基于FSAGE的OFDM系统信道与频偏联合干扰消除算法  

Interference cancellation algorithm for joint frequency offset and channel in OFDM system based on FSAGE algorithm

作　　者：李玉峰[1,2] 关庆阳[2] 沈连丰[1] 

机构地区：[1]东南大学移动通信国家重点实验室,南京210096 [2]沈阳航空航天大学电子信息工程学院,沈阳110136

出　　处：《东南大学学报（自然科学版）》2013年第6期1141-1146,共6页Journal of Southeast University：Natural Science Edition

基　　金：国家自然科学基金资助项目(61171081);江苏省博士后科学基金资助项目(1101077C);航空科学基金资助项目(20122654004)

摘　　要：针对正交频分复用(OFDM)系统服务应用在诸如城区等信道多径衰落严重的场景,提出一种信道及载波频偏联合干扰消除的频域空间选择性期望最大化(frequency-space-alternating generalized expectation-maximization,FSAGE)算法.该算法首先对频域频偏进行预估计及预消除,然后通过权值迭代方式进行信道干扰消除及频偏精确跟踪.仿真结果表明,该算法能够降低信道与频偏干扰消除算法的迭代次数和处理时延,有效地消除由于信道多径衰落以及频偏引入的联合干扰.与空间选择性期望最大化(space-alternating generalized expectation-maximization,SAGE)算法相比,所提出算法的性能有较大提高.当信噪比为20 dB时,可获得较优的误码率.Aiming at orthogonal frequency division multiple（OFDM）systems in serious multi-chan-nel fading environments such as in an urban service scene,a frequency-space-alternating generalized expectation-maximization （FSAGE）algorithm is proposed to cancellthe interference introduced by frequency offset and channel fading.The algorithm first estimates and pre-cancellthe frequency off-set,and then removes the channel interference and precisely tracks the frequency offset by weighting the iterative method.Simulation results show that the algorithm can reduce the cancellation iterative times and processing delay,and effectively eliminate the interference introduced by multi-path fading channel and frequency offset.Compared with the space-alternating generalized expectation-maximi-zation （SAGE）algorithm,the performance of the proposed algorithm is greatly improved.When the signal-to-noise ratio （SNR）is 20 dB,the algorithm has a proper bit error rate （BER）.

关 键 词：正交频分复用 频域空间选择性期望最大化算法 时变信道 频偏 

分 类 号：TN911.72[电子电信—通信与信息系统]