Cognitive detection method of radio frequencies on power line networks

In the [1.8-30] MHz frequency band, EMC standards prohibit power line communications (PLC) to emit on the frequencies which could be used by HAM radio in order to protect them. This implies an transmit power restriction in these radio frequencies and consequently a throughput limitation. With the aim to increase the data rates, the solutions envisaged today consist in limiting the number of notched frequencies as well as in increasing the used frequency band, which can henceforth overlap with the FM band [87.5-108] MHz for future PLC systems. With the current static notching solution, the whole frequencies of the FM band can be notched during PLC transmission. As in a given environment and at a given time, only a part of the FM radio frequencies are really received, a cognitive EMC approach is proposed in this paper. The power line network is demonstrated to be a good antenna that can detect all present radio frequencies and a cognitive detection method is proposed. By means of simulations, it is also shown that the use the cognitive technique improves the data rates of the PLC systems.