ABSTRACT
This chapter examines the various transmission technologies that can be used in a mobile radio system. It explores the three multiple-access schemes, namely, Frequency-division multiple access (FDMA), Time-division multiple access (TDMA), and Code-division multiple access (CDMA). These methods are analyzed independently, according to their own characteristics. The basics of the three access schemes and their advantages and disadvantages are also considered. In particular, for the FDMA case we discuss the effects of nonlinearities of the radio equipment circuitry. In TDMA systems the main issues are timing hierarchy, synchronization, and efficiency measures. CDMA systems are then analyzed in the light of information of the spread-spectrum technology. FDMA is intrinsically a narrowband architecture whereas CDMA is wideband. TDMA, on the other hand, can be implemented either as a narrowband or as a wideband system. Narrowband systems divide the total frequency spectrum into as many channels as the technology allows.
