The paper proposes a method for spectral shaping suitable for communication over distribution power lines. The method includes a spectral-shaper that provides periodic spectral nulls to the original pulse spectrum. These nulls are designed to be located at harmonics of the line voltage. The receiving end contains a comb filter to remove additive harmonic noise without distorting the original signal. A data precoder scheme is suggested to remove the effect of ISI introduced by both the spectral-shaper and the comb filter. The paper discusses practical considerations for applying the proposed scheme to distribution power line carrier (DPLC) applications. A line-locked system concept is discussed, and the effect of clock phase jitter on the system performance is investigated. Compared to unfiltered BPSK system, the proposed scheme achieves a process gain of 8.5 dB in SNR at BER of 10-5 when the phase jitter of the system clock is = 4*10-3 radians. At greater jitter levels, it is shown that the region of SNR where the proposed scheme outperforms the unfiltered system depends mainly on the amount of clock phase jitter. |
