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

What are tri-state devices , why they are essential in a bus oriented syste...

why they are essential in a bus oriented system? Ans) In a multiplexed bus system, many devices are linked to a common bus. If 2 or more devices attempt to use the bus at the si

Instruction set design considerations, Some of the fundamental consideratio...

Some of the fundamental considerations for instruction set design includes selection of:  A set of data-types (For example: integers, long integers, doubles, character strin

Search method for searching a sorted file, The search method for searchi...

The search method for searching a sorted file that needs increased amount of space is The search technique for searching a sorted file that needs increased amount of space

Describe memory and memory unit, Q. Describe Memory and Memory unit? In...

Q. Describe Memory and Memory unit? Input devices can fetch instructions or data only sequentially though a program may or may not be executed sequentially because looping, jum

Name the four steps in pipelining, Name the four steps in pipelining. F...

Name the four steps in pipelining. Fetch  : Read the instruction from the memory. Decode : Decode the instruction and get the source operand. Execute : Perform the operat

Differences between flexgrid control and dbgrid control, Normal 0 ...

Normal 0 false false false EN-IN X-NONE X-NONE MicrosoftInternetExplorer4

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

What is a heap, What is a heap? The heap is an area of memory that is ...

What is a heap? The heap is an area of memory that is dynamically allocated. As a stack, this may grow and shrink throughout runtime. Not like a stack, a heap is not LIFO show

What is an compiled languages, What is an compiled languages In compile...

What is an compiled languages In compiled languages the instructions into machine code and kept them  in a separate file for later implementation. Many modern compilers can com

Define the example client-server implementations, Define the Example Client...

Define the Example Client-server Implementations Once you accept the client-server mindset, the process of architecting and developing applications becomes rather easy. Clearly

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