Explain frequency division multiplexing, Computer Engineering

Assignment Help:

Explain FDM and show how CCITT standards help in building the base band?

Frequency Division Multiplexing: This is the process of combining some information channels through shifting their signals to various frequency groups in the spectrum therefore they can be transmitted simultaneously over common transmission service.

The bandwidth of a telephone speech signal is quite less than 4 kHz. Where, the available bandwidth on unloaded cables pair is fine above 100 kHz. Therefore this is possible, by using modulation techniques, for divide up the cable bandwidth then a number of telephone speech paths can be carried at the same time along a single cable pair. The normal arrangement contains 24 telephone channels per cable pair, the modulation in 24 channels being carried out within the two stages. In the primary stage, 12 channels are multiplexed together to form that is commonly termed as a basic group. This basic group arrangement is demonstrated in figure. Each of the 12 telephone signals are single side-band amplitude modulated on to carriers spaced at 4 kHz intervals 64 kHz to 108 kHz. The lower side-band (LSB) is utilized in every case. The 12 base-band signals are thus translated in the frequency band from 60 kHz 108 kHz as demonstrated. The block diagram for the channel translating equipment is specified in figure. To form a 24-channel system, to basic groups are occupied together. One basic group (B) is transmitted directly as this stands. Another basic group (A) is amplitude modulated on to a carrier are 120 kHz and the lower side-band is occupied such as to take the frequency range from 12 kHz to 60 kHz as demonstrated in figure. by using two stages of modulation for basic group A, this is possible to decrease the physical size of the component needed for the LSB filters of the figure, because the lowest cut- off frequency needed is at 64 kHz quite than 12 kHz when the whole block of 24 channels were assembled together in one stage of modulation.

855_Basic Group Arrangement.png

FIG - Basic Group Arrangement

1635_Channel Translating Equipment.png

FIG - Channel Translating Equipment


Related Discussions:- Explain frequency division multiplexing

State the drawbacks of laptop as compared to PC, State the drawbacks of lap...

State the drawbacks of laptop compared to PC The main disadvantages of laptops compared to desk top PCs are: -  They tend to be more expensive to purchase -  It's easie

Define range which a normalised mantissa can signify, Now let's define rang...

Now let's define range which a normalised mantissa can signify. Let's presume that our present representations has normalised mantissa so left most bit can't be zero so it has to b

Concurrently read exclusively write, Q. Concurrently read exclusively write...

Q. Concurrently read exclusively write? It's one of the models based on PRAM. In this model, processors access the memory location simultaneously for reading whereas exclusivel

Dpsd -asynchronous circuits, an asyncronous sequential circuit is described...

an asyncronous sequential circuit is described by the the exitatio function and the output function y=x1x2''+(x1=x2'')y output function z=y a)draw the logic diagram of the circuit.

Functions for various communication modes, Q. Functions for various communi...

Q. Functions for various communication modes? MPI offers both non-blocking and blocking send/transmitting and receive operations for all modes. Functions for various commun

State the approaches to organizing stored program control, Determine the ap...

Determine the approaches to organizing stored program control There are 2 approaches to organizing stored program control: 1.  Centralized: In this control, all control equi

What is centralized spc, What is centralized SPC, what are its modes of ope...

What is centralized SPC, what are its modes of operation? In this centralized control, all the control equipment is replaced through a single processor that must be quite power

Enumerate about the specialised hardware, Enumerate about the Specialised h...

Enumerate about the Specialised hardware Specialised hardware such as protected memory or cryptographic memory module for storing and protecting the keys proves to be a good s

Effect of is on humans - information system, Effect of IS on Humans - Infor...

Effect of IS on Humans - Information System We have concentrated in this chapter on the ways that IS has evolved making it more useful and more user-friendly. This proliferat

Illustrate single in-line memory modules, Q. Illustrate Single In-line Memo...

Q. Illustrate Single In-line Memory Modules? From early days of semiconductor memory till the early 1990s memory was manufactured, brought and installed as a single chip. Chip

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