时频双选信道OFDM系统的ICI消除与均衡

在正交频分复用（OFDM）系统中，因高速移动造成的多普勒效应导致子载波间正交性的破坏并产生载波间干扰（ICI）。为了消除ICI，本文通过分析ICI分布特性及带状矩阵特性，提出了低复杂度的迭代干扰抵消算法和基于最小均方误差准则的排序串行干扰抵消(MMSE-OSIC)算法。仿真结果表明，与传统子载波间干扰频域均衡算法相比，新算法在计算复杂度和性能之间取得了良好的平衡，且MMSE-OSIC算法可以利用时变信道的时间分集特性在高信噪比情况下有效地消除“地板效应”。 

ICI Cancellation and Equalization for OFDM over Doubly-Selective Channel

In orthogonal frequency division multiplexing (OFDM) systems, Doppler effect introduced by high mobility leads to the loss of subcarrier orthogonality and the occurrence of inter-carrier interference(ICI). In order to eliminate ICI, by exploiting the ICI distribution and banded matrix property, a novel low complexity iterative interference cancellation algorithm and minimum-mean-squared error with ordering successive interference cancellation (MMSE OSIC) algorithm are proposed. Compared with the traditional ICI one-tap frequency domain equalization algorithm, simulation results show that the new schemes obtain the tradeoff between computational complexity and performance. The proposed MMSE-OSIC could effectively eliminate “error floor” by using the time diversity of time-varying channel in high SNR environments.