Digital Communication - Study Mode

[#81] A 1.0 kHz signal is flat top sampled at the rate of 1800 samples/sec and the samples are applied to an ideal rectangular LPF with cut-off frequency of 1100 Hz, then the output of the filter contains
Correct Answer

(C) 800 Hz and 1000 Hz components
(F) 800 Hz and 900 Hz components

[#82] The outputs of 18 numbers of 20 Hz low pass filters are sampled, multiplexed and A/D converted. If the sampling is at the Nyquist rate of 40 samples/s, corresponding to signal of 20 Hz band-width and if we use 3 bits/sample to represent each voltage sample, the bit rate is
Correct Answer

(C) 2.16 × 10 3 bits/s

[#83] The modulation techniques used to convert analog signal into digital signal are
Correct Answer

(A) Pulse code modulation

[#84] One of the following bandpass digital modulation schemes is not suitable for transmission over nonlinear bandpass channels:
Correct Answer

(B) ASK

[#85] A signal of maximum frequency of 2 MHz modulated by 4 GHz carrier is DSB/SC. If the resultant signal is sampled ideally as low pass signal, the minimum sampling frequency should be
Correct Answer

(B) 8 MHz