基于LTE-Advanced标准的LDPC码编码器设计与实现

Design and implementation of LDPC code encoder in LTE-Advanced standard

针对LTE-Advanced标准,在分析其低密度奇偶校验(LDPC)码校验矩阵构造基础上,设计了一种低成本高吞吐率的准循环LDPC码编码器结构。通过分析校验矩阵的子矩阵结构,将整个校验矩阵划分为全零子矩阵及循环移位单位子矩阵的块状结构,进行串行编码。实验结果表明,与同类方法相比,设计的编码器编码时间约为同类最理想时间的32%,资源消耗约为同类最理想情况的33%,在编码时间和资源消耗上达到平衡,满足LTE-Advanced标准低成本高传输的要求。此外,改变校验矩阵存储单元的参数,可实现不同码长码率的LDPC码编码。

By analyzing the structure of Low-Density Parity-Check （LDPC） code check matrix in LTE-Advanced standard, this paper proposed a low-cost encoder with high input packet throughput on Quasi Cyclic-LDPC （QC-LDPC） code. With exploiting the number of null matrices in the mother parity check matrix, the whole parity check matrix could be partitioned into an array of block matrices, where each block matrix was either a null sub-matrix or a cyclic shift of an identity sub-matrix, and then it encoded serially. The experimental results show that the proposed encoder＇s coding time is the same as 32% of the ideal time and the resources consumption is the same as 33% of the ideal situation within the analogous methods. This result achieves the balance between coding time and resources consumption, which means the designed encoder meets the LTE-Advanced standard： low cost with high transmission. In addition, by changing the parameters in the ROM which saves the check matrix, the proposed encoder is flexible to implement the encoding of LDPC code with different code length or rate.