Sir Elvin

are entities that convey meaning.

are the electric or electromagnetic encoding of data.

refers to information that is continuous and take on continuous values

refers to information that has discrete states and take on discrete values.

can have infinite number of values in a range.

can have only a limited number of values.

has infinitely many levels of intensity over a period of time.

can have only a limited number of defined values.

completes a pattern within a measurable time frame, called period, and repeats that pattern over subsequent identical periods

completes a pattern within a measurable time frame, called

The completion of one full pattern

changes without exhibiting a pattern or cycle that repeats over time.

a sine wave, cannot be decomposed into simpler signals.

is composed of multiple sine waves.

is the most fundamental form of periodic analog signal.

is the absolute value of its highest intensity, proportional to the energy it carries

refers to the amount of time, in seconds, a signal needs to complete 1 cycle.

refers to the number of periods in 1 seconds.

describes the position of waveform relative to time 0.

is another characteristic of a signal traveling through a transmission medium.

shows changes in signal amplitude with respect to time.

is concerned with only the peak value and the frequency.

can be decomposed into a series of simple sine waves with discrete frequencies

can be decomposed into a combination of an infinite number of simple sine waves with continuous frequencies

is the range of frequencies contained in a composite signal.

is the transmission of signals that vary discretely with time between two values of some physical quantity, on value representing binary 0 and 1.

is assigned to one voltage level to binary 1 and another for binary 0

are often digitized to be able to use digital transmission facilities.

encoding is the representation of digital information by a digital signal.

o in this scheme, all the signal levels are either above or below the axis.

o the voltage are on the both sides of the axis.

o there are three voltage levels: positive, negative, and zero

o the level of signal depends on the type of bit that it represents; if a bit is 0 or 1, then their voltage will be positive and negative respectively.

o Inversion of the voltage level that represents 1 bit.

o Signal changes between bits, uses three voltage levels

o an encoding scheme in which signal changes at the middle of the bit interval but does not return to zero.

 Changes the signal at the middle of the bit interval but does not return to zero for synchronization.

 Changes in the middle of the bit but changes phase only when 1 is encountered.

o a neutral zero voltage represents binary 0. Binary 1’s are represented by alternating positive and negative voltages.

o Bit 1 is encoded as zero voltage and the bit 0 is encoded as alternating positive and negative voltages.