nhardsync0+1 + ierror(j)=2 + endif + else + n=n+1 !Data bit + rxdata(n)=p + ierr=0 + if(id(j)*p.lt.0) then + ierr=1 + ierror(j)=1 + endif + nhard0=nhard0+ierr + nhard=nhard+ierr + endif + enddo + + do j=118,233 + xx=(j-116.5)*2.0/117.0 - 1.0 + yii=1. + yqq=0. + if(nterms.gt.0) then + yii=aa(1) + yqq=bb(1) + do i=2,nterms + yii=yii + aa(i)*xx**(i-1) + yqq=yqq + bb(i)*xx**(i-1) + enddo + endif + z0=cmplx(yii,yqq) + z=zz(j)*conjg(z0) + p=aimag(z) + n=n+1 + rxdata(n)=p + ierr=0 + if(id(j)*p.lt.0) then + ierr=1 + ierror(j)=1 + endif + nhard0=nhard0+ierr + nhard=nhard+ierr + enddo + + return +end subroutine msksoftsym