List of top Electronics and Communication Engineering Questions on communication systems

To save transmitted power, the carrier of an AM signal obtained by sinusoidal modulation to a depth of modulation equal to 1, has been recovered. The percentage saving in power is________.
If carrier and modulating frequency are 100 kHz and 5 kHz respectively, the bandwidth of AM transmission will be _______.
The envelope detector is a/an _______.
An FM signal having a modulation Index of $M$ is passed through a frequency tripler. The FM signal at the output of tripler will have a modulation index of _______.
Flat-top sampling leads to
As the bandwidth approaches infinity, the channel capacity becomes (Referring to Shannon-Hartley theorem: \(C = B \log_2(1 + S/N)\))
The input to a matched filter is given by \( S(t) = 10 \sin(2\pi \times 10^6 t), 0<t<1 \) second. The peak amplitude of the filter output is (Note: The duration \(0<t<1\) second is very long for a 1 MHz signal. This implies many cycles. Energy of the signal will be large.)
Which of the following modulation scheme gives the maximum probability of error?
The number of bits per sample in a PCM system with sinusoidal input is increased from n to n+1. The improvement in signal to quantization noise ratio will be
In delta modulation (DM) system, the granular noise occurs when the modulating signal
Companding is used in PCM to
The main advantage of TDM over FDM is
The maximum permissible distance between two samples of a 2 kHz signal is
A narrowband FM does not have the following feature
The figure of merit ratio of FM to PM for single tone modulating signal is
The image channel rejection in superheterodyne receiver comes from
The plot of modulation index versus carrier amplitude yields a
The positive RF peaks of an AM voltage rise to maximum value of 12V and drop to a minimum value of 4V. Assuming single tone modulation, the modulation index is
Thermal noise is independent of
Which factor determines the range resolution of a radar?
A DSB-SC signal can be demodulated using
In QAM, both ______ of a carrier frequency are varied.
For a modulation index much less than 1, the FM signal is considered as
A TDMA system uses 25 MHz for the forward link, which is broken into radio channels of 200 kHz. If 8 speech channels are supported on a single radio channel, how many simultaneous users can be accommodated?
Coherent demodulation of FSK signal can be detected using