# Interference Mitigation Strategies in Beyond 5G Wireless Systems: A Review
## 3 Classification and Evolution of Interference Management Strategies in B5G Networks
### Classification and Analysis of Interference Management Strategies in B5G Networks
#### 3.2.3 Inter-Cell Interference  
ICI takes place at the level of the network system as a result of interaction between adjacent cells. Figure 6 demonstrates the ICI of cellular networks. This interaction is either because of operating on the same channel known as co-channel interference or because of the overlap between neighboring channels known as adjacent channel interference [126]. Moreover, the estimation can be used in the DOL precoding and UL data reception for the same cohesion interval. Pilot reuse causes serious interference issues which are mainly because of the high number of user terminals in the same interference area and the limited length of the coherence interval which results in the degradation in the sum rate of the system [127]. The aforementioned interference is considered a type of ICI in which users sharing the same pilot sequence are exposed to interference during the UL training session [128]. ICI minimizes ST and network capability and has a detrimental effect on the performance of cell-edge UE. Environmental attention is also a major issue, as carbon dioxide emissions continue to increase due to the dense spread of BSs [129]. Careful management of ICI is important to enhance B5G network performance. Over the past few years, various approaches have been used to mitigate its effects. [PERSON] et al. [128] proposed a distance-based cell range extension technique combined with almost blank subframe (ABS) allocation. Their study showed this hybrid strategy successfully mitigated ICI and improved LB in 5G heterogeneous deployments. A DL model for narrowband physical random-access channel (NPRACH) detection in the presence of ICI is developed in [129]. Their method improved detection reliability in 5G UL scenarios, especially in dense environments with overlapping coverage areas. [PERSON] et al. [130] proposed a novel inter-cellular media access control scheduling algorithm to promote the QoE in 4G and B5G wireless systems. The authors indicated that the proposed scheduler outperforms current solutions in different scenarios. In [131], the authors applied maximum rank planning (MRP) as a new inter-cell IM \begin{table}
\begin{tabular}{p{113.8 pt} p{113.8 pt} p{113.8 pt} p{113.8 pt} p{113.8 pt}} \hline
**Issue** & **Methodologies** & **Advantages** & **Limitations/Future Works** & **Ref.** \\ \hline To maximize the network total rate while preserving standards for to enhance the minimum throughput of UEs. & Precise penalty techniques are integrated with iterative convex optimization. & Improving the traffic offloading and IM. & The UL transmission scenario was not considered. & [121] \\ \hline To minimize the cross-tier interference of different BSs cells to primary users and mitigate same-tier interference among BSs cells & Fractional programming strategy and dual decomposition technique. & Maximizing the EE of the proposed scenario. & This work will be extended to unlimited cooperation among flying cells. & [122] \\ \hline To minimize the effect of co-tier and cross-tier interference between D2D users and cellular users and optimize the performance of HetNet. & Matching theory-based distributed RA scheme. & Maximizing the SE of the proposed system by 93\% compared to conventional schemes. & PA strategy will be considered. & [123] \\ \hline To minimize the effect of inter-cluster interference in HetNets. & Advanced waveform UFMC. & \(\bullet\) HFMC. & Mitigating the effect of frequency offsets. & The DOL transmission scenario was not considered. & [124] \\ \hline To mitigate the effect of co-tier and cross-tier interference in HetNet. & \(\bullet\) PA strategy. Joint co-tier and cross-tier IM technique. & Maximizing the SE compared to the traditional schemes. & The UL transmission scenario was not considered. & [125] \\ \hline \end{tabular}
\end{table} 
Table 3: _Cont._mechanism for the very dense uncoordinated spread of SCs targeted by B5G networks.