1. Introduction to Communication Systems
EENGR 3810 Chapter 1
Introduction to Communication Systems

2. No Homework for this chapter.
Chapter 1 Homework
No Homework for this chapter.

3. Communication System History
1837 Morse Transmitted What?
Dots and dashes
1876 Bell transmitted voice by what method?
Telephone
1894 Marconi transmitted messages by what method?
Wireless

4. Communication System Information Input Source: originates the message
Human voice (Analog signals)
Computer keyboard (Digital data signals)
Input transducer
converts message to electrical waveform
baseband signal

5. Communication System Transmitter
Modulates baseband signal with a Carrier signal
Transmits modulated signal
Transmission medium (Channel)
Wire
Radio link

6. Communication System Receiver
Demodulates baseband signal from modulated signal
Sends demodulated signal to output transducer
Output Transducer
Converts electrical signal to original form

7. Frequency Bands.

8. Propagation of Radio Frequencies

9. Analog Communication Systems

10. Amplitude Modulation (AM) Double Side-band Full Carrier (DSBFC) Signal Generation

11. AM DSBFC Transmitter (AM Transmitters will be covered later
AM DSBFC Transmitter (AM Transmitters will be covered later. This is an example.)

12. AM Superheterodyne Receiver (AM receivers will be covered later
AM Superheterodyne Receiver (AM receivers will be covered later. This is an example.)

13. FM with a sinusoidal baseband modulating signal

14. FM Transmitter Block Diagram (FM Transmitters will be covered later
FM Transmitter Block Diagram (FM Transmitters will be covered later. This is an example.)

15. FM Receiver Block Diagram (FM receivers will be covered later
FM Receiver Block Diagram (FM receivers will be covered later. This is an example.)

16. Digital Communication Systems

17. Digital Communication Systems
More rugged than analog communication systems
Avoids accumulation of noise and distortion
Binary system
+A/2 and –A/2, where A = signal amplitude
encoded as rectangular pulses
Transmitting scheme
Digitize the signal
Use pulse-code modulation to transmit digital signals
takes samples of signals
quantizes samples
Regenerative repeater stations along communication path
cleans out noise and distortion in received signal
retransmits clean signal
prevents accumulation of noise and distortion

18. PCM Transmission System Block Diagram (PCM will be covered later.)