Device and method for performing authentication in wireless power transfer system

1. A wireless power transmitter comprising:

a power converter configured to transfer a wireless power to a wireless power receiver; and

a communicator/controller configured to control the wireless power,

wherein the communicator/controller is further configured to:

transmit, to the wireless power receiver, a bit pattern requesting permission to communicate;

receive, from the wireless power receiver, a response packet granting the permission in response to the bit pattern; and

transmit, to the wireless power receiver in a power transfer phase in which the wireless power is transferred, an auxiliary data transport (ADT) data packet after receiving the response packet, and

wherein a header of the ADT data packet is set to a value informing a retransmission of a previous ADT data packet, based on receiving a not acknowledge (NAK) in response to the previous ADT data packet from the wireless power receiver.

2. The wireless power transmitter of claim 1 , wherein the bit pattern includes 8 bits.

3. The wireless power transmitter of claim 2 , wherein the bit pattern includes four ‘0’s and four ‘1’s.

4. The wireless power transmitter of claim 1 , wherein the ADT data packet is a packet to which a bit stream for authentication is divided.

5. A method of transmitting a bit pattern, the method performed by a wireless power transmitter and comprising:

transmitting, to a wireless power receiver, the bit pattern requesting permission to communicate;

receiving, from the wireless power receiver, a response packet granting the permission in response to the bit pattern; and

transmitting, to the wireless power receiver in a power transfer phase in which a wireless power is transferred, an auxiliary data transport (ADT) data packet after receiving the response packet,

wherein a header of the ADT data packet is set to a value informing a retransmission of a previous ADT data packet, based on receiving a not acknowledge (NAK) in response to the previous ADT data packet from the wireless power receiver.

6. The method of claim 5 , wherein the bit pattern includes 8 bits.

7. The method of claim 6 , wherein the bit pattern includes four ‘0’s and four ‘1’s.

8. The method of claim 5 , wherein the ADT data packet is a packet to which a bit stream for authentication is divided.

9. A wireless power receiver comprising:

a power pickup circuit configured to receive a wireless power from a wireless power transmitter; and

a communicator/controller configured to control the wireless power,

wherein the communicator/controller is further configured to:

receive, from the wireless power transmitter, a bit pattern requesting permission to communicate;

transmit, to the wireless power transmitter, a response packet granting the permission in response to the bit pattern; and

receive, from the wireless power transmitter in a power transfer phase in which the wireless power is transferred, an auxiliary data transport (ADT) data packet after transmitting the response packet, and

wherein a header of the ADT data packet is set to a value informing a retransmission of a previous ADT data packet, based on transmitting a not acknowledge (NAK) in response to the previous ADT data packet to the wireless power transmitter.

10. The wireless power receiver of claim 9 , wherein the bit pattern includes 8 bits.

11. The wireless power receiver of claim 10 , wherein the bit pattern includes four ‘0’s and four ‘1’s.

12. The wireless power receiver of claim 9 , wherein the ADT data packet is a packet to which a bit stream for authentication is divided.