【摘要】 为克服正交频分复用(OFDM)系统中因时变多径衰落信道破坏子载波的正交性引起载波间干扰(ICI),从而导致系统性能下降的问题,提出了一种基于最小均方误差(MMSE)估计和迭代算法相结合的迭代干扰抵消算法。为了消除一般MMSE均衡方法将载波间干扰当作加性高斯白噪声(AWGN)所带来的误差,该算法先使用MMSE方法对传输信号进行初值估计,再通过迭代干扰抵消和MMSE均衡相结合,来消除由时变信道所带来的载波间干扰。多次仿真表明,在时变多径衰落信道中使用本算法能够有效地消除载波间干扰,使系统性能得到很好的改善。更多还原

【Abstract】 To overcome the problem that the time-varying multipath fading channel in an orthogonal frequency division multi- plexing(OFDM)system leads to the loss of subcarrier orthogonality which in turn causes the inter-carrier interference (ICI)and increases the system’s inaccuracy in signal detection,this paper proposes an iterative ICI cancellation algo- rithm based on the combination of the minimum mean square error(MMSE)estimation with the iterative algorithm.To avoid the inaccurate assumption in conventional one-tap ICI cancellation that ICI is modeled as the additive white Gaus- sian noise(AWGN),the algorithm uses the MMSE principle to estimate the initial value of the transmitted signal,and then eliminates the ICI caused by the time-varying multipath fading channel by the iterative ICI cancellation and MMSE equalization.The extensive simulations show that through a small number of iterations the ICI can be cancelled effective- ly,and the system performance can be improved.更多还原