In this paper, the effect of the time difference of arrival (TDoA) on synchronous types or asynchronous types of OFDMA-based multi-hop relay (MR) systems is investigated. Effective SINRs for downlinks and uplinks are defined to measure the degree of interference due to TDoA in asymmetric MR systems. A path selection technique based on the effective SINR is then proposed to determine the optimal paths for the uplink and downlink independently. It is shown that asymmetric routing can improve the performance of OFDMA-based MR systems when the proposed technique is applied to the path selection of the uplink taking into account the effect of the TDoA.
['Kyung Soo Woo', 'Chang Hwan Park', 'Hyun Il Yoo', 'Jaekwon Kim', 'Seung Hee Han', 'Yong Soo Cho']
A path selection technique for two-hop relay systems with TDoA