Summary of the technology
Power Line Communications (PLC) is an emerging field that enables to carry data on a
conductor that is also used simultaneously for AC electric power transmission or
electric power distribution to consumers. The widespread use of these technologies is
however, compromised by the presence of impulsive noise that arises from interferences generated by devices connected to the power line. Therefore removal of impulsive noise is critical to get a high performance of PLC systems. UVIGO researchers have developed a novel methodology to mitigate impulsive noise by monitoring those carriers of the radiofrequency spectrum that are free of transmission in PLC systems. The identification of the noise signals allows its selective removal keeping the quality of the overall PLC signal.
New and innovative aspects
A novel methodology to mitigate impulsive noise by monitoring those carriers of the radiofrequency spectrum that are free of transmission in PLC systems. The identification of the noise signals allows its selective removal keeping the quality of the overall PLC signal.
Main advantages of its use
• The method is able to cancel the impulsive noise pulses leaving the signal sample contribution unscathed. • It is not necessary any hardware modification. The method is fully firmware. • The method is easy to incorporate in the firmware of the PLC receivers. • The cancelling method is independent of the rest of stages of the PLC receiver. No feedback with the following stages. • The Bit Error Rate improves more than 100 times over the threshold detection and blanking method.
The method has four stages: • First, it detects where the IN candidate samples are, by using the procedure of spotting the pulse locations where the samples exceed a specific threshold in the time domain. • Second, it extracts the idle carriers which correspond to the carriers where no information has been transmitted. • Third, with the location of the samples allegedly impaired by IN and with the complex values of the idle carriers, the system outputs an estimation of the complex values corresponding to the IN pulses allegedly located. The system is smart enough to know if the candidate samples are IN or not, and to discriminate the IN contribution from that of the desired signal. • Fourth, the estimated complex values of the IN pulses are subtracted from the original sequence, obtaining the clean sequence.