考虑传输衰减的航空数据总线误码率研究

Research on Bit Error Rate of Avionic Data Bus Considering Transmission Attenuation

在航空电子系统中,为机载电子设备提供高效可靠的实时通信是航空数据总线的基本要求,而传输线是航空数据总线进行数据传输的重要载体。通过分析传输线结构、分布参数及集总参数模型,得出了其状态转移函数、频谱特性和衰减特性。结合传输线电气特性,进一步分析了信号在传输中由于衰减而引起的传输错误,获得了传输线电气参数和误码率关系的理论数值模型。利用所推导的数值模型对ARINC429总线性能进行深入研究,在考虑传输中所允许的最小信噪比情况下,计算了不同线径传输线的误码率值。计算结果表明:传输线径的微小变化有可能会导致数据总线误码率数量级的变化。该研究工作为航空数据总线以物理指标选择传输线提供了参考依据。

In avionics systems, it is a basic requirement for the avionic data bus to provide efficient and reli- able real-time communication for airborne electronic equipment, and the transmission line is an important carder for transferring data over the avionic data bus. The state transition function, spectral characteristics and attenuation characteristics are obtained by analyzing the structure, the distributed parameter and lumped parameter model of the transmission line. The transmission error caused by signal attenuation during transmission is further analyzed considering the electrical characteristics of the transmission line, and the theoretical numerical model of the relationship between the electrical parameter and the bit error rate is obtained. By using the numerical model deduced from the study, the performance of the ARINC429 bus is studied in detail. Meanwhile, the bit error rates of the transmission lines with different diameters are calculated considering the permitted minimum signal-to-noise ratio in transmission. The results show that even slight changes in the diameter of the transmission line may lead to order-of-magnitude changes in the bit error rate of the data bus. The physical data for the aviation data study provides a reference for selecting the transmission line by means of bus.