Blind Equalization Algorithm for Circle High-order QAM Signals

Aiming at equalizing circle high-order QAM signals, a hybrid blind equalization algorithm based on region is proposed. The algorithm modified a region based multi-modulus blind equalization algorithm suitable for square QAM signals by redividing the constellation and combines it with modified multi-modulus blind equalization algorithm to construct a new error function which matches the circle constellation well. Decision directed algorithm and data reusing are brought in to make up a hybrid blind equalization algorithm with low residual error and high convergence rate. Compared with other blind equalization algorithms, the new algorithm is more suitable for circle high-order QAM signals. It not only reduces the residual error but also cut down the number of symbols needed to get convergence greatly. Simulation results prove the feasibility of the new algorithm.