%硬判決
function?decoder_output=viterbi_hard（yL）?
global?G;
n=size（G1）;?
K=size（G2）;?
number_of_states=2^（K-1）;?
%------------------------------------------------
%-------------生成各分支的輸出--------------------
%------------------------------------------------
for?j=0:number_of_states-1?
????for?t=0:1?
????????[next_statememory_contents]=next_state_fun（jtK）;?
????????input（j+1next_state+1）=t;?
????????branch_output=rem（memory_contents*G‘2）;?
????????nextstate（j+1t+1）=next_state;?
????????output（j+1t+1）=bin2deci（branch_output）;?
????end?
end?
%------------------------------------------------
metric_of_states=zeros（1number_of_states）;?????????????????%各狀態(tài)的度量metric
metric_of_states_c=zeros（number_of_states2）;???????????????%各狀態(tài)兩個(gè)輸入的度量
length_seq=length（y）/n;???????????????????????????????%符號(hào)個(gè)數(shù)
decoder_output=zeros（1length_seq-K+1）;?????????????????????%解碼輸出
channel_output_matrix=reshape（ynlength_seq）;????????%將解調(diào)輸出的比特按符號(hào)排列?
survivor_state=zeros（number_of_stateslength_seq+1）;????????%留存路徑?
input_of_state=zeros（number_of_stateslength_seq+12）;??????%匯聚到各狀態(tài)的分支對(duì)應(yīng)的輸入
state_sequence=zeros（1length_seq+1）;???????????????????????
count=zeros（1number_of_states）;
for?i=1:length_seq-K+1?
%------------------------------------------------
????for?j=0:number_of_states-1?
????????for?t=0:1
????????????binary_output=deci2bin（output（j+1t+1）n）;??????%將各分支的輸出轉(zhuǎn)換為2進(jìn)制
????????????branch_metric=Hamming_dis（channel_output_matrix（:i）‘binary_output）;???????%計(jì)算分支度量
????????????count（nextstate（j+1t+1）+1）=count（nextstate（j+1t+1）+1）+1;??????????????????
????????????metric_of_states_c（nextstate（j+1t+1）+1count（nextstate（j+1t+1）+1））=metric_of_states（j+1）+branch_metric;???%計(jì)算累積度量（加）
????????????input_of_state（nextstate（j+1t+1）+1:count（nextstate（j+1t+1）+1））=survivor_state（j+1:）;???????????????????%該分支所在路徑的對(duì)應(yīng)的輸入
????????????input_of_state（nextstate（j+1t+1）+1icount（nextstate（j+1t+1）+1））=t;???????????????????????????????????????
????????end;
????end;
%----------------比較匯聚到同一狀態(tài)的兩條路徑，選取距離較小的-----------------????
????for?j=0:number_of_states-1
????????if?metric_of_states_c（j+11）>=metric_of_states_c（j+12）
????????????metric_of_states（j+1）=metric_of_states_c（j+12）;
????????????survivor_state（j+1:）=input_of_state（j+1:2）;
????????else
???????????metric_of_states（j+1）=metric_of_states_c（j+11）;?
???????????survivor_state（j+1:）=input_of_state（j+1:1）;
????????end;
????end;
????count=zeros（1number_of_states）;
?%--------------------------截短輸出------------------------------------
????if?i>L
????????[min_metriclocation]=min（metric_of_states）;
????????decoder_output（i-L）=survivor_state（locationi-L）;
????end;??
end??
?%---------------------最后L個(gè)比特譯碼輸出--------------------------------
[min_metriclocation]=min（metric_of_states）;
decoder_output（length_seq-K+1-L+1:length_seq-K+1）=survivor_state（locationlength_seq-K+1-L+1:length_seq-K+1）;
%?=========================================================

?屬性????????????大小?????日期????時(shí)間???名稱
-----------?---------??----------?-----??----
?????文件????????3130??2017-12-04?11:53??viterbi_hard.m
?????文件????????2688??2018-01-02?15:59??viterbi_soft.m