it is the introduction about signals

1. IMPORTANT POINTS

2. Important Points
 All real life signals are analog.
 Analog signal seems to be better then digital but they
are not.
 Digital signals are used in communication Process.
 Digital signal are used minimize the effect of noise.
 Noise is unwanted signal.
 It is very important to understand this concept so that
we may get further knowledge.
 Lets take it as example.

3. Example
 We need a transmitter to transmit signal and a receiver
to receive that signal.
 For their connectivity we need some source or medium
like channel(cable).

4. Example
 Lets have values we have to transmit the signal of 2.5 v
and we have the range of transmitter up to 5v.
 When we transmit this signal value will be changed
due to effects.

5. Example
 We suppose that receiver receives a signal of 2.7 with
effect of 0.2.
 This 0.2 is the noise which will removed in digital
system.
 Have a look in case of digital.

6. Example
 As we know that we have the certain levels in digital
system.
 We will have value according to levels only.
 In this case we have limit 0-5 so we have 4 levels and if
the noise comes then the effect is neglected.
 So we get the accurate signal.
 In real life we can have example of movies. In HD print
we have two type 720 and 1080.
 Both have different space because of their levels more
levels need more space.

7. Important
 This is applicable only for small signals.
 For long signal we have many advance methods
 Special devices are used to convert the analog signal
into digital signal.
 Digital signals are only in circuits.
 We cant see or feel them they exist as soft data exist.
 Hope you learn it.
 See you next.
 Allah Hafiz