基于TD-NLMS的航空移动通信OFDM系统载波频率偏移消除

摘要

针对航空移动通信中时变的信道环境和多普勒频移造成的子载波间干扰(ICI),提出了一种时域自适应归一化最小均方误差算法(TD-NLMS)来消除航空移动信道正交频分复用(OFDM)系统中载波频率偏移引起的干扰.该算法首先对接收的时域信号进行频偏预估计和预补偿,然后对剩余载波频移进行消除.仿真结果表明:在航空移动信道环境中,新算法可以很好的对旋转相位进行补偿,与最小二乘算法相比,误码率性能有明显提高,可以实现对载波频率偏移的消除.%Towards the complex channel environment and the inter-carriers interference (ICI) caused by Doppler frequency offset, a time domain adaptive algorithm based on normalized least mean square (TD-NLMS) is proposed to eliminate the interference caused by the carrier frequency offset (CFO) in aeronautical mobile communication OFDM system. In this algorithm, the CFO in time domain is estimated and compensated, and then the residual CFO is eliminated with TD-NLMS method. The simulation results show that in the aeronautical mobile channel environment, the use of the proposed algorithm can not only compensate the phase rotation, but also reduce the bit error rate to improve the accuracy and eliminate the CFO compared with that of the least square (LS) algorithm.