超宽带系统中基于DFT的TOA/DOA联合估计方法

DFT-Based Joint TOA and DOA Estimation in Impulse Radio Ultra Wideband

针对现有的脉冲超宽带(Impulse radio ultra wideband,IR-UWB)系统中到达时间(Time-of-arrival,TOA)和波达方向(Direction-of-arrival,DOA)联合估计精度不足的问题,提出了一种基于离散傅里叶变换(Discrete Fourier transform,DFT)的TOA和DOA联合估计方法。该算法首先在频域上对接收信号建模,通过DFT处理频域接收信号的协方差矩阵得到两根天线的TOA粗估计结果。然后通过设计补偿矩阵对时延向量进行相位补偿。搜索可得粗估计结果的补偿值,进一步对TOA参数作出精确估计。最后根据两根天线的到达时间差与DOA之间的关系得到信号的DOA估计值,从而实现TOA和DOA的联合估计。仿真结果表明,所提算法的参数估计性能优于矩阵束算法和传统传播算子算法,且该优势随着信噪比的增大更为明显;同时所提算法无需复杂的特征值分解以及广义逆求解步骤,更易于工程实现。

In order to improve the joint estimation accuracy of time of arrival(TOA) and direction of arrival(DOA)in existing impulse radio ultra wideband(IR-UWB)systems,a joint estimation method of TOA and DOA based on discrete Fourier transform(DFT) is proposed.First,the received signal is modeled in the frequency domain.Second,the rough TOA estimation results of the two antennas can be obtained via processing DFT on the covariance matrix of the received signal in the frequency domain.Based on the rough estimation results,we search the compensation value with a small interval,thereby the accurate estimation of TOA can be obtained.Third,according to the relationship between the time difference of arrival of the two antennas and DOA,we obtain the DOA estimation results,thus realize the joint estimation of TOA and DOA.The simulation results show that the performance of the proposed algorithm is better than that of the matrix pencil algorithm and the traditional propagation method,and the advantage becomes more obvious with the increase of SNR.Moreover,the proposed algorithm is easier to be implemented in engineering because it does not need complex eigenvalue decomposition and generalized inverse solution steps.