Study On The Technology Of The ICA-based Blind MIMO-OFDM Receivers

In order to meet the users’ requirements of higher quality and higher data rates,wirelesscommunication technologies,under limited spectrum resources,faced with the serious challengesabout how to improve the efficient use of system bandwidth.The technology of MIMO-OFDMtakes the advantages of both MIMO and OFDM,and it will be the key technology for the nextgeneration mobile communication because of its high system capacity,spectrum efficiency andstrong anti-interference ability. In this paper,we apply the blind signal processing technology forthe MIMO-OFDM system to realize the blind extraction of mixed-signal at the receiver side, inorder to improve system spectral efficiency.The benefits of applying the blind method to theMIMO-OFDM system are that we can save spectrum resources and increase the spectrumutilization because we do not need to insert a training sequence or pilot at the transmitter side.Independent component analysis, which can extract the statistically independent and non-Gaussian components from the mixed-signals, is one of the most effective methods of the blindsource separation algorithm. In this paper, we introduce the correlation to the transmitted data viaprecoding. We can use the introduced correlation at the receiver side to overcome the scaling andorder indeterminacies of ICA.In addition, we study the preprocessing technique of ICA andespecially focus on the performance of ICA based on the source signals AR modeling. Severalsimulation experimental results demonstrate that the source signals AR modeling can improve theperformance of the ICA algorithm on numerical stability.In this paper,we do some researches about the ICA-based blind MIMO-OFDM receivers.Ourpurpose is to reduce the complexity of the receiver’s algorithm and improve receiver performance.By using a method of joint channel estimation and data detection,we apply the ICA algorithm atone reference sub-carrier,then we get the estimation of the other sub-carriers using the MMSEdetection method, we use SIC to eliminate the estimation error between the sub-carriers caused bythe MMSE method.We also present the complexity and performance comparison of three ICA-based blind MIMO-OFDM receivers,especially the proposed receiver obtains the performanceclose to the case with perfect CSI at receiver,but its complexity is about70%lower than themethod of applying ICA in each sub-carrier.