1. Lecture 7: Noise to ASK, FSK and PSK 1nd semester 1438-1439
By: Adal ALashban

2. Outline - Several types of noise.
- Additive white Gaussian noise (AWGN).
- Signal to noise ratio (SNR).

3. Noise - Several types of noise: 1- Thermal noise. 2- Induced noise.
3- Crosstalk noise.
4- Impulse noise.

4. Noise 1- Thermal Noise: 2- Induced Noise: 3- Crosstalk Noise:
Is the random motion of electrons in a wire which creates an extra signal not originally sent by the transmitter.
2- Induced Noise:
Comes from sources such as motors and appliances.
3- Crosstalk Noise:
Is the effect of one wire on the other.

5. Noises 4- Impulse Noise:
Is a spike (a signal with high energy in a very short time) that comes from power lines, lighting and so on.

6. Additive White Gaussian Noise (AWGN)
Is a basic noise model used in Information theory to mimic the effect of many random processes that occur in nature.

7. Signal to Noise Ratio (SNR)
- SNR: Ratio between signal power to the noise power.
- A high SNR: Means the signal is less corrupted by noise.
- A low SNR: Means the signal is more corrupted by noise.

8. Two Cases of SNR: a High SNR and a Low SNR

9. Any Questions ?