Transceiver52M: sigproc: Wrap internal phase on frequency shift
The call into table lookup will loop on values outside of the
table range. With continuously increasing phase, this leads
to an eventual permanent hard spin. Wrap the phase value to
prevent that from happening.
Signed-off-by: Thomas Tsou <tom@tsou.cc>
diff --git a/Transceiver52M/sigProcLib.cpp b/Transceiver52M/sigProcLib.cpp
index d5f92b7..3d2bba6 100644
--- a/Transceiver52M/sigProcLib.cpp
+++ b/Transceiver52M/sigProcLib.cpp
@@ -613,6 +613,10 @@
while (xP < xPEnd) {
(*yP++) = (*xP++)*expjLookup(phase);
phase += freq;
+ if (phase > 2 * M_PI)
+ phase -= 2 * M_PI;
+ else if (phase < -2 * M_PI)
+ phase += 2 * M_PI;
}
}