Output Error Sign Based Variable Step Size CMA Blind Equalization Algorithm
Xiao Yin · Dalian Minzu Xueyuan xuebao · 2014
To sovle the contradictory problem in convergence rate and precision of constant modulus blind equalization algorithm with constant step size,a new variable step size method based on the sign decision of the output error is proposed. The output error can be obtained according to the constant modulus criterion and decision directed criterion respectivelly after each iteration. If the output error sign in the two criterion is consistent,the small step size is used in the algorithm. Otherwise,the maxmum step size calculated according to the adaptive equalization principle the input sign of the euqalizer is used for updating the equalizer coefficient. Compared with the existing variable step- size blind equalization algorithm,the proposed algorithm in the paper is without manual parameter setting,so it is more beneficial to engineering application. Computer simulation results show that the CMA blind equaliaztion with the variable step size based on the sign decision of the output error has a good performance.