The expeditious evolution of wireless technologies and their convergence with diverse applications signify the coming next wave of our increasingly connected society. With the dramatically growing data traffic, massive connected devices and diverse services to be supported, the future success of our society relies heavily on our technical capabilities in the provisioning of massive capacity/connectivity and diverse services from people, society and industry, while using the very limited spectrum. The focus of this lecture is to analyze the main technical challenges of the converged next generation wireless and broadcast systems, identify the essential key spectrum access technologies for highly efficient wireless communications, and present our ongoing research and activities in the related areas. Specifically, this talk will cover the following aspects: i) Technical challenges of highly spectrum-efficient wireless communications; ii) OFDM based 2D and Massive MIMO based 3D transmission schemes; iii) Non-orthogonal Multiple Access (NOMA) and layered division multiplexing (LDM).