Analysis of Transparent Mode IEEE 802.16j System Performance with Varying Numbers of Relays and Associated Transmit Power

In this paper, the system capacity of IEEE 802.16j systems operating in transparent mode is investigated under varying numbers of relays and associated transmit power. The study is based on an extended variant of an analytical model defined in previous work and used to determine the throughput gain that can be achieved under a max-min fairness constraint. The study finds that significant overall throughput gains can be achieved over 802.16e systems: 125% and 55% gain with and without spatial reuse, respectively. However, the overall throughput gain drops as the transmit power at the relays (RSs) decreases despite the fact that a greater number of concurrent transmissions can be achieved due to less interference among the RSs´ transmissions. Decreasing the transmit power at the RSs eventually leads to a significant reduction of the achievable throughput gain even though a large number of RSs are deployed in scenarios with or without spatial reuse.