受时变性影响，正交频分复用( OFDM) 系统的频域信道矩阵是近似限带的．利用接收端窗函数可以增强信道的限带特性，但也导致信道无法采用线性模型进行表征．针对该问题，文中将窗函数与信道的时变性隔离开来，提出了加窗－线性信道模型．随后研究了该模型下的时变信道估计方法，并对该算法进行了简化，降低了算法的计算量．从仿真结果可以看出: 窗函数可以抑制信道矩阵的带外子载波间干扰; 与传统OFDM 系统的性能相比，文中算法的性能提升了约2.5 dB．

Due to the time-varying characteristics,the channel matrix in the frequency domain of OFDM ( OrthogonalFrequency Division Multiplexing) system is approximately banded.Although the receiver window can improve theband-limited characteristics of time-varying channels,the equivalent channel cannot be modeled linearly.In orderto solve this problem,a new windowed-LTV ( Linear Time-Varying) model is proposed,which separates the timevaryingcharacteristics of the receiver window from those of the channel.Moreover,a time-varying channel estimationmethod of the model is investigated,and a simplified algorithm is presented to reduce the computational complexity.Simulated results show that the receiver window reduces the inter-subcarrier interference out of the band ofthe channel,and that,as compared with the traditional OFDM methods,the proposed algorithm brings about a performanceimprovement of 2.5 dB.