多载波系统中基于镶嵌算法的载频间干扰消除方案

Inter-Carrier Interference Cancellation Based on Cyclic Embedding for Multicarrier Communication Systems

为消除正交频分复用(OFDM)系统中的载波间干扰,在对干扰系数分析与合理估计的基础上,提出了一种基于频域均衡思想的解相关干扰抑制方案.通过干扰矩阵的循环镶嵌算法来消除载频间干扰,抑制系统中的地板效应.与传统的频域均衡方法相比,该方案省去了迭代运算与信道矩阵的求逆运算,计算简便,具有稳定的收敛性,并且适用于无线多径信道和高速移动的环境.仿真结果表明:在系统归一化频偏为0.2时,该方案的系统信干比比标准的OFDM系统提高了32dB,比干扰自消除方案提高了5dB;在系统误码率为10-4时,该方案的信噪比比干扰自消除方案提高了2～3dB.

In order to eliminate intercarrier interference (ICI) of orthogonal frequency-division multiplexing (OFDM) communication systems, based on interference coefficients analysis and reasonable estimation, a novel decorrelation interference cancellation scheme using frequency-domain equalization was proposed. By using the cyclic embedding algorithm of interference matrix, this scheme can directly eliminate intercarrier interference and restrain the floor effect of systems. Compared to the conventional frequency-domain equalization, the new scheme has better convergence reliability and lower computational complexity without requiring the iterative operation and the inverse operation of matrix, and is suitable for applying to the wire less multipath channel and high speed mobile environments. Simulation results indicate that the signal-to-interference ratio of the proposed scheme can be 32 dB more than the standard OFDM system, 5 dB more than the interference self-cancellation scheme when the normalized frequency offset is 0.2, and the signal-to-noise ratio of the proposed scheme can be increased 2-3 dB when the bit error ratio is 10-4.