In accordance with embodiments of the present invention, data is modulated for transmission phase modulation. A method of transmitting data in a wireless power transmitter, includes transmitting a wireless power signal; encoding data to be transmitted into symbols; determining a phase shift to represent the symbols; and phase modulating the wireless power signal with the phase shift. A method of receiving data in a wireless power receiver includes receiving a wireless power signal that includes a phase modulated data signal; determining a period of each cycle of the wireless power signal; providing a running average over N−1 cycles of the wireless power signal, where N represents the number of cycles of the wireless power signal in which each phase modulation is provided; and decoding the data from the running average.