OFDM系统在循环前缀不足时的两种高效迭代均衡方法

Two Efficient Iterative Equalization Schemes for OFDM Systems with Insufficient CP

本文提出两种新的用于循环前缀(CP)不足时正交频分复用(OFDM)系统的迭代均衡方法。首先,我们提出并行迭代均衡(PIE)方法,该方法分别使用时域判决反馈方法和频域并行迭代方法来消除符号间干扰(ISI)和子载频间干扰(ICI)。为了改进PIE的性能,提出基于高斯-塞德尔迭代的串行迭代均衡(SIE)方法。在不增加计算复杂度的情况下,SIE具有比PIE更快的收敛速度。仿真结果表明,新方法可以在几次迭代后得到接近CP足够情况下的系统性能,PIE的性能与传统的迭代干扰消除方法相同,而SIE则提供好得多的收敛性能。

This paper presents two novel iterative equalization schemes for orthogonal frequency-division multiplexing （OFDM） systems when the cyclic prefix （CP） is not sufficient. First,we introduce the parallel iterative equalization （PIE） scheme, which uses time-domain decision-feedback method and frequency-domain parallel iterative method to suppress intersymbol interference （ISI） and intercarrier interference （ICI）, respectively. In order to improve the performance of PIE, successive iterative equalization （SIE） scheme based on Gauss-Seidel iteration is proposed. SIE offers faster convergence rate than PIE without increasing the computational complexity. It is shown that the proposed schemes can approach the system performance with sufficient CP after only a few iterations. PIE has the same performance as conventional iterative interference cancellation method,while SIE provides significantly better convergence performance.