On the system capacity of relay-aided Powerline Communications

Powerline Communications (PLC) is a favorable communication technique for many smart grid applications such as AMI and powerline health monitoring. With the existing powerline infrastructure, PLC provides both communication security and ubiquitousness. However, long-distance communication is very challenging in PLC due to its frequency-dependent channel and noise characteristics. To provide reliable communications at long transmission distances, relay communications has been proposed in powerline environments. However the capacity features of relay-aided (RA-) PLC have not been fully investigated. In this paper, we analyze the performance of RA-PLC from an information-theoretic perspective. With empirical channel models, the end-to-end SNR is first computed, and then the optimal carrier frequency and signal bandwidth are determined. Finally, the system capacity is analyzed and numerical results are presented to reveal the features of RA-PLC. Through comparison with the direct-link (DL-) PLC system, the benefits of RA-PLC are also illustrated. In addition, the effects of power allocation and relay location selection on the system capacity are investigated.