适合WSN的超宽带两步TOA估计算法

结合低速率能量检测与高速率匹配滤波的两步超宽带TOA估计算法适合WSN定位。通过采样获得低速率能量序列，找出直达路径(direct path,DP)在序列中的位置，即TOA粗估计。在该能量采样周期内进行相关滤波，由相关峰确定DP位置，即TOA精确估计。能量采样周期、能量块选择门限、相关峰检测门限是TOA估计的关键参数，对它们进行讨论，并给出一种基于最大最小能量比(MMR)的归一化门限模型。在IEEE 802.15.4a信道下的仿真结果表明：算法的运算量低于单一滤波匹配算法，精度优于基于能量检测的非相干算法

Two step UWB TOA estimation method for WSN ranging

Jointing energy detection and match-filter method can speed up the estimation process and perform accurate estimation. In first step,obtained a rough TOA by non-coherent low-rate energy samples. Then, in the second step,estimated a precise TOA of the direct-path (DP)by correlation match-filter within energy sample periods obtained in anterior step. In proposed algorithm,the parameters such as energy sample period and normalized thresholds play important role.So,discussed and modeled their effects based on maximum-to-minimum energy ratio and noise statistics. Simulation results in IEEE 802.15.4a channel demonstrate that the proposed method outperforms the non-coherent energy-detection method, and decreases the computation-quantity comparing to match-filter. So, the proposed method is more appreciate to WSN node.