In order to fully utilize the soft decision ability of the outer decoder in a concatenated system, reliability information (called soft output) from the inner decoder or equalizer is required. In this paper, based on...In order to fully utilize the soft decision ability of the outer decoder in a concatenated system, reliability information (called soft output) from the inner decoder or equalizer is required. In this paper, based on the analysis of typical implementations of soft output VA, a novel algorithm is proposed by utilizing the property of Viterbi algorithm. Compared with the typical implementations, less processing expense is required by the new algorithm for weighting the hard decisions of VA. Meanwhile, simulation results show that, deterioration in performance of this algorithm is usually small for decoding of convolutional code and negligible for equalization.展开更多
Turbo码已被广泛应用于第三代移动通信技术(3rd Generation mobile communication technology,3G)、第四代移动通信技术(4th Generation mobile communication technology,4G)等通信系统中.为了提高信道编码效率,在Turbo码的实际应用中...Turbo码已被广泛应用于第三代移动通信技术(3rd Generation mobile communication technology,3G)、第四代移动通信技术(4th Generation mobile communication technology,4G)等通信系统中.为了提高信道编码效率,在Turbo码的实际应用中常结合删余技术.由于部分校验位的缺失,删余Turbo码的盲识别难度更高,且目前针对删余Turbo码的交织识别研究较少.本文在删余Turbo码的随机交织器识别中,基于对数符合度的概念,提出利用软输出维特比算法(Soft Output Viterbi Algorithm,SOVA)对后验信息进行更新以辅助识别,从而弥补对数符合度的近似计算所导致的性能损失.仿真结果表明:与现有的相关算法相比,本文算法具有更好的性能;加之对数符合度和SOVA两者的计算复杂度均相对较低,所以本文算法也具备较高的实时性.展开更多
文摘In order to fully utilize the soft decision ability of the outer decoder in a concatenated system, reliability information (called soft output) from the inner decoder or equalizer is required. In this paper, based on the analysis of typical implementations of soft output VA, a novel algorithm is proposed by utilizing the property of Viterbi algorithm. Compared with the typical implementations, less processing expense is required by the new algorithm for weighting the hard decisions of VA. Meanwhile, simulation results show that, deterioration in performance of this algorithm is usually small for decoding of convolutional code and negligible for equalization.
文摘Turbo码已被广泛应用于第三代移动通信技术(3rd Generation mobile communication technology,3G)、第四代移动通信技术(4th Generation mobile communication technology,4G)等通信系统中.为了提高信道编码效率,在Turbo码的实际应用中常结合删余技术.由于部分校验位的缺失,删余Turbo码的盲识别难度更高,且目前针对删余Turbo码的交织识别研究较少.本文在删余Turbo码的随机交织器识别中,基于对数符合度的概念,提出利用软输出维特比算法(Soft Output Viterbi Algorithm,SOVA)对后验信息进行更新以辅助识别,从而弥补对数符合度的近似计算所导致的性能损失.仿真结果表明:与现有的相关算法相比,本文算法具有更好的性能;加之对数符合度和SOVA两者的计算复杂度均相对较低,所以本文算法也具备较高的实时性.
