低密度奇偶校验码(LDPC)的性能取决于多种因素,包括度分布对、码字的长度以及环的分布。环的存在会影响LDPC码的译码门限和误码平层,尤其是长度比较小的环对LDPC码的性能影响很大。因此,有必要在构造LDPC码时消去长度比较小的环。文中提供了一种有效的消环算法,降低了LDPC码的误码平层。
The performance of LDPC codes depends on various factors, including degree distribution pair, the length of code word and the distribution of loop. The loops will affect the decoding threshold and the decoding error floor of LDPC codes. Particularly, loops with short lengths have great influence on the performance of LDPC codes. Therefore, it is necessary to remove loops with short lengths in code construction. This paper offers an efficient loop-removal algorithm which lowers the decoding error floor.