Chapter 13. Emerging Technology
Published Online: 9 OCT 2001
Copyright © 2001 John Wiley & Sons, Inc.
Radio Frequency Circuit Design
How to Cite
Davis, W. A. and Agarwal, K. K. (2001) Emerging Technology, in Radio Frequency Circuit Design, John Wiley & Sons, Inc., New York, USA. doi: 10.1002/0471200689.ch13
- Published Online: 9 OCT 2001
Book Series Editors:
- Kai Chang
Series Editor Information
Texas A&M University
Print ISBN: 9780471350521
Online ISBN: 9780471200680
- emerging technology;
- spectrum conversion;
- wireless Internet;
The rapid surge in wireless telephones has revolutionized the way people communicate with one another and has brought new impetus to design of radio frequency circuits. The ubiquitous cell phone appears to be only the beginning of possibilities for new forms of communication.
The military introduced the first wireless communication system, and it was limited to voice. The mobile voice service allowed effective deployment of forces in the battle. The equipment was bulky and voice quality was poor. Other agencies such as police, fire, ambulance, marine, and aviation have used mobile communications to facilitate their operations. After World War II the Federal Communications Commission (FCC) established a citizens band at 460 MHz and below allowing private individuals the opportunity to use mobile radio for personal purposes.
Second-generation systems in the 900 or 1800 MHz frequency band use complex modulation schemes such as Gaussian minimum shift keying (GMSK), frequency shift keying (FSK), or quadrature phase shift keying (QPSK). The second-generation systems are much more flexible in channel allocation, and they automatically select a base station with strongest signal to communicate. In addition to voice communication, a range of data services is provided by these systems. Presently second-generation systems are commercially deployed in many countries of the world.
Third-generation (3G) wireless systems are evolving with the aim of universal access worldwide and a single set of standards meeting a wide range of services and applications. These systems will truly fulfill the dream of “communication-anywhere-anytime.”
Researchers are beginning to talk about the fourth-generation (4G) systems with powerful attributes such as flexibility and adaptability. Global mobility functions will be supported by software defined radios (SDR), use of digital signal processing (DSP) methods, and low-cost intelligent multimode terminals. The three driving forces for the future global communication remain unchanged as bandwidth, spectrum conservation, and mobility. These areas are currently challenging engineers and researchers. This chapter briefly reviews these three items and presents the efforts to improve efficiency and management.