A spectrum-efficient broadcast scheme based on network coding in cellular MIMO systems

In this paper, a network coding broadcast (NC-BC) scheme is proposed to improve the spectral efficiency for multipleinput and multiple-output (MIMO) transmissions. Particularly by network coding the base station broadcast message with each user message respectively, NC-BC can save the radio resource allocated for base station broadcasting, which is necessary in conventional time division-based scheme. Moreover, the iterative precoding design for NC-BC is studied for approaching the optimal performance, and the sub-optimal precoding design with low complexity is also provided. The simulation results show that the proposed NC-BC scheme with precoding optimization can further improve the system transmission performance.