针对空时编码技术在空间激光通信应用中受到的限制,提出了一种基于强度叠加编码的空间光多输入多输出(MIMO)通信算法,设计了算法中使用的码元——光强码的编码和解码规则,分析了不同天线阵列组合下的系统信道容量,给出了最佳判决门限选择方法,并在此基础上计算了不同系统组成下的误码率。仿真计算表明,与单发单收系统相比,强度叠加编码的光MIMO系统在信道容量方面有1倍以上提升,而误码性能优势也在10 dB以上的信噪比条件下得到充分发挥。 Aiming at the limitation of space-time coding technology in space laser communication, a space-based multi-input multiple-output (MIMO) communication algorithm based on intensity overlay coding is proposed, and the symbol-optical code Encoding and decoding rules. The system channel capacity under different antenna array combinations is analyzed, and the optimal decision threshold selection method is given. Based on this, the bit error rate under different system components is calculated. The simulation results show that compared with single-antenna single-output system, the strength-superimposed optical MIMO system has more than one-fold improvement in channel capacity, while the error performance advantage is also fully exerted under the SNR of 10 dB or more.