Cooperative RS Selection Schemes for IEEE 802.16j Networks

The specification of IEEE 802.16j defines the operation of multi-hop relay stations (RSs) with cooperative communication as an optional functionality to achieve space diversity gain. One of the key issues in cooperative communication using RSs is to determine which RSs should be used as cooperative nodes, i.e., cooperative relay selection. In this paper, we investigate the conditions that should be tested for RSs to operate as cooperative nodes based on the signal intensity data. We also propose two cooperative RS selection schemes for determining a group of cooperative RSs out of all candidate RSs: max-min-max cooperative RS selection and joint cooperative RS-path selection. The first scheme selects a group of RSs with the highest diversity gain, whereas the second scheme selects the cooperative RSs and paths simultaneously that could yield the highest system throughput. Simulation results are presented to evaluate and compare the performance of the two schemes.