1. S. Mandayam/ ECOMMS/ECE Dept./Rowan University Electrical Communications Systems ECE.09.331 Spring 2009 Shreekanth Mandayam ECE Department Rowan University http://engineering.rowan.edu/~shreek/spring09/ecomms/ Lecture 9b March 24, 2009

2. S. Mandayam/ ECOMMS/ECE Dept./Rowan University Plan Wideband FM Signals Time domain and spectrum Power Broadcast standards Digital Communications Introduction Digital Communications Transceiver (CODEC/MODEM)

3. S. Mandayam/ ECOMMS/ECE Dept./Rowan University ECOMMS: Topics

4. S. Mandayam/ ECOMMS/ECE Dept./Rowan University Analyzing FM Signals - Battle Plan!!! Instrument Demo Signals Systems Time Domain Complex Envelope Spectrum Single-tone FM Narrowband FM Wideband FM Bessel Functions Power Performance Transmitters Receivers Standards Modulation Index Efficiency Bandwidth Noise

5. S. Mandayam/ ECOMMS/ECE Dept./Rowan University FM Signal & Spectrum Single-tone FM Signal Single-tone FM Spectrum 0 f c -3f m f c -2f m f c -f m f c f c +f m f c +2f m f c +3f m |S(f)| / (A c /2) f J0()J0() J1()J1() J2()J2() J3()J3()

6. S. Mandayam/ ECOMMS/ECE Dept./Rowan University ECOMMS: Topics

7. S. Mandayam/ ECOMMS/ECE Dept./Rowan University Digital Communications Some Milestones Claude Shannon, 1948 X.25 (Telephony) IEEE 802.3 (Ethernet) ARPANET, 1969 IEEE 802.5 (FDDI) ISO-OSI 7-layer Network Reference Model CDMA GSM VOIP SIP protocols.com

8. S. Mandayam/ ECOMMS/ECE Dept./Rowan University Digital Communications: Rationale Information Theory: What is the fundamental limit on the compression and refinement of information generated by the source? What is the fundamental limit on the transmission rate of information over a noisy channel? How do we approach these limits?

9. S. Mandayam/ ECOMMS/ECE Dept./Rowan University Principle 1 0 1 0……… 1 0 Analog message Digital code Digital message Sinusoidal carrier modulate AM FM PM AM & PM 1 0

10. S. Mandayam/ ECOMMS/ECE Dept./Rowan University Digital Communication Paradigms Multiplexer Message 2 Message 3 Message 1 1 2 3 S 1 2 2 3 S Demultiplexer Message 2 Message 3 Message 1 Packetizing Message 2 Message 3 Message 1 1H H 2 3 H H 2 1H 3 H H 2 1H 3 H Message 2 Message 3 Message 1 Depacket -izing Circuit Switching Packet Switching Sync bits Header bits

11. S. Mandayam/ ECOMMS/ECE Dept./Rowan University Digital Communications Transceiver Anti- aliasing Filter SamplingQuantization Data Encryption Encoder Source Encoder Error Control Encoder Channel/ Line Encoder Modulator MUX Audio Amp Source Decoder Data Encryption Decoder Error Control Decoder Equalization / Decision Circuits Demod- ulator DEMUX Reconstruction/ DAC ADC CODEC MODEM Analog o/p Multiple access channel Analog i/p

12. S. Mandayam/ ECOMMS/ECE Dept./Rowan UniversitySummary