Device and method for performing authentication in wireless power transfer system

A method of data transmission performed by a wireless power transmitter, the method comprising:

• transferring wireless power to a wireless power receiver by using magnetic coupling between the wireless power transmitter and the wireless power receiver;
• receiving, from the wireless power receiver in a negotiation phase or a power transfer phase, a received power packet (RPP) including a value of power received by the wireless power receiver;
• transmitting a bit pattern requesting the wireless power receiver for the wireless power transmitter-to-the wireless power receiver data transmission in response to the RPP;
• receiving a response packet from the wireless power receiver in response to the bit pattern;
• and
• transmitting a data stream to the wireless power receiver,
• wherein the data stream includes a plurality of auxiliary data transport (ADT) data packets, and each ADT data packet includes a header, and
• wherein, based on that the wireless power transmitter receives a not acknowledge (NAK) in response to a previous ADT data packet from the wireless power receiver, the wireless power transmitter retransmits the previous ADT data packet including the header indicating the retransmission of the previous ADT data packet.

A wireless power receiver comprising:

• a power pickup configured to receive wireless power from a wireless power transmitter by using magnetic coupling between the wireless power transmitter and the wireless power receiver;
• and
• a controller configured to control the wireless power and to perform transmission or reception of data based on communication with the wireless power transmitter,
• wherein the controller transmits, to the wireless power transmitter in a negotiation phase or a power transfer phase, a received power packet (RPP) including a value of power received by the wireless power receiver, receives a bit pattern requesting the wireless power transmitter-to-the wireless power receiver data transmission, transmits a response packet to the wireless power transmitter in response to the bit pattern, and receives a data stream from the wireless power transmitter,
• wherein the data stream includes a plurality of auxiliary data transport (ADT) data packets, and each ADT data packet includes a header, and
• wherein, based on that the controller transmits a not acknowledge (NAK) in response to a previous ADT data packet to the wireless power transmitter, the controller receives again the previous ADT data packet including the header indicating a retransmission of the previous ADT data packet.

A method of data reception performed by a wireless power receiver, the method comprising:

• receiving wireless power from a wireless power transmitter by using magnetic coupling between the wireless power transmitter and the wireless power receiver;
• transmitting, to the wireless power transmitter in a negotiation phase or a power transfer phase, a received power packet (RPP) including a value of power received by the wireless power receiver;
• receiving a bit pattern requesting the wireless power transmitter-to-the wireless power receiver data transmission;
• transmitting a response packet to the wireless power transmitter in response to the bit pattern;
• and
• receiving a data stream from the wireless power transmitter,
• wherein the data stream includes a plurality of auxiliary data transport (ADT) data packets, and each ADT data packet includes a header, and
• wherein, based on that the wireless power receiver transmits a not acknowledge (NAK) in response to a previous ADT data packet to the wireless power transmitter, the wireless power receiver receives again the previous ADT data packet including the header indicating a retransmission of the previous ADT data packet.