ICA-based Signal Equalization for Digital Receivers

A technique using Independent Component Analysis (ICA) for blind receiver signal processing is investigated. The problem of the receiver signal processing is viewed as of signal equalization and implementation imperfections compensation. Based on this, a model similar to a general ICA problem is developed for the received signal. Then, the use of ICA technique for blind signal equalization in the time domain is presented. The equalization is regarded as a signal separation problem, since the desired signal is separated from interference terms. A common problem using ICA-based techniques is to find a satisfactory number of the mixing signals to populate the mixing matrix. This problem is addressed in the paper by over-sampling of the received signal. By using ICA for equalization, besides channel equalization, other transmission imperfections such as DC bias offset, carrier phase and IQ imbalance will also be corrected. Simulation results for a system using 16-QAM modulation are presented to show the performance of the proposed scheme.