Digital Communication Systems Assessment

What are the main elements of a digital communication system?

• Modem, Router, Firewall, Switch

• Signal, Noise, Protocol, Bandwidth

• Source, Transmitter, Channel, Receiver, Destination

• Encoder, Decoder, Amplifier, Filter

List two advantages of digital communication systems.

• Limited range of communication

• Lower cost of hardware

• 1. Increased speed of data transmission, 2. Improved reliability through error correction.

• Simplified user interface

What is pulse code modulation (PCM)?

• A method for amplifying analog signals

• A technique for compressing digital audio files

• A way to convert digital signals into analog waves

• Pulse Code Modulation (PCM) is a technique for digitally representing analog signals by sampling and quantizing their amplitudes.

Explain the process of sampling in PCM.

• Sampling in PCM requires continuous sampling of the signal without intervals.

• Sampling in PCM involves taking discrete samples of an analog signal at regular intervals and quantizing these samples to create a digital representation.

• PCM sampling involves converting digital signals back to analog form.

• Quantization in PCM is done before sampling the analog signal.

What is quantization error in PCM?

• Quantization error is the process of converting digital signals to analog.

• Quantization error is the total error in the PCM system.

• Quantization error is the difference between the actual analog signal value and the quantized value in PCM.

• Quantization error is the noise introduced during signal transmission.

Define companding in PCM systems.

• Companding is a method to increase the bit rate in PCM systems.

• Companding is a technique in PCM systems that compresses and expands audio signals to reduce dynamic range and improve signal quality.

• Companding refers to the process of filtering out noise in audio signals.

• Companding is a technique used to convert analog signals to digital without any compression.

What is differential Pulse Code Modulation?

• A technique for compressing audio files without any loss of quality.

• Differential Pulse Code Modulation (DPCM) is a method of encoding signals by transmitting the difference between successive samples.

• A process that involves sampling signals at a constant rate.

• A method of encoding signals by transmitting the sum of successive samples.

Describe Delta modulation and its application.

• Delta modulation is a method for image processing.

• Delta modulation is used in applications such as speech encoding, audio transmission, and low-bandwidth communication systems.

• Delta modulation is primarily used for video compression.

• Delta modulation is mainly applied in high-bandwidth communication systems.

What is Adaptive Delta Modulation?

• A technique for enhancing audio quality by reducing noise.

• A form of digital modulation that does not adapt to signal changes.

• A method for compressing images using fixed step sizes.

• Adaptive Delta Modulation is a signal encoding technique that adjusts the quantization step size dynamically based on the signal's characteristics.

Explain the concept of Amplitude Shift Keying (ASK).

• Amplitude Shift Keying (ASK) is a technique that changes the frequency of a carrier wave.

• Amplitude Shift Keying (ASK) is a method that alters the waveform shape of the carrier signal.

• Amplitude Shift Keying (ASK) uses phase changes to encode data.

• Amplitude Shift Keying (ASK) is a modulation technique that varies the amplitude of a carrier wave to represent digital data.