Adaptive code partitioning for fast h0andover in IEEE 802.16e systems

Ranging is one of the major sources of handover latency in IEEE802.16e systems. It is due to the retransmission of ranging signals because of collision in contention based ranging. To reduce the handover latency, we need to make the possibility of retransmission low. We propose an adaptive code partitioning scheme that we utilize for fast handover in this paper. This scheme allocates a portion of codes only for the retransmission of ranging signals. The portion of this region is also adjusted adaptively in this scheme. Performance of the proposed scheme is evaluated by simulation. We analyzed the system capacity or the number of MSs that can be supported with reliable handover. Simulation results show that the proposed scheme leads to about 28.6% capacity improvement.