OFDM系统基于导频的DFT信道估计改进算法

DFT-based pilot-symbol-aided channel estimation in OFDM systems

针对实际OFDM系统中存在非整数倍采样多径时延、导频非均匀插入以及噪声区间不连续的情况,分别采用加窗、导频LS估计值归位、噪声功率迭代的方法,对基于导频的DFT信道估计算法进行改进,并通过计算机仿真验证改进算法性能。仿真结果表明,改进算法性能介于LS算法与LMMSE算法之间,优于传统DFT算法,在信噪比20 d B时提供近3 d B性能增益,同时简化算法复杂度,适合硬件实现。

Considering non-sample-spaced muhipath time delay, non-equal pilot interpolation and non- successive noise interval, an improved DFT-based pilot-symbol-aided channel estimation algorithm is pro- posed by data windowing, LS estimation results putting back and noise power iteration. The improved al- gorithm is verified by simulation. Simulation results show that the performance of the improved algorithm is between perfporrnances of LS and LMMSE, thus its performance is better than that of traditional Dlrl＂ algorithms and provides approximately 3dB gain at SNR of 20dB. Meanwhile, it can simplify the com- olexitv and is suitable for the hardware realization.