Commit Graph

6 Commits

Author SHA1 Message Date
robekl
39f6d6c831 Performance improvements (#746)
* Misc minor performance improvements

* Use more concise loop syntax

* Use more concise Collection sort syntax

* Use StringUtils pad methods

* Optimize some loops and double-map-lookups

* Optimize array instantiation

There are two styles to convert a collection to an array: either
using a pre-sized array (like c.toArray(new String[c.size()])) or
using an empty array (like c.toArray(new String[0]).

In older Java versions using pre-sized array was recommended,
as the reflection call which is necessary to create an array
of proper size was quite slow. However since late updates of
OpenJDK 6 this call was intrinsified, making the performance
of the empty array version the same and sometimes even better,
compared to the pre-sized version. Also passing pre-sized array
is dangerous for a concurrent or synchronized collection as
a data race is possible between the size and toArray call
which may result in extra nulls at the end of the array,
if the collection was concurrently shrunk during the operation.

* Cleanup string concatenation

* Use EnumMap where possible

* Use FastMath instead of Math

* Initialize complex things only once

* Reduce method size to aloow more JIT inlining

* remove map of short->float

* Move field to local variable

* Cleanup Map lookup

Co-authored-by: Rob Ekl <xwq876@zebra.com>
2020-04-25 07:57:56 -04:00
Denny Sheirer
f934676bd0 #296 APCO25 Phase II Decoder Implementation (#589)
P25 Phase 2 Decoder implementation.
2019-11-17 06:56:52 -05:00
Denny
c36f6901af 39 - Adds P25/LSM support to the DemodulatorViewerFX application and
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.
2018-03-24 11:03:18 -04:00
Denny
bfaacb309d 39 - WIP - incorporates the latest P25 C4FM decoder from master and
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.
2018-03-24 06:59:41 -04:00
Denny
45a6c5a0b6 330 WIP - implements the new data-directed symbol timing and phase
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.
2018-03-04 11:42:23 -05:00
Denny
148ddd0bd5 330 WIP - P25 C4FM decoder fully functional using DQPSK decoder and
new symbol timing error detector.  Each component now has a subclass
that supports instrumentation for use with the DemodulatorViewerFX
application.
2018-02-25 08:56:34 -05:00