Research On Channel Estimation And Pilot Design In MIMO-OFDM Systems

Orthogonal Frequency Division Multiplexing (OFDM) has been standardized for a variety of applications, such as digital audio broadcasting (DAB), digital video broadcasting (DVB), wireless local area network (WLAN), and asymmetric digital subscriber line (ADSL), due to its simple implementation and robustness against frequency-selective fading channels. Combing OFDM with multiple antennas has been shown to mitigate the fading effect, and to provide significant increase in capacity through the use of transmitter and receiver diversity. However, such systems rely upon the knowledge of channel state information at the receiver, or they are determined by the performance of channel estimate.Understanding channel's propagation mechanism and setting up accurate and effective channel model are critical for evaluating estimation algorithms and pilot designs. This dissertation describes properties and modeling methods for multipath fading channel in chapter 2 and MMO channel in chapter 4, which are the preparations for later research.Channel state information can be obtained through two types of methods.