复杂条件下多用户的频偏估计算法研究

Research on an algorithm for multi-user frequency-offset estimation under complicated conditions

针对瑞利衰落信道存在定时不准、移动车载、多UE(用户设备)间干扰和收发端具有固有频偏的情况,提出了一种全新的适用于LTE(长期演进)系统多UE下基站侧的频偏估计方法。该方法先估计由于加窗产生的频域展宽大小,分析频带相邻的UE带来的频偏干扰功率的大小和范围,设计去除相邻UE带来的干扰;再利用频偏与互相关函数的关系估计频偏。链路仿真结果表明,该方法降低了UE间干扰,很大程度上克服了多径效应与定时不准带来的影响,得到了优于在这之前的各种方法的频偏估计拟合度和误块率性能。

For Rayleigh fading channels with inaccurate timing, vehicle moving, inter-User Equipment （UE） interference and innate frequency offset at the receiver/transmitter sides, this paper proposes a novel method suitable for the frequency offset estimation at multi-UE base station side of LTE systems. It first estimates the size of frequency domain broadening generated by window function. Then it analyzes the size and scope of the frequency offset interferences brought about by band-adjacent UE and designs to eliminate these interferences. Finally, it estimates the frequency offset by utilizing the relationship between the frequency offset and the cross-correlation function. The link simulation results show that this method reduces the inter-UE interferences and overcome the influences resulted from multipath effects and inaccurate timing to a great extent, achieving superior frequency offset estimation fitting and block error rate performance to those in various conventional methods.