Title :
Capacity comparison for FH/FDMA, CDMA and FDMA/CDMA schemes
Author :
Rojas, Alfonso ; Gorricho, Juan Luìs ; Paradells, Josep
Author_Institution :
Politech. Univ. of Catalonia, Barcelona, Spain
Abstract :
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
Keywords :
cellular radio; channel capacity; code division multiple access; fading; frequency division multiple access; frequency hop communication; power control; radiofrequency interference; radiowave propagation; telecommunication control; CDMA; FDMA/CDMA; FH/FDMA; base station; calls per cell; capacity bounds; capacity comparison; cellular systems; clustered CDMA; hard handovers; information theory; macrodiversity; mobile communications; multiplexing method; power control; propagation model; signal to interference ratio; signal to noise-interference; slow fading; Base stations; Fading; Frequency division multiaccess; Information theory; Interference; Mobile communication; Multiaccess communication; Power control; Power system modeling; Time division multiple access;
Conference_Titel :
Vehicular Technology Conference, 1998. VTC 98. 48th IEEE
Conference_Location :
Ottawa, Ont.
Print_ISBN :
0-7803-4320-4
DOI :
10.1109/VETEC.1998.686540