DIGITAL COMMUNICATION (EC-502) - Important Questions

State, define and explain the sampling theorem for a low-pass signal, including aliasing effect and crosstalk.

Explain the generation and detection of a PWM signal with the help of block diagram.

Explain ideal sampling. Also, derive an expression for the sampled signal spectrum.

Describe what quantization is, why it is required, and derive an expression for quantization noise.

Explain what differential coding / encoding is, how it is achieved, and discuss its advantages and disadvantages.

Explain the working, generation and detection of delta modulated signal with the help of block diagram.

Explain the working, generation and detection of a BPSK system with the help of block diagram.

Explain the concept, generation and detection of QPSK signal with the help of block diagram.

Discuss the spectral properties of QPSK and MSK.

Explain Differential Phase Shift Keying (DPSK) in detail, including principle, transmitter, receiver and working.

Explain the Gram-Schmidt orthogonalization procedure for transforming linearly independent vectors into orthogonal vectors.

Explain the working and concept of the matched filter and correlator detector.

Derive the error probability of a QPSK system.

Explain channel capacity and Shannon's information capacity theorem for channel coding.

Write short notes on any two of the following: (a) Shannon's theorem and Shannon-Hartley theorem (b) Linear block codes (c) Convolutional codes and burst error correcting codes.