合作定位节点选择策略

Node selection algorithm in cooperative positioning

合作定位是指接收机之间通过合作网络交换关键定位信息实现协同定位的新技术,接收机进行合作定位过程中可供使用的辅助节点包括可视卫星和已定位邻居接收机。接收机之间的合作增加定位过程中的可用辅助节点数量,进而增加位置估计的计算量和计算时间,在可用辅助节点较多时,定位实时性很难得到保证。提出改进次优节点选择算法,计算备选节点之间单位向量差作为节点价值,选择拥有最大价值的节点作为辅助节点。将新算法与4种典型的节点选择算法进行了对比,仿真实验证明该算法能够在较短时间内选择出接近最优算法得到的组合,综合性能优于现有节点选择算法。

Cooperative positioning refers to a new positioning technique that receivers share critical positioning information with each other by communication system so as to achieve relative localization.The receivers estimated their position with available secondary nodes which included the localized neighbor receivers and the visible satellites.The cooperation of receivers resulted in the increasing of the available secondary nodes for position estimation,so the calculated amount and the computing time were increased.With the increasing of available secondary nodes,the receivers may fail to estimate their position in real-time.A new node selection algorithm called improved quasi-optimal node selection algorithm was proposed. The nodes to be selected obtained an importance value by calculating the unit vector differences between nodes,and the ones with the maximum importance value were selected as the secondary nodes in each iterate.The new algorithm was compared with four typical node selection algorithms. Simulation result shows that the nodes selected by the proposed algorithm are very close to the ones selected by the optimal algorithm,but the former algorithm costs less time.And the comprehensive performance of the new algorithm is better than the typical node selection algorithm.