Ergodic Capacity of Power Line Communication System for Applications of Power Distribution Networks with Amplify- and- Forward Relaying

In this paper, the capacity of power line communication (PLC) system in the applications of distribution networks is investigated. Unlike the conventional application of PLC in high-voltage networks, using relays in distribution networks is necessary considering their longer channel lengths and meshed structure. Then, determination of the average maximum capacity of communication system, so-called Ergodic capacity, is necessary demand for selection of appropriate PLC system in distribution network. The capacity of a communication system depends on various factors such as the channel characteristics, the system bandwidth and the noises in the network. In comparison with the studies in the field of PLC system, the PLC system with amplify- and- forward relaying considering the impulsive noises has not been analyzed. In this paper, using the practical models of channel and noise, the ergodic capacity of channel is calculated a function of input signal' signal to noise ratio. In this proposed scheme, the affecting parameters including statistical channel distribution, distance between source and relay nodes, distance between relay and destination nodes, the transmitted signal power and signal to impulsive noise ratio are considered. To do so, the signal to noise ratio in destination node is formulated with mathematical expressions, and then, the ergodic capacity is obtained using the Shannon theorem. Furthermore, the impact of assigned power to the source and relay on the capacity is investigated. Finally, by simulating a sample channel, the ergodic capacity is obtained for the different values of transmitted signal power, impulsive signal to noise ratio and channel length. The simulation results show that the average capacity changes linearly in terms of path losses; such that for SNR=20 dB and in the presence of the relay, by reducing the length of the line from 200 m to 10 m, the capacity increases by approximately 3.5 bits/s/Hz.