中文摘要：

在考虑分布式多入多出（MIMO）系统中各收发天线对之间的频偏均可能不同的一般情况下,推导出了平坦衰落MIMO信道模型下的最大似然频偏估计。针对收端是否采用分布式天线的两种不同情况,分别提出了一种只涉及一维最大化问题的较低复杂度频偏估计方法。仿真结果表明,所提频偏估计方法在平坦衰落MIMO信道下可以获得令人满意的估计性能;而在收端仍采用集中式天线这一特殊情况下,利用所有接收天线上的接收信号进行联合估计,可以进一步提高估计性能。

英文摘要：

In consideration of the general case where the frequency offsets（FO） between each transmitting anten- na and each receiving antenna are possibly different in distributed multi-input multi-output（MIMO） systems, the maximum likelihood（ML） FO estimation in flat - fading MIMO channels is derived. Aiming at the cases with co- located and distributed receiving antennas, two low-complexity FO estimation methods involving only 1-dimen- sional maximization are proposed, respectively. Simulation results show that the proposed FO estimation methods can achieve satisfactory performance in flat-fading MIMO channels. While in the special case where the receiv- ing antennas are still co-located, the estimation performance can be further improved by joint estimation using all receiving antennas.