Recently proposed splitting receivers, utilizing both coherently and non-coherently processed signals for detection, have demonstrated remarkable performance gain compared to conventional receivers in the single-antenna scenario. In this paper, we propose a multi-antenna splitting receiver, where the received signal at each antenna is split into an envelope detection (ED) branch and a coherent detection (CD) branch, and the processed signals from both branches of all antennas are then jointly utilized for recovering the transmitted information. We derive a closed-form approximation of the achievable mutual information (MI) in terms of the key receiver design parameters, including the power splitting ratio at each antenna and the signal combining coefficients from all the ED and CD branches. We further optimize these receiver design parameters and demonstrate important design insights for the proposed multi-antenna ED-CD splitting receiver: 1) the optimal splitting ratio is identical at each antenna, and 2) the optimal combining coefficients for the ED and CD branches are the same, and each coefficient is proportional to the corresponding antenna's channel power gain. Our numerical results also demonstrate the MI performance improvement of the proposed receiver over conventional non-splitting receivers.

翻译：摘要：近期提出的分裂接收机通过联合利用相干与非相干处理信号进行检测，在单天线场景下展现出相比传统接收机显著的性能增益。本文提出一种多天线分裂接收机，其中每根天线的接收信号被分裂为包络检测（ED）支路和相干检测（CD）支路，所有天线的两路处理信号随后被联合用于恢复传输信息。我们推导了可达互信息（MI）关于关键接收机设计参数的闭式近似表达式，参数包括每根天线的功率分裂比以及所有ED与CD支路的信号合并系数。进一步优化这些接收机设计参数，并揭示所提出的多天线ED-CD分裂接收机的重要设计准则：1）每根天线的最优分裂比相同；2）ED与CD支路的最优合并系数相同，且每个系数与对应天线的信道功率增益成正比。数值结果也证明了所提接收机相比传统非分裂接收机的互信息性能提升。