大秦线重载组合列车800MHz无线数据传输系统及关键技术

800 MHz Radio Data Transmission System and Its Key Techniques for the Heavy Haul Combined Train of Daqin Railway

大秦线重载组合列车800 MHz无线数据传输系统是在每台机车上配置2台无线数据传输设备,采用800 MHz工作频段和无线数据传输技术。系统实现的关键技术有:通过对电波在平原开阔地带、长直隧道和曲线隧道内传播特性的理论计算和实际测试验证,确定800 MHz频段为系统的工作频段;采用时间分集、频率分集、空间分集、前向纠错和重传相结合的混合纠错方式、交织编码处理和减少电波近体阻挡等措施,提高无线数据传输的成功率;采用广播和转发相结合的通信方式,确保系统的实时性和可靠性。试验和试运行结果表明:800 MHz频段无线信道数据传输比特误码率随着接收电平值增大而减小;确定系统最小接收电平值为0dBμV(95%时间、地点概率)。实际应用结果验证了系统能够较好地满足大秦线开行重载组合列车对无线数据传输的要求。

The 800 MHz radio data transmission system of Daqin Railway heavy haul combined train has 2 sets of radio data transmission equipments in each locomotive,adopting 800 MHz working frequency band and radio data transmission techniques.The key techniques of this system include the following aspects.Through theoretical calculation and many practical tests of the propagation characteristics in plain and open areas,long straight tunnel and in curve tunnel,800 MHz is determined as the working frequency band of system.The comprehensive application of temporal, spatial, frequency diversity, mixed error correction mode of forward error correction and retransmission, interleaved coded, and also the measures to reduce nearby block of signal have effectively improved the success rate of radio data communication. The combination of broadcasting and relay transmission has ensured the reliability and real-time quality of the system. Results during test run period indicate that the BER （bit error rate） of 800 MHz increases along with the reduction of the received signal level, and the minimum received signal level of system is 0 dBμV （95% time and land probability）. These practical application results prove that this system can well meet the radio data communication requirements of heavy haul combined train in Daqin Railway.