中文摘要：

将SLT（system Luby transform）码，尤其是高码率短码长的SLT码与低密度校验（low density parity check， LDPC）码等信道纠错码级联，可以通过增加少量的译码开销来有效地提高译码增益。然而，基于传统的设计方法得到的编码包度数分布难以保证在这种情况下得到性能良好的码字。结合级联译码的场景，在传统的优化方法基础上，增加了对编码包度数分布的优化，同时改进了具体的构造方法，从而给出了一种高码率短码长的SLT码的设计方法。仿真结果显示，新方法设计的码字能够取得良好的性能。

英文摘要：

The performance of error control coding （e. g., low density parity check codes） can be improved by the concatenating system Luby transform （SLT） code of high rate and short length as outer codes. However, the traditional constructive method is only designed to the constructed SLT code of a middle or low rate. To solve the problem, a novel constructive method is given by optimizing the degree distribution of the parity packets as well as the message packets. The constructive process is also improved to achieve a better performance. Simulation results show that SLT codes constructed by the new method perform well as the outer codes.