1 files changed, 70 insertions, 0 deletions
diff --git a/viterbi_generator/tests/utils/make_increment.m b/viterbi_generator/tests/utils/make_increment.m
new file mode 100644
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+++ b/viterbi_generator/tests/utils/make_increment.m
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+function [ INCREMENT ] = make_increment(SYMBOLS,NEXT,Rhh)
+%
+% MAKE_INCREMENT:
+%           This function returns a lookuptable containing the
+%           metric increments related to moving from state n to m.
+%           The data is arranged so that the increment accosiated 
+%           with a move from state n to m is located in 
+%           INCREMENT(n,m). To minimize computations only legal
+%           transitions are considdered.
+%
+% SYNTAX:   [ INCREMENT ] = make_increment(SYMBOLS,NEXT,Rhh)
+%
+% INPUT:    SYMBOLS: The table of symbols corresponding the the state-
+%                    numbers.
+%           NEXT:    A transition table containing the next legal
+%                    states, as it is generated by the code make_next.
+%           Rhh:     The autocorrelation as estimated by mf.m.
+%
+% OUTPUT:   INCREMENT:
+%                    The increment table as described above.
+%
+% SUB_FUNC: None
+%
+% WARNINGS: There is no syntax checking on input or output.
+%
+% TEST(S):  By hand, against expected values.
+%
+% AUTOR:    Jan H. Mikkelsen / Arne Norre Ekstrøm
+% EMAIL:    hmi@kom.auc.dk / aneks@kom.auc.dk
+%
+% $Id: make_increment.m,v 1.6 1997/09/22 11:39:34 aneks Exp $
+
+% IN THIS PEACE OF CODE THE SYNTAX CHECKING IS MINIMAL
+% THIS HAS BEEN CHOSEN TO AVOID THE OVERHEAD. RECALL THAT
+% THIS CODE IS EXECUTED EACH TIME A BURST IS RECEIVED.
+
+% FIND THE NUMBER OF SYMBOLS THAT WE HAVE
+%
+[M,Lh]=size(SYMBOLS);
+
+% INITIALIZE THE INCREMENT MATRIX
+%
+INCREMENT=zeros(M);
+
+% RECALL THAT THE I SEQUENCE AS IT IS STORED IN STORED AS:
+% [ I(n-1) I(n-2) I(n-3) ... I(n-Lh) ]
+%
+% ALSO RECALL THAT Rhh IS STORED AS:
+% [ Rhh(1) Rhh(2) Rhh(3) ... Rhh(Lh) ]
+%
+% THE FORMULA TO USE IS:
+% INCREMENT(n,m)
+% =
+% real(conj(I(n))*(I(n-Lh)*Rhh(Lh)+I(n-Lh+1)*Rhh(Lh-1)+...+I(n-1)*Rhh(1))
+%
+% THEY CAN THUS BE MULTIPLIED DIRECTLY WITH EACH OTHER
+
+% LOOP OVER THE STATES, AS FOUND IN THE ROWS IN SYMBOLS.
+%
+for n=1:M, 
+  % ONLY TWO LEGAL NEXT STATES EXIST, SO THE LOOP IS UNROLLED
+  %
+  m=NEXT(n,1);
+
+  INCREMENT(n,m)=real((conj(SYMBOLS(m,1))*SYMBOLS(n,:))*Rhh(2:Lh+1).');
+  m=NEXT(n,2);
+
+  INCREMENT(n,m)=real((conj(SYMBOLS(m,1))*SYMBOLS(n,:))*Rhh(2:Lh+1).');
+end
+