Nonlinear Signal Estimation Using Semi-Blind Mutually Referenced Equalizers in Convolutive Mixture

Nonlinearity is a common source of signal and channel distortion in digital communication. In many circumstances, such distortions must be compensated by equalization algorithms or devices. This paper presents a semi-blind equalization method for nonlinear multichannel signal recovery in convolutive mixtures. The proposed work takes into account quadratic nonlinearities and applies the mutually referenced equalization (MRE) approach to estimate the equalizer as well as estimate the transmitted signal from the nonlinear convolutive mixture. The proposed semi-blind model combines both data and pilots in addition to the MRE technique to develop a cost function that provides an equalization solution. The proposed technique has various advantages, including robustness to channel order misspecification, implementational simplicity, and provides a single solution for several equalization delays. The simulation results show that the proposed technique has intriguing performance features with robustness to low SNR.