Wireless Location Algorithm Based On The Scattering Information Of Study

The wireless location algorithm based on the scatter information is described in this paper. First, two scatter models are analyzed: ROS (ring of scatters) model and DOS (disk of scatters) model. The simulation results show that NLOS (non-linear of sight) error of the ROS model is higher than DOS model's. Meanwhile, three LOS (linear of sight) location algorithms are analyzed. These algorithms are simulated both on the LOS situation and NLOS situation. The simulation results show: if there are three base stations, the performance of those LOS algorithms is similar. But the location error of the NLOS situation is bigger than the LOS situation's. Therefore, new algorithm on the NLOS situation is necessary to be developed.Second some scatter location algorithms are analyzed. Because one kind of the scatter location algorithm depends on the scatter model, two scatter location algorithms are analyzed which can make precise location to the scatters and mobile station, non-linear least square scatter location algorithm and closed-form scatter location algorithm. The simulation results show that the non-linear least square scatter location algorithm has two limitations: (1) at least six multipath signal are needed. (2) worse non-linear cost function is existed, so the location error is big. Closed-form scatter location algorithm can answer the first question, but it requires three scatters and base station to be on the same line. The restriction is not easy to be satisfied practically.Two new algorithms are given based on the above researches. The first new algorithm which makes use of two base stations to locate mobile station needs only three scatters. These scatters can be at the arbitrary place. It breaks through the restriction of the closed-form scatter location algorithm. The second new algorithm is similar to the first new algorithm, but it doesn't need DOA (direction of arrive). Two algorithms are simulated based on the ROS and DOS model, and the results show that the performance is better than non-linear least square scatter location algorithm's and closed-form scatter location algorithm's. The second algorithm on the multi-reflect model are also simulated, and the results show that the performance is better than the LOS algorithm's.The algorithm is compatible to the error which caused by multi-reflect.