ESTIMATION OF CARRIER FREQUENCY OFFSETS FOR MIMO SYSTEMS WITH DISTRIBUTED TRANSMIT ANTENNAS  

作　　者：Deng Kai Tang Youxi Lei Xia Li Shaoqian 

机构地区：[1]National Anti-jamming Communications Laboratory, University of Electronic Science and Technology of China, Chengdu 610054, China

出　　处：《Journal of Electronics(China)》2007年第4期455-461,共7页电子科学学刊（英文版）

基　　金：the National Natural Science Foundation of China (No. 60272009, No. 60572090, No. 60472045, No. 60496313 and No. 60602009).

摘　　要：The problem of estimating the carrier frequency offsets in Multiple-Input Multiple-Output (MIMO) systems with distributed transmit antennas is addressed. It is supposed that the transmit antennas are distributed while the receive antennas are still centralized, and the general case where both the time delays and the frequency offsets are possibly different for each transmit antenna is considered. The channel is supposed to be frequency flat, and the macroscopic fading is also taken into consideration. A carrier frequency offset estimator based on Maximum Likelihood (ML) is proposed, which can separately estimate the frequency offset for each transmit antenna and exploit the spatial diversity. The Cramer-Rao Bound (CRB) for synchronous MIMO (i.e., the time delays for each transmit antenna are all equal) is also derived. Simulation results are given to illustrate the per- formance of the estimator and compare it with the CRB. It is shown that the estimator can provide satisfactory frequency offset estimates and its performance is close to the CRB for the Signal-to-Noise Ratio (SNR) below 20dB.The problem of estimating the carrier frequency offsets in Multiple-Input Multiple-Output （MIMO） systems with distributed transmit antennas is addressed. It is supposed that the transmit antennas are distributed while the receive antennas are still centralized, and the general case where both the time delays and the frequency offsets are possibly different for each transmit antenna is considered. The channel is supposed to be frequency flat, and the macroscopic fading is also taken into consideration. A carrier frequency offset estimator based on Maximum Likelihood （ML） is proposed, which can separately estimate the frequency offset for each transmit antenna and exploit the spatial diversity. The Cramer-Rao Bound （CRB） for synchronous MIMO （i.e., the time delays for each transmit antenna are all equal） is also derived. Simulation results are given to illustrate the per- formance of the estimator and compare it with the CRB. It is shown that the estimator can provide satisfactory frequency offset estimates and its performance is close to the CRB for the Signal-to-Noise Ratio （SNR） below 20dB.

关 键 词：Multiple-Input Multiple-Output （MIMO） Distributed antenna Carrier frequency offset estimation Maximum Likelihood （ML） Cramer-Rao Bound （CRB） 

分 类 号：TN914[电子电信—通信与信息系统]