A Residual Carrier Tolerant QAM Receiver Architecture Based on Time-Varying Blind Source Separation

In case of Quadrature amplitude modulated (QAM) transmission, the residual carrier affects the quality of the received signal. We show that the carrier tracking problem is equivalent to a time-varying Blind source separation (BSS) problem if there exists a residual carrier. This motivates us to propose a new receiver architecture, that is tolerant to residual carrier, based on a Recursive least squares (RLS) BSS algorithm. Simulations are provided to show the promising performance of the proposed algorithm for tracking the residual carrier and for improving the quality of the received signal.