目前存在的各种信道估计方法，通常假设信道参数在一个正交频分复用(OFDM)符号内是恒定不变的。但是在高速场景中，信道在一个 OFDM 符号内呈现出较为明显的变化，这时子载波间干扰(ICI)就会影响传统的信道估计方法，使估计性能明显下降。本文提出通过幂级数基的形式来建模无线信道变化的方法，将时变的信道估计转变成有限参数变量在幂级数基上的投影，这大大减少了估计信道参数的个数。理论分析及仿真结果表明，该方法能有效地跟踪和估计时变的信道参数，具有良好性能。%Current channel estimation methods usually assume that the channel coefficients within an Orthogonal Frequency Division Multiplexing(OFDM) symbol period are constant. However, in high-speed scenario, the channels within an OFDM symbol vary obviously. The Inter-Carrier Interference(ICI) will affect the performance of conventional channel estimation methods, which degrades the performance greatly. A method in which the variations of wireless channels are modeled in the form of power series is proposed. The number of channel coefficients is reduced greatly by converting the time-varying channels to the projections of finite parameter variables on the basis of power series. Theoretical analysis and simulation results show that the method can achieve a good performance by tracing and estimating the time-varying channel coefficients efficiently.
展开▼
