Jared Boone
3c33e20156
Rename MatchedFilter::decimation_factor.
2015-11-06 09:40:05 -08:00
Jared Boone
7a59823211
Stop computing channel spectrum during FSK demod.
...
Data is unused, as screen is displaying decoded packets.
2015-11-06 09:40:05 -08:00
Jared Boone
ddd34793a6
Default constructors and configure methods for baseband classes.
2015-11-06 09:40:05 -08:00
Jared Boone
51df92a05a
Rename baseband_ais -> ais_baseband.
...
So that ais_baseband and ais_application filenames can be sorted near each other.
2015-11-06 09:40:04 -08:00
Jared Boone
26c23dc8a0
Use new FIR decimation in FSK demodulator.
...
Reduces FIR calculation effort when output samples are skipped at FIR filter, not after.
2015-11-06 09:40:04 -08:00
Jared Boone
86b068be62
Early calculation to reduce pressure on registers.
2015-11-06 09:40:04 -08:00
Jared Boone
a074e7d8d8
Remove commented code.
2015-11-06 09:40:04 -08:00
Jared Boone
424c0eac3f
FIRAndDecimateBy2Complex: expose decimation_factor, bring work function into class.
2015-11-06 09:40:04 -08:00
Jared Boone
cde15e4271
Generalize fir_and_decimate_by_2_complex_fast.
...
Permit decimation_factors other than 2.
Permit tap counts != 64 (but still must be multiple of 8).
Half the amount of tap memory required.
Performance is significantly degraded due to greater flexibility -- most likely due to separate sample buffer shift phase, instead of performing shift during output sample calculation.
2015-11-06 09:40:04 -08:00
Jared Boone
be78ed657f
Remove taps_count template arg for FIRAndDecimateBy2Complex.
...
Use heap to allocate samples and taps buffers, so filters of different lengths can be supported.
2015-11-06 09:40:04 -08:00
Jared Boone
0f73d6061a
Remove old decimating FIR code.
2015-11-06 09:40:04 -08:00
Jared Boone
015e5516d5
Update/consolidate AIS RRC matched filter taps.
2015-11-06 09:40:04 -08:00
Jared Boone
dab801e167
AIS RX tweak of clock recovery constant for better performance.
2015-11-06 09:40:03 -08:00
Jared Boone
58b97dea68
AIS RX performance improved with 32-tap RRC.
2015-11-06 09:40:03 -08:00
Jared Boone
f82fd1f8d7
Tease apart utility.hpp, other header dependencies.
...
Trying to get a host-testable FSK demodulator, and finding a lot of M4- and ChibiOS-specific code is getting included. Boo.
2015-11-06 09:40:03 -08:00
Jared Boone
e049097f49
Remove spurious commented code.
2015-11-06 09:40:03 -08:00
Jared Boone
4aae77f565
MatchedFilter improvements
...
Use single set of taps for positive and negative filters.
Reverse taps (since new samples are pushed into buffer from the high end).
Make complex multiply explicit to avoid fancy but irrelevant arithmetic checks.
Compute negative filter from conjugation of positive filter taps.
Move filter power and difference calculations into MatchedFilter.
2015-11-06 09:40:03 -08:00
Jared Boone
ab28639a3d
Use std::move to move samples in buffer.
...
Yes, std::rotate works, but it's fancy and does unnecessary work.
2015-11-06 09:40:02 -08:00
Jared Boone
4141d6fe0f
Untemplate MatchedFilter, a different way.
2015-11-06 09:40:02 -08:00
Jared Boone
fe94cfa45a
De-std::vector MatchedFilter, was chewing up far too much memory.
2015-11-06 09:40:02 -08:00
Jared Boone
64ed539554
Change LinearResampler.advance to external use only.
2015-11-06 09:40:02 -08:00
Jared Boone
4ed385d15e
Prioritize PacketBuilder found_end_flag() over packet_truncated().
2015-11-06 09:40:02 -08:00
Jared Boone
c2e7f9a6f4
Shorten AIS training sequence match length.
2015-11-06 09:40:02 -08:00
Jared Boone
d92c962c0c
Set MatchedFilter taps with separate method.
