频率选择性衰落OFDM的半盲信道估计算法研究

从系统性能分析和设计的角度详细地研究了基于无线HIPERLAN2通信协议的OFDM(orthogonal frequency division multiplexing,正交频分多路复用技术)系统信道估计与均衡的一种半盲算法,提出了结合直接法和Cholesky分解法的切换盲算法。这种半盲算法综合了全盲算法得到的信息与已知导频符号,充分利用了原发信号的统计特性和OFDM帧结构中插入的导频符号,克服了全盲和导频训练序列存在的问题^[6,7],且不需额外的带宽。仿真结果表明,在误比特率和收敛性方面,该算法比现有的主要三种全盲算法有更好的收敛和抗干扰特性。

A semi-blind channel identification algorithm for OFDM in frequency selective fading channels

In this paper, in view of the performance analysis and practical application, a channel semi-blind estimation and equalization algorithm for OFDM system are described in details based on HIPERLAN2 wireless communication protocol, and formulate a novel switching scheme combining the classical direct method with Choleshy decomposition method. The proposed algorithm takes advantage of the statistical properties and a priori information about the pilot inserted into the frame structure of OFDM, and utilizes blind algorithms for maximum bandwidth efficiency, thus overcomes the existing problems in all blind and pilot aided training sequence without need of extra bandwidth [6,7]. The computer comprehensive simulation results show that the proposed algorithm has much better performance over the others in terms of BER and the rate of convergence.