The combination of the effects of Doppler frequency shifts (due to mobility) and phase noise (due to the imperfections of oscillators operating at a high carrier frequency) poses serious challenges to Orthogonal Frequency Division Multiplexing (OFDM) wireless transmissions in terms of channel estimation and phase noise tracking performance and the associated pilot overhead required for that estimation and tracking. In this paper, we use separate sets of Basis Expansion Model (BEM) coefficients for modelling the time variation over intervals of several OFDM symbols of the channel paths and the phase noise process. Based on this model, an efficient solution approximating the maximum-likelihood joint estimation of these BEM coefficients is derived and shown to outperform state-of-the-art phase noise compensation methods
翻译:多普勒频率变化(由于流动性)和阶段噪音(由于在高载荷频率下运行的振动器不完善)的综合效应,在频道估计和阶段噪音跟踪性能方面,以及这种估计和跟踪所需的相关试点间接费用方面,对矫形频率多发分多发传输(OFDM)无线传输构成严重挑战。在本文件中,我们分别使用几套基础扩展模型(BEM)系数来模拟频道通道和阶段噪音过程若干调离DM符号的间隔时间变化。根据这一模型,得出并展示出一种高效的接近最大相似性联合估计这些BEM系数的有效解决方案,以超越最先进的阶段噪音补偿方法。