mirror of https://github.com/saitohirga/WSJT-X.git
572 lines
15 KiB
Fortran
572 lines
15 KiB
Fortran
program wsprcpmd
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! Decode WSPRCPM data read from *.c2 or *.wav files.
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! WSPRCPM is a WSPR-like mode based on full-response CPM.
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!
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! Modulation Capabilities include:
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! support for multi-h cpm with two modulation indexes: [h1,h2].
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! h1,h2 (modulation index) are variable; h1=h2=0.5 is MSK, h1=h2=1.0 is standard
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! fsk intended for noncoherent demodulation.
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! demodulator uses noncoherent sequence detection with variable window size.
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! symbol demodulation is done symbol-by-symbol - each symbol is
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! estimated using a data frame comprising N symbol intervals, where N can
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! be 1, 3, 5, 7, 9, 11. The central symbol is estimated and then the window
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! is stepped forward by one symbol.
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! soft symbols are decoded by log-domain belief propagation followed by ordered-
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! statistics decoding.
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!
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! Currently configured to use (204,68) r=1/3 LDPC code, regular column weight 3.
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! 50 data bits + 14 bit CRC + 4 "0" bits. The 4 "0" bits are unused bits that
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! are not transmitted. At the decoder, these bits are treated as "AP" bits.
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! This shortens the code to (200,64) r=0.32, slightly decreasing the code rate.
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!
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! Frame format is:
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! s32 d200 p32 (264) channel symbols
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!
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use crc
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include 'wsprcpm_params.f90'
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parameter(NMAX=120*12000)
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character arg*8,message*22,cbits*50,infile*80,fname*16,datetime*11
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character*120 data_dir
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character*32 uwbits
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character*68 dmsg
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complex csync(0:32*100-1) !Sync symbols only, from cbb
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complex cpreamble(0:32*100-1) !Sync symbols only, from cbb
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complex cp2(0:32*100-1)
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complex ctwks(0:32*100-1)
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complex ctwkp(0:32*100-1)
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complex c2(0:120*12000/53-1) !Complex waveform
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complex ctmp(0:4*32*100-1)
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complex cframe(0:264*100-1) !Complex waveform
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complex cd(0:264*100-1) !Complex waveform
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complex c1(0:9,1:2),c0(0:9,1:2)
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complex ccor(0:1,264)
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complex csum,cp(0:1,1:2),cterm
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complex ccohs(0:31)
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complex ccohp(0:31)
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real*8 fMHz
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real rxdata(ND),llr(204) !Soft symbols
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real sbits(264),sbits1(264),sbits3(264)
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real ps(0:8191),psbest(0:8191)
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integer iuniqueword0
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integer isync(32) !Unique word
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integer ipreamble(32) !Preamble vector
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integer ihdr(11)
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integer*2 iwave(NMAX) !Generated full-length waveform
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integer*1,target :: idat(9)
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integer*1 decoded(68),apmask(204),cw(204)
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integer*1 hbits(264),hbits1(264),hbits3(264)
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data ipreamble/1,1,1,1,1,1,1,1,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,1,1,1,1,1,1,1,1/
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data iuniqueword0/z'30C9E8AD'/
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write(uwbits,'(b32.32)') iuniqueword0
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read(uwbits,'(32i1)') isync
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ipreamble=2*ipreamble-1
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isync=2*isync-1
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fs=12000.0/NDOWN !Sample rate
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dt=1.0/fs !Sample interval (s)
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tt=NSPS*dt !Duration of "itone" symbols (s)
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baud=1.0/tt !Keying rate for "itone" symbols (baud)
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txt=NZ*dt !Transmission length (s)
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h1=0.80 !h=0.8 seems to be optimum for AWGN sensitivity (not for fading)
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h2=0.80
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twopi=8.0*atan(1.0)
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dphi11=twopi*baud*(h1/2.0)*dt
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dphi01=-twopi*baud*(h1/2.0)*dt
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dphi12=twopi*baud*(h2/2.0)*dt
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dphi02=-twopi*baud*(h2/2.0)*dt
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k=0
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phi=0.0
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do i=1,32
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if( mod(i,2) .eq. 0 ) then
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dphi1=dphi11
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dphi0=dphi01
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else
