基于改进CHAN的超宽带定位误差校正算法

摘要

短距离无线通信是构建物联网的重要技术之一,其中超宽带技术被认为是未来短距离无线通信的主流技术.如今,室内定位已经成为超宽带技术一个重要的应用领域.在基于到达时间差的定位误差校正算法中,CHAN算法具有在LOS环境下精度较高和计算复杂度较低等优点.在室内环境中,由于地形复杂和遮挡物增多,非视距问题使CHAN算法的定位精度明显下降.为了实现高精度的实时室内定位,提出一种基于残差加权和CHAN算法的误差校正算法.该算法的重点是通过CHAN算法初步计算出移动台位置的中间估计结果,并建立残差函数来衡量中间结果的准确程度,通过残差加权的方式优化CHAN算法在非视距环境中的性能.在不同噪声水平下进行了对比实验,结果表明该算法与CHAN算法相比对超宽带定位的NLOS误差有显著的抑制作用,改善了定位的性能.%Short distance wireless communication is one of the important technology to build the Internet of Things.Ultra-wideband is expec-ted to become the mainstream of short distance wireless communication technology in the future.At present,indoor positioning has become an important application field of ultra-wideband.Among positioning error mitigation algorithm based on arrival time difference,The algorithm of CHAN has high precision in LOS environment and low computational complexity.In the indoor environment,due to non line-of-sight er-ror caused by the obstacles and complex terrain,positioning accuracy of CHAN is significantly declined.To realize real-time indoor positio-ning with high precision,we propose an error mitigation algorithm based on residual weighting and CHAN.Its main idea is to use CHAN to calculate the intermediate position estimates of the mobile station,and take residual to measure the accuracy of these intermediate results.In addition the performance of CHAN is optimized in non line-of-sight environment by means of residual weighting.Simulation shows that the proposed algorithm effectively restrains NLOS error compared with CHAN and improves the precision of positioning in NLOS environment.