Dynamic Random Access Channel Allocation Scheme Based on the Pseudo-Bayesian Algorithm in OFDMA System

摘要

Random Access Channel (RACH) is an uplink contention-based transport channel usually used for initial channel access, bandwidth request, etc. How to use RACH resources effectively is very important in wireless communication system. In this paper, a dynamical RACH allocation scheme is proposed for Orthogonal Frequency-Division Multiple Access (OFDMA) systems. Based on the Pseudo-Bayesian algorithm, this mechanism predicts the number of RACHs for the next frame according to the current load. A new dynamic RACH assignment algorithm and an adaptive access probability method are adopted by the proposed scheme to improve the utilization ratio of RACH resources and increase the successful access rate. Numerical simulation shows that the proposed strategy achieves both improvement in the utilization ratio of RACHs and reduction in the access delay compared with other RACH allocation schemes.