Research On Pilot Pollutions Of CDMA Communication Network Optimization

Pilot pollution is one of the problems universally exited in CDMA communication network optimization, and comprehensive application of various technologies is needed to solve this problem. Meanwhile, for pilot pollution problems in complicated scenes, the effects of traditional optimization methods are not satisfactory, seeking new optimization methods according to the actual conditions is necessary. So this thesis makes an intensive study of pilot pollution of CDMA communication network.On the basis of the introduction of relevant theories, this thesis discusses the causes, optimization ideas and flow path of pilot pollution problems, and also proposes various technical methods to solve pilot pollution. In the meantime, detailed description of pilot pollution solutions and optimization are given combined with cases of on-site optimization of pilot solutions. Main works are as follows:1) Introduction of theoretical knowledge of transmission loss and transmission models of wireless signals are given, CDMA20001x voice service is chosen as an example to introduce the forward and reverse link budget of urban scene of CDMA network.2) On the basis of the causes, optimization ideas and optimization flows for pilot pollution problems of CDMA network, the thesis respectively proposes conventional solutions for pilot pollution and solutions for pilot pollution under special scenes. Solutions like antenna feeder adjustment, parameter optimization, use of special antenna and adjustment of indoor distribution system are introduced aimed at conventional solutions for pilot pollution which include pilot pollution with indoor distribution and pilot pollution without indoor distribution. As for optimization of pilot pollution under special scenes, the thesis carries out research in three respects covering antenna radome, indoor pilot frequency coverage and automatic simulation planning, the principles and application effects of the technical schemes as well as their advantages compared with conventional technical means are elaborated. 3) This thesis intensively researches the comprehensive application conditions of various technical means upon the cases of on-site optimization of pilot pollution. On the basis of conventional optimization schemes, the thesis also makes corresponding technical schemes according to the characteristics of each optimization scene. Antenna radome technology is applied to Chongqing Special Project Optimization, indoor pilot frequency coverage scheme is applied to Beijing Special Project Optimization, and automatic simulation planning is applied to Tianjin Special Project Optimization. The measurements prove that the application of new technical schemes effectively improves the network performance indexes such as Ec/Io, FER and Tx Power. It can reduce the proportion of pilot pollution problems and realize network optimization.