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1.2 Mã trellis không gian-thời gian (STTC)
1.2.1 Giới thiệu
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JAs?S&$a+@"l&?]QB(!&$AQ"#(!$l+552NCQ6&?S&$a+@P&K'+$3
$l+X*QCG($<(!X‘QZXX'($8/A&$‚Lh/Z(!KB?S$T>@_(!I(($"(!
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J'C@^CXAL€@"l&/4&$XA^(!@^CY(&D>$>($!$/4&$8HK&D>^(!@^C
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1.3 Nguyên lý giải mã mã lưới
1.3.1 Giải mã sử dụng giản đồ lưới
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!>(Ut=0 *t=6 eILhQs(!$FH$]sAS
0
=00f2$@TX*@^CXAJ11
$RKB!I?SL€!I?SX&$AQ>output = 18L_@E&$CGt(L>(!Qs(!$F1
:
s
t=1. 1>C@T8X*input = 01$RKB!I?SL€~CG[@4($&$Aoutput = 18&O($"
XaG@$[!I(@EJ"*$R&$CxK($a(@"l&L€J1 1 0 1 0 0
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1.3.2 Khoảng cách Hamming trong giải mã lưới
$">@SK[8H$AI(!&F&$>??(!hJLcHg%H$F&($>C!•>9Lc($4
+$v(2“MXm/ZQY(8!ILh=IGQ>JxK@_(@cX*iK@^CY(8&$CxK($a(
@"l&J1111e$>GXR1101f2
UL_@E/"*8>$NG&T9&F&$@U1
,
8?B&$Ainput = 11 (h=0)X?B&$A
input = 00 (h=2).
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,

110102
1.3.3 Giải mã sử dụng thuật toán Viterbi
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$t($a(@"l&$<(!(&$m($=F&QA(!$^C$[&F&Q"#(!$l+2
1_@E/"*$t$'(&F&$?KB?S$T>=F&@4($@"#(!@c($N(!>G&IH$
&TJx=IGQ>2
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,
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,
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:
X* h=02
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,

0
<= S
1
<= S
2
<= S
3
<= S
4
<= S
5
<= S
6
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