Capacity comparison for FH/FDMA, CDMA and FDMA/CDMA schemes

• Published in: VTC '98. 48th IEEE Vehicular Technology Conference. Pathway to Global Wireless Revolution (Cat. No.98CH36151) Vol. 2; pp. 1517 - 1522 vol.2
• Main Authors: Rojas, A., Luis Gorricho, J., Paradells, J.
• Format: Conference Proceeding
• Language: English
• Published: IEEE 1998
• Subjects: Base stations; Fading; Frequency division multiaccess; Information theory; Interference; Mobile communication; Multiaccess communication; Power control; Power system modeling; Time division multiple access
• ISBN: 0780343204; 9780780343207
• ISSN: 1090-3038; 2577-2465
• DOI: 10.1109/VETEC.1998.686540

The paper presents some calculations on the design of future cellular systems. It describes the calculation of the signal to interference ratio. This result is used later to show the effects on the capacity of the CDMA and FDMA systems. Looking into the future it is not clear what type of multiplexing method, that is TDMA, FDMA or CDMA, could be the best solution for mobile communications. The propagation model and hard handovers are dealt with as an introduction to the problem. In this case, from a CDMA point of view the power control is done by one base station as in an FDMA system. Also, the results related to the factor f on FDMA/CDMA hybrid system (a clustered CDMA with hard handovers) are presented. Slow fading is examined and the comparison is made with a more sophisticated power control that can be implemented when macrodiversity is used. Results are compared from the information theory perspective giving bounds on the capacity of these systems. The capacity is discussed from a more realistic point of view assuming the minimal signal to noise-interference (S/I) that a system can support and obtaining limits on the maximum number of calls per cell.