Pilot symbol assisted modulation for powerline communications

Power lines provide medium for high data rate communications. Experimental results point out that the channel is stationary piecewise with sudden variations. Moreover, the channel is frequency selective in the range 0-25 MHz. Pilot symbol assisted modulation, which consists in a discrete multitone modulation associated with pilot tone, can he adapted to indoor power line communications. Pilot tones provide information for the detection of the sudden variation of the channel, the estimation of the noise power spectral density and the frequency response of the channel. For stationary slates, simulations show that PSAM with 4096 subcarriers and simple interpolation techniques, such as DFT or spline cubic for the estimation of the frequency response, generate low bit error rate degradations with a high data rate.