一种改进的数字同频直放站自适应反馈干扰抑制算法

基于数字地面电视广播(Digital Terrestrial Television Broadcasting,DTTB)同频直放站的回波干扰抑制,提出了一种变步长块LMS(Variable Step- size Block Normalized Least Mean Square,VSSBNLMS)自适应算法.此算法的目的是为了提高传统回波干扰抑制的自适应算法的收敛速度和降低计算复杂度.其将输入信号分为长度相等的块,在每一个数据块内,权值向量只更新一次,有效地降低了计算复杂度.另外,该算法通过输出误差控制更新步长的变化,与传统的归一化LMS(NLMS)和块LMS(BLMS)算法相比,提高了收敛速度.仿真结果表明,该算法具有良好的收敛速度和回波干扰抑制性能.

An improved adaptive feedback interference cancellation algorithm for digital on-channel repeaters

A variable step-size block normalized least mean square(VSSBNLMS) algorithm is derived to cancel the feedback interference in a Digital On-Channel Repeater(DOCR) for the Digital Terrestrial Television Broadcasting(DTTB) networks.Its purpose is to improve the conventional adaptive algorithm′s convergence speed and decrease the computational complexity for the feedback interference cancellation.By dividing the input signal into blocks with the same length and updating the tap weights once per every block,the computational complexity can be decreased effectively.Furthermore,variable step-size is applied to increase the convergence speed.Compared with the NLMS and BLMS algorithms,VSSBNLMS algorithm achieves more rapid convergence.Simulations illustrate the computational complexity is reduced and the echo interference cancellation performance is satisfying.