Research On Fast Deployment Algorithm Of Access Points In WLAN Indoor Localization System

With the rapid development of wireless communication technology and the growing demands of location-based services, wireless location technology obtains more and more attention. For outdoor environments GPS can provide accurate positioning information, while for the indoor environments, GPS can't give users'position because of the poor signal coverage. So the users'location-based service needs are met by the WLAN indoor positioning system in the indoor environments.The signal coverage in WLAN positioning system should not only meets the requirement of the wireless communication, but also meet positioning requirements, so how to set up WLAN indoor positioning system including determining the number of the access points and deploying them have great impact on the performance of positioning in the system. This paper studies on how to achieve the rapid deployment of access points in WLAN indoor positioning systemFirst, the signal space Euclidean distance between the access points is proposed as the judge basis of the deployment, which also tells if the signal coverage is favorable for the positioning or not. The paper demonstrates that in a certain range, the signal space Euclidean distance between reference points is larger, the probability of fault location is smaller. On this basis, an optimization method for rapid deployment of APs is proposed, and the specific process of the deployment using genetic algorithm is detailed.Second, the optimal algorithm for APs'deployment proposed is applied to the open indoor environment. First the paper discusses the principle of determining the size of reference points in the target environment, and then combining with the signal transmission model for indoor environment and the optimization solutions for rapid deployment, the optimal number and APs'placement in four kinds of open environments are given. Comparing with the experience deployments for APs, the paper concludes that the deployments proposed in this paper can decrease the positioning errors, so it can provides optimal APs'deployment ultimately in the indoor environment.At last the paper applies proposed optimal APs'deployment programs to the multi-wall indoor environment. First, signal transmission model better response to the multi-wall indoor environment is proposed based on the measured data. This model is improved based on the classical logarithm model and it meets the characteristics of the signal transmission both in the corridor and the office rooms. The 12th floor of building 2A in HIT Science Park is used as experimental subject, and the results of APs'deployment using genetic algorithm are given.In this paper, a fast algorithm for APs'deployment in indoor environment is proposed based on the characteristics of the signal coverage in the positioning system, and which is applied to two typical indoor environments, ultimately verifying the feasibility of the algorithm. The results in this paper provide an effective solution of compensating the lack of location algorithms and improving positioning accuracy.