信道压缩表示的OFDM快衰落信道估计

Estimation of Fast Fading Channel for OFDM Systems Using Compressed Channel Expression

针对正交频分复用系统提出基于信道压缩表示的快衰落信道估计算法.该方法采用一种紧凑型信道冲激响应(channel impulse response,CIR)矩阵及信道核向量的信道压缩表示方法,减少了CIR矩阵中的未知元素数目.推导了等效信道模型以及CIR矩阵与信道核向量之间的闭式表达式,利用最小二乘和线性最小均方差估计器估计出信道核向量,并由其重构出CIR矩阵,从而实现了信道压缩表示的OFDM快衰落信道估计.仿真结果表明,该算法能对快衰落信道进行有效估计,并降低系统传输BER.

An algorithm using channel compressed expression for estimation of fast fading channel in orthogonal frequency division multiplexing （OFDM） systems is proposed. Specifically, a compressed channel expression based on compact channel impulse response （CIR） matrix and channel kernel vector is introduced, and an equivalent channel model is derived. Both least square （LS） and linear minimum mean square error （LMMSE） estimators are formulated to estimate the channel kernel vector. The CIR matrix is reconstructed from the channel kernel vector. Simulation results show that the proposed algorithm has better estimation accuracy and lower BER as compared to some existing estimation techniques.