An Efficient ICA Based Approach to Multiuser Detection in MIMO OFDM Systems

This paper proposes an ICA-based MIMO-OFDM system which efficiently overcomes problems inherent to ICA by using a precise and robust signal reconstruction method. It exploits the predetermined characteristics introduced to transmitted signals by a convolutional encoder at the transmitter to solve permutation indeterminacy, amplitude scaling ambiguity and phase distortion. Since, the introduced characteristics are only dependent on the convolutional code, despite the previous method, the proposed method is channel independent and robust. Moreover, the method is precise, because the accuracy of the introduced characteristics are fulfilled by an optimized convolutional code. We have compared the performance of the proposed MIMO-OFDM system with joint detection (JD) method which estimates the channels by using two training OFDM blocks. Although the JD method is a training based method, the performance of the proposed blind method is favorably comparable over slowly varying channels, and it dominates JD method over fast varying channels.