Performance Improvement through Relay-Channel Partitioning and Reuse in OFDMA Multihop Cellular Networks

The integration of multihop capabilities in orthogonal frequency-division multiple access (OFDMA) cellular systems through the deployment of relay stations is believed to be one of the promising solutions for the next-generation wireless communications. In this paper, four fixed resource allocation schemes with different partition and reuse factors are discussed. They are 7-part partitioning (PF7), 4-part partitioning (PF4), partial reuse (PR), and full reuse (FR) schemes. The co-channel interferences of these four schemes in a multi-cell scenario are full-queue analyzed. Through the use of a proposed Monte-Carlo simulation algorithm, the empirical cumulative density function (CDF) curves of user´s signal-to-interference-plus-noise ratio (SINR) in the worst case are gained in different scenarios. Simulation results show that multihop transmissions are greatly advantageous for improving throughput and reducing outage when compared with single-hop transmissions, and can especially improve the performance of cell-edge users. Among these four schemes, PF7 and PF4 mitigate co-channel interferences by relay-channel partitioning, while the other two schemes PR and FR improve the throughput by relay-channel partitioning as well as reuse.