Abstract: Concerning the defect that Volterra structure equalizer has large amount of computation, an improved adaptive equalizer of nonlinear satellite channel was proposed, and a new cascade structure of a linear equalizer and a nonlinear equalizer were obtained by analyzing the truncated Volterra series. The third-order nonlinear memory term multiplying in the Volterra equalizer expression was converted to second-order nonlinear memory term multiplying in the new structure equalizer. When signals passed through the equalizer, the number of complex multiplications was reduced. The simulation results show that the number of complex multiplications of improved nonlinear satellite channel adaptive equalizer is 1/9 times as that of Volterra equalizer when channel has strong memory depth. Meanwhile, 16 Amplitude Phase Shift Keying (16APSK) signal equalized by the improved adaptive equalizer has more compact constellation points.

Key words: Volterra equalizer, nonlinear satellite channel, improved structure, cascade, computation

摘要： 针对常用的Volterra结构均衡器运算量大的问题，提出一种改进结构的非线性卫星信道自适应均衡器。通过对截断Volterra级数进行数学分析，得到了具有非线性均衡器和线性均衡器级联形式的新均衡器结构。新结构均衡器将Volterra结构均衡器表达式中的三阶记忆项相乘转变为新模型非线性部分的二阶记忆项相乘，降低了信号通过均衡器所需的复数乘法次数。仿真结果表明,改进结构的非线性卫星信道自适应均衡器运算所需的复数乘法次数在信道记忆很深的情况下约为Volterra结构均衡器的1/9，有利于信号的实时处理。与此同时，经改进均衡器均衡输出的16振幅移相键控调制（16APSK）信号的星座点更为紧凑。

关键词: Volterra均衡器, 非线性卫星信道, 改进结构, 级联, 运算量