Coordinate transformation based Super-Exponential Iterative blind equalization algorithm

Constant Modulus Algorithm (CMA) with simple structure and robustness is not suitable for equalizing nonconstant modulus higher order QAM signals, it is necessary to turn nonconstant modulus higher order QAM signals into constant modulus fourth-order QAM in order to make CMA be used to equalize higher order QAM signals. Based on analyzing the coordinate transformation prinicple and Super-Exponential Iterative (SEI) property, a Super-Exponential Iterative blind equalization algorithm based on Coordinate Transformation (CT-SEI) is proposed. The proposed CT-SEI algorithm can obtain high convergence rate via using SEI algorithm and small steady-state error via turning nonconstant modulus higher order QAM signals into constant modulus fourth-order QAM. The performance of the proposed algorithm can be proofed by underwater acoustic channel simulation.