DIGITAL COMMUNICATION (EC-502) - Important Questions

Explain the generation and detection of a PWM signal.

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

Write short notes on any two of: Natural Sampling, RZ Signalling, Matched Filter, Linear Block Codes.

Explain Ideal sampling. Also, derive an expression for it.

Discuss the generation of PPM and PWM signals.

Given a digital signal with a bit rate of 1 Mbps and a bandwidth efficiency of 0.8, calculate the required bandwidth for transmission. Define Aliasing.

Write sampling theorem for low pass and band pass signals. Also explain time division multiplexing in brief.

Compare PAM, PWM and PPM and describe generation and detection of any one.

Explain in detail natural sampling and flat-top sampling, Manchester code, and polar signaling.

Write technical short note on following:

Explain different types of sampling and explain aperture effect and aliasing effect.

Explain the generation of a PWM wave with the help of a suitable diagram.

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

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

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

Define Bandwidth. Transfer 01101001 in to Manchester code.

For a given voltage range and number of quantization bits, calculate number of quantization levels and step size, and state advantages of differential encoding.

Draw block diagram of PCM system and explain it is detail.

Brief short notes on i) quantization and quantization noise, ii) delta and adaptive delta modulation, and iii) RZ and bipolar signaling.

Explain companding and inter symbol interference.

Discuss about different line encoding techniques.

Explain the polar signaling and RZ signaling.

Describe eye pattern and on-off signaling.

Explain how to generate and detect an ADM (adaptive delta modulation) signal.

Discuss the spectral properties of QPSK and MSK.

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

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

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

Describe how QPSK modulates digital signals using phase shifts and discuss its advantages over BPSK.

Discuss the concepts of M-ary PSK and M-ary FSK.

Differentiate following with neat diagram.

Explain the minimum shift keying in detail.

Discuss in brief with examples: i) Concept of M-ary PSK and M-ary FSK; ii) Matched filter and correlator detector.

With the help of block diagram explain the generation and detection of coherent and non coherent BFSK signal.

Explain the generation and detection of following: QAM

Discuss the concept of M-ary PSK.

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

Derive the error probability of a QPSK system.

Discuss the applications where each modulation technique is commonly used and the factors that influence the choice of modulation scheme in different digital communication systems.

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

Write short notes on any two: matched filter, Shannon's theorem, error correcting codes.

Explain the Gram-Schmidt orthogonalization procedure and the concept of signal space for computation of probability of error.

Derive the error probability for BPSK, QPSK and QAM systems.

Derive the probability of error for a BPSK system.

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

Discuss the applications of error correcting codes in digital communication and their importance for reliable transmission over noisy channels.

Describe the fundamental concepts behind the Shannon-Hartley theorem, including the relationship between channel capacity, bandwidth and signal-to-noise ratio (SNR). https://www.rgpvonline.com

For a (7, k) Hamming error-correcting code, calculate the number of data bits and describe convolutional codes.

Describe following in brief:

State Shannon's theorem and the Shannon-Hartley theorem and describe the concept of convolutional codes.

Explain block codes and cyclic codes.

Draw encoder and decoder circuits and describe burst error correcting codes.

Derive the expression for channel capacity in terms of mutual information and find capacity for a noise-free channel.

Find the channel capacity of a Binary Symmetric Channel for given crossover probabilities.

Discuss linear block codes and cyclic codes.