Explain multiplexing systems, Electrical Engineering

Assignment Help:

Q. Explain Multiplexing Systems?

A multiplexing system is one in which two or more signals are transmitted jointly over the same transmission channel. There are two commonly used methods for signal multiplexing. In frequency-division multiplexing (FDM), various signals are translated to nonoverlapping frequency bands. The signals are demultiplexed for individual recovery by bandpass filtering at the destination. FDM may be used with either analog or discrete signal transmission. Time - division multiplexing (TDM), on the other hand, makes use of the fact that a sampled signal is off most of the time and the intervals between samples are available for the insertion of samples from other signals. TDM is usually employed in the transmission of discrete information. Let us now describe basic FDM and TDM systems.

Figure (a) shows a simple FDM system which is used in telephone communication systems. Each input is passed through a low-pass filter (LPF) so that all frequency components above 3 kHz are eliminated. It is then modulated onto individual subcarriers with 4-kHz spacing. While all subcarriers are synthesized from a master oscillator, the modulation is achieved with single sideband (SSB). The multiplexed signal, with a typical spectrum as shown in Figure (b), is formed by summing the SSB signals and a 60-kHz pilot carrier. The bandpass filters (BPFs) at the destination separate each SSB signal for product demodulation. Synchronization is achieved by obtaining the local oscillator waveforms from the pilot carrier. Telephone signals are often multiplexed in this fashion.

681_Multiplexing Systems.png

A basic TDM system is illustrated in Figure (a). Let us assume for simplicity that all three input signals have equal bandwidths W. A commutator or an electronic switch subsequently obtains a sample from each input every Ts seconds, thereby producing a multiplexed waveform with interleaved samples, as shown in Figure (b). Another synchronized commutator at the destination isolates and distributes the samples to a bank of low-pass filters (LPFs) for individual signal reconstruction.More sophisticated TDM systems are available inwhich the sampled values are converted to pulse modulation prior to multiplexing and carrier modulation is included after multiplexing. Integrated switching circuits have made the TDM implementation much simpler than FDM.


Related Discussions:- Explain multiplexing systems

What do mean by flow of electron, Flow of electrons - Electrons flow down a...

Flow of electrons - Electrons flow down a wire that is what current, is. Good conductors like copper and silver and aluminum have free electrons in their outer shells, and they jum

Explain bandwidth and applications of rc coupled amplifier, Q. Explain the ...

Q. Explain the bandwidth for the curve and the applications of an RC coupled amplifier. Frequency response curve of an RC coupled amplifier was shown above(prev page). The cut

Wye-delta transformation., what is the literature review about wye delta tr...

what is the literature review about wye delta transformation?? for 3 paragraphs atleast*

Types of multiplexing techniques, (a) List three types of Multiplexing tech...

(a) List three types of Multiplexing techniques. (b) Give two advantages of "Multiplexing". (c) Given the total duration for the signal is 8 ns. What is the bit rate for

Power system, a rectangular surge of 2us duration and magnitude of 100Kv tr...

a rectangular surge of 2us duration and magnitude of 100Kv travels along a line of surge impedance 500 ohms. The latter is connected to another line of equal impedance through an i

Describe the function of material handling system, a) Diagram FMS layout co...

a) Diagram FMS layout configurations with labeling. b) what are the basic components of FMS?Discuss in briefly. c) Describe the function of material handling system.

Sketch voltage and the energy stored in the capacitor, Q. Considering the c...

Q. Considering the circuit shown in Figure, sketch v(t) and the energy stored in the capacitor as a function of time.

Electrical drives and actuators, 'Electric drives' is a term used to descri...

'Electric drives' is a term used to describe DC and AC electric motors that provide continuous rotarmotion. They are often controlled by 'electronic drivesystems' designed to contr

Define causal system - discrete time systems, Define Causal System - Discre...

Define Causal System - Discrete Time Systems? A causal system is one which produces an output only when there is an input. All physical systems are causal. In general, a causal

Write Your Message!

Captcha
Free Assignment Quote

Assured A++ Grade

Get guaranteed satisfaction & time on delivery in every assignment order you paid with us! We ensure premium quality solution document along with free turntin report!

All rights reserved! Copyrights ©2019-2020 ExpertsMind IT Educational Pvt Ltd