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

Cpopy 16 bit data register pair , cpopy 16 bit data  Register pair E...

cpopy 16 bit data  Register pair Example  : Copy  16 bit  data 3 E 21H  in register pair BC Solution   :The  statement  is LXI B 3E 21H 16  bit data  3E 21H in reg

DC motor and DC generator, write down the similarities between motors and g...

write down the similarities between motors and generators

Determine the armature current, A 2300-V, three-phase, wye-connected, round...

A 2300-V, three-phase, wye-connected, round rotor synchronousmotor has a synchronous reactance of 3 per phase and an armature resistance of 0.25  per phase. The motor operates on

Show maximum power transfer, Q. Show Maximum Power Transfer? In order t...

Q. Show Maximum Power Transfer? In order to investigate the power transfer between a practical source and a load connected to it, let us consider Figure , in which a constant v

Properties of carbon and tungsten in lamp, explain the proprty and the appl...

explain the proprty and the application of carbon and tungsten in lamp?

Explain about folded network, Q. Explain about Folded network? Folded ...

Q. Explain about Folded network? Folded network: When all the outlets/inlets are connected to the subscriber lines, logical connection appears as displayed in figure. In this

Determine self inductances of coils, Determine self inductances of coils: ...

Determine self inductances of coils: The number of turns in two coupled coils A and B are 600 and 1700 respectively. While a current of 6 A flows in coil B, the total flux in

Determine the power delivered to the delta-connected load, Q. A balanced de...

Q. A balanced delta-connected load with a per-phase impedance of 30+j10  is connected in parallel with a balanced wye-connected load with a per phase impedance of 40-j10 . This l

Differentiate between n and p type semiconductors, Differentiate between n ...

Differentiate between n and p type semiconductors. n - Type semiconductor:- (i) If small amount of pentavalent impurity is added with, to a pure semiconductor giving a la

Wireless and communication, With a maximum excess delay of and a chip durat...

With a maximum excess delay of and a chip duration of , the multipath components fall in delay bins. This means that we experience leakage of energy between chips and the channel i

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