接收分集OFDM系统的信道估计研究

研究了天线分集OFDM系统的高速无线数据传输特点，通过计算信道冲击响应与参考信号的相关函数，提出了一种增强型的信道估计方法。理论分析与计算机仿真表明，该方法能够有效地降低加性噪声对信道估计的影响，提高信道估计精度。在采用QPSK调制的一发四收的接收分集OFDM系统中，该增强型的信道估计方法的性能明显好于最小二乘信道估计和基于DFT的信道估计。
关 键 词 OFDM系统; 信道估计; 接收分集; 多径衰落信道

Research on Channel Estimation for OFDM Systems with
Receiver Diversity
Han Bing Gao Xiqi You Xiaohu
(National Communication Research Lab, Southeast University Nanjing 210096)
Abstract Receiver diversity for Orthogonal Frequency Division Multiplexing system in high-speed wireless data transmission is investigated. An improved channel estimate method that calculates the correlation of the channel impulse response and a reference signal to extract the channel information from its noisy version is proposed. It is demonstrated by theoretical analysis and computer simulation that for QPSK modulated OFDM systems with one transmitter antenna and four receiver antennas, the performance of the improved channel estimator outperforms Least Square and Discrete Fourier Transform-based channel estimator greatly.
Key words OFDM system; channel estimation; receiver diversity; multipath fading channel