1. 06 Jan, 2019 2 commits
  2. 21 Dec, 2018 1 commit
  3. 03 Dec, 2018 1 commit
  4. 27 Nov, 2018 1 commit
    • Manolis Surligas's avatar
      Complete redesign of the BPSK decoder · 1bc575cc
      Manolis Surligas authored
      This commit implements a new approach for the BPSK AX.25 decoding. It
      seems that the GNU Radio equalizers (both CMA and LMS) are not ideal for
      bursty transmissions. After they loose 'lock', they tend to converge
      quite slow again.
      
      The equalizing problem is again solved using an AGC2 block. However, the
      placement of this block is quite critical. In older versions the AGC was
      placed several steps after resampling and filtering. This resulted to
      poor equalization and noise increase. Now the AGC is placed as early as
      possible when the signal has a large span.
      1bc575cc
  5. 25 Nov, 2018 2 commits
  6. 24 Nov, 2018 2 commits
  7. 23 Nov, 2018 8 commits
  8. 30 Jul, 2018 1 commit
  9. 18 Jul, 2018 6 commits
    • Patrick Dohmen's avatar
      Connect waterfall sink in front of filter · 0064bc83
      Patrick Dohmen authored
      Connecting the waterfall sink behind the FFT Filter causes the
      waterfall to show only the filtered APT signal. Fixing this needs
      an additional resampler.
      0064bc83
    • Patrick Dohmen's avatar
      Fix NOAA APT waterfall bandwidth · e831d815
      Patrick Dohmen authored
      The flowgraph for decoding NOAA APT images generates a waterfall with a
      bandwidth depending on the default samplerate of the SDR hardware.
      USRPB200 defaults to 500 ksps, which produces an output of 125 ksps
      after the "first_stage_decimation" which is fixed to a value of 4.
      Changing the hardware to an "rtlsdr" also changes the default
      samplerate to 1 Msps which results in a waterfall bandwidth of 250 kHz
      (+- 125 kHz). Connecting the waterfall sink behind the FFT Filter,
      which has a decimation set to match an output samplerate of 125 kHz,
      seems to be correct! This produces waterfalls with a bandwidth of
      125 kHz (+- 62,5 kHz).
      
      Fixes issue #128
      e831d815
    • Manolis Surligas's avatar
      Tune CW parameters · 6b1e3d38
      Manolis Surligas authored
      * Set the loop bandwith of the PLL to a lower value, to get rid off the
      DC leakage and improve SNR
      * Set the AGC update rate to a higher value
      * Decrease the CW decoding threshold
      6b1e3d38
    • Manolis Surligas's avatar
      Fix CW decoder · 85219e5d
      Manolis Surligas authored
      * Fix CW decoder
      * Link with boost chrono to avoid a linking error in boost 1.67
      85219e5d
    • Patrick Dohmen's avatar
      Improve sensitivity · dbfb6e65
      Patrick Dohmen authored
      dbfb6e65
    • Patrick Dohmen's avatar
      Add a BPSK decoder Script · 9d41d898
      Patrick Dohmen authored
      Add a BPSK decoder script for frames transmitted in AX.25, using G3RUH
      scrambling and without. Baudrate is set via parameter "baudrate", all
      filters, taps, offsets, etc are calculated using this parameter. Decoder
      tested with 1k2 bps and 9k6 bps.
      9d41d898
  10. 27 Apr, 2018 1 commit
  11. 25 Mar, 2018 3 commits
  12. 24 Mar, 2018 3 commits
  13. 20 Mar, 2018 1 commit
  14. 23 Feb, 2018 2 commits
  15. 08 Feb, 2018 1 commit
  16. 02 Feb, 2018 1 commit
  17. 19 Jan, 2018 1 commit
  18. 11 Jan, 2018 1 commit
    • Manolis Surligas's avatar
      Fix METEOR flowgraph · 22cb5e18
      Manolis Surligas authored
      * Set the METEOR flowgraph in non-X mode
      * Reduce the stored bandwidth by a factor of 2. Captures have shown that
      twice the bandwidth of the METEOR is enough for RRC and clock recovery
      22cb5e18
  19. 10 Jan, 2018 2 commits