适用于准循环LDPC码译码器的新型循环移位置换结构设计

Design of Novel Cyclic Shift Permutation Structure for Quasi-Cyclic LDPC Codes Decoder

循环移位置换单元是准循环LDPC码的部分并行译码器的重要组成部分。该文研究并证明了Reverse Banyan交换结构在实现信息循环移位时各个基本交换单元的连接规律。基于该规律设计了基于可预置选路算法的无阻塞循环移位置换结构。相比Benes交换结构和Reverse Banyan交换结构,提高了信息循环移位交换的速率,且占用较少的硬件资源和面积。最后设计了一个出线转换单元,该单元适用于各种循环移位交换结构。

Cyclic shift permutation structure is an important part of partial parallel decoder for quasi-cyclic LDPC codes. When the information is exchanged, a connecting law of basic switch units in Reverse Banyan network is researched and proved. Then a nonblocking permutation structure based on presetting routing algorithm for cyclic shift is designed. Compared with Benes exchange structure and Reverse Banyan exchange structure, the novel structure increases the exchange speed for information cyclic shift and occupies less hardware resource and area. Finally, an output converting unit is designed, which is adaptable for all kinds of switch structures.