基于校验方程符合度下的Turbo码编码器盲识别

针对目前Turbo码分量编码器参数识别算法容错性不好、计算量大的缺点，该文提出一种基于校验方程符合度的新算法。首先，根据码元约束长度较小的特点，构建出编码器生成多项式数据库，然后通过遍历多项式数据库，计算出每种多项式所对应的平均校验方程符合度值，其最大值所对应的索引号即为多项式库中的正确多项式索引号，从而完成编码多项式的识别。该算法仅仅遍历有限的多项式数据库，其计算量较小，只与截获的数据量有关；算法采用的数据为软判决信息，故其容错性能较好。仿真结果表明：在信噪比为0 dB条件下，仅需要截获10码块，交织长度为100的码元数据量，参数的识别率就能达到90%以上。

Blind Recognition of Turbo Code Encoder Based on Conformity of Parity-check Equation

In order to solve the defects of poor error tolerance and large calculation amount in current Turbo-code encoder recognition algorithms, a new algorithm based on conformity of parity-check equation is proposed. Firstly, according to small code constraint length, the coding polynomial database is built, then each polynomial of average conformity of parity-check equation is calculated by traversing the database, as a result, the Turbo-code encoder can be realized, because the correct polynomial can make the conformity maximum. The algorithm has small amount of calculation because of finite traversal, which is only related to amount of intercepted data, besides, this algorithm has good error tolerance by soft decisions. The simulation results show that the correct ratio of recognition can reach 90% at SNR of 0 dB by the 10 intercepted code blocks, and the length of each block is 100.