基于LSQR算法和加窗技术的判决反馈均衡器  

LSQR-based and windowing decision feedback equalization

作　　者：韩华[1] 吴乐南[1] 

机构地区：[1]东南大学信息科学与工程学院,江苏南京210096

出　　处：《电路与系统学报》2010年第6期117-121,共5页Journal of Circuits and Systems

基　　金：国家自然科学基金项目资助(60872075);国家863计划项目资助(2008AA01Z227)

摘　　要：在正交频分复用(OFDM)系统中,高速移动造成的多普勒效应破坏了子载波间的正交性并产生载波间干扰(ICI)。为了消除ICI,确保快时变信道下的可靠通信,该文提出了一种低复杂度加窗LSQR(least square QR)判决反馈均衡器(Decision Feedback Equalization,DFE)。借助加窗技术和时域LSQR迭代计算,该算法减少了残存的ICI,有效克服了"地板效应";此外,该算法还利用带状矩阵LDLH分解降低了计算复杂度。理论分析和仿真结果表明,在快时变信道下与已有的块状线性均衡(Block Linear Equalization,BLE)算法比较,该算法在复杂度相当的情况下可以进一步改善系统的误码率性能。In orthogonal frequency division multiplexing （OFDM） systems, Doppler effect introduced by high mobility leads to the loss of subcarrier orthogonality and the occurrence of inter-carrier interference （ICI）. In this paper, a novel low complexity windowing least square QR Decision Feedback Equalizer （LSQR-DFE） is proposed in order to eliminate ICI and enable reliable communication over rapidly time-varying channels. The proposed equalization algorithm is able to reduce the residual ICI and overcome error floor by means of windowing and time-domain LSQR iterative computation; and in addition, to reduce complexity by exploiting banded matrix LDLu factorization. Compared with existing minimum mean square error block linear equalization（MMSE-BLE） algorithms, theoretical analysis and simulation results show that the proposed equalization algorithm can further improve the BER performance under the same complexity over rapidly time-varying channels.

关 键 词：正交频分复用 载波间干扰 加窗判决反馈均衡器 快时变信道 

分 类 号：TN92[电子电信—通信与信息系统]