关键词: 修正常数模算法, 变步长, 判决引导算法, 星座图匹配误差函数, 剩余码间干扰

Abstract: This paper proposes a novel Varying Step Size Modified Constant Modulus Algorithm（VSS-MCMA）. And on this basis, this paper presents another new decision directed variable step size MCMA（DD-VSS-MCMA） based on the Mean Square Error（MSE）, that is, the VSS-MCMA is switched to the DD algorithm when the MSE is small enough. Furthermore, the constellation matched error（CME） function is inserted into the cost function of the DD-VSS-MCMA and the CME-DD-VSS-MCMA algorithm is put forward. The simulation results show that the proposed VSS-MCMA can simultaneously improve the convergence and the steady-state residual ISI performance compared with MCMA, DD-VSS-MCMA can further reduce the residual Inter-Symbol Interference（ISI）, and the presented CME-DD-VSS-MCMA can speed up the convergence and can attain slower residual ISI.  

Key words: modified constant modulus algorithm, variable-step-size, decision-directed, constellation matched error, residual Inter-Symbol Interference（ISI）