摘要
通过添加适当的循环前缀(CP)的正交频分复用(OFDM)技术是一种去除高速通信中符号间干扰的有效方法,但低压电力线作为载波通信通道使用时是一种时变多径信道,采用 OFDM 技术进行高速载波通信时信号的正交性会因此而受到一定程度的破坏,产生子载波间干扰(ICI)。该文采用基于多层感知器(MLP)的均方差(MSE)准则实现了一种时变信道的非线性均衡。为了验证所提出的非线性均衡方法的有效性,选取具有宽带耦合放大器的实际低压电力线通信(PLC)信道作为实验用非线性信道模型。对比了基于 MSE准则的线性和非线性均衡器对系统性能的影响,表明该文采用的非线性均衡方法可以更有效地补偿信道的多径性和时变性造成的影响和改善电力线载波通信系统的性能。
Orthogonal Frequency Division Multiplexing (OFDM) with a suitably chosen guard interval is considered as an effective means for eliminating intersymbol interference of high-rate transmission over dispersive channels. Time variance of the channel, however, leads to a loss of subchannel orthogonality, resulting in an interchannel interference (ICI). In this paper, a multilayer perceptron scheme trained with MSE criterion was proposed for the nonlinear channel equalization. The proposed method was used in a realistic low voltage power lines with wideband coupling amplifier, which formed a nonlinear channel for the experiments. The performances of traditionally used linear equalizer and the nonlinear equalizers trained with MSE criterion proposed in this paper are compared. The effectiveness of the proposed approach is demonstrated via experiments by applying it to a PLC OFDM system with time-varying multipath fading channel.
出处
《中国电机工程学报》
EI
CSCD
北大核心
2005年第4期71-75,共5页
Proceedings of the CSEE
