城市空间无线定位信号传播模型校正方法研究

城市空间中的无线定位信号会因建筑物的遮挡等原因发生不同程度的衰落,信号的传播模型能够较好地描述这种衰落情况。传播模型是时分码分-正交频分复用(TimeCode DivisionOrthogonal Frequency Division Multiplexing,TC-OFDM)信号进行广域室内外无缝定位网络规划的基础,传播模型的准确性直接关系到基站布局规划的合理性。在对经典室外传播模型和现有模型校正方法研究的基础上,提出了一种新型的基于非线性最小二乘法的Okumura-Hata校正模型,通过添加校正因子使模型更加接近实测数据。误差分析和仿真结果表明,相比传统的室外传播模型,所提出的校正模型可以提高TC-OFDM信号的预测准确度5dB以上,为TC-OFDM基站的合理布局提供理论依据。

Research on Correction Method of Wireless Positioning Signal Propagation Model in Urban Area

The wireless location signal in urban area will fade due to the block of buildings and some other reasons. And propagation model can describe this fading more precisely. The propagation model is one basis of the wide-area indoor and outdoor seamless location network planning of Time Code Division-Orthogonal Frequency Division Multiplexing (donated as TC-OFDM). The accuracy of the propagation model is directly related to the rationality of the base station layout planning. Classical outdoor propagation model and existing model correction method have been studied, then a Okumura-Hata correction model is proposed based on nonlinear least squares method. The difference between actual data and model predictive data becomes smaller by adding correction factors in the model. The error analysis and simulation results show that the proposed correction model can improve the prediction accuracy of TC-OFDM signal of more than 5dB and provide the theoretical basis for the reasonable layout of TC-OFDM base station.