Exploring Digital Communications Concepts

What is quantization in digital communications?

• Quantization refers to the method of encoding data into binary format without any loss.

• Quantization is the technique used to increase the bandwidth of a signal.

• Quantization is the process of converting continuous signals into discrete values for digital representation.

• Quantization is the process of amplifying weak signals for better transmission.

Explain the difference between uniform and non-uniform quantization techniques.

• Uniform quantization uses equal intervals for quantization, while non-uniform quantization uses variable intervals based on input value distribution.

• Uniform quantization is faster than non-uniform quantization.

• Non-uniform quantization uses fixed intervals for quantization.

• Uniform quantization is only used in audio processing.

What does the Sampling Theorem state about signal sampling?

• A signal can be perfectly reconstructed from its samples if sampled at a rate greater than twice its highest frequency.

• A signal cannot be reconstructed if sampled below its highest frequency.

• Sampling a signal at its highest frequency is sufficient for reconstruction.

• A signal can be reconstructed from its samples at any sampling rate.

Define Nyquist rate and its significance in sampling.

• The Nyquist rate is irrelevant in digital signal processing.

• The Nyquist rate is twice the highest frequency of a signal, crucial for preventing aliasing in sampling.

• The Nyquist rate is half the sampling frequency.

• The Nyquist rate is the highest frequency of a signal.

List the main components of a Pulse Code Modulation (PCM) system.

• Modulator

• Digital Signal Input

• Analog Signal Output

• The main components of a Pulse Code Modulation (PCM) system are: Analog Signal Input, Sampler, Quantizer, Encoder, Decoder, Digital-to-Analog Converter (DAC), and Output Signal.

What role does the quantizer play in a PCM system?

• The quantizer converts continuous signal amplitudes into discrete values in a PCM system.

• The quantizer filters out noise from the signal in a PCM system.

• The quantizer encodes the signal into binary format directly.

• The quantizer amplifies the signal in a PCM system.

Describe the process of encoding in PCM.

• The process of encoding in PCM involves sampling, quantization, and binary encoding of the analog signal.

• The encoding process in PCM is limited to converting digital signals to analog.

• PCM encoding requires only quantization without binary encoding.

• The process of encoding in PCM involves only sampling the analog signal.

What is the purpose of a decoder in a PCM system?

• To convert digital signals back to analog format.

• To amplify analog signals before transmission.

• To store digital signals for future use.

• To compress audio signals for better quality.

How is Signal-to-Noise Ratio (SNR) calculated for PCM signals?

• SNR = 10 * n + 2 dB

• SNR = 3.01 * n + 5 dB

• SNR = 6.02 * n + 1.76 dB

• SNR = 12 * n - 1 dB

What factors affect the SNR in a PCM system?

• Factors affecting SNR in a PCM system include quantization noise, bit depth, signal bandwidth, and external noise.

• Sampling rate

• Data compression

• Channel capacity