dennis.sheirer
31482a1014
P25 Decoder - improved LSM decoding and IMBE audio decoding. Includes redesigned audio output class to handle automatic start/stop of audio playback based on availability of audio data.
2015-06-08 01:05:19 +00:00
dennis.sheirer
bc5080aa4a
P25 - updated automatic and direct frequency control to cleanup the code and allow P25 to better track frequency and PPM changes in the tuner and provide a cleaner implementation of the AFC component in the processing chain of all of the other decoders.
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Changed C4FM symbol filter to reset frequency tracking values when the tuner's frequency or PPM values change.
Moved all frequency control pieces into the source.tuner.frequency package.
2015-05-04 00:55:04 +00:00
dennis.sheirer
2c4b3ab1b5
P25 - enhancement for LSM demod phase lock errors - adds new sync pattern detectors to detect Costas Loop phase lock errors and apply immediate correction to enable accurate symbol slicing.
2015-04-26 16:58:25 +00:00
dennis.sheirer
c12123a81b
P25 - work in progress to improve CQPSK LSM audio output. Audio output is still choppy but greatly improved over the previous test release.
2015-04-25 23:21:20 +00:00
dennis.sheirer
52f2e3bdca
P25 audio work in progress - started work on exposing 88-bit (11-byte) IMBE voice frames from LDU messages. Added deinterleave, derandomize and the Golay(23,12,7) error detection and correction to LDU voice messages. Hamming edac still remains to be implemented. Plan to create a separate project to produce an imbe FormatConversionProvider that will convert 88-bit imbe frames to PCM audio that is then in a standard format for audio playback, recording, or conversion to another format like shoutcast.
2015-03-01 15:40:25 +00:00
dennis.sheirer
d87acad189
P25 - adds icons to decoding channel display for talkgroups and addresses. Includes new super high-resolution (not) fire truck and rescue truck icons.
2015-02-24 01:19:27 +00:00
dennis.sheirer
ebee420478
P25 cleanup.
2015-02-20 01:52:04 +00:00
dennis.sheirer
7d948c4af4
P25 LSM work in progress. CQPSK demodulator is working now, but there is a slight phase error in the constellation (it's rotated right by 5-10 degrees). I'm not sure if this is an error coming from the decoder, or if it's reflecting a phase imbalance from the source tuner i/q data.
2015-02-16 23:14:23 +00:00
dennis.sheirer
a65e821e85
P25 LSM decoder work in progress. Adds a CQPSK decoder based on Max's (KA1RBI) scope.py and gardner loop.
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The CQPSK decoder is starting to take shape, but needs more tweaking and testing. It's not keeping a good lock on strong P25 signals. I have to add some more features to the intrumentation package to allow me to visualize the internals of the CQPSK decoder so that I can get a better sense of what needs fine tuning.
The CQPSK decoder may work for anyone that wants to sync the repo and run the build script.
2015-02-10 00:42:08 +00:00
