Abstract: The accuracy of prediction of time of arrival（TOA） and angle of arrival（AOA） in wireless indoor positioning is the most important parameter for indoor positioning systems.Orthogonal frequency division multiplexing（OFDM） is an efficient technique for high-speed digital transmission over multipath fading channels.In this paper，a jointed TOA/AOA super-resolution algorithm for OFDM positioning is proposed.Using the obtained channel frequency response（CFR） and the frequency domain received signal on each antenna，a MUSIC super-resolution algorithm is used to recover the time delay and angle of signal arrivals from a mobile device to a base station and/or an access point.Then，the estimated TOA and DOA of the first arrival path（FAP） are used in a proposed hybrid time/direction of arrival position location scheme.In simulations，the OFDM signal with pilot symbols transmission in a multipath fading channel is considered to illustrate the efficiency of the proposed algorithms.Results show that the positioning precision is high enough for actual application，especially in the environment with only one access point and base station.

Key words: Orthogonal Frequency Division Multiplexing（OFDM）, Time Of Arrival（TOA）, Direction of Arrival/Angle of Arrival（DOA/AOA）, super-resolution, MUSIC algorithm

摘要： 对无线信号到达时间（TOA）和到达角度（AOA）的精确估计是室内无线定位的关键。正交频分复用（OFDM）是适合多径衰落环境的一种高速传输技术。提出一种联合TOA和DOA的二维定位方法用于OFDM信号定位。算法首先通过信道估计得到信道的频率响应（CFR），对CFR采用超分辨率算法估计信道时延。首径（first arrival path，FAP）的时延估计就是接收信号的TOA估计。将天线阵列接收信号通过DFT变换到频域，利用同样的算法估计信号各径的AOA/DOA。最后联合TOA和AOA在二维平面上确定目标位置。由于信号是多径、多载波信号，对各载波的DOA/AOA估计在载波间进行处理，再结合各径脉冲响应的幅值，选出属于首径的DOA/AOA估计。在多径环境下仿真表明算法有效且定位精度能够满足实际需要，尤其适合环境中只有一个基站或接入点的情况。

关键词: 正交频分复用（OFDM）, 到达时间（TOA）, 信号到达方向/到达角度, 超分辨率, MUSIC算法