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 is difference between voltage and potential, Voltage is referred as Po...

Voltage is referred as Potential difference among two points. Potential means its force. I think so.voltage defination is 100% correct.

Input output operations , Input Output Operations Many times microproc...

Input Output Operations Many times microprocessor has to  accept data  from input port and send data to  output  port to  interact with the  real world. Input  port is  tri st

Explain classification of amplifiers on biasing conditions, Q. Explain the ...

Q. Explain the classification of amplifiers on the biasing conditions? Based on the amount of transistor bias and amplitude of the input signal, amplifiers can be classified as

Find the thevenin equivalent of the circuit, (a) Find the Thevenin equivale...

(a) Find the Thevenin equivalent of the circuit shown in Figure (a) at the terminals A-B. (b) Determine the impedance that must be connected to the terminals A-B so that it is m

FLOW CHART TO RUN MOTOR, IFYOU AVE TWO DC MOTOR,RELAY,TWO BATTERYAND MICROC...

IFYOU AVE TWO DC MOTOR,RELAY,TWO BATTERYAND MICROCONTROLLER FLOW CHART TO RUN MOTOR AND CONTROL TWO BATTERIES

What is meant by doping, What is meant by doping? How does it affect a semi...

What is meant by doping? How does it affect a semiconductor? Doping: The process through which an impurity is added to semiconductor is termed as doping. A semiconductor to th

Microcontroler based elevator system, -micro controller AT89C51 -dc motor -...

-micro controller AT89C51 -dc motor -magnetic sensors -load sensors -how to connect all the components? and give me a circuit diagrams -how to interface all the component with m

Weighted resistor and the r-2 r ladder d/a converters, Q. What is the basic...

Q. What is the basic difference between the weighted resistor and the R-2 R ladder D/A converters?

Working with various instructions using debug, The purpose of this experime...

The purpose of this experiment is to introduce you to a powerful 80x86 assembly/machine language utility called DEBUG. Preparing Your DEBUG Environment If you have an older

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