OFDM系统中抗频偏的改进方案

在高速移动环境下,宽带正交频分复用(orthogonal frequency division multiplexing,OFDM)系统在传输过程中因频率偏差都会导致严重的子载波间干扰(inter-carrier interference,ICI)。本文在分析频偏导致ICI成因基础上,结合共轭消除方案和编码权值优化方案,提出一种有效的ICI自消除新方案。仿真结果表明,所提出的方案在较大频偏范围内具有较高的载干比(carrier-to-interference ratio, CIR)和较低的误比特率(bit error rate, BER),且能有效消除传统自消除编码性能的“平层效应”,进而获得了系统性能的改善。

Improved scheme of resistance frequency offset in OFDM system

The frequency offset of the broadband orthogonal frequency division multiplexing (OFDM) system will lead to inter-carriers interference (ICI) in high mobile environment. Based on the analysis of the frequency offset causing ICI, a new effective self-cancellation scheme for mitigating ICI is proposed, which connects with the conjugate solution and the optimized coefficients. Simulation results show that the new scheme can acquire higher carrier-to-interference ratio (CIR) and lower bit error rate (BER) in a wide range of frequency offset, and can validly remove the “error floor”, and obtain the performance improvement.