GATE EC 2022: Communication System Quiz 8

Which of the following statement is correct with respect to receivers in analog communication?

A signal x(t) = 100 cos (24π × 10³)t is ideally sampled with a sampling period of 50 μ sec and then passed through an ideal lowpass filter with cut off frequency of 15 KHz.

Which of the following frequencies is/are present at the filter output?

A band pass signal with and is uniformly distributed in the range from. This signal is sent on a channel whose maximum capacity is using PCM. The best SNR (in dB) that could be achieved is ______

The capacity of a Gaussian channel with a bandwidth of 1MHz and S/N ratio of 30dB is

The power spectral density of the stationary noise process N(t) having auto correlation R_uu(t) = Ke^-3|t| is

A message signal m(t) and a carrier signal C(t) are applied to an amplitude modulation shown

The message signal m(t) is band-limited to f_m, where f_c≫ 3f_m. The BPF has a unity passband gain over a Bandwidth of 2f_m centred at f_c. The input-output characteristic of non-linear device is y(t) = 8x(t) + 2x²(t). If average power of message signal m(t) is 16W, find the % transmission efficiency of resultant AM signal.