Fleetsync II decoder to use it. Adds instrumented version of the decoder
and a new Fleetsync2 FX pane to the DemodulatorViewerFX tool.
Note: the remaining AFSK-1200 based decoders will all be ported to use
this new AFSK1200 decoder (MDC1200, Tait1200, LowJack1200).
Deprecates the Listener<Boolean> interface method in the MessageFramer
to optimize for primitive booleans and reduce impact on memory. Will
remove this interface once the AFSK1200 decoders are updated.
channelizer sub-system is functionally complete.
Updated the channelizer and synthesizer filter design methods to use a
Kaiser windowed Nyquist filter. Updated the synthesizer filter design
to use a new cutoff frequency of 105% of the channel bandwidth to
resolve a slight dip in the synthesized channel gain at the channel
union region.
Updated the 2 channel output processor to use a low-pass filter that
is designed for the runtime channel sample rate versus hard-coded 12.5
khz.
Testing and redesign continues ...
filter structure. Updated the channel results array buffer to produce
reusable buffers.
This has dropped the overall memory usage considerably when profiling.
Resolved issue in the processing chain where polyphase channel sources
were not being stopped and were stacking up in memory.
that is currently up/down converting the signal of interest, but the
synthesizer is not correctly combining the original two channels.
Some experimentation with the tap count for the channelizer indicates
that we can cut the tap count in half and still have decent decoding
on the P25 decoder when paired to an aligned channelized output. The
2-channel synthesized output decodes partially, but needs more work.
Resolved issue with channel gain in the channelizer that was making the
sample values so small that they were registering as zero when converted
from float to 16-bit int value in the complex wave recorder.
adds Feed forward gain support to the C4FM DQPSK demodulator which seems
to improve output from the interpolating sample buffer at each symbol
period. Updates the symbol timing gain for C4FM to decrease the gain a
bit since the feed forward gain is providing a better interpolated symbol.
updates the LSM decoder to follow the same design pattern. Adds LSM
decoder support to the demodulator viewer application. The current
symbol timing gain for LSM is set too high -- is using the C4FM gain
and causes too much fluctuation in the timing error.
error calculator. After increasing the gain for symbol timing, this
new symbol evaluator class seems to track the signal very accurately
despite lots of noise and ISI.
based on the P25 LSM decoder using a costas loop and a gardner detector.
Updates the Demodulator Viewer FX application to add in a symbol chart
and a phase error chart. The decoder won't lock on yet ... still a wip.
produces a significant reduction in memory usage, especially for tuners
like the airspy and hackrf that produce 10/20 MSPS sample rates. This
is observed to be around 66% reduction in peak memory usage and provides
a more stable memory utilization across time reducing stress on the
garbage collector.
Use of these reusable memory buffers will be pushed further down into
the processing chain modules to ensure we keep new object creation
to the lowest levels possible.
