Florida Institute of technologies ECE 5221 Personal Communication Systems Prepared by: Dr. Ivica Kostanic Lecture 1: Introduction (Chapter 1) Spring 2011

Florida Institute of technologies Page 2  Wireless communication  Parts of cellular communication system  Cellular system idea  Fundamental concepts in cellular communication Outline Important note: Slides present summary of the results. Detailed derivations are given in notes.

Florida Institute of technologies Types of wireless systems  Three types of wireless communication oOptical communication  Uses EM waves in optical range  Laser, Infra red, visible light oRadio communication  Uses EM waves in RF portion of spectrum  Prevalent way of wireless communication  Focus of this course oAcoustic communication  Used acoustic waves  Suitable for underwater communication  Personal communication systems oUsed by “everybody” oUsually portable oExamples:  Cell-phones, WiFi, Bluetooth, pagers,  walkie-talkie, dispatch services, etc. Page 3

Florida Institute of technologies Generic layout of a radio system Transmitter Transmitting Antenna Input Information Receiving Antenna Receiver Output Information Transmission Medium (Air) Major components: o Source o Transmitter o TX and RX antenna o Receiver o Sink Page 4

Florida Institute of technologies Wireless comm. milestones (1) Page 5

Florida Institute of technologies Wireless comm. milestones (2) Page 6

Florida Institute of technologies Wireless systems examples Page 7

Florida Institute of technologies Before cellular + Very good coverage - Limited Capacity - in 1970s, NY mobile phone system had just 12 (!) channels available - No roaming capabilities - Bulky and expensive subscribers’ units R~30mi ‘Boomer’ Site High-powered transmitter at the highest point in town Page 8

Florida Institute of technologies Cellular System Requirements Large Subscriber capacity Efficient usage of spectrum Nationwide compatibility Widespread availability Adaptability to traffic density Service for vehicles and portables Support of special services Telephone quality of service Affordability (Bell Systems Technical Journal 1979) Page 9

Florida Institute of technologies Cellular concept  Coverage zone (market) divided into smaller areas (cells) served by lower power transmitters using lower towers  Each transmitter is assigned a portion of the available channels  After a sufficient distance the same channels are reused to increase spectrum efficiency Page 10 Cellular concept Spectrum allocation

Florida Institute of technologies Frequency reuse N=4 N=7 Single Cluster Multiple Clusters Page 11

Florida Institute of technologies Capacity Improvement - Example Page 12