mirror of
https://github.com/saitohirga/WSJT-X.git
synced 2024-11-07 09:44:16 -05:00
85 lines
1.9 KiB
Fortran
85 lines
1.9 KiB
Fortran
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program ft8q3
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! Test q3-style decodes for FT8.
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use packjt77
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parameter(NN=79,NSPS=32)
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parameter(NWAVE=NN*NSPS) !2528
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parameter(NZ=3200,NLAGS=NZ-NWAVE)
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character arg*12
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character msg37*37
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character c77*77
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complex cwave(0:NWAVE-1)
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complex cd(0:NZ-1)
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complex z
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real xjunk(NWAVE)
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real ccf(0:NLAGS-1)
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integer itone(NN)
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integer*1 msgbits(77)
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! Get command-line argument(s)
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nargs=iargc()
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if(nargs.ne.3) then
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print*,'Usage: ft8q3 DT f0 "message"'
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go to 999
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endif
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call getarg(1,arg)
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read(arg,*) xdt !Time offset from nominal (s)
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call getarg(2,arg)
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read(arg,*) f0 !Frequency (Hz)
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call getarg(3,msg37) !Message to be transmitted
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fs=200.0 !Sample rate (Hz)
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dt=1.0/fs !Sample interval (s)
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bt=2.0
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! Source-encode, then get itone()
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i3=-1
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n3=-1
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call pack77(msg37,i3,n3,c77)
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call genft8(msg37,i3,n3,msgsent37,msgbits,itone)
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! Generate complex cwave
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call gen_ft8wave(itone,NN,NSPS,bt,fs,f0,cwave,xjunk,1,NWAVE)
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do i=0,NZ-1
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read(40,3040) cd(i)
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3040 format(17x,2f10.3)
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enddo
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lagbest=-1
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ccfbest=0.
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nsum=32*2
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do lag=0,nlags-1
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z=0.
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s=0.
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do i=0,NWAVE-1
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z=z + cd(i+lag)*conjg(cwave(i))
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if(mod(i,nsum).eq.nsum-1 .or. i.eq.NWAVE-1) then
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s=s + abs(z)
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z=0.
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endif
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enddo
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! ccf(lag)=abs(z)
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ccf(lag)=s
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write(42,3042) lag-100,(lag-100)/200.0,ccf(lag)
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3042 format(i5,f10.3,f10.0)
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if(ccf(lag).gt.ccfbest) then
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ccfbest=ccf(lag)
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lagbest=lag
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endif
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enddo
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z=0.
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do i=0,NWAVE-1
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z=z + cd(i+lagbest)*conjg(cwave(i))
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if(mod(i,32).eq.31) then
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amp=abs(z)**2
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pha=atan2(aimag(z),real(z))
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j=i/32
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write(43,3043) z,j,amp,pha
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3043 format(2f12.0,i6,f12.0,f12.6)
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endif
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enddo
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999 end program ft8q3
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