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dphi1=dphi12
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dphi0=dphi02
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endif
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dphi=dphi0
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if( isync(i) .eq. 1 ) dphi=dphi1
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do j=1,100
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phi=mod(phi+dphi,twopi)
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csync(k)=cmplx(cos(phi),sin(phi))
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k=k+1
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enddo
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enddo
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k=0
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phi=0.0
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do i=1,32
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if( mod(i,2) .eq. 0 ) then
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dphi1=dphi11
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dphi0=dphi01
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else
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dphi1=dphi12
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dphi0=dphi02
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endif
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dphi=dphi0
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if( ipreamble(i) .eq. 1 ) dphi=dphi1
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do j=1,100
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phi=mod(phi+dphi,twopi)
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cpreamble(k)=cmplx(cos(phi),sin(phi))
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k=k+1
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enddo
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enddo
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dphi1=twopi*baud*(h1/2.0)*dt*10 ! dt*10 is samp interval after downsample
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dphi2=twopi*baud*(h2/2.0)*dt*10 ! dt*10 is samp interval after downsample
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cp(1,1)=cmplx(cos(dphi1*10),sin(dphi1*10))
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cp(0,1)=conjg(cp(1,1))
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cp(1,2)=cmplx(cos(dphi2*10),sin(dphi2*10))
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cp(0,2)=conjg(cp(1,2))
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do j=1,2
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if( j.eq.1 ) then
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dphi=dphi1
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else
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dphi=dphi2
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endif
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phi0=0.0
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phi1=0.0
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do i=0,9
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c1(i,j)=cmplx(cos(phi1),sin(phi1))
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c0(i,j)=cmplx(cos(phi0),sin(phi0))
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phi1=mod(phi1+dphi,twopi)
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phi0=mod(phi0-dphi,twopi)
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enddo
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enddo
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nargs=iargc()
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if(nargs.lt.1) then
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print*,'Usage: wsprcpmd [-a <data_dir>] [-f fMHz] [-c ncoh] file1 [file2 ...]'
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go to 999
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endif
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iarg=1
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data_dir="."
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call getarg(iarg,arg)
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if(arg(1:2).eq.'-a') then
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call getarg(iarg+1,data_dir)
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iarg=iarg+2
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endif
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call getarg(iarg,arg)
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if(arg(1:2).eq.'-f') then
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call getarg(iarg+1,arg)
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read(arg,*) fMHz
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iarg=iarg+2
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endif
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ncoh=1
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npdi=32
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if(arg(1:2).eq.'-c') then
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call getarg(iarg+1,arg)
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read(arg,*) ncoh
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iarg=iarg+2
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npdi=32/ncoh
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endif
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write(*,*) 'ncoh: ',ncoh,' npdi: ',npdi
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open(13,file=trim(data_dir)//'/ALL_WSPR.TXT',status='unknown', &
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position='append')
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xs1=0.0
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xs2=0.0
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fr1=0.0
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fr2=0.0
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nav=0
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ngood=0
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do ifile=iarg,nargs
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call getarg(ifile,infile)
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open(10,file=infile,status='old',access='stream')
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j1=index(infile,'.c2')
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j2=index(infile,'.wav')
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if(j1.gt.0) then
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read(10,end=999) fname,ntrmin,fMHz,c2
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read(fname(8:11),*) nutc
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write(datetime,'(i11)') nutc
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else if(j2.gt.0) then
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read(10,end=999) ihdr,iwave
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read(infile(j2-4:j2-1),*) nutc
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datetime=infile(j2-11:j2-1)
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call wsprcpm_downsample(iwave,c2)
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else
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print*,'Wrong file format?'
