1. Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. Chapter Thirteen Channel Coding and Encryption

2. Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. Square array for error correction by parity checking Figure 13.1-1

3. Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. Interleaved check bits for error control with burst errors Figure 13.1-2

4. Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. FEC system Figure 13.1-4

5. Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. ARQ system Figure 13.1-6

6. Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. ARQ schemes (a) stop-and-wait (b) go-back (c) selective repeat Figure 13.1-7

7. Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. Convolutional encoder with n=2, k=1, and L=2 Figure 13.3-2

8. Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. (a) Code trellis (b) state diagram for (2, 1, 2) encoder (c) illustrative sequence Figure 13.3-4

9. Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. Termination of (2, 1, 2) code trellis Figure 13.3-7

10. Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. Encoder subject to catastrophic error propagation (a) encoder (b) state diagram Figure 13.3-9

11. Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. Illustration of the Viterbi algorithm for maximum- likelihood decoding Figure 13.3-11

12. Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. Turbo encoder Figure 13.3-16

13. Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. RSC encoder with Figure 13.3-17

14. Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. Turbo decoder Figure 13.3-18

15. Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. Secret key system Figure 13.4-1

16. Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. Public/private key system Figure 13.4-2

17. Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. Permutation examples (a) straight (b) expanded (c) compressed Figure 13.4-3

18. Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. S-box example Figure 13.4-4

19. Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. DES flowchart Figure 13.4-5

20. Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. Substitute and permute block Figure 13.4-6

21. Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. Key generator flowchart Figure 13.4-7

22. Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. 32 to 48 bit expansion Figure 13.4-8

23. Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. Details of 48 to 32-bit S-box Figure 13.4-9