Spectrum analyzer based measurement and detection of MW/SW broadcast radios on power lines for cognitive PLC

For smart grid applications, power line communications (PLC) have become a promising candidate to support some emerging services. Although it may employ frequencies above 500 kHz to guarantee reliable performance and fast response, potential interferences between such PLC access system and medium wave (MW)/short wave (SW) broadcast radios may be caused. This paper targets to evaluate the interference level specifically, based on which some detection and mitigation solutions are also proposed as cognitive PLC approaches. It starts with spectrum analyzer based measurements on the loop antenna and at two typical low voltage (LV) power line access networks in China to investigate the ingress caused by MW/SW broadcast radios, and the Electro Magnetic Interference (EMI) issue of PLC is also assessed by a field test. Then by performing a statistical analysis on the narrow-band radio interference level above the power line noise floor, an Adaptive Detection (AD) method for identifying radio stations is presented. Moreover, cooperative detection in cognitive radio (CR) is introduced as well by merging the detecting results achieved at different positions of the network to enhance the performance. Finally, the design aspects for such cognitive PLC access system are briefly discussed.