OFDM系统中相位噪声的自适应补偿技术及性能仿真

相位噪声对正交频分复用OFDM系统的性能有着关键性影响,其产生的通用相角错误CPE会使信道失真系数逐符号旋转,因而必须采用逐符号更新信道估计值的方法。提出了一种基于判决反馈的低通滤波算法来克服CPE所产生的信道旋转并提高信道估计的性能。该方法可通过导频子载波估计CPE所产生的信道旋转,并将解调后子载波的判决值通过低通滤波的方式降低信道估计的方差。文中采用了归纳法对该算法进行了理论分析,分析结果和仿真均证明了该算法的有效性,以及在计算量,收敛性方面的优势。

Adaptive Compensation Technique for Phase Noise in OFDM System and Performance Simulation

Phase noise is a key issue for the performance of OFDM system.CPE generated by phase noise can make rotation of channel distortion coefficient symbol by symbol.Therefore,the value of channel estimation should be updated with the variation of the received symbols.An algorithm based on decision feedback and low pass filter was proposed in order to overcome the rotation of channel distortion,which caused by CPE,and enhance the performance of channel estimation.Pilot sub-carriers were used to estimate the rotation of channel response caused by CPE.For lower deviation,low pass filter was employed to the decision of sub-carriers after demodulation.Analysis by induction method for the proposed algorithm is available.Simulation results and analysis demonstrate advantages of this algorithm in computational complexity, convergence,and performance.