基于扩频序列的高铁无线信道测量仿真系统研究

Research on Wireless Channel Measurement Simulation System in High-speed Railway Based on Spread Spectrum Sequences

为了评估不同扩频序列对高铁无线信道测量性能的影响,构建了基于扩频滑动相关的高铁无线信道测量仿真系统。在发射端分别生成Random、m、Kasami、Gold、ZC、Golay等6种扩频序列,通过COST207丘陵场景的标准信道模型传输调制信号,在接收端利用滑动相关算法估计出信道冲击响应。研究结果表明:Golay序列、ZC序列和m序列的自相关特性优于另外3种序列,进行高铁无线信道测量时误差相对较小;接收端利用估计的信道冲击响应可以有效提取信道的多径时延和多普勒扩展特性。仿真结果为构建可工程化应用的高铁无线信道测量系统提供了技术支撑。

In order to evaluate the influence of different spread spectrum sequences on the measurement performance of wireless channels in high-speed railway,a wireless channel measurement simulation system in high-speed railway is constructed based on spread spectrum sliding correlation in this paper.Six different spread spectrum sequences are generated at the transmitter,namely Random sequence,m sequence,Kasami sequence,Gold sequence,ZC sequence,and Golay sequence.And the modulated signal is transmitted through the standard channel model of COST207 hilly scene,and the receiver uses sliding correlation algorithm to estimate the channel impulse response.The research results show that the autocorrelation characteristics of Golay sequence,ZC sequence and m sequence are better than the other three sequences,and the error is relatively small while measuring the wireless channel in high-speed railway.The receiver can effectively extract the multipath delay and Doppler spread characteristics of the channel by using the delay Doppler spread function.The simulation results provide technical support for constructing a high-speed railway wireless channel measurement system for engineering applications.