Abstract:

By the analysis of the development of key technologies and QoS (Quality of Service) requirements of the real-time traffic in mobile communication systems, a simple and efficient random access scheme which is suitable for TD-OFDMA systems is proposed. In this scheme, the network terminals adopt different random access processing methods by utilizing the special FRRACH (First Refusal Random Access Channel) according to the delay sensitivity of the traffic. The new scheme efficiently avoids the packet collision and guarantees QoS requirements for the real-time traffic. Theoretical analysis and simulation results show the new scheme is superior to current random access schemes with respect to resource efficiency in random access process, successful access probability and average delay.

Key words: Orthogonal Frequency Division Multiple Access , First Refusal Random Access CHannel, Random Access CHannel, Random Access