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

Sql requirements in the sap development system, Which interface converts SQ...

Which interface converts SQL requirements in the SAP development system to those of the database? Database Interface converts SQL in the SAP.

Show the steps of execution of instructions, Q. Show the steps of execution...

Q. Show the steps of execution of instructions? Fetch First Instruction into CPU: Step 1: Find/calculate the address of first instruction in memory. In this machine illust

Measuring and improving cache performance, Measuring and Improving Cache Pe...

Measuring and Improving Cache Performance: 1. Reduce the possibility that 2 different memory block will contend for the similar cache location 2. Additional cache levels

Multiple valued logics, Multiple valued logics: Multiple valued logics...

Multiple valued logics: Multiple valued logics, where altered types of truth value such as "unknown" are may be allowed. These have some of the particular advantages of fuzzy

How many types of keys used to encrypt and decrypt data, How many types of ...

How many types of keys used to encrypt and decrypt data in Secure Sockets Layer? Two forms of keys are used as ciphers to decrypt and encrypt data. Private keys are referred to

What functions connect( )& accept( ) call in socket interfac, What function...

What functions connect( ) and accept ( ) call in Socket interfacing? connect() system call: Clients use procedures connect to initiate connection with an exact server. The

Explains the various levels of parallel processing, Levels of parallel proc...

Levels of parallel processing We could have parallel processing at four levels. i)  Instruction Level: Most processors have numerous execution units and can execute numero

How many select lines will a 32:1 multiplexer will have, How many select li...

How many select lines will a 32:1 multiplexer will have ? Ans. 5 select lines will be required for 32 inputs, as 2 5 = 32.

Define the system users, Q. Define the System users? System users are d...

Q. Define the System users? System users are defined as the people who employ information systems or who are affected by information system on a regular basis i.e. validating,

Define the internal users of system, Q. Define the Internal Users of system...

Q. Define the Internal Users of system? Internal Users are employees of business for that an information system is built. Illustration are clerical and service staff, technic

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