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go to 999
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endif
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close(10)
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fa=-100.0
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fb=100.0
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fs=12000.0/53.0
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npts=120*12000/53
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nsync=32
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call getcandidate2(c2,npts,fs,fa,fb,fc1,xsnr) !First approx for freq
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fcest=fc1
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do iii=1,2
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izero=226
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dphi=twopi*fcest*dt
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ctwks=cmplx(0.0,0.0)
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ctwkp=cmplx(0.0,0.0)
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phi=0
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do i=0,nsync*NSPS-1
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phi=mod(phi+dphi,twopi)
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ctwks(i)=csync(i)*cmplx(cos(phi),sin(phi))
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ctwkp(i)=cpreamble(i)*cmplx(cos(phi),sin(phi))
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enddo
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imax=100
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xcmax=-1e32
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do it = -imax,imax
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its=izero+it
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ccohs=0.0
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do k=0,npdi-1
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is=k*ncoh*nsps
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ccohs(k)=sum(c2(its+is:its+is+ncoh*nsps-1)*conjg(ctwks(is:is+ncoh*nsps-1)))
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ccohs(k)=ccohs(k)/(ncoh*nsps)
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enddo
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! term1=sum(abs(ccohs(0:npdi-1))**2)
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itp=izero+it+232*100
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ccohp=0.0
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do k=0,npdi-1
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is=k*ncoh*nsps
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ccohp(k)=sum(c2(itp+is:itp+is+ncoh*nsps-1)*conjg(ctwkp(is:is+ncoh*nsps-1)))
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ccohp(k)=ccohp(k)/(ncoh*nsps)
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enddo
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csum=0.0
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terms=0.0
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do n=1,npdi-1
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do k=n,npdi-1
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csum=csum+ccohs(k)*conjg(ccohs(k-n))
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enddo
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terms=terms+abs(csum)
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enddo
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csum=0.0
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termp=0.0
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do n=1,npdi-1
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do k=n,npdi-1
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csum=csum+ccohp(k)*conjg(ccohp(k-n))
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enddo
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termp=termp+abs(csum)
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enddo
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!write(23,*) it,terms,termp
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xmetric=sqrt(terms*termp)
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if( xmetric .gt. xcmax ) then
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xcmax=xmetric
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ibestt=it
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endif
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enddo
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istart=izero+ibestt
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if(iii .eq. 2) goto 887
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ctmp=0.0
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ctmp(0:32*100-1)=c2(istart+232*100:istart+264*100-1)*conjg(ctwkp)
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call four2a(ctmp,4*32*100,1,-1,1) !c2c FFT to freq domain
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xmax=0.0
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ctmp=cshift(ctmp,-200)
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do i=150,250
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xa=abs(ctmp(i))
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if(xa.gt.xmax) then
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ishift=i
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xmax=xa
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endif
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enddo
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dfp=1/(4*5300.0/12000.0*32)
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delta=(ishift-200)*dfp
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! need to add bounds protection
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xm1=abs(ctmp(ishift-1))
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x0=abs(ctmp(ishift))
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xp1=abs(ctmp(ishift+1))
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xint=(log(xm1)-log(xp1))/(log(xm1)+log(xp1)-2*log(x0))
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delta2=delta+xint*dfp/2.0
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fcest=fcest+delta2
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enddo
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887 write(*,'(i4,i5,5(2x,f9.5))') ifile,istart,xcmax,fc1,fcest
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xdt=(istart-226)/100.0
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if(abs(xdt).le.0.1) ngood=ngood+1
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xs1=xs1+xdt
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xs2=xs2+xdt**2
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fr1=fr1+fc1
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fr2=fr2+fc1**2
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nav=nav+1
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!**************
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! fcest=0.0
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! istart=226
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do ijitter=0,2
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io=ijitter
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if(ijitter.eq.2) io=-1
