Test: Digital Transmission - Electronics and Communication Engineering (ECE) MCQ

The SNR will be

The output signal-to-quantization-noise ratio of a 10-bit PCM was found to be 30 dB. The desired SNR is 42 dB. It can be increased by increasing the number of quantization level.In this way the fractional increase in the transmission bandwidth would be (assume log₂10 = 0.3)

The amplitude of a random signal is uniformly distributed between –5V and 5V. If the signal to quantization noise ratio required in uniformly quantizing the signal is 43.5dB, the step size of the quantization is approximately-

A signal having a bandwidth of 5 MHz is transmitted using the Pulse code modulation (PCM) scheme as follows. The signal is sampled at a rate of 50% above the Nyquist rate and quantized into 256 levels. The binary pulse rate of the PCM signal in Mbits per second is ___.

For a PCM signal the compression parameter μ = 100 and the minimum signal to quantization-noiseratio is 50 dB. The number of bits per sample would be.

A sinusoidal message signal is converted to a PCM signal using a uniform quantizer. The required signal-to-quantization noise ratio (SQNR) at the output of the quantizer is 40 dB. The minimum number of bits per sample needed to achieve the desired SQNR is __________ . 

A speech signal has a total duration of 20 sec. It is sampled at the rate of 8 kHz and then PCM encoded. The signal-to-quantization noise ratio is required to be 40dB. The minimum storage capacity needed to accommodate this signal is

The input to a linear delta modulator having f_a step-size Δ = 0.628 is a sine wave with frequency f_m and peak amplitude E_m. If the sampling frequency f_s = 40 kHz, the combination of the sinc-wave frequency and the peak amplitude, where slope overload will take place is

A sinusoidal signal with peak-to-peak amplitude of 1.536 V is quantized into 128 levels using a mid-rise uniform quantizer. The quantization-noise power is

signal is sampled at 8 kHz and is quantized using 8 bit uniform quantizer. Assuming SNR_q for a sinusoidal signal, the correct statement for PCM signal with a bit rate of R is

A 1.0 kHz signal is flat-top sampled at the rate of 180 samples sec and the samples are applied to an idealrectangular LPF with cat-off frequency of 1100 Hz, then the output of the filter contains

The Nyquist sampling interval, for the signal sinc(700t) + sinc(500t) is

A signal x(t) = 100 cos(24π x 10³)t is ideally sampled with a sampling period of 50 sec and then passed through an ideal lowpass filter with cutoff frequency of 15 KHz. Which of the following frequencies is/are present at the filter output

In a PCM system, if the code word length is increased form 6 to 8 bits, the signal to quantization noise ratio improves by the factor.

Four signals g₁(t) , g₃(t), g₂(t) and g₄(t) are to be multiplexed and transmitted. g₁(t)  and g₄(t) have a bandwidth of 4 kHz, and the remaining two signals have bandwidth of 8 kHz,. Each sample requires 8 bit for encoding. What is the minimum transmission bit rate of the system.

Three analog signals, having bandwidths 1200 Hz, 600 Hz and 600 Hz, are sampled at their respective Nyquist rates, encoded with 12 bit words, and time division multiplexed. The bit rate for the multiplexed signal is

The minimum sampling frequency (in samples/sec) required to reconstruct the following signal form its samples without distortion would be