Novel OFDMA Uplink Initial Ranging Scheme for IEEE 802.16e

OFDMA uplink synchronization for IEEE 802.16e is mainly accomplished by initial ranging, thus initial ranging which includes multiuser ranging code detection, multiuser timing offset and power estimation at the base station is one of the most important processes for TDD OFDMA systems. To overcome the existing ranging method´s drawbacks namely high complexity, high probability of a false alarm and of misdetection, a novel OFDMA uplink initial ranging scheme is present in this paper. Simulations indicate that this scheme offers lower computational complexity and better performance over the existing methods for a wide range of SNR values and with a large number of ranging users.