In this paper, approximate outage probability (OP) expressions are derived for uplink cell-free massive multiple-input-multiple-output (CF-mMIMO) system. The access points (APs) of the system considered have imperfect channel state information (CSI). The approximate expressions are derived first using conditional expectations and then using a novel dimension reduction method that approximates higher-order integration by several single order integrations. Similar expressions are also derived for conventional massive MIMO (mMIMO) systems. The OP approximations are then used to characterize the performance of cell-edge users of CF-mMIMO systems and compare the designs of CF-mMIMO and mMIMO systems. The derived expressions have a close match with the simulated expression for OP.

翻译：本文为无上链细胞大规模多投入-多输出(CF-MMIMO)系统得出了近似断裂概率表达式,认为系统中的接入点有不完善的频道状态信息(CSI),其大致表达式首先使用有条件的预期,然后使用一种新颖的减少维度方法得出,该方法通过几个单顺序集成近似于较高顺序集成。常规大型MIMO(MMIMO)系统也得出类似表达式。然后,OP近似值用于描述CF-MIMIMO系统的细胞尖端用户的性能,并比较CF-MIMO和MIMO系统的设计。衍生的表达式与OP的模拟表达式十分接近。