Layered-Division Multiplexing Multicell Cooperative Multicast-Broadcast Beamforming

In this paper, a layered-division multiplexing (LDM) based non-orthogonal transmission framework is proposed to enhance the spectral efficiency of Multicast- Broadcast Single Frequency Network (MBSFN). In this framework, different ranges of MBSFN areas are incorporated into a two-layer LDM system, one layer is for small scale local services, the other layer is for large scale global service. To optimize the proposed transmission framework, we design a cooperative beamforming scheme and abstract it as a max-min fair (MMF) problem. We transform the problem into the difference of convex (DC) structure and design a concave-convex procedure (CCCP) based algorithm to find a local optimal of the problem. In addition, performance upper bounds and baselines are formed through semidefinite relaxation (SDR). The results show that the proposed CCCP-based algorithm performs close to upper bounds and better than the SDR-based approach. And this LDM-based non-orthogonal transmission framework also acquires better spectral efficiency than the orthogonal transmission frameworks.