关键词: 正交频分复用, 导频设计, 穷举法, 均方误差, 长期演进

Abstract:

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.

Key words: orthogonal frequency division multiplexing, pilot design, exhaustive method, mean square error, longterm evolution