Resource allocation for spatial-frequency domain based interference alignment scheme in MIMO-OFDM systems

Interference alignment (IA) needs multiple dimensions, which can be achieved by extending time, frequency or spatial domain. However, using time or frequency domain for alignment requires an exponential number of resources as the degrees of freedom increases. In addition, it is impractical to employ many number of antennas in the spatial-domain-based interference alignment system. In this paper, we consider MIMO-OFDM systems over K-user interference channels and present resource allocation criteria based on the IA scheme utilizing spatial and frequency domain simultaneously. Then, we propose a low complexity resource allocation scheme appropriate to both spatial and frequency domain IA. We show that a single additional subcarrier in the proposed resource allocation scheme is enough to improve the sum-rate performance close to the optimal performance.