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.