中文摘要：

为了将渐进添边（Progressive edge—growth，PEG）算法应用于准循环低密度校验码（Low density paritycheck codes，LDPC codes）的构造，本文从最小化环长和减少短环周期的角度，提出一种新颖的准循环LDPC码的编码构造方法。利用该方法构造出一个码率为1／2的LDPC码，并通过计算机仿真得到其误帧率曲线，其性能优于3GPP中相同码长码率的Turbo码。该LDPC码不仅性能优异，而且编译码方法简单、复杂度低，能够节省存储空间，适用于未来移动通信以及深空通信。

英文摘要：

In order to apply progressive edge-growth （PEG） algorithm to the construction of quasi-cyclic low density parity-check （LDPC） codes, a new construction method for quasi-cyclic LDPC codes is proposed by minimizing the girth and reducing the short ring cycle. By the method, a 1/2-rate LDPC code is constructed and its frame error ratio （FER） curve is obtained by numerical simulations. It is demonstrated that it outperforms the Turbo code in 3GPP specifications. Moreover, with low complexity and small storage space, the code is easy for encoding and decoding. Thus it is applicable to future mobile communications and deep-space communications.