Pentti A. Leppänen – författare

In Time Division Multiple Access (TDMA), within a given time frame a particular user is allowed to transmit within a given time slot. This technique is used in most of the second-generation digital mobile communication systems. In Europe the system is known as GSM, in USA as DAMPS and in Japan as MPT. In Code Division Multiple Access (CDMA) every user is using a distinct code so that it can occupy the same frequency bandwidth at the same time with other users and still can be separated on the basis of low correlation between the codes. These systems like IS-95 in the USA are also developed and standardized within the second generation of the mobile communication systems. CDMA systems within a cellular network can provide higher capacity and for this reason they become more and more attractive. At this moment it seems that both TDMA and CDMA remain viable candidates for application in future systems. This book provides enough information for correct understanding of the arguments in favour of one or other multiple access technique.The final decision about which of the two techniques should be employed will depend not only on technical arguments but also on the amount of new investments needed and compatibility with previous systems and their infrastructures. The book comprises a collection of specially written contributions from some prominent specialists in wireless communications and presents the major, up to date, issues in this field. The material is grouped into four chapters: communication theory, covering coding and modulation; wireless communications; antenna and propagation; and advanced systems and technology. The book describes clearly the issues and presents the information in such a way that informed decisions about third generation wireless systems can be taken.

Code Division Multiple Access (CDMA) has become one of the main candidates for the next generation of mobile land and satellite communication systems. CDMA is based on spread spectrum techniques, which have been used in military applications for over half a century. Only recently however, has it been recognized that spread spectrum techniques, combined with some additional steps, can provide higher capacity and better flexibility for the mobile cellular radio communications. This work comprises a set of contributions from distinguished world scientists in the field. These papers review the basic theory and some of the most important problems related to spread spectrum and CDMA. The topics covered centre on the information theory aspects of CDMA, interference suppression and performance analysis. The material presented in this book summarizes the main problems in modern CDMA theory and practice and gives a solid starting point for studying this complex and still challenging field. It is intended for all researchers and designers working in mobile communication systems and provides an excellent text for a course on the subject.

Broadband Satellite Communications for Internet Access is a systems engineering methodology for satellite communication networks. It discusses the implementation of Internet applications that involve network design issues usually addressed in standard organizations. Various protocols for IP- and ATM-based networks are examined and a comparative performance evaluation of different alternatives is described. This methodology can be applied to similar evaluations over any other transport medium.

In Time Division Multiple Access (TDMA), within a given time frame a particular user is allowed to transmit within a given time slot. This technique is used in most of the second-generation digital mobile communication systems. In Europe the system is known as GSM, in USA as DAMPS and in Japan as MPT. In Code Division Multiple Access (CDMA) every user is using a distinct code so that it can occupy the same frequency bandwidth at the same time with other users and still can be separated on the basis of low correlation between the codes. These systems like IS-95 in the USA are also developed and standardized within the second generation of the mobile communication systems. CDMA systems within a cellular network can provide higher capacity and for this reason they become more and more attractive. At this moment it seems that both TDMA and CDMA remain viable candidates for application in future systems. Wireless Communications: TDMA versus CDMA provides enough information for correct understanding of the arguments in favour of one or other multiple access technique. The final decision about which of the two techniques should be employed will depend not only on technical arguments but also on the amount of new investments needed and compatibility with previous systems and their infrastructures. Wireless Communications: TDMA versus CDMA comprises a collection of specially written contributions from the most prominent specialists in wireless communications in the world today and presents the major, up to date, issues in this field. The material is grouped into four chapters: Communication theory, covering coding and modulation, Wireless communications, Antenna & Propagation and Advanced Systems & Technology. The book describes clearly the issues and presents the information in such a way that informed decisions about third generation wireless systems can be taken. It is essential reading for all researchers,engineers and managers working in the field of Wireless Communications.

Broadband Satellite Communications for Internet Access is a systems engineering methodology for satellite communication networks. It discusses the implementation of Internet applications that involve network design issues usually addressed in standard organizations. Various protocols for IP- and ATM-based networks are examined and a comparative performance evaluation of different alternatives is described. This methodology can be applied to similar evaluations over any other transport medium.