Electronic device and method, performed by electronic device, of obtaining location information
Provided is a method, performed by an electronic device, of obtaining location information. In detail, provided is a method, performed by an electronic device, of obtaining relative location information with respect to anchor devices by wirelessly communicating with the anchor devices.
1. A method, performed by an electronic device, of obtaining location information, the method comprising:
receiving an initiation message transmitted from a first anchor device;
receiving a response message transmitted from a second anchor device, the response message including information about a first reply time of the second anchor device and information about a transmission time of the response message, the information about the first reply time comprising a time interval between a reception time of the initiation message by the second anchor device and the transmission time of the response message by the second anchor device;
receiving, from the first anchor device, a final message including information about a second reply time of the first anchor device and information about a transmission time of the final message, the information about the second reply time comprising a time interval between a reception time of the response message by the first anchor device and a transmission time point of the final message by the first anchor device;
measuring a reception time of the initiation message, a reception time of the response message and a reception time of the final message by the electronic device; and
obtaining information about a time difference of arrival (TDoA) related to the first device and the second device based on the measured reception time of the initiation message, the measured reception time of the response message and the measured reception time of the final message.
2. The method of claim 1 ,
wherein the initiation message comprises an address list including an address of the second anchor device.
3. The method of claim 2 ,
wherein the initiation message comprises a slot index.
4. The method of claim 1 ,
wherein the initiation message, the response message, and the final message are scheduled by a backend controller.
5. The method of claim 1 ,
wherein the final message further comprises a round-trip time of the first anchor device with respect to a third anchor device.
6. The method of claim 1 , wherein the method further comprises:
calculating a difference between a first distance between the first anchor device and the electronic device and a second distance between the second anchor device and the electronic device based on the TDoA,
wherein the TDoA is calculated based on the first reply time of the second anchor device, a round-trip time of the first anchor device, a time interval between the reception time of the initiation message by the electronic device and the reception time of the response message by the electronic device, the second reply time of the first anchor device, and a time interval between the reception time of the response message by the electronic device and the reception time of the final message by the electronic device.
7. The method of claim 1 , further comprising:
performing compensation based on a clock of one of the electronic device, the first anchor device, and the second anchor device.
8. The method of claim 1 , further comprising:
performing compensation based on a ratio between an interval of transmitting the initiation message via the first anchor device, the interval being measured by using a clock of the first anchor device, and an interval of receiving, via the second anchor device, the initiation message from the first anchor device, the interval being measured by using a clock of the second anchor device.
9. The method of claim 1 , further comprising receiving location information of at least one of the first anchor device or the second anchor device.
10. The method of claim 1 ,
wherein at least one of the initiation message or the final message transmitted from the first anchor device comprises location information of the first anchor device, and
wherein the response message transmitted from the second anchor device comprises location information of the second anchor device.
11. An electronic device comprising:
a communicator;
a memory; and
at least one processor configured to control an operation of the electronic device by executing a program stored in the memory,
wherein the communicator is configured to:
receive an initiation message transmitted form a first anchor device;
receive, from a second anchor device, a response message including information about a first reply time of the second anchor device and information about a transmission time of the response message, the information about the first reply time comprising a time interval between a reception time of the initiation message by the second anchor device and the transmission time of the response message by the second anchor device; and
receive, from the first anchor device, a final message including information about a second reply time of the first anchor device and information about a transmission time of the final message, the information about the second reply time comprising a time interval between a reception time of the response message by the first anchor device and a transmission time point of the final message by the first anchor device; and
wherein the at least one processor is configured to measure a reception time of the initiation message, a reception time of the response message and a reception time of the final message by the electronic device, and obtain information about a time difference of arrival (TDoA) related to the first device and the second device based on the measured reception time of the initiation message, the measured reception time of the response message and the measured reception time of the final message.
12. The electronic device of claim 11 ,
wherein the initiation message comprises an address list including an address of the second anchor device.
13. The electronic device of claim 12 ,
wherein the initiation message comprises a slot index.
14. The electronic device of claim 11 ,
wherein the initiation message, the response message, and the final message are scheduled by a backend controller.
15. The electronic device of claim 11 ,
wherein the final message further comprises a round-trip time of the first anchor device with respect to a third anchor device.
16. The electronic device of claim 11 , wherein the at least one processor is further configured to:
calculate a difference between a first distance between the first anchor device and the electronic device and a second distance between the second anchor device and the electronic device based on the TDoA,
wherein the TDoA is calculated based on the first reply time of the second anchor device, a round-trip time of the first anchor device, a time interval between the reception time of the initiation message by the electronic device and the reception time of the response message by the electronic device, the second reply time of the first anchor device, and a time interval between the reception time of the response message by the electronic device and the reception time of the final message by the electronic device.