Chen Liu 0006 Qi Yang 0006 Haowen Wang Xuemin Hong Jianghong Shi Biyu Tang System capacity analysis of hybrid cellular networks with cognitive radio relay. 1-5 2015 WCSP https://doi.org/10.1109/WCSP.2015.7341296 conf/wcsp/2015 db/conf/wcsp/wcsp2015.html#LiuYWHST15