Heterogeneous Network Interference Suppression Strategy

In the Future 5G networks,user data traffic to be increased 1,000 times,the user experience must also have a high rate of growth,which gives 5G wireless access networks to bring great challenges.To increase the base station coverage and system capacity,we deploy low-power nodes in traditional cellular networks by increasing the cell density to increase the base station coverage and system capacity.Forming ultra-dense of heterogeneous networks(HetNets)by deploying various low-power nodes to increase the base density,is one of the key technologies of the most promising 5G network performance goals.In order to maximize the utilization of the frequency,3GPP generally use the same frequency network,in this case,the inter-layer interference between low-power stations and Macro base node and the interference between low-power and low-power stations will be severely constrained heterogeneous networks performance.Therefore,the study of interference suppression technology has important significance for heterogeneous networks.The main contributions and innovations of this paper are as follows:(1)Research on the same layer downlink interference suppression issue,a joint resource allocation algorithm to improve the performance of cell edge users was proposed.The Algorithm is divided into two steps: subcarrier allocation and hybrid power allocation.In the subcarrier allocation algorithm,the cell edge users preference channel gain good subcarriers to improve their performance,WSA algorithm used to maximize link throughput;in the hybrid power allocation algorithm,namely Community Centre users average power distribution,cell edge users can amend adopt a water surface and the relatively low complexity linear injection method for power distribution.Simulation data show that cell-edge user throughput gain of more than 25%,the resulting hybrid power distribution system throughput approaching all use water injection to get the throughput and greatly reduces the complexity.Average allocated power to cell center users,Cell edge users using a linear water injection for power distribution,water surface can be corrected and the relatively low complexity.The simulation results show that the edge user throughput is greatly increased,the throughput of the system of mixed power distribution approximation is approximate to the throughput that all users use liner water-filling algorithm,besides,and the proposed scheme reduces the computation complexity.(2)Research on interference suppression in HetNets in the frequency domain.Macro-Femto two networks as an example,combined with layer radio resource allocation we proposed a hybrid frequency allocation scheme,which divides the cell into inner region and outer region by setting coverage area(FCA)threshold of a co-channel Femto base station,to reduce the interference between the layers through allocating different frequency to inter region and outer region.To further enhance their performance,we allocated subcarrier and power for Macro users within the cell.Simulation results show that the algorithm proposed reduces the interlayer interference,throughput is improved.(3)Research on interference suppression in HetNets in the Time domain.Macro-Femto two networks as an example,we proposed an improved time-domain interference suppression technology strategy combined with CRE technology.Available domain sub-frames in the method are divided into normal sub-frames and ABS sub-frames,and the introduction of user fairness factor,and to narrow the difference between the average throughput of Pico users and bias user by adjusting fairness factor,we use Poisson Point Process(PPP)model to analyze the performance of the method.Simulation results show that,compared to other methods,this method can reduce the difference between the average throughput Pico users and offset users and Improve their overall average throughput,and ensure performance and fairness of users.