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Diffstat (limited to 'viterbi_generator/tests/utils/make_start.m')
| -rw-r--r-- | viterbi_generator/tests/utils/make_start.m | 63 |
1 files changed, 63 insertions, 0 deletions
diff --git a/viterbi_generator/tests/utils/make_start.m b/viterbi_generator/tests/utils/make_start.m new file mode 100644 index 0000000..83275fd --- /dev/null +++ b/viterbi_generator/tests/utils/make_start.m @@ -0,0 +1,63 @@ +function [ START ] = make_start(Lh,SYMBOLS) +% +% MAKE_START: +% This code returns a statenumber corresponding to the start +% state as it is found from Lh. The method is to use the table +% of symbolic start states as it is listed in the report made +% by 95gr870T. For the table lookups are made in SYMBOLS. in +% order to map from the symbol representation to the state number +% representation. +% +% SYNTAX: [ START ] = make_start(Lh,SYMBOLS) +% +% INPUT: SYMBOLS: The table of symbols corresponding the the state- +% numbers. +% Lh: Length of the estimated impulseresponse. +% +% OUTPUT: START: The number representation of the legal start state. +% +% SUB_FUNC: None +% +% WARNINGS: The table of symbolic representations has not been verified +% but is used directly as it is listed in the report made +% by 95gr870T. +% +% TEST(S): The function has been verified to return a state number +% which matches the symbolic representation. +% +% AUTOR: Jan H. Mikkelsen / Arne Norre Ekstrøm +% EMAIL: hmi@kom.auc.dk / aneks@kom.auc.dk +% +% $Id: make_start.m,v 1.2 1997/09/22 11:40:17 aneks Exp $ + +% WE HAVEN'T FOUND IT YET. +% +START_NOT_FOUND = 1; + +% OBTAIN THE SYMBOLS FROM Lh. THIS IS THE TABLE LISTED IN THE REPORT MADE +% BY 95gr870T. (SATEREPRESENTATION IS SLIGHTLY CHANGED). +% +if Lh==1, + start_symbols = [ 1 ]; +elseif Lh==2, + start_symbols = [ 1 -j ]; +elseif Lh==3, + start_symbols = [ 1 -j -1 ]; +elseif Lh==4, + start_symbols = [ 1 -j -1 j ]; +elseif Lh==5, + start_symbols = [ 1 -j -1 j 1]; +else + fprintf('\n\nError: Illegal value of Lh, terminating...'); +end + +% NOW MAP FROM THE SYMBOLS TO A STATE NUMBER BY SEARCHING +% SYMBOLS. +% +START=0; +while START_NOT_FOUND, + START=START+1; + if sum(SYMBOLS(START,:)==start_symbols)==Lh, + START_NOT_FOUND=0; + end +end |