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

Source and destination are named the same, What happens if the both source ...

What happens if the both source and destination are named the same? Ans) The import operation present in MS Access does not overwrite or change any of the existing tables or obj

Example on public divisor, Q. Example on PUBLIC DIVISOR? Linker appends...

Q. Example on PUBLIC DIVISOR? Linker appends all segments having the same name and PUBLIC directive with segment name into one segment. Their contents are pulled together in co

Explain about encoding technique used in bitmaps indexes, Bitmaps commonly ...

Bitmaps commonly use one bitmap for each single distinct value. Number of bitmaps used can be decreased by opting for a dissimilar type of encoding. Space can be optimized but when

What are the types of instructions, Q. What are the types of Instructions? ...

Q. What are the types of Instructions? Computer instructions are translation of high level language code to machine level language programs. So from this point of view machine

Slot machine, A special Slot Machine is introduced in a new casino; this ma...

A special Slot Machine is introduced in a new casino; this machine has a digital interface of a 3X3 grid. An interface button named as SPIN for making the machine spin. There are f

Characters in vi editor, What is the command used to replace many character...

What is the command used to replace many characters in Vi Editor? Ans) For replace most of the character in vi editor press esc key and then press R for change many character.

Explain how the different access methods work, Question: (a) Primary an...

Question: (a) Primary and secondary memory differs in their way they access data: (i) Mention the four generic access methods usually present in a computer system. (ii) E

Every sheet in a workbook in excel, Is there a way to apply the same format...

Is there a way to apply the same formatting to every  sheet in a workbook in Excel? Ans)  Yes. To do this, you will require to right click on one of the worksheet tabs and th

Databse, defination of query ?

defination of query ?

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