基于动态可变分段误差函数的常数模盲均衡算法

Constant modulus blind equalization algorithm based on dynamic variable segment error function

为了克服常数模算法(CMA)收敛速度慢,稳态误差大的缺点,在分析基于可变分段误差函数的常数模盲均衡算法的基础上,提出了基于动态可变分段误差函数的常数模盲均衡算法.该算法利用均方误差(MSE)来动态调节误差函数的分段点位置,误差函数特性在均衡过程中随着MSE不断变化,使得算法误差模型与发射信号的模型不断匹配,从而具有增加收敛速度和减小稳态误差的特点.分别用混合相位水声信道和最小相位水声信道对提出的新算法进行仿真实验,结果表明:对于混合相位水声信道,新算法的收敛速度明显快于CMA,且具有更小的稳态均方误差;对于最小相位水声信道,新算法的稳态均方误差明显小于CMA,而收敛速度相当.

In order to overcome the shortcomings of slow convergence speed and large steady-state error of Constant Modulus Algorithm（CMA） , on the basis of analysis of constant modulus blind equalization algorithm based on varia- ble segment error function, a constant modulus blind equalization algorithm based upon dynamic variable segment error function（DVSCMA） was proposed. The blind equalization algorithm adjusts the section position of the error function dynamically by using the Mean Square Error （MSE） , and the characteristics of the error function is chan- ging in the balancing process with the MSE, which enables the error model and the transmit signal model to match continuously, thus accelerate the convergence speed and reduce the steady state error. The new algorithm is simula- ted by using mixed-phase and minimum phase of underwater acoustic channel. The simulation results demonstrate that the proposed algorithm has significantly faster convergence rate and lower steady-state mean square error com- pared with the CMA for the mixed-phase of underwater acoustic channel, while the new algorithm has significantly lower steady-state mean square error and very close convergence rate compared with the CMA for the minimum phase of underwater acoustic channel.