NOISE CONSIDERATION

Which of the following is not a type of noise in PCM?

• A. Thermal noise
• B. Shot noise
• C. Impulse noise
• D. Phase noise

What is the primary cause of quantization noise?

• A. Sampling error
• B. Signal distortion
• C. Limited number of quantization levels
• D. Amplifier noise

Which of the following is not a way to reduce quantization noise?

• A. Increasing the number of quantization levels
• B. Using a companding technique
• C. Using a low-pass filter
• D. Increasing the sampling rate

What is the effect of increasing the number of quantization levels?

• A. It reduces quantization noise
• B. It increases quantization noise
• C. It has no effect on quantization noise
• D. It causes distortion in the signal

What is the purpose of using a companding technique?

• A. To reduce quantization noise
• B. To increase the dynamic range of the signal
• C. To reduce the bandwidth required for transmission
• D. To reduce the effect of interference

What is the effect of using a low-pass filter on a PCM signal?

• A. It reduces quantization noise
• B. It increases quantization noise
• C. It eliminates quantization noise completely
• D. It has no effect on quantization noise

A PCM signal with a sampling rate of 8 kHz and 8-bit quantization is being transmitted over a channel with a bandwidth of 4 kHz. What is the minimum signal-to-noise ratio (SNR) required to achieve a bit error rate (BER) of 10^-3?

• A. 26 dB
• B. 33 dB
• C. 40 dB
• D. 47 dB

A PCM signal with a sampling rate of 16 kHz and 12-bit quantization is being transmitted over a channel with a bandwidth of 8 kHz. What is the maximum SNR improvement that can be achieved by using a companding technique?

• A. 6 dB
• B. 12 dB
• C. 18 dB
• D. 24 dB

A PCM signal with a sampling rate of 8 kHz and 8-bit quantization is being transmitted over a channel with a bandwidth of 3 kHz. Which of the following techniques can be used to reduce the effect of aliasing?

• A. Nyquist criterion
• B. Low-pass filter
• C. Bandpass filter
• D. All of the above

A PCM signal with a sampling rate of 16 kHz and 12-bit quantization is being transmitted over a channel with a bandwidth of 10 kHz. If the signal-to-noise ratio (SNR) is 40 dB, what is the theoretical maximum bit rate that can be achieved?

• A. 200 kbps
• B. 240 kbps
• C. 320 kbps
• D. 480 kbps