Performance analysis of random access channel in OFDMA systems

The random access channel (RACH) in OFDMA systems is an uplink contention-based transport channel that is mainly used for subscriber stations to make a resource request to base stations. In this paper we focus on analyzing the performance of RACH in OFDMA systems such that the successful transmission probability, correctly detectable probability and throughput of RACH are analyzed. We also choose an access mechanism with binary exponential backoff delay procedure similar to that in IEEE 802.11. Based on the mechanism, we derive the delay and the blocking probability of RACH in OFDMA systems.