A method for transmitting data over a power signal to at least one lamp, said power signal comprising alternating high-power and low-power sections, said method comprising: modulating said power signal in one or more interface regions based upon at least one data symbol to generate a modulated signal having one or more modulated portions, each modulated portion having a first average power, each of said interface regions comprising adjacent portions of a high-power section and a low-power section, said adjacent portions having a second average portion; wherein said first average power is about the same as said second average power.