Capacity evaluation of the OFDMA-CDMA ranging subsystem in IEEE 802.16-2004

Ranging in wireless access is the process to acquire up-link synchronization, control the power between personal subscriber station and base station and perform the bandwidth request to BS. In this paper, we evaluate the capacity of a ranging subchannel in terms of the ranging code error probability versus the number of active users to attempt ranging, referring to specifications for the Korea´s 2.3 GHz band wireless broadband portable Internet service based on the IEEE 802.16-2004 standard. We consider the additive white Gaussian noise and the two-ray Rayleigh fading channels. The result shows that the capacity in the case of two-ray Rayleigh fading channel decreases about one-third, comparing with that in the case of additive white Gaussian noise channel.