Improved mutimodulus blind equalization algorithm for multi-level QAM signals with impulsive noise

To solve the significant performance degradation in the blind equalization for multi-level quadrature amplitude modulation (QAM) signals, an improved multimodulus algorithm based on the real part (or the imaginary part) of the transmitted signals is developed in this paper. Theoretical analysis illustrates that the proposed algorithm can roughly half the computational complexity and fundamentally suppress the well-known steady-state maladjustment of classical constant modulus algorithm and multimodulus algorithm. Moreover, the large maladjustment in the iteration process can be completely removed, thus the proposed algorithm can work well in impulsive noise environment. Finally, simulation results show the effectiveness of the proposed algorithm under both Gaussian and impulsive noise environments.