Cognitive power line communication system for multiple channel access

Current carrier-sense multiple access (CSMA) scheme only allows single transmission in power line channel at any one time although the channel might not be fully occupied. In this paper, we propose cognitive power line communication (CPLC) systems where the CPLC devices are able to utilize the unused spectrum. When applying CPLC using orthogonal frequency division multiple access (OFDMA), it could dynamically allocate subcarriers to different users in the system for simultaneous transmissions. Three CPLC schemes are designed and their performances are compared against Homeplug 1.0 system under different application scenarios. The simulation results clearly show that one of the proposed schemes consistently outperforms Homeplug 1.0 under all simulated application scenarios without compromising quality of service for primary users. With the good results obtained, we are convinced that OFDMA can be applied onto CPLC system.