一种新的低压电力线通信比特和功率分配算法

为了提高低压电力线通信的传输速率和信道容量,提出了一种新的比特和功率分配算法。利用正交频分复用(OFDM)自适应比特分配方法动态调整了信号的调制方式,在此基础之上分析了电力信道传输信号的误码率。选取电力线多径传输模型作为信道模型,结合注水法和通信服务质量(QoS)提出了基于特定QoS的约束注水法,得出了最大化信道容量的闭式解,分析了影响信道容量的主要因素。仿真结果表明:4QAM调制方式对应的误码率最小。与已有注水法相比,所提功率分配算法的性能最优,当信噪比为40dB时,信道容量可达960Mbps,从而实现了电力信道传输速率的大幅升级。

Study of Channel Capacity for Indoor Low Power-line based on QoS Strategy

Low power-line is an important transmission medium to provide broadband services to end-users.In order to maximize power-line channel capacity within the limited transmission bandwidth and power,the OFDM adaptive modulation and the method of bound water injection based on the specific QoS is proposed in this paper.Set power-line channel multipath propagation model as the foundation,the closed form expression of the maximum channel capacity is given from the view of limited power of the input signal.The influence of indoor power-line channel branches number and branch length and end-load on channel capacity is analyzed. Also,in order to maximize the transmission bits of the input signals in different channel conditions,OFDM is adopted to make discretization of modulation of the input signals.The simulation result shows that the mainly factors that affect the channel capacity of indoor low power-line is line length,branch number and load impendence.In the same experimental situation,the channel capacity proposed in this paper can reach 960Mbps compared to the other methods and thus meeting the demand of high speed index in low power-line carrier communication system.