Capacity estimation for 3rd generation CDMA cellular systems

This paper presents a computationally efficient analytical method for estimating the capacity of third generation cellular systems based on W-CDMA schemes. Closed form expressions are presented for average energy per bit to interference ratio (E_b/I_O) and outage probability for typical interference scenarios. The average E_b/I_O and outage probability figures are used to determine the capacity of the system. The capacity of different modes of operation (e.g. voice, low rate data, high rate data) is considered. The results are compared with those available in the literature published by ETSI (see The ETS·UMTS Terrestrial Radio Access (UTRA) ITU-R RTT Candidate Submission, SMG2, 1998). This paper concentrates on the analysis of the forward link, but this method can be easily extended to the reverse link. The capacity results calculated in this paper are lower than those presented in the ETSI publication. The difference can be attributed to the different assumptions used in this paper compared to the ETSI publication; power control and signal variability