针对非理想载波同步下的正交频分复用（orthogonal frequency-division multiplexing,OFDM）系统，提出一种快衰落信道估计算法.首先，提出一种紧凑型广义信道冲击响应（generalized channel impulse response,G-CIR）自相关矩阵的对角化方法，使其随机性仅体现在对角阵中;然后，提出一种紧凑型G-CIR矩阵的压缩表示方法及其等效信道模型，减少了待估计元素个数；最后，利用最小二乘（least square,LS）估计器估计出压缩后的信道，从而实现了非理想载波同步下的OFDM快衰落信道估计.仿真结果表明，该算法能对非理想载波同步下的快衰落信道进行有效估计，并且提高了误码率（bit error rate,BER）性能.

A fast-fading-channel estimation algorithm is proposed in this paper for orthogonal frequency-division multiplexing (OFDM) systems with imperfect carrier synchronization. Specifically, diagonalizing decomposition is proposed for autocorrelation of a compact matrix of generalized channel impulse response (G-CIR). In such decomposition, only the diagonal matrix is random. A compressed expression of the G-CIR matrix and its equivalent channel model are derived. Finally, a least square (LS) estimators is formulated to estimate the compressed channel, from which the CIR matrix is reconstructed. Simulation results demonstrated that the proposed scheme has better estimation accuracy and lower bit error rate (BER) over the existing techniques.