本文研究在隧道场景中使用双泄漏同轴电缆（leaky coaxial cable，LCX）和单个LCX研究孔径效应对多输入多输出（multiple-input multiple-output，MIMO）性能的影响。从理论上研究了LCX槽口中的孔径效应。然后在矩形隧道和拱形隧道中使用1.8 GHz的LCX进行了2×2 MIMO测量。 测量结果表明：在隧道场景中，双LCX和单LCX部署的孔径效应的概率非常有限。 最后提供了双LCX和单LCX情况下的信道容量结果，这些结果可以为在隧道中采用MIMO技术提供前瞻性指导。
This paper studies the influence of keyhole effect on multiple-input–multiple-output (MIMO) performance by using double leaky coaxial cables (LCXs) and a single LCX in tunnel scenario. The keyhole effect in the slots of LCX was theoretically studied. Then, a 2×2 MIMO measurement campaign using LCXs at 1.8 GHz in a rectangle tunnel and an arched tunnel were carried out. The measured results reveal that the keyhole effect does not exist in double LCXs case, and meanwhile the keyhole probability in single LCX case is also limited. Finally, the results of channel capacity in double LCXs case and single LCX case are provided. These results can provide a prospective guidance for employing MIMO technology in tunnels.