Research And Application In TD-SCDMA Wireless Network Optimization

Cell Optimization and Scramble code Optimization is important stage during the TD-SCDMA wireless network optimization, and then obtains a satisfying networks quality. Today, the amount of network is increasing, cells are more intensity and the task of network optimization is harder; meaning while, mobile phone user request more high quality network. Engineers largely depend on corresponding optimization software in the network optimization work. We could conclude that it is a trend that provide excellent scheme by cell optimization tools.One mathematic model of cell optimization is set up. Research the relation between azimuth, down tilt and transmitted power and the network coverage; propose the cell parameter evaluate method. Since cell optimization problem is combinatorial optimization problems, genetic algorithm is used to solve this problem. Genetic Algorithm has been developed which chromosome coded by binary matrix. For getting a rapid convergence, a special crossover method named patch-crossover has been posted. Scaling function applied to the fitness function to avoid local convergence.One mathematic model has been set up for the scramble code optimization problem; and one evaluate method has been proposed after analysis the principle of the interference. Since scramble code optimization is combinatorial optimization problems, an algorithm combine Genetic Algorithm and Tabu Search be used to solve the Scramble code planning problem. For getting a rapid convergence, a special crossover method named patch-crossover has been posted. To avoid blind search, Tabu search was used for the individual mutation.We selected two experimental networks in two city individual to test the cell optimization algorithm and the scramble code algorithm. The result of cell optimization is presented and the outstanding performance of this optimization algorithm is illustrated. The PCCPCH RSCP coverage ratio, PCCPCH C/I coverage ratio, Pilot pollution index and over coverage index increase Individual in different degree. Meaning while, the scramble code KPI, Downlink pilot code KPI has improved and the PCCPCH Interfere Bad Quality decreased in different degree.