1 files changed, 6 insertions, 1 deletions
diff --git a/gr-trellis/src/examples/python/test_turbo_equalization1.py b/gr-trellis/src/examples/python/test_turbo_equalization1.py
index cbca2c8410..dfe1a2d82e 100755
--- a/gr-trellis/src/examples/python/test_turbo_equalization1.py
+++ b/gr-trellis/src/examples/python/test_turbo_equalization1.py
@@ -2,13 +2,18 @@
 
 from gnuradio import gr
 from gnuradio import trellis, digital, filter
-from gnuradio import analog
 from gnuradio import eng_notation
 import math
 import sys
 import random
 import fsm_utils
 
+try:
+    from gnuradio import analog
+except ImportError:
+    sys.stderr.write("Error: Program requires gr-analog.\n")
+    sys.exit(1)
+
 def make_rx(tb,fo,fi,dimensionality,tot_constellation,K,interleaver,IT,Es,N0,type):
     metrics_in = trellis.metrics_f(fi.O(),dimensionality,tot_constellation,digital.TRELLIS_EUCLIDEAN) # data preprocessing to generate metrics for innner SISO
     scale = gr.multiply_const_ff(1.0/N0)