Satellite communication systems with the long transmission distance, dynamic channel states and limited energy consumption properties. To improve the image data transmission efficiency in the satellite communication systems, a class of rateless codes which can provide unequal error protection (UEP) property and equal water-fall region performance is proposed in this paper. As existing Luby Transform (LT)-based UEP codes with a property termed unequal recovery time (URT), which means that the data with different reliability requirements would be recovered with different overheads, which property would leading to a lower transmission efficiencies when all the portions of data have to be recovered. To overcome this drawback of existing UEP codes, the proposed UEP codes are carefully designed to provide equal water-fall region performances of all the portions of data. By using the well-known asymptotically analysis tool named as And-Or Tree, the asymptotic error performances of the proposed codes are given, and compared with the conventional LT-based UEP codes. All the theoretical analysis results and numerical results all prove that compared with conventional LT-based UEP codes, the proposed codes can provide higher transmission efficiency in the image data transmission in satellite communication systems.

具有长传输距离，动态信道状态和有限的能耗特性的卫星通信系统。为了提高卫星通信系统中图像数据的传输效率，本文提出了一种无速率码，可以提供不平等的误码保护（UEP）特性和相等的降水区性能。由于现有的基于Luby变换（LT）的UEP代码具有称为不等恢复时间（URT）的属性，这意味着具有不同可靠性要求的数据将以不同的开销进行恢复，而当所有这些操作都将导致较低的传输效率时，部分数据必须恢复。为了克服现有UEP代码的这一缺点，建议的UEP代码经过精心设计，以提供所有数据部分相同的瀑布区域性能。通过使用著名的渐近分析工具And-Or Tree，给出了所提出代码的渐近错误性能，并将其与基于LT的常规UEP代码进行了比较。所有的理论分析结果和数值结果都证明，与常规的基于LT的UEP码相比，所提出的编码可以在卫星通信系统的图像数据传输中提供更高的传输效率。