Commit Graph

5 Commits

Author SHA1 Message Date
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
Denny
96d9d6f750 [WIP] Adds locking mechanism to tuner controllers so that the
polyphase channel manager can block users from changing frequency and/or
sample rate when polyphase channels are allocated.
2018-02-04 06:30:25 -05:00
Denny
05fa5c25fd #39 WIP - adds support for timestamped complex buffers so that decoded
messages and events can be accurately timestamped, and more importantly,
allocated traffic channels can request to be pre-loaded with buffered
samples to ensure that traffic channels don't miss any samples that
are currently missed due processing latency inherent in current buffer
sizing.  This should reduce the clipping of starting messages or voice
on the traffic channels.

Restructures processing path for tuner frequency and sample rate change
events.  The tuner now embeds these events in the sequence of buffers
that are generated immediately after the event occurs since those are
the buffers that will be impacted by the change.  Previously, the change
event would be broadcast throughout the system and would impact any
buffered/cached buffers.  This also reduces the number of source event
change listeners that have to be managed.  Note: this change is not yet
implemented in all tuners ... only in the TestTuner implementation.

Updates the polyphase channelizer to now buffer channel results and then
dispatch the buffer to the channel output processors to improve efficiency
of using float arrays versus single value complex float processing.
2018-01-13 09:10:57 -05:00
Denny
d2e7f008c8 WIP - implements tuner source manager to calculate and update the tuner's
center frequency each time we allocate a new DDC/channel.  Adds
 support for broadcasting channel count change source events so that the
 tuner can accurately convey sourced channel counts via tuner events.

 Completes changeover of polyphase channel manager to support arbitrary
 bandwidth channels.  The new approach provides greater compatibility
 across any tuner sample rates.  Likewise, all decoders will have to be
 updated to adapt to any channel sample rate, although channel bandwidths
 will be at least 12.5 kHz and likely no more than 25.0 kHz, with a 2x
 oversampling that produces channel sample rates in range 25.0 - 50.0
 kHz.
2018-01-07 07:46:41 -05:00
Denny
236df8f3f4 Merges from master branch. 2017-12-27 10:10:51 -05:00