diff --git a/common.py b/common.py
index e797b67..c418e96 100644
--- a/common.py
+++ b/common.py
@@ -12,6 +12,10 @@ carrier_index = 0
 Fc = frequencies[carrier_index]
 Tc = 1.0 / Fc
 
+symbols = np.array([complex(x, y)
+                   for x in np.linspace(-1, 1, 4)
+                   for y in np.linspace(-1, 1, 4)]) / np.sqrt(2)
+
 Tsym = 1e-3
 Nsym = int(Tsym / Ts)
 baud = int(1/Tsym)
diff --git a/sigproc.py b/sigproc.py
index a3efd1e..73c5192 100644
--- a/sigproc.py
+++ b/sigproc.py
@@ -56,9 +56,7 @@ class QAM(object):
             S = self.symbols[index]
             yield self._dec[S]
 
-_xs, _ys = np.linspace(-1, 1, 4), np.linspace(-1, 1, 4) # QAM-16
-_symbols = np.array([complex(x, y) for x in _xs for y in _ys]) * np.sqrt(0.5)
-modulator = QAM(_symbols)
+modulator = QAM(common.symbols)
 
 modem_bps = common.baud * modulator.bits_per_symbol * len(common.frequencies)