Study On Geometric Factor And Hetnet Macro And Micro Co-Channel Technology In WCDMA Network Planning

With the rapid development of3G mobile communication network as well as smart phone, user’s traffic is developed from simple web service to the traffic which need a lot of data, such as broadband voice, multimedia services, video telephone and video conference, so the data traffic shows unprecedented and explosive growth. Therefore, the mobile communication network is needed to expand capacity, especially for the WCDMA standard which is most widely used in the world, the expansion is imminent. Currently, there is a technology called a heterogeneous network HetNet which can significantly improve the overall efficiency of the system and the network capacity, through deploying low power micro NodeB in the macro cell in the WCDMA network, it can both realize the depth of coverage and enhance the network capacity, meet the demand of the data traffic which has been explosive growth in the mobile internet era, but also maximize the use of existing frequency resources, while resolve the problem that the base station sites are difficultly acquired. Therefore, In this article, the WCDMA Hetnet macro and micro co-channel network planning has been further studied, the principles of network planning has been given, and several ways has been proposed to improve the downlink capacity of the network.Network estimate is the pre-planning of wireless network planning, the reasonableness and amount of projects for the network subsequent deployment are directly affected by the estimation accuracy. In this article, the parameter of geometric factors is first deeply studied which affect the capacity of HSDPA in WCDMA network estimate, then though modeling and simulating, the distribution of the results is obtained, while the results of simulation is compared with the statistics data of current network, the accuracy of simulation results is verified. At the same time the reasonableness of the distribution of the geometric factor under different scenarios is verified by simulating and analyzing a variety of parameters that affect the geometry factor.Secondly, the network topological structure and application scenarios of HetNet macro and micro co-channel network planning is given, and the principles of macro and micro planning is elaborated by combining the basis and experience of macro’s network planning, while the planning recommendation on project is proposed, through analyzing the interference which is encountered during the HetNet macro and micro co-channel network planning, especially for the downlink interference problem, three strategies are proposed, which are the downtilt adjustment of macro, the power adjustment of macro, the power and the ratio of pilot power adjustment of macro, etc. so the downlink interference can be reduced to improve the downlink capacity.Finally, based on the actual map of an area and the existing macro network, the simulation tools called Atoll is used to simulate, and the coverage and capacity gains are obtained at the different adjustment strategies of macro after the micro is deployed, the negative gain is obtained when the micro is deployed near the macro at the strategy of the downtilt adjustment of macro, while there is4%to12%gain when the micro is deployed middle and far the macro; the power adjustment of macro generally emerges no gain or negative gain; there is within10%gain at the strategy of the power and the ratio of pilot power adjustment of macro. At the same time the number and location of the micro deployment is comparative studied, the study find the micro deployment that the number of4-5and deployed middle and far the macro will have greater gain.