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cframe=c2(istart+io:istart+io+264*100-1)
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call downsample2(cframe,fcest,cd)
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dts=10*dt
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s2=sum(cd*conjg(cd))/(10*264)
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cd=cd/sqrt(s2)
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do nseq=1,7
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if( nseq.eq.1 ) then ! noncoherent single-symbol detection
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sbits1=0.0
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do ibit=1,264
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if( mod(ibit,2).eq.0 ) j=1
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if( mod(ibit,2).eq.1 ) j=2
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ib=(ibit-1)*10
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ccor(1,ibit)=sum(cd(ib:ib+9)*conjg(c1(0:9,j)))
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ccor(0,ibit)=sum(cd(ib:ib+9)*conjg(c0(0:9,j)))
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sbits1(ibit)=abs(ccor(1,ibit))-abs(ccor(0,ibit))
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hbits1(ibit)=0
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if(sbits1(ibit).gt.0) hbits1(ibit)=1
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enddo
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sbits=sbits1
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hbits=hbits1
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sbits3=sbits1
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hbits3=hbits1
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elseif( nseq.ge.2 ) then
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ps=0
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if( nseq.eq. 2 ) nbit=3
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if( nseq.eq. 3 ) nbit=5
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if( nseq.eq. 4 ) nbit=7
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if( nseq.eq. 5 ) nbit=9
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if( nseq.eq. 6 ) nbit=11
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if( nseq.eq. 7 ) nbit=13
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numseq=2**(nbit)
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do ibit=nbit/2+1,264-nbit/2
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ps=0.0
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pmax=0.0
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do iseq=0,numseq-1
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csum=0.0
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cterm=cmplx(1.0,0.0)
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k=1
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do i=nbit-1,0,-1
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ibb=iand(iseq/(2**i),1)
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csum=csum+ccor(ibb,ibit-(nbit/2+1)+k)*cterm
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if( mod(ibit-(nbit/2+1)+k,2) .eq. 0 ) j=1
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if( mod(ibit-(nbit/2+1)+k,2) .eq. 1 ) j=2
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cterm=cterm*conjg(cp(ibb,j))
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k=k+1
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enddo
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ps(iseq)=abs(csum)
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if( ps(iseq) .gt. pmax ) then
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pmax=ps(iseq)
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ibflag=1
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endif
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enddo
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if( ibflag .eq. 1 ) then
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psbest=ps
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ibflag=0
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endif
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call getmetric2(2**(nbit/2),psbest,numseq,sbits3(ibit))
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hbits3(ibit)=0
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if(sbits3(ibit).gt.0) hbits3(ibit)=1
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enddo
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sbits=sbits3
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hbits=hbits3
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endif
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rxdata(1:200)=sbits(33:232)
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rxav=sum(rxdata(1:200))/200.0
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rx2av=sum(rxdata(1:200)*rxdata(1:200))/200.0
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rxsig=sqrt(rx2av-rxav*rxav)
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rxdata=rxdata/rxsig
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sigma=0.90
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llr(201:204)=-5.0
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llr(1:200)=2*rxdata/(sigma*sigma)
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apmask=0
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apmask(201:204)=1
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max_iterations=40
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ifer=0
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call bpdecode204(llr,apmask,max_iterations,decoded,cw,nharderror,niterations)
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nhardmin=-1
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if(nharderror.lt.0) call osd204(llr,apmask,5,decoded,cw,nhardmin,dmin)
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if(sum(decoded).eq.0) cycle
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if(nhardmin.ge.0 .or. nharderror.ge.0) then
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idat=0
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write(dmsg,'(68i1)') decoded
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read(dmsg(1:50),'(6b8.8,b2.2)') idat(1:7)
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idat(7)=idat(7)*64
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read(dmsg(51:64),'(b14.14)') ndec_crc
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ncalc_crc=iand(crc14(c_loc(idat),9),z'FFFF')
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nbadcrc=1
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if(ncalc_crc .eq. ndec_crc) nbadcrc=0
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else
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cycle
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endif
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if( nbadcrc.eq.0 ) then
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write(cbits,1200) decoded(1:50)
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1200 format(50i1)
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read(cbits,1202) idat
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1202 format(8b8,b4)
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idat(7)=ishft(idat(7),6)
