An efficient feedback architecture design for three-user MIMO interference channels

In this paper, an efficient feedback structure is proposed to reduce the feedback overhead of three-user multiple input multiple output interference channels (MIMO-IFC). We present a sequential and iterative feedback structure based on interference cancellation condition. Compared to the previous feedback structure for interference alignment (IA) in K-user MIMO-IFC [1], the proposed method does not need a cooperation between receivers. Even though the proposed scheme inherently requires the infinite number of iterations to remove the residual interference clearly, almost all of the residual interference is eliminated by the low number of iterations enough that its total feedback overhead is dramatically reduced compared to the conventional approach [2]. Furthermore, in order to improve throughput performance, we propose a concatenated receive filter for maximizing the effective SINR.