摘要
在室内无线定位领域,Wi-Fi技术因其低成本和广泛普及性更具研究价值和应用前景,而基于时延参数估计的定位算法则能满足高精度定位需求。针对现有各类时延估计算法在室内真实多径环境下估计精度差、复杂度较高的问题,提出一种基于前沿检测互相关和子载波相位差拟合LDCC-PDF(Leading-edge Detection based Cross-Correlation and Phase Difference Fit)的分级时延估计算法。首先对收发信号进行互相关,通过分步检测得到整数倍基带采样周期粗时延估计值,再对频域各收发数据子载波的相位差进行线性拟合,得出小数倍采样精时延估计值。以802.11n标准的长训练序列作为定位信号对算法进行了性能仿真。实验结果表明,该算法估计精度高,抗噪声性能良好,单径条件下均方根时延定位误差小于0.3米,多径非视距传输环境下误差小于1米。
Wi-Fi technology has its research value and application prospect in indoor positioning field due to its low cost and wide popularity, and positioning algorithm based on time delay estimation （TDE） can meet the requirement of high-precision positioning. Aiming at the problems of poor accuracy and high complexity of the existing TDE algorithms in indoor real multipath environment, this paper presents a hierarchical time delay estimation algorithm based on leading- edge detection cross correlation and subcarrier phase difference fit （LDCC-PDF）. First, we perform cross correlation to the transmitted and received signal, getting the coarse time delay estimation of integer baseband sampling by the stepwise detection. Then the phase difference of each subcarrier in the frequency domain is linearly fitted, and the time delay estimation is obtained. The performance of the algorithm is simulated by using the long training sequence of 802. lln as the positioning signal. The experimental results show that the proposed algorithm has high accuracy and good anti-noise performance. The root-mean-square delay positioning error is less than 0. 3 m for single path and less than 1 m for multi-path NLOS transmission.
出处
《计算机应用与软件》
2017年第6期156-161,168,共7页
Computer Applications and Software
