Transceiver Design Based on Interference Alignment in MIMO Interfering Broadcast Channels

In this paper, we propose a non-iterative transceiver design based on interference alignment (IA) for MIMO interfering broadcast channels with arbitrary number of cells and users per cell. We consider the case where a base station has more antennas than a user, which is a typical scenario of downlink transmission in the cellular network. By aligning the interference from other cells efficiently, we show that the proposed transceiver design can achieve the degrees of freedom (DOF) of $d$ per user, i.e., total DOF of $\sum_{i=1}^{C}K_{i}d$, where $C$ is the number of cells, $K_{i}$ is the number of users for the $i$-th cell, and $d$ is the number of streams per user. Accordingly, we investigate conditions for the antenna configuration to attain the total DOF of $\sum_{i=1}^{C}K_{i}d$. We also analyze the computational complexity and achievable DOF of the proposed transceiver design. Finally, simulation results are provided to assess the sum-rate performance and achievable DOF of the proposed transceiver design, which validates the advantage of our design over existing schemes.