基于阵列天线的低复杂度OFDMA上行链路载频偏估计方法

Low Complexity CFO Estimation for OFDMA Uplink Based on Array-Antenna

提出一种基于阵列天线的正交频分多址(OFDMA)上行链路载频偏闭式盲估计方法,基站端配备阵列天线,该方法基于各天线阵元的空域快拍之间存在的旋转不变性,结合子空间平滑的思想,可在低运算复杂度的条件下,利用波达方向矩阵法得到信号空间的原始基底,由此可进一步同时获得各子载波对应用户的波达方向(DOA)与载频偏的闭式估计.该方法支持任意子载波分配方案以及满负载系统,并且可根据当前系统负载动态调整估计复杂度.理论分析和仿真结果验证了本文方法的有效性.

A novel method is proposed for multiuser carrier frequency offset（CFO） estimation for orthogonal frequency division multiple access（OFDMA） uplink with generalized carrier assignment scheme.The base station is equipped with array-antenna.Each user＇s CFO and direction of arrival（DOA） can be estimated by the DOA-Matrix method utilizing the rotation invariance of the space-domain snapshot matrix.The method is still effective even in fully loaded system with all subcarriers allocated to users,and the computational complexity can be adjusted dynamically according to the system load.Simulation results illustrate the high performance of the proposed algorithm.