DTTB同频直放站改进的回波抵消器

基于数字地面电视广播(DTTB)同频直放站,设计了一种改进的回波抵消器(EC),采用滤波器分段的方法,将传统回波抵消器的有限冲激响应滤波器分割为若干个子滤波器,并与最小均方(LMS)算法相结合,估计各个子滤波器的输出误差信号功率。通过比较子滤波器的误差信号功率,自适应地选取子滤波器的个数或整个FIR滤波器的阶数。改进的回波抵消器克服了在回波抵消器设计中信道阶数先验知识不足的缺点。仿真表明,与传统的回波抵消器相比,改进的回波抵消器获得了较小的残留回波干扰。

Improved Echo Canceller for on-Channel Repeater in DTTB Networks

This paper designs an improved echo canceller for on-channel repeater in the digital terrestrial television broadcasting (DTTB) networks. The finite impulse response (FIR) filter of the conventional echo canceller is split into several sub-filters and the output error power for the different sub-filters is estimated. Based on comparison of the output error power of the different sub-filters, the improved echo canceller adaptively selects the number of sub-filters or the tap length for the echo canceller. The improved echo canceller overcomes the fault of unknown knowledge of the tap length for the echo canceller design. Simulations illustrate that the improved echo canceller can attain the lower residual echo interference compared with the conventional echo canceller.