An Adaptive Backoff Algorithm for OFDMA Systems

Orthogonal Frequency Division Multiplexing Access (OFDMA) will be adopted in next generation wireless communication systems, as they provide multiple access channels for initial channel access, resource request, etc. In this paper, for OFDMA systems, an effective and adaptive backoff algorithm is presented based on the Pseudo Bayesian Broadcast algorithm. It not only provides a dynamic backoff window according to the load, but also supports different Quality of Service (QoS) for various access traffics. Through simulation, the proposed algorithm has the advantage of high successful random access rate and low access delay compared with the traditional backoff algorithm.