Commit Graph

10 Commits

Author SHA1 Message Date
Denny
09b209496b Resolves issue with NPE in 3/4 rate decoder. 2018-09-22 09:19:15 -04:00
Denny
b15a3e59a0 Resolves #411
Updates decoder types to specify channel sample rate and pass/stop
frequencies for requested channels.  Updates tuner channel source
managers to accept a channel specification for channels that are
allocated.
2018-09-09 09:49:05 -04:00
Denny
994e78f42b Resolves issue with polyphase filter gain and channel output processor gain 2018-09-05 07:16:51 -04:00
Denny
b8a46af836 Creates new HeterodyneChannelSourceManager that uses frequency translation
and CIC decimation for each channel provided by the tuner.
2018-09-05 07:15:57 -04:00
Denny
e88944e53d Updates all reusable buffer queues to automatically set the user count
to 1 on all provided buffers by default.
2018-07-01 07:08:52 -04:00
Denny
ad560db5ea [WIP] Removes all usage of Buffer, RealBuffer and ComplexBuffer. 2018-06-30 06:54:36 -04:00
Denny
c13315f731 [WIP] The Two-Channel synthesizer is now fully-functional and the
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 ...
2018-05-20 07:21:14 -04:00
Denny
341e740e77 [WIP] updated the 2 channel synthesizer to use a more SIMD friendly
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.
2018-05-10 08:08:20 -04:00
Denny
cbc228d798 [WIP] The 2 channel synthesizer appears to be working after restructuring.
Check-point commit.  I'm going to optimize the code so that it can
leverage SIMD instructions.
2018-05-06 07:37:24 -04:00
Denny
488b2e02ce [WIP] Work continues on resolving issues with the 2-channel synthesizer
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.
2018-04-29 06:19:39 -04:00