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call wqdecode(idat,message,itype)
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nsnr=nint(xsnr)
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freq=fMHz + 1.d-6*(fc1+fbest)
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nfdot=0
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write(13,1210) datetime,0,nsnr,xdt,freq,message,nfdot
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1210 format(a11,2i4,f6.2,f12.7,2x,a22,i3)
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write(*,1212) datetime(8:11),nsnr,xdt,freq,nfdot,message,'*',idf,nseq,ijitter,nharderror,nhardmin
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1212 format(a4,i4,f5.1,f11.6,i3,2x,a22,a1,i5,i5,i5,i5,i5)
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goto 888
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endif
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enddo ! nseq
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enddo !jitter
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888 continue
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enddo !files
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avshift=xs1/nav
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varshift=xs2/nav
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stdshift=sqrt(varshift-avshift**2)
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avfr=fr1/nav
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varfr=fr2/nav
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stdfr=sqrt(varfr-avfr**2)
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write(*,*) 'ngood: ',ngood
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write(*,'(a7,f7.3,f7.3)') 'shift: ',avshift,stdshift
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write(*,*) 'freq: ',avfr,stdfr
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write(*,1120)
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1120 format("<DecodeFinished>")
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999 end program wsprcpmd
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subroutine getmetric2(ib,ps,ns,xmet)
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real ps(0:ns-1)
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xm1=0
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xm0=0
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do i=0,ns-1
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if( iand(i/ib,1) .eq. 1 .and. ps(i) .gt. xm1 ) xm1=ps(i)
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if( iand(i/ib,1) .eq. 0 .and. ps(i) .gt. xm0 ) xm0=ps(i)
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enddo
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xmet=xm1-xm0
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return
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end subroutine getmetric2
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|
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subroutine downsample2(ci,f0,co)
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parameter(NI=264*100,NH=NI/2,NO=NI/10) ! downsample from 100 samples per symbol to 10
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complex ci(0:NI-1),ct(0:NI-1)
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complex co(0:NO-1)
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fs=12000.0/53.0
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df=fs/NI
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ct=ci
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call four2a(ct,NI,1,-1,1) !c2c FFT to freq domain
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i0=nint(f0/df)
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ct=cshift(ct,i0)
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co=0.0
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co(0)=ct(0)
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! b=3.4*0.875/0.715
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! b=2.6*0.5625/0.715
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b=12.0
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do i=1,NO/2
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arg=(i*df/b)**2
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|
filt=exp(-arg)
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! filt=0.0
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! if( i*df .le. b ) filt=1.0
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|
co(i)=ct(i)*filt
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|
co(NO-i)=ct(NI-i)*filt
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|
enddo
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|
co=co/NO
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call four2a(co,NO,1,1,1) !c2c FFT back to time domain
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return
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end subroutine downsample2
|
|
|
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subroutine getcandidate2(c,npts,fs,fa,fb,fc1,xsnr)
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|
parameter(NDAT=100,NFFT1=8*NDAT,NH1=NFFT1/2)
|
|
complex c(0:npts-1) !Complex waveform
|
|
complex c2(0:NFFT1-1) !Short spectra
|
|
real s(-NH1+1:NH1) !Coarse spectrum
|
|
real ss(-NH1+1:NH1) !Smoothed coarse spectrum
|
|
real w(0:NFFT1-1)
|
|
real pi
|
|
logical first
|
|
data first/.true./
|
|
save first,w
|
|
|
|
if(first) then
|
|
pi=4.0*atan(1.0)
|
|
do i=0,NFFT1-1
|
|
w(i)=sin(pi*i/(NDAT-1))**2
|
|
enddo
|
|
first=.false.
|
|
endif
|
|
|
|
nspec=int((npts-NFFT1)/NDAT)+1
|
|
df1=fs/NFFT1
|
|
s=0.
|
|
do k=1,nspec
|
|
ia=(k-1)*NDAT
|
|
ib=ia+NFFT1-1
|
|
c2(0:NFFT1-1)=c(ia:ib)*w
|
|
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
|
|
do i=-NH1+1+4,NH1-4
|
|
ss(i)=sum(s(i-4:i+4))/9.0
|
|
enddo
|
|
! do i=-NH1+1+8,NH1-8
|
|
! ss(i)=sum(ss(i-4:i+4))/9.0
|
|
! enddo
|
|
do i=-20,20
|
|
write(52,*) i*df1,ss(i)
|
|
enddo
|
|
|
|
smax=0.
|
|
ipk=0
|
|
fc1=0.
|
|
ia=nint(fa/df1)
|
|
ib=nint(fb/df1)
|
|
do i=ia,ib
|
|
f=i*df1
|
|
if(ss(i).gt.smax) then
|
|
smax=ss(i)
|
|
ipk=i
|
|
fc1=f
|
|
endif
|
|
enddo
|
|
|
|
xint=(log(ss(ipk-1))-log(ss(ipk+1)))/(log(ss(ipk-1))+log(ss(ipk+1))-2*log(ss(ipk)))
|
|
fc1=fc1+xint*df1/2.0
|
|
! The following is for testing SNR calibration:
|
|
sp3n=sum(s(ipk-5:ipk+5))
|
|
base=(sum(s)-sp3n)/(NFFT1-11.0)
|
|
psig=sp3n-11*base
|
|
pnoise=(2500.0/df1)*base
|
|
xsnr=db(psig/pnoise)
|
|
return
|
|
end subroutine getcandidate2
|
|
|
|
subroutine wsprcpm_downsample(iwave,c)
|
|
|
|
! Input: i*2 data in iwave() at sample rate 12000 Hz
|
|
! Output: Complex data in c(), sampled at 400 Hz
|
|
|
|
include 'wsprcpm_params.f90'
|
|
parameter (NMAX=120*12000,NFFT2=NMAX/53)
|
|
integer*2 iwave(NMAX)
|
|
complex c(0:NZ-1)
|
|
complex c1(0:NFFT2-1)
|
|
complex cx(0:NMAX/2)
|
|
real x(NMAX)
|
|
equivalence (x,cx)
|
|
|
|
df=12000.0/NMAX
|
|
x=iwave
|
|
call four2a(x,NMAX,1,-1,0) !r2c FFT to freq domain
|
|
i0=nint(1500.0/df)
|
|
c1(0)=cx(i0)
|
|
do i=1,NFFT2/2
|
|
c1(i)=cx(i0+i)
|
|
c1(NFFT2-i)=cx(i0-i)
|
|
enddo
|
|
c1=c1/NFFT2
|
|
call four2a(c1,NFFT2,1,1,1) !c2c FFT back to time domain
|
|
c=c1(0:NZ-1)
|
|
|
|
return
|
|
end subroutine wsprcpm_downsample
|
|
|