短波地空通信换频策略研究

Research of Frequency Changing Strategy for HF Air-Ground Communication

针对短波地空通信,推导出了飞机飞行位置与时间的函数关系,结合位置关系,并基于ITS区域信噪比数据,采用插值算法确立了各信道航线信噪比随时间的分布曲线,依据信噪比的分布,得出了一种依据信噪比排序的换频策略。该策略给出了飞机在整个航线上的实时频率使用计划,从而保证信道通信质量始终处于较高的水平,并把REL作为信道质量的评估标准,经仿真验证,该换频策略下的航线平均信噪比和航线通信可靠度有了较大提高,确保了飞机在飞行过程中的通信始终处于最佳信道上,克服了任一频率只适合一定空域通信的缺陷。

According to the present High Frequency （HF） Air- Ground Communications, this paper derives the function relation between aircraft flying position and time, simultaneously proposes a new frequency changing strategy based on SNR sorting. This new strategy based on ITS area SNR data ascertains the distribution curve of each channel＇s SNR along time on the route through interpolation method. At the same time, real time frequency application plan on the whole route of plane is given by this strategy, thus ensuring that the channel communication quality should be maintained at a high level, and the REL be regarded as the evaluation standard of channel quality. Simulation results demonstrate the great improvement on average SNR and communication reliability on the route, which insures communications during flying always being at the optimal channel and overcomes the disadvantage that one frequency only fits one area＇s communications.