Liping Wang 0003 Yusheng Ji Fuqiang Liu 0001 Joint Optimization for Proportional Fairness in OFDMA Relay-Enhanced Cellular Networks. 1-6 2010 WCNC https://doi.org/10.1109/WCNC.2010.5506125 conf/wcnc/2010 db/conf/wcnc/wcnc2010.html#WangJL10