Efficient Techniques For In-Band System Information Broadcast In Multi-Cell Massive Mimo

In this paper we consider joint beamforming of data to scheduled terminals (STs) and broadcast of system information (SI) to idle terminals (ITs) on the same time-frequency resource in multi-cell multi-user massive MIMO systems. We propose two different multi-cell approaches to the broadcast of SI, i) synchronous broadcast of same SI symbols from all cells (SAME-SI), and ii) synchronous broadcast of statistically independent SI symbols from each cell (DIFF-SI). We also consider the traditional orthogonal access (OA) approach where a fraction of physical resource is reserved for broadcast of SI. Through analysis and simulations, it is observed that for both SAME-SI and DIFF-SI, joint beamforming and broadcasting (JBB) is more energy efficient than OA.