Optimal Pilot-Assisted Setting Method And The Application Of Channel Estimation In MIMO-OFDM Systems

The next generation mobile communication systems (B3G or 4G) are expected to providedata rate up to 100Mbps or even 1Gbps in order to support the multimedia services. Thecombination of MIMO and OFDM technique has greatly improved the communication capacityand transmission data rate, in the meantime, MIMO-OFDM system can effectively combatmulti-path fading, interference and noise. So this system has been considered widely as one ofthe most available scheme in physical layer of B3G/4G wireless communication system.However, for the broadband wireless mobile communication systems, the radio channel isfrequency selective and time-varying. An accurate estimation of channel is necessary fordiversity combining and decoding algorithm of space-time code. The accuracy of channelestimation will influence the performance of MIMO-OFDM systems directly. Channelestimation is one of the core problems must be solved in the application of MIMO-OFDMsystems, so this paper focus on this research area.After the introduction and analysis of channel's characteristic, the principle ofMIMO-OFDM systems is introduced in this paper. Corresponded to channel estimation coretechnique, several pilot-based channel estimation algorithms are probed, the performance of LSalgorithm and MMSE algorithm is also compared and analyzed. Furthermore, we deduce anoptimal pilot style method based on minimizing the MSE rule, and propose a novel channelestimation algorithm combining DFT iterative algorithm. Theoretical analysis and computationalsimulation results indicate that the proposed algorithm can acquire higher estimation accuracycompared to the method in IEEE 802.16 standard.