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 is double entry - verification, What is Double entry - Verification ...

What is Double entry - Verification In this approach, data is entered twice (using two different people); data is only accepted if both versions match up. Generally used to ve

De morgans laws, De Morgan's Laws : With continuing the relationship b...

De Morgan's Laws : With continuing the relationship between ^ and ? , we can also needs De Morgan's Law to rearrange sentences involving negation in conjunction with these con

Enginering mechanics, if 2 forces are equal at an angle alpha between them...

if 2 forces are equal at an angle alpha between them - its resultant R and its direction

Explain what is the difference among isr & function call, In ISR there is n...

In ISR there is no return value but in function call there is return value

Explain about shared features of olap, Shared executes most of the security...

Shared executes most of the security features into OLAP. If multiple accesses are needed admin can make essential changes. The default security level for all OLAP products is read

Distinguish between http and true streaming, Question: 1. Distinguish ...

Question: 1. Distinguish between HTTP and True streaming, stating the advantages and disadvantages of both type of media streaming. 2. Name two online services which provi

Determine the workarounds in multiple inheritances, What are several issues...

What are several issues for selecting best workarounds in multiple inheritances? Some restrictions methods are used. Use two approaches of delegations, which is an implementati

Explain minimum hardware to indicate direction of rotating, The circle can ...

The circle can rotate clockwise and back. By using minimum hardware build a circuit to indicate the direction of rotating? Two sensors are required to determine the direction o

Define about the objects, Define about the Objects The object notation...

Define about the Objects The object notation is the same in basic form as that for a class. There are three differences among the notations, these are given below: With

What is artificial intelligence fuzzy logic, Fuzzy logic is a form of vario...

Fuzzy logic is a form of various-valued logic; it deals with reasoning that is approximate rather than fixed & exact. In contrast with traditional logic theory, where binary sets h

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