Review of PCM system Remaining part of sampling (post ad pre aliasing filters) Review of quantization and Non uniform quantization Derivations of SNR Advantages and disadvantages of PCM PCM word size Sources of Corruption

1. EE344 Communication Systems

2. Coded System
 IN CODED SYSTEM, each message symbol or
amplitude is transformed into a group of symbols
 It has efficient exchange of bandwidth for signal to
noise ratio.
 PCM
 DM
 ADM

3.  Review of PCM system
 Remaining part of sampling (post ad pre aliasing
filters)
 Review of quantization and Non uniform
quantization
 Derivations of SNR
 Advantages and disadvantages of PCM
 PCM word size
 Sources of Corruption

4. BINARY PCM SYSTEM
 PCM system
 Elements of PCM system
 Analog message-Low pass filter-sampler-quantizer-encoder-PCM signal
 The quantization and encoding part are usually performed in same circuit
known as ADC
 Input SNR
 Output SNR
 Figure of merit (FOM)

5. Remaining part of sampling process
Sampling Theorem and its Proof
Sampling Methods
 Ideal
 Natural
 Flattop
Rate of sampling
 Sampling at Nyquist interval
 Under sampling--- Aliasing (post and pre filtering)
 Over sampling

6. Aliasing

7. Pre filtering

8. Post filtering

11. Quantization
 Basics -Already done in previous lecture

12. Why is quantization required?

14.  Some derivations and formulas related to
quantization

25. performance

38. PCM word size

39. PCM word size