[Commit-gnuradio] [gnuradio] 04/18: polar: added more details in README about usage of channel construction code

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commit c5f44044e0a5cb815829574455f4c7304cc1f77d
Author: Johannes Demel <address@hidden>
Date:   Tue Dec 1 16:56:30 2015 +0100

    polar: added more details in README about usage of channel construction code
---
 gr-fec/python/fec/polar/README.md | 30 +++++++++++++++++++++++++++---
 1 file changed, 27 insertions(+), 3 deletions(-)

diff --git a/gr-fec/python/fec/polar/README.md 
b/gr-fec/python/fec/polar/README.md
index d425e86..4274491 100644
--- a/gr-fec/python/fec/polar/README.md
+++ b/gr-fec/python/fec/polar/README.md
@@ -1,9 +1,33 @@
 POLAR Code Python test functions module
 ===========
 
-This directory contains all the necessary files for POLAR code testcode.
-It serves as a reference for C++ implementations.
+This directory contains all the necessary files for POLAR code testcode and 
channel construction.
 
+Test code
+====
+The test code serves as a reference for the C++ implementations.
+'common', 'encoder' and 'decoder' are part of this test code.
+'testbed' exists to play with this test code.
+
+
+Channel Construction
+=====
 'polar_channel_construction' exposes functionality to calculate polar channels 
for different sizes.
 It may be used to calculate Bhattacharyya parameters once and store them in a 
file in '~/.gnuradio/polar'.
-Frozen bit positions are recalculated on every run.
\ No newline at end of file
+Frozen bit positions are recalculated on every run.
+
+'polar_channel_construction' provides a command-line interface for all the 
channel construction code.
+These features are also accessible via the Polar Configurator block in GRC.
+
+BEC
+====
+BEC channel construction can be calculated explicitly because the BEC 
represents a special case which simplifies the task.
+All functionality regarding this channel is located in 
'channel_construction_bec'.
+
+AWGN
+====
+In general channel construction for polar codes is a very time consuming task.
+Tal and Vardy proposed a quantization algorithm for channel construction which 
makes it feasible.
+The corresponding implementation is located in 'channel_construction_awgn'.
+It should be noted that this more of a baseline implementation which lacks all 
the advanced features the original implementation provides.
+However, simulations show that BEC channel construction with a design-SNR of 
0.0dB yields similar performance and should be preferred here.
\ No newline at end of file