【2017年整理】一种OFDM系统中导频信号的设计方法-.doc

一种OFDM系统中导频信号的设计方法 孙乐1,2, 杨 维1,2, 许昌龙2 1. 北京交通大学轨道交通控制与安全国家重点实验室，北京 100044 2. 东南大学 移动通信国家重点实验室，南京 210096 摘要：从系统设计的角度研究了正交频分复用（Orthogonal Frequency Division Multiplexing, OFDM）系统中的信道估计技术，提出一种最优导频的设计方法。该方法首先根据信道的最大多径时延和最大多普勒频移来确定导频符号的时域和频域间隔，并利用穷举法列举所有可能的导频图样，最终根据估计信道和实际信道的均方误差(Mean Square Error, MSE)结果得到最优的导频图样。为了验证设计方法的正确性和有效性，将提出的设计方法应用到长期演进(Long Term Evolution, LTE)系统，利用曲线验证最优导频的优越性，仿真结果表明应用所设计的最优导频图样的系统与应用原始LTE导频图样相比具有更好的误码率(Bit Error Rate, BER)性能。 关键词：正交频分复用；导频设计；穷举法；均方误差；长期演进 中图分类号：TN929.533 文章编号： A novel method for the optimal pilot pattern design in Orthogonal Frequency Division Multiplex systems Sun Le1,2, Yang Wei1,2 , Xu Changlong2 1. State Key Laboratory of Rail Traffic Control and Safety, Beijing Jiaotong University, Beijing, 100044, China 2. National Mobile Communications Research Laboratory, Southeast University, Nanjing 210096, China Abstract: A novel method for the optimal pilot pattern design is proposed for Orthogonal Frequency Division Multiplex (OFDM) systems. Firstly, the spacing in the time and frequency domain between two pilot symbols are determined according to the largest multi-path delay and the maximum Doppler frequency shift, respectively. Then the exhaustive search method is used to list all possible pilot patterns. Finally, the mean square error between the estimated channel and actual channel are calculated in order to obtaining the minimum one which corresponds to the optimal pilot pattern. In order to verify the correctness and effectiveness, the proposed method is then applied to the LTE system. Simulation results show that the system Bit Error Rate performance of the optimal pilot pattern obtained by the proposed algorithm is better than that of the original one in LTE system. Key words: Orthogonal Frequency Division Multiplex (OFDM); Pilot pattern design; Exhaustive search method; Mean Square Error (MSE); Long Term Evolution (LTE) 1.引言 在下一代移动通信系统中，数据的相干检测和译码都需要预先知道收发天线间的信道信息，因此信道估计成为下一代移动通信系统的关键技术之一。为了获得移动信道的频率响应，