Compute-forward multiple access (CFMA) is a multiple access transmission scheme based on Compute-and-Forward (CF) which allows the receiver to first decode linear combinations of the transmitted signals and then solve for individual messages. This paper extends the CFMA scheme to a two-user Gaussian multiple-input multiple-output (MIMO) multiple access channel (MAC). We first derive the expression of the achievable rate pair for MIMO MAC with CFMA. We prove a general condition under which CFMA can achieve the sum capacity of the channel. Furthermore, this result is specialized to SIMO and 2-by-2 diagonal MIMO multiple access channels, for which more explicit sum capacity-achieving conditions on power and channel matrices are derived. Numerical results are also provided for the performance of CFMA on general MIMO multiple access channels.

翻译：计算转发多址接入（CFMA）是一种基于计算转发（CF）的多址传输方案，该方案允许接收机首先解码发送信号线性组合，进而求解单个消息。本文将CFMA方案扩展至两用户高斯多输入多输出（MIMO）多址信道（MAC）。我们首先推导了采用CFMA的MIMO MAC可达速率对的表达式，并证明了CFMA能够实现信道和容量的一般条件。进一步，将该结果特化至SIMO及2×2对角MIMO多址信道，推导了在这些场景下关于功率和信道矩阵的更为显式的和容量实现条件。本文还提供了CFMA在一般MIMO多址信道上性能的数值结果。