归零Turbo码参数的盲识别

Blind Recognition of Parameters of Turbo Code on Trellis Termination

针对归零Turbo码码率、码组起点、交织起点、交织长度参数识别问题,首先引入矩阵秩量比的概念,推导出适用于归零Turbo码矩阵秩量比下限,提出了基于秩量比判决门限的码长识别算法;其次,遍历一交织帧输出码元,找出最小秩量比对应的位置,实现交织起点和码组起点的识别;然后,依靠完整的交织帧输出数据,利用分析矩阵实现码率与分量编码器中寄存器个数识别;最后,由以上识别的参数计算出交织长度。仿真结果表明:在信噪比为5 dB时,单靠信息序列,各部分的识别概率能达到80%以上;在交织长度为100时,提出的识别算法与传统算法相比,性能相近,识别时间大约缩短为原来的1/3。

For the problems of the parameter recognition of the code rate,code block starting point, inter-laced starting point and interlaced length of Turbo code on trellis termination,this paper firstly introduces the quantity relative ratio of matrix rank,deduces the low limit of matric rank ratio applicable to the Turbo code on trellis termination,and proposes the recognition algorithm of the interlaced frame output codelength based on the judgement threshold of quantity relative ratio. Secondly, it finds the position of the minimum matric rank ratio by traversing a interlaced frame output code to achieve the recognition of interlaced start-ing point and code block starting point. Thirdly,the code rate and the number of register in the component encoder are recognized by using analysis matrix. Finally,the interlaced length can be calculated by above recognized parameters. Simulation results show that the identification probability of each parameter can reach more than 80% by the information sequences when the signal - to - noise ratio （SNR） is 5 dB, and when the interlaced length is 100,the proposed algorithm has similar performance with the traditional algorithm,but the recognition time is reduced about 2/3.