## 1 Introduction
### Relevant Works  
Many recent studies have focused on the reliability and latency aspects of URLLC as essential requirements in applications such as the industrial internet of things (IIoT), virtual reality, and autonomous vehicles [20]. [PERSON] et al. [7; 21] discuss the communication theoretic principles as a critical component in supporting URLLC system design, such as the use of various diversity resources, the design of packets, and access protocols. In this context, potential enablers for high reliability include diversity, multi-connectivity, and modulation and coding schemes. In this work, we focus on MC-enabled diversity schemes. Diversity is the capability to exploit channel variations over time, frequency, and space for communication robustness, and play an essential role in boosting reliability. We can achieve diversity gains using time, frequency, and spatial diversity mechanisms. Time diversity considers re-transmission, e.g., hybrid automatic repeat requests (HARQ). Time diversity is usually hard to implement because of the latency constraint presented in mission-critical applications [22]. Frequency diversity uses transfer over sub-band or multiple carrier frequencies separated by coherence bandwidth for one transmission. However, due to bandwidth constraints, and to achieve high reliability, using frequency diversity requires impractically high signal-to-noise ratios in practical channel condition [23]. Hence, spatial diversity seems to be more attractive and considered as one of the key enablers to improve network performance as a low cost, and power-efficient solution [24]. In spatial diversity, multiple antennas physically separated from each other are used to transmit to the user. The authors in [25] discuss the concept of multi-connectivity to achieve high reliability and increase the performance of wireless networks using standard diversity schemes like joint decoding, selection combining, and maximum ratio combining. The work in [26] proposed interface diversity, where each interface is based on different technologies to offer URLLC without intervention in baseband/physical layer design. Furthermore, cooperative diversity emerges as a workable alternative to direct communication [27; 28]. Dual connectivity achieves superior reliability at the cost of lower mean spectral efficiency (because of redundancy) as potential solutions concerned with high-reliability [29; 30]. Reference [31] propose a multi-connectivity concept in CRAN to reduce mobility-related link failures and cell-edge degradation. However, small cell deployment is necessary for dual and multi-connectivity, which would lead to an increase in interference over the network, and the necessary deployment problem becomes complicated. To overcome this problem in our work, we use interfering nodes to cooperate or coordinate to transmit to the intended user equipment (UE). The cooperation techniques turn interference from foe to friend while having a diversity gain with the CRAN architecture. Furthermore, ref. [32] discuss CRAN technology to support URLLC, lowering the latency of URLLC traffic with the functional split of the central unit and the radio unit. This decentralization is an alternative where distributed RRHs can improve cloud accessibility with low latency and high-reliability [33]. The rate allocation problem in downlink cellular networks with stringent reliability constraints is investigated in [34]. This work concludes that an ultra-reliable region is achieved by using multiple antennas at the receiver for finite and infinite blocklength coding. Motivated by the merits of CRAN [31; 32; 33], we establish an MC framework through spatially distributed RRHs, using cooperation strategies enabled by CRAN to achieve URC in an interference-limited communication scenario.