18.channel coding(6).ppt [호환 모드] -...
TRANSCRIPT
![Page 1: 18.Channel Coding(6).ppt [호환 모드] - KOCWcontents.kocw.net/KOCW/document/2015/korea_sejong/... · 2016-09-09 · 6 page Free Distance of Convolutional Codes Distance properties:](https://reader033.vdocuments.site/reader033/viewer/2022050223/5f68671add1e6e771b528b06/html5/thumbnails/1.jpg)
디지털통신
제14주
![Page 2: 18.Channel Coding(6).ppt [호환 모드] - KOCWcontents.kocw.net/KOCW/document/2015/korea_sejong/... · 2016-09-09 · 6 page Free Distance of Convolutional Codes Distance properties:](https://reader033.vdocuments.site/reader033/viewer/2022050223/5f68671add1e6e771b528b06/html5/thumbnails/2.jpg)
Signal Processing Lab., http://signal.korea.ac.krDept. of Elec. and Info. Engr., Korea Univ.
2016년 6월 27일2 page
Example of Hard-Decision Viterbi Decoding Summary (cont’d)
![Page 3: 18.Channel Coding(6).ppt [호환 모드] - KOCWcontents.kocw.net/KOCW/document/2015/korea_sejong/... · 2016-09-09 · 6 page Free Distance of Convolutional Codes Distance properties:](https://reader033.vdocuments.site/reader033/viewer/2022050223/5f68671add1e6e771b528b06/html5/thumbnails/3.jpg)
Signal Processing Lab., http://signal.korea.ac.krDept. of Elec. and Info. Engr., Korea Univ.
2016년 6월 27일3 page
![Page 4: 18.Channel Coding(6).ppt [호환 모드] - KOCWcontents.kocw.net/KOCW/document/2015/korea_sejong/... · 2016-09-09 · 6 page Free Distance of Convolutional Codes Distance properties:](https://reader033.vdocuments.site/reader033/viewer/2022050223/5f68671add1e6e771b528b06/html5/thumbnails/4.jpg)
Signal Processing Lab., http://signal.korea.ac.krDept. of Elec. and Info. Engr., Korea Univ.
2016년 6월 27일4 page
Path Memory Length h: (4 or 5) times K
Required Path Storages u = h2K-1
![Page 5: 18.Channel Coding(6).ppt [호환 모드] - KOCWcontents.kocw.net/KOCW/document/2015/korea_sejong/... · 2016-09-09 · 6 page Free Distance of Convolutional Codes Distance properties:](https://reader033.vdocuments.site/reader033/viewer/2022050223/5f68671add1e6e771b528b06/html5/thumbnails/5.jpg)
Signal Processing Lab., http://signal.korea.ac.krDept. of Elec. and Info. Engr., Korea Univ.
2016년 6월 27일5 page
Soft-Decision Viterbi Decoding
![Page 6: 18.Channel Coding(6).ppt [호환 모드] - KOCWcontents.kocw.net/KOCW/document/2015/korea_sejong/... · 2016-09-09 · 6 page Free Distance of Convolutional Codes Distance properties:](https://reader033.vdocuments.site/reader033/viewer/2022050223/5f68671add1e6e771b528b06/html5/thumbnails/6.jpg)
Signal Processing Lab., http://signal.korea.ac.krDept. of Elec. and Info. Engr., Korea Univ.
2016년 6월 27일6 page
Free Distance of Convolutional Codes Distance properties:
Since the code is linear, the minimum distance of the code is the minimum distance between each of the codewords and the all-zero codeword.
This is the minimum distance in the set of all arbitrary long paths along the trellis that diverge and remerge to the all-zero path.
![Page 7: 18.Channel Coding(6).ppt [호환 모드] - KOCWcontents.kocw.net/KOCW/document/2015/korea_sejong/... · 2016-09-09 · 6 page Free Distance of Convolutional Codes Distance properties:](https://reader033.vdocuments.site/reader033/viewer/2022050223/5f68671add1e6e771b528b06/html5/thumbnails/7.jpg)
Signal Processing Lab., http://signal.korea.ac.krDept. of Elec. and Info. Engr., Korea Univ.
2016년 6월 27일7 page
Free Distance of Convolutional Codes (cont’d)
![Page 8: 18.Channel Coding(6).ppt [호환 모드] - KOCWcontents.kocw.net/KOCW/document/2015/korea_sejong/... · 2016-09-09 · 6 page Free Distance of Convolutional Codes Distance properties:](https://reader033.vdocuments.site/reader033/viewer/2022050223/5f68671add1e6e771b528b06/html5/thumbnails/8.jpg)
Signal Processing Lab., http://signal.korea.ac.krDept. of Elec. and Info. Engr., Korea Univ.
2016년 6월 27일8 page
Performance Bounds for Convolutional Codes (cont’d)
Error correction capability of convolutional codes is given by
For a given code rate, increasing the constraint length usually increases the free distance.
For a given constraint length, decreasing the coding rate usually increases the free distance.
But the coding gain is upper bounded
2/)1( fdt
)(10loggain coding 10 fcdR
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Signal Processing Lab., http://signal.korea.ac.krDept. of Elec. and Info. Engr., Korea Univ.
2016년 6월 27일9 page
![Page 10: 18.Channel Coding(6).ppt [호환 모드] - KOCWcontents.kocw.net/KOCW/document/2015/korea_sejong/... · 2016-09-09 · 6 page Free Distance of Convolutional Codes Distance properties:](https://reader033.vdocuments.site/reader033/viewer/2022050223/5f68671add1e6e771b528b06/html5/thumbnails/10.jpg)
Signal Processing Lab., http://signal.korea.ac.krDept. of Elec. and Info. Engr., Korea Univ.
2016년 6월 27일10 page
Comparison of Free Distance
![Page 11: 18.Channel Coding(6).ppt [호환 모드] - KOCWcontents.kocw.net/KOCW/document/2015/korea_sejong/... · 2016-09-09 · 6 page Free Distance of Convolutional Codes Distance properties:](https://reader033.vdocuments.site/reader033/viewer/2022050223/5f68671add1e6e771b528b06/html5/thumbnails/11.jpg)
Signal Processing Lab., http://signal.korea.ac.krDept. of Elec. and Info. Engr., Korea Univ.
2016년 6월 27일11 page
Performance Bounds for Convolutional Codes (Hard-Decision Decoding)
1/3
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Signal Processing Lab., http://signal.korea.ac.krDept. of Elec. and Info. Engr., Korea Univ.
2016년 6월 27일12 page
Performance Bounds for Convolutional Codes (Soft-Decision Decoding)
![Page 13: 18.Channel Coding(6).ppt [호환 모드] - KOCWcontents.kocw.net/KOCW/document/2015/korea_sejong/... · 2016-09-09 · 6 page Free Distance of Convolutional Codes Distance properties:](https://reader033.vdocuments.site/reader033/viewer/2022050223/5f68671add1e6e771b528b06/html5/thumbnails/13.jpg)
Signal Processing Lab., http://signal.korea.ac.krDept. of Elec. and Info. Engr., Korea Univ.
2016년 6월 27일13 page
Path Memoryh = 32