卫星信道中基于部分解耦的volterra均衡算法

对信道中大功率放大器产生的非线性特性实现快速有效地均衡是提高卫星通信系统性能关键技术之一。文中首先建立了基于volterra级数的卫星信道模型，并分析了信道对二维调制信号所产生的非线性影响；针对基于最小均方误差实现的volterra均衡器收敛速度慢这一问题，提出了基于复基带volterra模型的部分解耦均衡算法，该算法使均衡器线性权系数收敛于线性滤波器最优解，并用拉格朗日乘数法构造了新的代价函数，使均衡器的各阶权系数满足约束，以达到均衡器各阶权系数之间的解耦。仿真结果表明，新算法在保证稳态误差的条件下，其收敛所需迭代次数相对于全耦合的最小均方误差算法从16 000次减小到1 000次。

Partially decoupled volterra equalizer for digital satellite channels

To improve the performance of satellite communication systems, one of the key problems is to realize the equalization of the nonlinearity generated by the high-power amplifier of the channel. This paper firstly establishes a satellite channel model based on volterra series and analyses the nonlinear effects of two-dimensional modulation signals generated by the channel. For the slow convergence of the volterra equalizer based on the minimum mean square error, a partially decoupled equalization algorithm based on the volterra model of complex baseband is proposed. To achieve the decoupling between the each weight of equalizer, the linear weights of equalizer are forced to converge to the optimal solution of the linear filter and the new cost function is constructed using the Lagrange multiplier method for the every order coefficients of the equalizer to satisfy the constraints. Simulation results show that, compared with the whole coupling minimum mean square error algorithm, the new algorithm ensures the steady-state error and the number of iteration required for the convergence of algorithm is reduced from 16 000 to 1 000 times.