Joint Estimation of Frequency Offset and Channel Parameters for MIMO-OFDM Systems

• Main Authors: Ming-Hua Lee, 李明華
• Other Authors: Miin-Jong Hao
• Format: Others
• Language: en_US
• Published: 2010
• Online Access: http://ndltd.ncl.edu.tw/handle/66352247475150856444

碩士 === 國立高雄第一科技大學 === 電腦與通訊工程所 === 98 === Multiple antennas technique can be used in OFDM systems to improve communication quality and capacity. If we want to take advantage of multiple input multiple output (MIMO) technique, accurate channel state information (CSI) is needed. With the number of antennas increasing, multipath channel estimation becomes more difficult. Moreover, MIMO OFDM is very sensitive to carrier frequency offset (CFO). In this thesis, joint frequency offset and channel estimation scheme for MIMO-OFDM systems is addressed. Conventional maximum likelihood (ML) solution for this joint case is too complex. We turn to Expectation-Maximization (EM) algorithm with an iterative scheme to overcome. We develop a frame structure as the transmission unit and the beginning of the frame is a preamble to estimate purpose. The simulation results verify the good performance of the CFO and channel estimators by making use of EM algorithm.