power line carrier communication

. A good quality service can be continuously ensured by a global operational satellite system. Thus, communication satellites would give a valuable service in addition to the submarine cable and high frequency radio systems. Geostationary communication satellites have enabled no..

Optical Communication - Optical Fibres - An optical fiber is a dielectric wave guide that transports light signals from one place to another just as a twisted-wire pair or a coaxial cable transports electrical signals. It consists of a central core within which the propagating electromagn..

Propagation of EM Waves in Atmosphere - In an Earth environment, electromagnetic waves propagate in ways that depend not only on their own properties but also on those of the environment itself. Since the various methods of propagation depend largely on frequency therefore the complete electromagne..

Wave propagation in unbounded medi..

. So, the signal power progressively decreases with increasing distance. The receiver operates on the output signal from the channel in preparation for delivery to the transducer at the destination. Receiver operations include amplification to compensate for transmission loss. These also ..

Let us now discuss the basic principles of wireless radio communications. We shall mainly concentrate on the principle of amplitude modulation and demodulation. The simplest scheme of wireless communication would be to convert the speech or music to be transmitted to electric si..

>Full names of the units do not begin with capital letter E.g., newton and not Newton. The symbols of units, named after a scientists, have initial capital letter. E.g., J for joule, K for Kelvin. Symbols do not have plural form. E.g., 5 kg (not 5 kgs), 25 m (not 25 metres). A unit symbol is repres..

The transmission lines used in telephony are of two kinds: open- wire and cable. The open-wire lines are gradually being superseded by cable construction, either overhead or underground, for two principal reasons. In the first place, many more circuits can be accommodated-there ..

The ratio of change of amplitude of carrier wave to the amplitude of normal carrier wave is called the modulation factor ..

In amplitude modulation, the sidebands contain the signal. The power in the sidebands is the only useful power. The power carrier by the side bands is only 33.3% even when there is 100% modulation. If modulation is 50%, then power carried by the si..