tentang coding

1. EEE358S Fundamentals of Communications Engineering Pulse Code Modulation Emmanuel O Bejide [email_address] http://www.uct.ac.za/depts/staff/rebejide/ Department of Electrical Engineering University of Cape Town

5. Analogue to Digital time Analogue waveform voltage 0000 0011 0101 0111 1001 1011 1101 1111 0010 0100 0110 1000 1010 1100 1110 0 1 1110 1000 0100 0010 0000 0011 0101 1011 Bit stream Sign bit PCM Codeword 3. Digitize into real integers 1. Sample analogue waveform at discrete times 2. Quantize into discrete levels Updated 9/2004 0 1 2 3 4 5 6 7 -1 -2 -3 -4 -5 -6 -7 -7 -4 -2 -1 0 1 2 5 4. To binary 1 1 1 0 1 0 0 0 0 1 0 0 0 0 1 0 1 0 0 0 0 0 0 0 1 1 0 1 0 1 1 1

6. Types of Encoding (to PCM Waveforms) Unipolar RZ NRZ Bipolar AMI Biphase Polar M L S Updated 9/2004 Polar Bipolar Unipolar

8. NRZ – Unipolar/Polar – L/M/S Coding Unipolar RZ NRZ Bipolar AMI Biphase Polar M L S Updated 9/2004 Polar Bipolar Uniolar

9. NRZ coding may be unipolar or polar 1 0 1 1 0 1 1 0 0 1 Unipolar NRZ-L Polar NRZ-L

11. (Polar) NRZ Coding 1 0 1 1 0 1 1 0 0 1 NRZ-L NRZ-M NRZ-S

13. RZ – Bipolar/Unipolar Coding Unipolar RZ NRZ Bipolar AMI Biphase Polar M L S Updated 9/2004 Polar Bipolar Unipolar

14. RZ Coding may be unipolar or bipolar 1 0 1 1 0 1 1 0 0 1 Unipolar RZ Bipolar RZ RZ-AMI Include RZ-AMI here for completeness, defer discussion Updated 9/2004

16. Biphase Coding Unipolar RZ NRZ Bipolar AMI Biphase Polar M L S Updated 9/2004 Polar Bipolar Unipolar

17. Biphase Coding 1 0 1 1 0 1 1 0 0 1 biphase-L biphase-M biphase-S

20. AMI Coding Unipolar RZ NRZ Bipolar AMI Biphase Polar M L S Updated 9/2004 Polar Bipolar Unipolar

21. (Bipolar) AMI Coding may be NRZ or RZ 1 0 1 1 0 1 1 0 0 1 NRZ-AMI RZ-AMI

24. B8ZS coding versus bipolar NRZ-AMI 0 0 0 0 0 1 0 0 0 1 NRZ-AMI B8ZS V V

26. HDB3 coding versus bipolar NRZ-AMI 0 0 1 1 0 1 0 0 0 0 NRZ-AMI HDB3 V B 0 V 0 V