Research On Interference Coordination Technology Combined With Key Technologies Of 5G

The users of one single LTE cellular cell share the entire frequency band orthogonally,so there is no co-channel interference in a single cell,but there is serious co-channel interference between the edge users in different cells.For a long time,inter-cell interference coordination technology is one important method to alleviate inter-cell interference.Its purpose is to manage radio resources and ensures that interference is controllable.With the development of wireless communication technology and the increasing demand of high communication quality,when coordinating resource usage between cells,the inter-cell interference coordination technology needs to comprehensively consider factors such as user distribution and service load while comprehensively improving network performance.Therefore,the thesis combines the current two 5G key technologies with traditional time domain and frequency domain interference coordination technologies,conducts research on interference coordination technology,and proposes two interference coordination schemes that keep pace with the times.The first part focuses on combining virtualization technology with traditional time domain interference coordination technology,and proposes a new interference coordination scheme based on virtual cell in time domain(V-FTR).Firstly,each cell is confirmed with scheduling frames and takes the advantage of fractional time reuse to mitigate inter-cell interference and overcomes the shortcoming of low multi-user diversity effect in frequency domain interference coordination technology.Then,exploiting the benefits of SDN/NFV paradigm for flexibly scheduling the entire network resource and the characteristic of the virtual cell technology,each cell conducts a virtual cell for the edge sector users and configures a virtual scheduling frame for the virtual cell according to the allocation mode of the scheduling frame of each cell so that the user belonging to the virtual cell can flexibly use the time domain resources of multiple cells to participate in scheduling.Besides,virtual cell technology can improve the utilization efficiency of time domain resource compared to the traditional time domain interference coordination technology.Another scheme combines CoMP and NOMA technologies to propose an inter-cell interference coordination scheme(CNIC)based on CoMP and NOMA technologies.First,each cell independently pairs NOMA users according to the characteristics of NOMA,and then the network constructs a CNIC user scheduling group among multiple cells based on CoMP and allocates the same frequency resource to the users in scheduling group.The cell function is configured according to the time slot,one certain cooperative user in the dominant cell chooses its assistant cell and make use of CoMP to cancel the interference between the dominant cell and assistant cell.Then by utilizing the power gain brought by the CoMP technology to the cooperative user,the interference between the dominant cell and ordinary cell can be eliminated based on SIC.In this way,the characteristics of the NOMA and CoMP technologies can be utilized to eliminate inter-cell interference,the system throughput and spectrum efficiency can be improved by the NOMA technology,and the cell capacity can be expanded too.In order to verify the performance of the proposed schemes,this thesis simulates the above two schemes in MATLAB simulation.The simulation results show that the V-FTR scheme can effectively improve the time-frequency utilization efficiency,user fairness and throughput of the system,especially the throughput of the edge users.In addition,the CNIC scheme can significantly increase the cell user capacity,system throughput and spectrum efficiency.