![Introduction to Pulse Code
Modulation (PCM)
• Basics of Digital Communication
• Presented by: [Your Name]](https://image.slidesharecdn.com/pulsecodemodulationbasicswithdiagrams-250721132416-87ce718f/85/Pulse_Code_Modulation_Basics_With_Diagrams-pptx-1-320.jpg)
![Step 1 - Sampling
• • Measures amplitude of analog signal at
regular intervals
• • Sampling rate must satisfy Nyquist Criterion:
• - fs ≥ 2 × fmax
• • CD audio uses 44.1 kHz sampling rate
• [Diagram: Analog Sine Wave with Sample
Points Shown at Regular Intervals]](https://image.slidesharecdn.com/pulsecodemodulationbasicswithdiagrams-250721132416-87ce718f/85/Pulse_Code_Modulation_Basics_With_Diagrams-pptx-5-320.jpg)
![Step 2 - Quantization
• • Converts sampled values into discrete levels
• • Approximates to nearest value from a set
• • Introduces quantization error
• [Diagram: Signal levels rounded to nearest
quantization level]](https://image.slidesharecdn.com/pulsecodemodulationbasicswithdiagrams-250721132416-87ce718f/85/Pulse_Code_Modulation_Basics_With_Diagrams-pptx-6-320.jpg)
![Step 3 - Encoding
• • Converts quantized values to binary codes
• • Bits per sample = log2(number of levels)
• • Example: 8-bit PCM = 256 levels
• [Diagram: Quantized Values Mapped to Binary
Codes]](https://image.slidesharecdn.com/pulsecodemodulationbasicswithdiagrams-250721132416-87ce718f/85/Pulse_Code_Modulation_Basics_With_Diagrams-pptx-7-320.jpg)
![PCM Example
• • Analog sine wave → Sampled at 8 kHz
• • Quantized into 16 levels
• • Encoded into 4-bit binary
• • See waveform diagram (optional for live
presentation)
• [Diagram: Analog to PCM waveform
conversion]](https://image.slidesharecdn.com/pulsecodemodulationbasicswithdiagrams-250721132416-87ce718f/85/Pulse_Code_Modulation_Basics_With_Diagrams-pptx-8-320.jpg)
![Questions & Answers
• Any Questions?
• [Encourage student participation]](https://image.slidesharecdn.com/pulsecodemodulationbasicswithdiagrams-250721132416-87ce718f/85/Pulse_Code_Modulation_Basics_With_Diagrams-pptx-14-320.jpg)
Pulse_Code_Modulation_Basics_With_Diagrams.pptx
- 1. Introduction to Pulse Code Modulation (PCM) • Basics of Digital Communication • Presented by: [Your Name]
- 2. What is PCM? • • PCM stands for Pulse Code Modulation • • Converts analog signals into digital form • • Used in telephony, audio, and data transmission • • Standard for digital audio in computers and CDs
- 3. Why Use PCM? • • Analog signals are prone to noise and distortion • • PCM offers: • - High accuracy • - Noise immunity • - Efficient digital storage and transmission
- 4. Basic Steps in PCM • 1. Sampling • 2. Quantization • 3. Encoding • 4. Transmission Sampling Quantization Encoding Transmission
- 5. Step 1 - Sampling • • Measures amplitude of analog signal at regular intervals • • Sampling rate must satisfy Nyquist Criterion: • - fs ≥ 2 × fmax • • CD audio uses 44.1 kHz sampling rate • [Diagram: Analog Sine Wave with Sample Points Shown at Regular Intervals]
- 6. Step 2 - Quantization • • Converts sampled values into discrete levels • • Approximates to nearest value from a set • • Introduces quantization error • [Diagram: Signal levels rounded to nearest quantization level]
- 7. Step 3 - Encoding • • Converts quantized values to binary codes • • Bits per sample = log2(number of levels) • • Example: 8-bit PCM = 256 levels • [Diagram: Quantized Values Mapped to Binary Codes]
- 8. PCM Example • • Analog sine wave → Sampled at 8 kHz • • Quantized into 16 levels • • Encoded into 4-bit binary • • See waveform diagram (optional for live presentation) • [Diagram: Analog to PCM waveform conversion]
- 9. Advantages of PCM • • High noise immunity • • Digital system compatibility • • Easy to store, encrypt, and compress
- 10. Disadvantages of PCM • • Requires more bandwidth • • Introduces quantization noise • • Needs precise synchronization
- 11. Applications of PCM • • Digital telephony • • CDs, DVDs, Blu-ray • • Satellite communication • • Voice over IP (VoIP)
- 12. Summary • • PCM converts analog to digital using: • - Sampling • - Quantization • - Encoding • • Widely used in modern digital communications
- 13. References • • Simon Haykin – Communication Systems • • William Stallings – Data and Computer Communications • • IEEE, TutorialsPoint, etc.
- 14. Questions & Answers • Any Questions? • [Encourage student participation]