一种关于OQPSK软解映射的新算法  

Novel Algorithm for OQPSK Soft Demodulation

作　　者：李纯[1] 童新海[2] 

机构地区：[1]解放军理工大学通信工程学院研究生1队,江苏南京210007 [2]解放军理工大学通信工程学院

出　　处：《军事通信技术》2014年第3期53-58,共6页Journal of Military Communications Technology

摘　　要：文章针对OQPSK信号最大似然估计计算复杂度较高的问题,提出了一种基于软解映射的算法对信息比特进行最大似然估计,相比基于网格的算法,计算复杂度大大降低,而性能与Max-Log-Map完全等价并给出了等价证明。以Max-Log-Map为代表的VA类算法,其本质是利用前后星座点的约束关系,而在OQPSK信号中,这种约束关系仅仅与两个相邻星座中相同的1个比特有关,约束长度仅仅为1,该比特的软信息仅与两个相邻星座的实部(或虚部)有关。A novel algorithm for OQPSK soft-demodulation was proposed under the additive Gaussian white noise to reduce the complexity of maximum likely estimation in the OQPSK de- modulation. The proposed algorithm is not only more computationally efficient than other trellis algorithms, but also attains better estimation performance than Max-Log-Map algorithm. As one of the representative VA algorithm, the core idea of Max-Log-Map algorithm is to demodulate by utilizing the constrained relationship between the constellations and their immediate neighbors. While in the OQPSK constellations, only one-bit in the corresponding position within two imme- diate constellation neighbors has the constrained relationship, one of which is the constraint length, and the soft information of this bit only depends on the real part and the image part of the corresponding constellation point.

关 键 词：偏置正交相移键控 软解映射 对数最大后验概率译码算法 

分 类 号：TN911.3[电子电信—通信与信息系统]