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，允许接收端先解码传输信号的线性组合，再求解各个消息。本文将CFMA方案扩展至两用户高斯多输入多输出（MIMO）多址接入信道（MAC）。我们首先推导了MIMO MAC在CFMA下可达速率对的表达式，并证明了CFMA能够达到信道和容量的一般条件。进一步地，将该结果特化至SIMO和2×2对角MIMO多址接入信道，推导出功率与信道矩阵上更明确的和容量可达条件。最后，针对一般MIMO多址接入信道上的CFMA性能给出了数值结果。