短波OFDM系统中基于迭代插值的信道估计

经典的线性插值算法具有实现简单的优点,但短波信道是靠电离层反射进行通信,而电离层的分布是随机变化的,导致短波信道随机变化.所以数据子载波的频域响应与相邻导频子载波频域响应之间不再满足线性关系,即线性插值算法不适用于短波OFDM系统中.基于此提出了一种迭代的插值算法,该算法利用了两个距离最近的子载波的信道响应的相关性越大的原理,利用信号的相关性进行迭代,从而得出频域的信道估计.仿真表明,该插值算法有效拟合了短波信道特性曲线,降低了系统的误比特率和均方误差.

Channel Estimation Based on Iterative Interpolation for Shortwave OFDM System

Classical linear interpolation algorithm has the advantage of simple, but Shortwave channel communicate with ionospheric reflection, Shortwave channel is random variation with change of ionosphere, so data subcarrier in the frequency response and the adjacent pilot subcarriers in the frequency domain response is not a linear relationship, that existing linear interpolation algorithm is not suitable for Shortwave OFDM system. Propose an Iterative interpolation algorithm for Shortwave OFDM system. The algorithm utilizes principle of the greater relevance with closer two subcarriers in the frequency domain response, and then use signal correlation signal to iterative to obtain the frequency domain channel estimation.The simulation results show that the Proposed interpolation algorithm can fit a shortwave channel characteristic curve, reducing the bit error rate and the mean square error of system.