基于均衡代价函数的信道阶数盲估计算法

A Blind Algorithm for Channel Order Estimation Based on Equalization Cost Function

针对信道阶数估计问题,利用单输入多输出(Single-Input Multiple-Output,SIMO)有限冲激响应(Finite Impulse Response,FIR)信道的结构特点和输入/输出信号的统计特征,提出了一种基于均衡代价函数的信道阶数盲估计算法.首先计算了归一化最小二乘均衡(Normalized Least Squares Equalization,NLSE)代价函数在理想条件下的理论渐近值,并指出其拐点与信道阶数之间的对应关系.然后分析了NLSE代价函数在实际条件下的近似值.最后引入了拐点优化因子,提出了一种基于NLSE代价函数拐点检测的信道阶数估计算法.理论分析和仿真结果表明,在信噪比(Signal-toNoise Ratio,SNR)较低和信道首尾系数较小的情况下,该算法比现有其它方法具有更强的鲁棒性,可以获得更小的接收信号均衡误差.

Addressing the problem of channel order estimation,a blind algorithm for channel order estimation is proposed based on the equalization cost function,which utilizes the architecture of single-input multiple-output（SIMO） finite impulse response（FIR） channels and the statistical characteristic of input/output signals.First,the theoretical asymptotic value of normalized least squares equalization（NLSE） cost function is calculated under the ideal condition,and the link between its corner and channel order is pointed out.Then,its approximate value is analyzed under the practical condition.Finally,a corner optimization factor is introduced,and a channel order estimation algorithm is proposed by exarnining the NLSE cost function corner.Theoretical analysis and simulation results show that the algorithm is more robust than the other existing techniques in the case of low signal-to-noise ratio（SNR） and small leading/trailing channel coefficients,which leads to smaller equalization error.