Hong-Xing Li Hui Yu Han-Wen Luo Jia Guo Chisheng Li Dynamic Subchannel and Power Allocation in OFDMA-Based DF Cooperative Relay Networks. 4118-4122 2008 GLOBECOM http://dx.doi.org/10.1109/GLOCOM.2008.ECP.790 conf/globecom/2008 db/conf/globecom/globecom2008.html#LiYLGL08