OFDM系统中基于卡尔曼滤波和FFT的信道估计算法

Kalman filter and FFT-based channel estimation algorithm in OFDM system

本文提出了一种OFDM系统中基于卡尔曼滤波和FFT的二维导频辅助信道估计算法。OFDM系统作为一个多载波传输系统,其信道估计需要在时间和频率两个方向同时进行。在这种新算法中,首先在时间方向上采用标量卡尔曼滤波器对导频处信道信息进行估计,然后在卡尔曼估计的基础上进行频率方向上的FFT插值,从而估计出全部的信道信息。在性能上这种新方法与基于维纳滤波器的信道估计算法接近,但实现更为简单,更适合应用于实时传输系统的信道估计。

This paper proposes a new channel estimation algorithm based on Kalman filter and FFT in 2D-pilot-symbolaided Orthogonal Frequency Division Multiplexing （OFDM） mobile communication system. As a multi-carrier transmission system, the channel estimation for OFDM is supposed to fulfill channel estimation in both time and frequency domain. In this new algorithm, a scalar Kalman filter is used to predict the channel impulse response （cir） in the time domain, and then FFT interpolation is performed in the frequency domain to get the whole picture of the channel information. The performance of this new algorithm is close to that of the Wiener filter-based algorithm, but this new algorithm is much easier to implement and much more suitable to be used in real-time transmission system.