More code cleanup; possible scheme for more frequency diversity in sync.

lib/superfox/rs_125_49.f90

@@ -1,76 +0,0 @@
-program rs_125_49
-
-  include 'sfox_params.f90'
-  character arg*8
-  integer dgen(256)                          !Generated data, i*4
-  integer*1 dgen1(7*KK)                      !Copy of dgen in 1-bit i*1 format
-  integer gsym0(NN)                          !Encoded data, Karn
-  integer gsym(NN)                           !Encoded data with errors
-  integer dat(256)                           !Decoded data, i*4
-  integer iera(0:100)                        !Positions of erasures
-  character c357*357,c14*14,chkmsg*15
-
-  nargs=iargc()
-  if(nargs.ne.2) then
-     print*,'Usage:   rs_125_49 nera nerr'
-     print*,'Example: rs_125_49   0   38'
-     go to 999
-  endif
-  call getarg(1,arg)
-  read(arg,*) nera
-  call getarg(2,arg)
-  read(arg,*) nerr
-
-! Initialize the Karn codec
-  call rs_init_sf(MM,NQ,NN,KK,NFZ)
-
-! Generate a message with sequential values in the range 0 to NQ-1
-  dgen=0
-  do i=1,KK-2
-     dgen(i)=i
-  enddo
-  write(c357,'(51b7.7)') dgen(1:KK)
-  read(c357,'(357i1)') dgen1
-  call get_crc14(dgen1,7*KK,ncrc0)
-  write(c14,'(b14.14)') ncrc0
-  read(c14,'(2b7.7)') dgen(50:51)
-
-  write(*,1000)
-1000 format('Generated data symbols, values 0-127:')
-  write(*,1002) dgen(1:KK)
-1002 format(20i4)
-
-  call rs_encode_sf(dgen,gsym0)              !Encode dgen into gsym0
-  write(*,1004)
-1004 format(/'Encoded channel symbols')
-  write(*,1002) gsym0(1:NN)
-  
-  gsym0(KK-1:KK)=0                           !Puncture by removing the CRC
-  gsym=gsym0
-  do i=1,nerr                    !Introduce errors in the first nerr positions
-     gsym(i)=mod(gsym(i)+1,NQ)
-  enddo
-  write(*,1006)
-1006 format(/'Recovered channel symbols, punctured and with additional errors:')
-  write(*,1002) gsym(1:NN)
-
-  do i=0,nera-1                     !Specify locations of symbols to be erased
-     iera(i)=i
-  enddo
-
-  call rs_decode_sf(gsym,iera,nera,dat,nfixed)  !Call the decoder
-  write(c357,'(51b7.7)') dat(1:KK)
-  read(c357,'(357i1)') dgen1
-  call get_crc14(dgen1,7*KK,ncrc)
-
-  write(*,1008)
-1008 format(/'Decoded result:')
-  chkmsg='Decode failed'
-  if(nfixed.ge.0 .and. ncrc.eq.0) chkmsg='CRC OK'
-  write(*,1002) dat(1:KK)
-  maxfix=(nn-kk)/2 + nera/2
-  write(*,1100) nerr,nera,nfixed,maxfix,trim(chkmsg)
-1100 format(/'punctured: 2','   nerr:',i3,'   nera:',i3,'   nfixed:',i3, &
-          '   maxfix:',i3,3x,a)
-
-999 end program rs_125_49

lib/superfox/sfox_clo.f90

@@ -28,6 +28,8 @@ subroutine sweep(f0,syncwidth,fsample,w,c,iz)
      if(i.eq.iz/2+1) a2=-a2         !Reverse sign of drift at midpoint
      x=s*(i-x0)
      dphi=(a0 + x*a2)*(twopi/fsample)
+!     j=i/(4*1024)
+!     dphi=(a0 + (j-1.5)*200.0 + x*a2)*(twopi/fsample)
      wstep=cmplx(cos(dphi),sin(dphi))
      w=w*wstep
      c(i)=w

lib/superfox/sfox_gen.f90

@@ -1,7 +1,6 @@
 subroutine sfox_gen(idat,f0,fsample,syncwidth,cdat)
 
   use sfox_mod
-!  include "sfox_params.f90"
   complex cdat(NMAX)                     !Generated complex waveform
   complex ctmp(NSYNC)
   complex w,wstep

lib/superfox/sfox_params.f90

@@ -1,16 +0,0 @@
-! Our code is RS(127,51).  We puncture two symbols to give (125,49)
-  parameter (NN=127)              !Channel symbols, before puncture
-  parameter (KK=51)               !Information symbols, before puncture
-  parameter (ND1=25)              !Data symbols before sync 
-  parameter (ND2=100)             !Data symbols after sync 
-  parameter (ND=ND1+ND2)          !Total data symbols (125)
-  parameter (NS=24)               !Sync symbols (for length)
-  parameter (NSPS=1024)           !Samples per symbol at 12000 S/s
-  parameter (NSYNC=NS*NSPS)       !Samples in sync waveform (24,576)
-  parameter (NZ=NSPS*(ND+NS))     !Samples in full Tx waveform (151,552)
-  parameter (NMAX=15*12000)       !Samples in iwave (180,000)
-  parameter (NFFT=32768)          !Length of FFT for sync waveform
-  parameter (NFFT1=2*NSPS)        !Length of FFTs for symbol spectra
-  parameter (MM=7)                !Bits per symbol
-  parameter (NQ=2**MM)            !Q, number of MFSK tones
-  parameter (NFZ=3)               !First zero

lib/superfox/sfoxtest.f90

@@ -171,7 +171,6 @@ program sfoxtest
         call timer('watterso',1)
 
         dat=aimag(sigr*cdat(1:NMAX)) + xnoise     !Add generated AWGN noise
-!        call plotspec(dat)     !### TEMPORARY, for SNR calibration ###
         fac=32767.0
         if(snr.ge.90.0) iwave(1:NMAX)=nint(fac*dat(1:NMAX))
         if(snr.lt.90.0) iwave(1:NMAX)=nint(rms*dat(1:NMAX))
@@ -188,7 +187,7 @@ program sfoxtest
         ferr=f-f1
         terr=t-xdt
         igoodsync=0
-        if(abs(ferr).lt.baud/2.0 .and. abs(terr).lt.tsym/8.0) then
+        if(abs(ferr).lt.baud/2.0 .and. abs(terr).lt.tsym/4.0) then
            igoodsync=1
            ngoodsync=ngoodsync+1
            sqt=sqt + terr*terr
@@ -249,7 +248,7 @@ program sfoxtest
      endif
      fgood0=fgood
      if(snrdb.ne.0.0) exit
-!     if(fgood.eq.0.0) exit
+     if(fgood.eq.0.0) exit
      if(fgoodsync.lt.0.5) exit
   enddo  ! isnr
   if(snrdb.eq.0.0) write(*,1320) threshold
@@ -259,4 +258,3 @@ program sfoxtest
 999 call timer('sfoxtest',101)
 end program sfoxtest
 
-! include 'plotspec.f90'    !### TEMPORARY, for SNR calibration ###