1. Communication Theory (EC ) charjee l Kumar ECE Department Rajalakshmi Engineering College EC COMMUNICATION THEORY Lecture NotesANNA UNIVERSITY ECE 5TH SEMESTER DETAILS: SUBJECT NAME. EC COMMUNICATION THEORY Lecture Notes for ECE – Fourth (4th) Semester posted by han EC Lecture Notes Syllabus.
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When low reverse biased voltage is applied, more capacitance is generated and thus decrease the frequency. Information theory is needed to enable the communication system to carry information signals from sender to receiver over a communication channel it deals with mathematical modelling and analysis of a communication system its major task is to answer to the questions of signal compression and data transfer rate.
The pre-emphasized signal is used to frequency modulate the carrier at the transmitting end. It generally consists of a pre-selector and an amplifier stage. These two symbols are combined into a new symbol with the probability equal to the sum of their individual probabilities.
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To allow efficient transmission — increase transmission speed and distance, eg; By using high frequency carrier signal, the information voice can travel and propagate through the air at greater distances and shorter transmission time Also, high frequency signal is less prone to noise and interference. IF or intermediate frequency section is the stage where its primary functions are amplification and selectivity. This means that theoretically, it is possible to transmit information nearly without error at any rate lefture a limiting rate, C.
Analogue Modulation — to transfer an analogue low pass signal over an analogue bandpass channel. Transmitter — Transmit the input message into electrical signals such as voltage or current into electromagnetic waves such as radio waves, lexture that is suitable for transmission and compatible with the channel.
Source Flow of information Destination Figure 1: This communicatiin accomplished by communicatioon the discriminator output through a filter, called the de-emphasis filter, denoted Hde f.
The Conditional probability of an event A given the occurrence of event B is. The difference between the signals in the two paths produces the NBFM signal.
Example — Microphone which converts sound energy to electrical energy. This loss of information m t at the output of the envelope detector is called the threshold effect. The slope circuit converts the instantaneous frequency variations of the FM input signal to instantaneous amplitude variations.
Computer Organization and Architecture: Computer Organization and Architecture. The remainder of this module will focus on FM for mobile radio.
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Pm is the power of the message. Registration Theoty your password? Periodic signal has the property that it is unchanged by a time shift of T. We think you have liked this presentation.
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In the receiver, the inverse operation, de-emphasis, is performed. Digital Modulation — to transfer a digital bit stream the carrier is a periodic train and one of the pulse parameter amplitude, width or position changes according to the audio signal.
The NBFM wave is next multiplied in frequency by using a frequency multiplier so as to produce the desired wideband FM. For diode, the rms shot noise current is given by: Since the information is closely associated with the uncertainty of the occurrence of a particular symbol, When the symbol occurs the information associated with its occurrence is defined as: Power content less Same bandwidth Disadvantages – receiver is complex and expensive.
Source coding in which the coding alphabet cannot exactly represent the source information. Signal — electrical voltage or current which varies with time and is used to carry message or information from one point to another.
This is accomplished by passing message signal m tthrough the pre-emphasis filter, denoted Hpe f. A Fourier transform converts the signal from the time domain to the spectral domain.
In angle modulation, the amplitude of the carrier signal is kept constant; hence, angle modulation methods are constant envelope transmissions.
This process makes the signal suitable for transmission and compatible with the channel. Hence I X,Y is termed mutual information. Vernon Hart 6 months ago Views: Frequency modulation is a special case of angle modulation phase modulation is another special case in which the angle of the carrier is varied proportionately to the amplitude of the baseband signal.
Communicatjon are 5 criteria of a transmission system; Capacity, Performance, Distance, Security and Cost which includes the installation, operation and maintenance. In the above equation, I X,Y is the Mutual information. A signal that does not satisfy the above periodicity property is theody a non-periodic signal.
EC COMMUNICATION THEORY Lecture Notes for ECE – Fourth (4th) Semester
Audio section com,unication the stage that amplifies the recovered information. The procedure is repeated until we are left with 2 symbols only for which 0 and 1 are assigned. It has location A to those of location B, and place the answer in location C.
Create a list for the symbols, in decreasing order of probability. Zodiac Signs And Horoscope Daily.