The Study Of Co-channel Interference Management For Heterogeneous Network In Lte-a

Heterogeneous network (Het-Net) is part of the long-term evolution advanced (LTE-A) study item and represents cellular deployments with a mixture of cells of different overlapping coverage areas, e.g., a number of relay and pico cells overlaid by a macro cell in the same frequency. Het-Net for LTE-A creates severe interference. It is an urgent task to overcome the interference for improving the system performance. In our study, we have proposed the three schemes for interference management.1. The cognitive interference model in interference zone (IZ) of the prac-tical heterogeneous scenario is proposed. Based on investigation of interaction between the macro base station (BS) and subnet nodes in this model, the strategy framework of the cognitive critical ratio and power reward factor is set up for interference management aim-ing to get the maximum net saving power. The study of interference management is transformed into a multiple objective non-linear pro-gramming (MONLP) of the maximum saving power for the macro BS and subnet nodes. To facilitate the best compromise solution for both, the MONLP is changed into single objective programming and genetic algorithm (GA) is employed to obtain the global optimum so-lution. In addition, the practical implementation using the proposed algorithm in Het-Net for LTE-A is designed. Finally, numerical eval-uation is used to test the applicability of the proposed algorithm, and svstem level simulation results demonstrate the effectiveness of the proposed interference management scheme.2. Load balancing and interference management are required in Het-Net design for LTE-A to maintain system performance. In this article, an inter-domain cooperative load balancing scheme focusing on reducing the effective resource utilization and mitigating the co-channel inter-ference is proposed in multi-domain Het-Net. First, the conception of multi-domain in Het-Net is set up and the co-channel interference is incorporated into the proposed load balancing scheme. Then the load balancing issue is modeled as a multi-domain load resource op-timization problem for minimizing the effective resource utilization. The detailed implementation for the proposed load balancing scheme is designed. In the numerical evaluation, the genetic algorithm (GA) as an optimization method is used to demonstrate that the total ef-fective load resource utilization is significantly reduced through our proposed inter-domain load balancing scheme. In the system level simulation, the performance results of SINR and throughput demon-strate that the proposed scheme has great advantages in interference management. At the same time, the performance for fairness and load balancing obtains the attractive gain.3. In Het-Net deployment, when multiple low-power nodes are deployed across macro coverage, the geographical coverage overlap can cause se-vere co-channel interference and unbalanced cost resource allocation. A scheme of multi-domain cooperative cost resource management in Het-Net is proposed, which can effectively allocate the power and load cost resource. The co-channel interference is incorporated in this scheme. The load resource utilization is changed into the optimization issue for the cost resource function. By the genetic algorithms, the optimal solution can be obtained. In numerical evaluation, compar-ing with the traditional intra-domain scheme, the utilization of cost in proposed scheme is better. And the43%of cost resource, using the inter-domain cost resource optimization scheme, can be saved. In system-level simulation, the results of SINR and cell average through- put demonstrate the attractive performance gain, due to mitigating more co-channel interference.