Multiplexing in Communication Systems

A technique that allows more than one signal to transmit through a single channel.

It makes the communication system economical by allowing multiple signals to be transmitted through a single channel.

Modulation.

<p>Because the overall result is noise, and the human ear is not capable of separating intermingled speeches.</p> Signup and view all the answers

<p>20 Hz to 20 kHz.</p> Signup and view all the answers

<p>It illustrates the difficulty in understanding the intermingled speeches, similar to the transmission of audio signals.</p> Signup and view all the answers

<p>The main difference is that AM varies the amplitude of the carrier signal, while FM varies the frequency of the carrier signal.</p> Signup and view all the answers

<p>The envelope in AM refers to the pattern of the peak values of the carrier signal, which exactly replicate the modulating signal at different points in time.</p> Signup and view all the answers

<p>FM involves changing the frequency of the carrier voltage in accordance with the instantaneous value of the modulating voltage.</p> Signup and view all the answers

<p>Pulse modulation is a type of modulation where the carrier signal is transmitted as a series of pulses. Examples of pulse modulation include PAM, PWM, PPM, and PCM.</p> Signup and view all the answers

<p>PM involves varying the phase of the carrier signal, while FM involves varying the frequency of the carrier signal.</p> Signup and view all the answers

<p>Continuous-wave modulation involves the continuous variation of the carrier signal in accordance with the instantaneous values of the modulating signal. It is significant in maintaining the integrity of the transmitted signal.</p> Signup and view all the answers

<p>The modulation index in frequency modulation is the ratio of frequency deviation to the modulating frequency.</p> Signup and view all the answers

<p>In phase modulation, the instantaneous phase of the carrier signal is varied in accordance with the instantaneous amplitude of the modulating signal.</p> Signup and view all the answers

<p>Pulse modulation can be used to transmit analog information, such as continuous speech or data, by sampling continuous waveforms at regular intervals.</p> Signup and view all the answers

<p>The primary advantage of pulse-width modulation (PWM) over pulse-position modulation (PPM) is that PWM still works if synchronization between transmitter and receiver fails, whereas PPM does not.</p> Signup and view all the answers

<p>The term used to describe the total variation in frequency of an F.M. wave from the lowest to the highest is carrier swing (CS).</p> Signup and view all the answers

<p>The key difference between analog and digital pulse modulation is that analog pulse modulation systems use continuous waveforms sampled at regular intervals, while digital pulse modulation systems transmit discrete signals.</p> Signup and view all the answers

<p>The disadvantage of pulse-duration modulation (PDM) when compared with pulse-position modulation (PPM) is that its pulses are of varying width and therefore of varying power content.</p> Signup and view all the answers

<p>The simplest form of pulse modulation is pulse-amplitude modulation (PAM).</p> Signup and view all the answers

<p>The amount by which the frequency of the carrier wave changes above or below the resting frequency is termed as frequency deviation (Δf).</p> Signup and view all the answers

<p>The carrier swing (CS) in frequency modulation is calculated using the ratio CS=2 Δf, where Δf is the frequency deviation.</p> Signup and view all the answers