多径效应对低压电力线信道容量的影响

多径效应会造成信号的传播衰减，降低传输速率和通信质量。以电力线多径传输函数为信道模型，在l～30MHz的频带上分析了信道分支数、分支长度对低压电力线信道容量的影响。采用约束注水法导出了信道容量的闭式最大解，在输入总功率受限的情况下，动态调整子信道功率约束值，保证了输入功率的优化分配。仿真结果表明：多径效应的信道分支数是影响低压电力线信道容量的主要因素。约束注水法控制下的信道容量最大可达700Mbps，可以实现高速数据的传输。

Influence of Muitipath Effect on Channel Capacity of Low Power-line

Muhipath effect will attenuate the signal propagation, reduce the transmission rate and the quality of com- munication. Set power-line muhipath transmission function as channel model,the influence of channel branches and branch length on channel capacity of low power-line in the frequenee band of 1 - 30MHz is analyzed. Bound water injection is uti- lized to calculate the maximum channel capacity and ensure the optimal distribution of input power in each sub-channel in the condition of limited input power. Simulation result shows that the mainly factor which affects the low power-line channel capacity is channel branch number. Under the control of bound water rejection, the maximum channel capacity can reach 700Mbps which can transmit high speed data.