在分数倍频偏(fractional frequency offset,FFO)估计中,噪声和信道衰落的影响可能会导致FFO估计结果的极性翻转,使得FFO估计精度大大降低,OFDM系统的同步性能不可避免地恶化。针对LTE-Advanced系统,设计了一种有效的利用主同步信号(primary synchronization signal,PSS)的镜像对称特性的FFO 极性估计算法,联合基于CP的FFO绝对值估计方法,给出了一种高精度的FFO估计方法。仿真结果表明,所提方法能有效地降低FFO估计精度翻转的问题,保证了同步性能。
Abstract
Traditional fractional frequency offset(FFO)estimation algorithm pay less attention to FFO polarity estimation.Noise and channel fading induced FFO estimation polarity reversion degrades the frequency synchronization performance inevitably.An efficient FFO polarity detection method was proposed in LTE-Advanced system to solve the problem,which utilized the mirror symmetry property of time-domain primary synchronization signal(PSS).Numerical results show that the proposed method can depress FFO polarity reversion efficiently.
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