一种OFDM无线网络TOA估计新算法

为了在OFDM无线网络定位服务(LBS)中实现精确的到达时间(TOA)测量，提出了一种OFDM系统TOA估计新算法．将TOA估计分为整数采样周期TOA估计和小数采样周期TOA估计．接收机利用训练符号的时频特性以迭代搜索的方法获得小数采样周期TOA估计，并利用估计结果修正小数采样周期时延带来的相关谱扩展，利用引导沿检测算法由修正后的相关谱估计整数采样周期TOA．仿真结果表明，该算法在信噪比高于0dB时TOA估计精度高于相关检测算法，10dB信噪比下其TOA估计精度比相关检测算法提高一倍以上．同时，可以用降低两个数量级以上的复杂度提供与现有超分辨率算法相当的TOA估计精度．

Novel TOA estimation algorithm for OFDM wireless networks

For accurate time of arrival (TOA) estimations for the location based services (LBS) in the OFDM wireless networks, a novel TOA estimation algorithm for OFDM is presented. The TOA estimation is separated into the estimation of the integral sampling interval TOA part and the estimation of the fractional sampling interval TOA part. At the receiver, the characteristics of the training symbol in the time and frequency domain are exploited, and the fractional TOA part is obtained with iterative searches. This estimated fractional part is then adopted to mitigate the correlation spectrum spread evoked. Subsequently, the integral TOA part is achieved from this modified correlation spectrum by the leading edge method. Simulation results show that the novel algorithm outperforms the correlation method at SNRs of over 0dB. The estimation accuracy is at least twice that of the correlation estimation at the SNR of 10dB. Meanwhile, the super resolution TOA estimations with a complexity lower than one percent of the complexity, but with a comparable accuracy, of the available super resolution estimations are provided.