Se-Jin Kim Seung-Yeon Kim Byung-Bog Lee Seungwan Ryu Hyong-Woo Lee Choong-Ho Cho Multi-Hop Relay Based Coverage Extension in the IEEE802.16j Based Mobile WiMAX Systems. 516-522 2008 NCM (1) http://doi.ieeecomputersociety.org/10.1109/NCM.2008.88 conf/ncm/2008-1 db/conf/ncm/ncm2008-1.html#KimKLRLC08