机上载荷获取的视频图像数据经压缩后在误码率为1×10-5的无线通信链路中传输时极易受到干扰, 从而使得地面终端无法正常解码显示。本文通过分析无人机测控下行链路数据传输误码模型, 设计了一种高效的纠删编码技术以提高压缩后码流的抗误码性能。该算法首先将编码后的数据按照一定数量的字节数进行分帧, 对分帧后的数据按列进行改进后的快速范德蒙纠删编码; 然后对编码后的数据再按帧格式进行快速循环冗余校验(CRC)编码; 最后将编码后的码流送入信道传输。仿真结果表明, 该纠删编码抗误码技术能够将误码率为1×10-5信道降低到1×10-8左右, 可以使得经过高压缩比后的视频码流正确解码显示。此外设计时使用的纠删编解码技术运算量低、延迟小、非常易于硬件实现。提出的高效纠删编码技术已成功应用于多项无人机测控系统。

The compressed data obtained from the load of an Unmanned Aerial Vehicle(UAV) are highly suffer from interference when it transmits in the wireless communication link with a rate of bit error of 1×10-5, so that the ground terminal can not decode and display the video data. This paper proposes an efficient erasure coding technology to improve the error resilience ability of the compressed stream based on analysis of the error mode of the down-link data transmission. Firstly, the encode data were framed according to the number of bytes and the improved fast Vandermonde erasure coding was used to the column data framed. Then the fast Cyclic Redundancy Check(CRC) was used for the encoded data according to the frame format. Finally, the stream was encoded and put into the transmission channel. Experiment results show that this erasure coding technology reduces the channel bit error rate from 1×10-5 to 1×10-8, and the compressed stream can be decoded and displayed correctly. Moreover, the technology has the features of low computational complexity, small delay, and easy implementation by the hardware. The erasure coding has applied to measuring and control systems of UAVs successfully.