2015-11-06 09:40:02 -08:00
Jared Boone
8198db768d
Move some MatchedFilter code to .cpp file.
2015-11-06 09:40:02 -08:00
Jared Boone
aff7865c61
Move (some) AIS bits to a separate file.
2015-11-06 09:40:02 -08:00
Jared Boone
7a5100baf1
Enlarge packet payload size 256 -> 1024 bits.
2015-11-06 09:40:01 -08:00
Jared Boone
68250b4d30
Expose weight() of FixedErrorFilter.
2015-11-06 09:40:01 -08:00
Jared Boone
474eaa8541
Template ClockRecovery for ErrorFilter type.
2015-11-06 09:40:01 -08:00
Jared Boone
9879af37d5
FixedErrorFilter constructor.
2015-11-06 09:40:01 -08:00
Jared Boone
727d4c8a1f
Const the FixedErrorFilter operator().
2015-11-06 09:40:01 -08:00
Jared Boone
93b9b9d9ef
LinearErrorFilter constructor.
2015-11-06 09:40:01 -08:00
Jared Boone
37b1d7cf2f
Remove payload_length from PacketBuilder, etc.
2015-11-06 09:40:01 -08:00
Jared Boone
cf3bff3b03
Decouple PacketBuilder PayloadHandler function from method type.
2015-11-06 09:40:01 -08:00
Jared Boone
1bdad62496
Simplify PacketBuilder pattern matching and symbol accumulation.
2015-11-06 09:40:00 -08:00
Jared Boone
36689f5c45
Refactor bit pattern matching.
...
Remove AccessCodeCorrelator, Unstuff classes.
2015-11-06 09:40:00 -08:00
Jared Boone
f918a774b7
Address implicit cast compiler warnings.
2015-11-06 09:40:00 -08:00
Jared Boone
0bc8f551de
Use matched filter for AIS GMSK demodulation demo.
...
Less than optimal for plain FSK, but flexible enough to also support GFSK/GMSK. Not at all optimized for SIMD instructions, so may not perform adequately at Bluetooth/GSM rates.
2015-11-06 09:40:00 -08:00
Jared Boone
a9c190b6bb
Matched filter implementation.
...
Essentially a complex FIR filter that's more flexible than the ones already in the code base. Refactor?!
2015-11-06 09:40:00 -08:00
Jared Boone
e9f28f9ef3
Provide configuration of symbol unstuffing.
2015-11-06 09:40:00 -08:00
Jared Boone
a00fcbaa8f
Unstuffing pattern length of zero should never match.
2015-11-06 09:40:00 -08:00
Jared Boone
05badaddda
Put symbol coding into PacketBuilder.
...
Removes stuffing symbols before placing them into packet buffer.
2015-11-06 09:40:00 -08:00
Jared Boone
c936e09702
Add bit unstuffing algorithm.
...
For use in AIS. Probably useful elsewhere, too...
2015-11-06 09:39:59 -08:00
Jared Boone
31ff13f1c0
Un-const Message in message handler interfaces.
...
I want to modify in place the messages that are received. Naughty, but oh well.
2015-11-06 09:39:59 -08:00
Jared Boone
5c31e803c8
Change interface to AccessCodeCorrelator, inline in header.
2015-11-06 09:39:59 -08:00
Jared Boone
a3cce5632e
Complete rewrite of clock recovery, lots of refactoring.
2015-11-06 09:39:59 -08:00
Jared Boone
8b2e75a299
Add LinearResampler implementation for clock recovery.
2015-11-06 09:39:59 -08:00
Jared Boone
f13e2d32c0
Add symbol coding namespace, NRZI decoder.
2015-11-06 09:39:59 -08:00
Jared Boone
934936d3f6
Enhancements to clock recovery
...
Linearly interpolate input and delayed samples, based on phase of internal symbol clock.
2015-11-06 09:39:59 -08:00
Jared Boone
291de8f869
Change channel_spectrum type to std::complex<float>.
...
Move FFT bit-reversal to complex<int16_t> -> complex<float> copy.
Change window so that adjacent bins have constant(-ish) gain.
Change window to float.
Change time domain samples to accumulate at even intervals over the FFT interval.
2015-10-14 11:10:24 -07:00
