As a revolutionary wireless transmission strategy, interference alignment(IA) can improve the capacity of the cell-edge users. However, the acquisitionof the global channel state information (CSI) for IA leads to unacceptableoverhead in the massive MIMO systems. To tackle this problem, in this paper, wepropose an IA and soft-space-reuse (IA-SSR) based cooperative transmissionscheme under the two-stage precoding framework. Specifically, the cell-centerand the cell-edge users are separately treated to fully exploit the spatialdegrees of freedoms (DoF). Then, the optimal power allocation policy isdeveloped to maximize the sum-capacity of the network. Next, a low-cost channelestimator is designed for the proposed IA-SSR framework. Some practical issuesin IA-SSR implementation are also discussed. Finally, plenty of numericalresults are presented to show the efficiency of the proposed algorithm.
展开▼
