为提升高速移动环境中列车通信系统在进行越区切换时的无线连接性能、实时业务服务质量等,提出了将异构网络应用于高速环境中以改善系统切换性能.将高铁列车车载移动中继同时连接到两个或多个异构网络中构建多链路软切换方案,使其同时保持多条链路连接,当一条链路进行切换时,其他链路保持通信连接,以此达到信号不中断、无缝切换的目的.分析对比现有的双层网络方案,验证车载移动中继通信性能在切换失败、链路重建过程期间是否恶化.切换性能分析和仿真结果均表明,异构网络中构建的多链路软切换方案可显著降低高速环境中信号切换时无线连接失败率,提高了无线通信性能.

Considering the difficulty in the switching of the filtering channel based on the traditional parallel micro-ring array,a new type of 2×2 router is designed using the spectral characteristics of coupling resonance to induce the transparency effect. First,the transmission matrix method is used to simulate and analyze the coherent interference and destructive interference conditions that produce Coupled Resonance Induced Transparency (CRIT),and control the two CRIT channels.Then we de-sign a new router and study the transmission coefficient and the micro-ring radius difference on the performance of the router. It is shown that the CRIT channel can be controlled flexibly by setting the coherence length.Larger router bandwidth can be achieved by increasing the micro-ring radius difference.The router can meet the requirements of stability,reliability,flexibility and anti-interference ability in the wavelength exchange and routing.

The user signal quality as well as the performance of transmission link experiences severe loss due to wireless channel fading and propagation loss in high-speed railway scenario.To improve the quality at the receiving end,spatial diversity was realized by means of cooperative communication technology based on the uncorrelated characteristics of the channels.The model of mobile communication system in high-speed railway was set up,and a cooperative scheme based on statistics was proposed.Mathematical analysis and simulation results show that the quality of the received signal and the performance of the transmission link are significantly improved using cooperative communication technology compared to that in non-cooperative communication mode.