从系统设计的角度研究了正交频分复用( OFDM) 系统中的信道估计技术，提出一种最优导频图样的设计方法．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，然后根据估计信道和实际信道的均方误差得到最优的导频图样．为了验证该设计方法的正确性和有效性，将其应用到长期演进( LTE) 系统中，利用曲线验证最优导频的优越性．在车载测试A 信道下的仿真结果表明，与应用原始LTE 导频图样的系统相比，应用所设计的最优导频图样的系统具有更好的误码率性能．

This paper deals with the channel estimation technology applied to orthogonal frequency division multiplexing ( OFDM) systems and proposes a novel method to design the optimal pilot pattern. In this method,first,the spacing in the time and the frequency domains between two pilot symbols are determined respectively according to the maximum multi-path delay and Doppler frequency shift. Then,all possible pilot patterns are listed by using
the exhaustive method. Finally,the optimal pilot pattern is obtained according to the mean square error between the estimated and the actual channels. In addition,the proposed method is applied to a long-term evolution ( LTE) system to verify its correctness and effectiveness,and the superiority of the optimal pilot pattern is verified by simulation curves. From the simulated results,it is found that,as compared with the system using the original LTE pilot pattern,the system using the optimal pattern is of higher BER ( Bit Error Rate) performance under the Vehicular Test A channel.