非理想信道下编码-预编码OFDM迭代译码性能界  

Performance Limits of Iterative Decoding for Coded-precoded OFDM with Imperfect Channel

作　　者：张国梅[1] 马小辉[2] 

机构地区：[1]西安交通大学电子与信息工程学院,陕西西安710049 [2]西安测绘研究所,陕西西安710054

出　　处：《无线电通信技术》2013年第4期28-32,共5页Radio Communications Technology

基　　金：国家科技重大专项资助项目(2011ZX03003-002-03)

摘　　要：针对信道估计精度会影响迭代译码性能的问题,分析了非理想信道估计下信道编码与预编码结合的OFDM系统迭代接收机的性能。利用信道估计误差强度来表征信道估计质量,推导了信道参数不理想时系统误码率的一般上界,并给出了一种经验下界。理论分析及仿真表明,信道估计误差不损失系统的分集增益,只造成编码增益下降。在各种系统参数选取下,误码率仿真曲线均落入理论分析上下界之间,且两者间距仅为0.6 dB左右,表明所提出的上下界可有效预测实际系统的渐近误码率性能。Considering that the channel estimation accuracy has a significant effect on the performance of an iterative decoder,the performance of joint channel coding and precoding orthogonal frequency division multiplexing（OFDM） with iterative decoding under imperfect channel estimation is analyzed.A general upper bound on the error performance is derived and an empirical lower bound is given with imperfect channel state information（CSI） through using the strength of channel estimation error（CEE） to characterize the quality of the channel estimate.Theoretical analysis and simulations show that CEE does not decrease the diversity order but only leads to a loss of coding gain.All the simulation bit error probability（BEP） curves for various system parameters accurately locate in the extension limited by the analytical lower and upper bounds.Furthermore,the gap between the lower and upper bounds is so small,i.e.,only around 0.6dB,that they could be used to predict the asymptotic BEP performance of the practical system effectively.

关 键 词：正交频分复用 迭代译码 非理想信道估计 性能界 

分 类 号：TN916.9[电子电信—通信与信息系统]