摘要
正交幅度调制(QAM)技术具有较高的功率效率和带宽利用率,已广泛应用于多种通信系统中.高阶QAM解映射搜索范围很大,复杂度高.为此,文中引入软判决贡献因子来衡量参考星座点对解映射的贡献,提出了缩小搜索范围的高阶QAM解映射算法;文中还讨论了算法的边界情况,研究了信道估计辅助的自适应搜索范围选择方案.仿真结果表明:在获得与全集合搜索范围相同的误码性能的前提下,文中所提算法大大减小了搜索范围,4096-QAM和1024-QAM解映射搜索范围仅分别为全集合搜索范围的12.7%和19.7%;文中算法能较好地平衡性能和解映射复杂度,具有较好的工程应用前景.
QAM （Quadrature Amplitude Modulation） is broadly used in various communication systems thanks to its high power efficiency and bandwidth utilization. High-order QAM, because of its wide search range, may result in high demapping complexity. In order to solve this problem, a novel concept of soft-decision contribution factor is introduced to evaluate the contribution of reference constellation to the demapping, and a demapping algorithm of high-order QAM within shrunk search range is proposed. Then, some boundary conditions of the algorithm are dis- cussed, and an adaptive selection scheme of search range is finally presented with the assistance of channel estima- tion. Simulated results indicate that （1） the proposed algorithm downsizes the search range without any sacrifice of BER performance; （2） 4096-QAM and 1024-QAM respectively shrink their search range to 12.7 % and 19.7 % of that of the whole constellation ; and （3） as the proposed algorithm makes good tradeoff between performance and demapping complexity, it has a good prospect of engineering application.
出处
《华南理工大学学报（自然科学版）》
EI
CAS
CSCD
北大核心
2014年第5期16-22,共7页
Journal of South China University of Technology(Natural Science Edition)
基金
国家自然科学基金资助项目(61271416)
航天支撑基金资助项目(2013-HT-XGD)
西北工业大学基础研究基金资助项目(JCY20130132)
关键词
正交幅度调制
解映射
信道估计
搜索范围
贡献因子
quadrature amplitude modulation
demapping
channel estimation
search range
contribution factor
