IP-OFDMA采样时钟频率偏差与残余频偏估计

Sampling clock frequency offset and residual frequency offset estimation methods based on IP-OFDMA

为提高基于网络协议的正交频分多址(IP-OFDMA)系统中采样时钟频率偏差与残余频偏的估计精度,结合IP-OFDMA的自身导频结构特点,对经典估计方法进行改进,提出3种不同采样时钟频率偏差与残余频偏的估计方法.通过抛弃低频区离散导频子载波,有效抑制了低频噪声对估计性能的影响,提高了估计精度.理论分析以及在AWGN和COST207信道两种系统带宽下的仿真结果表明了该3种方法在复杂度和估计精度方面的差别,并给出选用原则和依据.

Three different sampling clock frequency offset and residual frequency offset estimation methods were developed to improve their estimation accuracy in internet protocol-orthogonal frequency division multiple access（IP-OFDMA） system, and the characteristics of the pilot structure in IP-OFDMA system was considered. The influence of low frequency noise on estimation performance was restrained by excluding the discrete pilots in low frequency domain, therefore the estimation accuracy was improved. Theoretical analysis and simulation results under AWGN and COST207 channels with two bandwidths reveal the difference of the three estimation methods in respect of complexity and estimation accuracy, and the selection principle to the three methods is given.