With the proliferation of mobile devices, the demand for high bandwidth in wireless networks rapidly increases. Small-cells are employed for increased spatial reuse of spectral resources with reduced cell sizes and dense deployments. In the dense deployment of small-cell networks, however, intercell interference is one of the performance limiting-factor in harnessing their potentials of reusing spectrum resources. In addition, unique design features of OFDMA systems pose critical challenges for developing resource management solutions. This motivates us to designing and building practical resource management systems that improve the spectrum efficiency in OFDMA-based 4G cellular networks. Considering network architecture (marco-cell and femto-cell) used in OFDMA networks, we take different approaches for designing resource management schemes. More specifically, we design an efficient video multicast algorithm, MuVi, that optimizes resource utilization while accommodating heterogeneous multiple users in the same OFDMA resource frames. MuVi differentiates video frames and incorporates an efficient radio resource allocation algorithm to optimize the overall video quality across all users in the multicast group. In multi-cell deployment, the interference from neighboring cells is pervasive and severely impacts the performance of interfering cells. Thus, a resource management solution should handle the interference across the femto-cells properly and maximize the spatial reuse to improve capacity. Towards this goal, we propose two solutions, RADION and ProBeam. RADION is a distributed resource management framework that maximizes resource reuse while providing resource isolation when neighboring cells are within transmission range of each other in the time and frequency domains. ProBeam is a practical multi-cell beamforming system that leverages smart antenna to increase spatial reuse in the space domain without sacrificing spectrum resources for resource isolation. We believe this dissertation was successful in developing some of the important building blocks to improve the performance of multi-cell networks. These contributions can be carried out for other resource management schemes in next-generation cellular networks (i.e., 5G) that try to improve the spectral efficiency in multi-domains.