From aa7afe4100486c0d11d1ba40ed72bd643a692070 Mon Sep 17 00:00:00 2001
From: drowe67 <drowe67@01035d8c-6547-0410-b346-abe4f91aad63>
Date: Tue, 3 Jun 2014 07:36:43 +0000
Subject: [PATCH] simple hf PER simulation

git-svn-id: https://svn.code.sf.net/p/freetel/code@1625 01035d8c-6547-0410-b346-abe4f91aad63
---
 codec2-dev/octave/hfper.m | 57 +++++++++++++++++++++++++++++++++++++++
 1 file changed, 57 insertions(+)
 create mode 100644 codec2-dev/octave/hfper.m

diff --git a/codec2-dev/octave/hfper.m b/codec2-dev/octave/hfper.m
new file mode 100644
index 00000000..b3396342
--- /dev/null
+++ b/codec2-dev/octave/hfper.m
@@ -0,0 +1,57 @@
+% hfper.m
+% David Rowe 2 June 2014
+% Quick and dirty HF PER calculator/simulator
+
+function hfper(ber, nbits, ntrials)
+
+  % Raw PER with no FEC --------------------------------------
+
+  nper = 0;
+  for i=1:ntrials
+      nerr = sum(rand(1,nbits) < ber);
+      if nerr >0
+          nper++;
+      end
+  end
+  printf("Raw PER..................: %0.3f\n", nper/ntrials);
+
+  % Half rate block code, e.g. Golay (23,12) with 3 bit error
+  % correcting capability
+
+  % Golay (23,12) that can correct 3 errors (fails at 4) ------
+
+  ncodeword = 23;
+  ncorrect = 3;
+  nper = 0;
+  for i=1:ntrials
+      nerr = sum(rand(1,ncodeword) < ber);
+      if nerr > ncorrect
+          nper++;
+      end
+  end
+  printf("One Golay codeword.......: %0.3f\n", nper/ntrials);
+
+  % Several Golay codewords concatenated ----------------------
+
+  m = floor(nbits/12);        % number of codewords
+
+  nper = 0;
+  for i=1:ntrials
+
+    % test each codeword in packet, if any of the codewords has > 4
+    % errors, entire packet is a dud
+
+    no_errors = 1;
+    for k=1:m
+      nerr = sum(rand(1,ncodeword) < ber);
+      if (nerr > ncorrect) && no_errors
+          nper++;
+          no_errors = 0;
+      end
+    end
+
+  end
+  printf("Packet protected by Golay: %0.3f\n", nper/ntrials);
+  
+endfunction
+ 
-- 
2.25.1