Station device, Wi-Fi system, and associated positioning method
A station device, a Wi-Fi system, and an associated positioning method are provided. The Wi-Fi system includes an AP1 device, an AP2 device, and the station device. The AP1 and the AP2 devices respectively transmit a first Wi-Fi signal and a second Wi-Fi signal. The station device receives a first-first Wi-Fi signal and a first-second Wi-Fi signal originating from the AP1 device. The station device receives a second-first Wi-Fi signal and a second-second Wi-Fi signal originating from the AP2 device. A first angle of arrival is estimated based on the first-first Wi-Fi signal and first-second Wi-Fi signal, and a second angle of arrival is estimated based on the second-first Wi-Fi signal and the second-second Wi-Fi signal. Based on the first angle of arrival, the second angle of arrival, and coordinate positions of the AP1 and AP2 devices, the station device performs a triangulation calculation to estimate its coordinate position.
1 . A mobile station device, comprising:
a first antenna, configured for receiving a first-first Wi-Fi signal being transmitted along a first-first transmission path, and receiving a second-first Wi-Fi signal being transmitted along a second-first transmission path;
a second antenna, configured for receiving a first-second Wi-Fi signal being transmitted along a first-second transmission path, and receiving a second-second Wi-Fi signal being transmitted along a second-second transmission path, wherein
the first-first Wi-Fi signal and the first-second Wi-Fi signal originate from a first Wi-Fi signal transmitted by a first access point device, and
the second-first Wi-Fi signal and the second-second Wi-Fi signal originate from a second Wi-Fi signal transmitted by a second access point device; and
a communication interface, electrically connected to the first antenna and the second antenna, configured for
calculating a first angle of arrival based on a separation distance between the first antenna and the second antenna and a first path difference between the first-first Wi-Fi signal and the first-second Wi-Fi signal, and calculating a second angle of arrival based on the separation distance between the first antenna and the second antenna and a second path difference between the second-first Wi-Fi signal and the second-second Wi-Fi signal; and
a control circuit, electrically connected to the communication interface, configured for performing a triangulation calculation to estimate a coordinate position of the mobile station device based on the first angle of arrival, the second angle of arrival, a coordinate position of the first access point device, and a coordinate position of the second access point device.
2 . The mobile station device according to claim 1 , wherein
the communication interface performs a trigonometric function calculation to the first path difference and the separation distance between the first antenna and the second antenna to estimate the first angle of arrival, and
the communication interface performs another trigonometric function calculation to the second path difference and the separation distance between the first antenna and the second antenna to estimate the second angle of arrival.
3 . The mobile station device according to claim 1 , wherein
the first antenna receives the first-first Wi-Fi signal at a first-first time point,
the first antenna receives the second-first Wi-Fi signal at a second-first time point,
the second antenna receives the first-second Wi-Fi signal at a first-second time point,
the second antenna receives the second-second WI-Fi signal at a second-second time point,
the communication interface estimates the first path difference based on a first time difference between the first-first time point and the first-second time point, and
the communication interface estimates the second path difference based on a second time difference between the second-first time point and the second-second time point.
4 . The mobile station device according to claim 3 , wherein
the communication interface calculates the first angle of arrival based on a speed of light, the separation distance between the first antenna and the second antenna, and the first time difference, and
the communication interface calculates the second angle of arrival based on the speed of light, the separation distance between the first antenna and the second antenna, and the second time difference.
5 . The mobile station device according to claim 3 , wherein
the first-first time point and the first-second time point are earlier than the second-first time point and the second-second time point, or
the first-first time point and the first-second time point are later than the second-first time point and the second-second time point.
6 . The mobile station device according to claim 1 , wherein
the control circuit executes an upper layer software to estimate the coordinate position of the mobile station device based on the first angle of arrival, the second angle of arrival, a coordinate position of the first access point device, and a coordinate position of the second access point device.
7 . The mobile station device according to claim 6 , wherein
the first access point device and the second access point device are placed in an indoor environment, wherein
the coordinate position of the first access point device and the coordinate position of the second access point device are predefined before the station device physically enters the indoor environment.
8 . The mobile station device according to claim 7 , wherein
the coordinate position of the first access point device and the coordinate position of the second access point device are represented in an absolute coordinate system or in a relative coordinate system.
9 . The mobile station device according to claim 1 , wherein
the first Wi-Fi signal carries a plurality of beacon packets when the station device is in communication with the second access point device or a third access point device.
10 . The mobile station device according to claim 1 , wherein
the first Wi-Fi signal carries a plurality of data packets when the station device is in communication with the first access point device.
11 . The mobile station device according to claim 1 , wherein
the first-first Wi-Fi signal corresponds to a first-first phase, the first-second Wi-Fi signal corresponds to a first-second phase, and the communication interface estimates the first path difference based on a first phase difference between the first-first phase and the first-second phase, and
the second-first Wi-Fi signal corresponds to a second-first phase, the second-second Wi-Fi signal corresponds to a second-second phase, and the communication interface estimates the second path difference based on a second phase difference between the second-first phase and the second-second phase.
12 . The mobile station device according to claim 1 , wherein
the communication interface receives a plurality of first-first incoming samples and a plurality of second-first incoming samples from the first antenna, and
the communication interface receives a plurality of first-second incoming samples and a plurality of second-second incoming samples from the second antenna, wherein
the first antenna transforms the first-first Wi-Fi signal to the plurality of first-first incoming samples,
the first antenna transforms the second-first Wi-Fi signal to the plurality of second-first incoming samples,
the second antenna transforms the first-second Wi-Fi signal to the plurality of first-second incoming samples, and
the second antenna transforms the second-second Wi-Fi signal to the plurality of second- second incoming samples.
13 . The mobile station device according to claim 12 , wherein
the communication interface compares signal strengths of the plurality of first-first incoming samples and selects one of the plurality of first-first incoming samples having the highest signal strength, and
the communication interface compares signal strengths of the plurality of first-second incoming samples and selects one of the plurality of first-second incoming samples having the highest signal strength,
the communication interface compares signal strengths of the plurality of second-first incoming samples and selects one of the plurality of second-first incoming samples having the highest signal strength, and
the communication interface compares signal strengths of the plurality of the plurality of second-second incoming samples and selects one of the plurality of second-second incoming samples having the highest signal strength.
14 . The mobile station device according to claim 13 , wherein
a receiving time point of the selected one of the plurality of first-first incoming samples is defined as the first-first time point,
a receiving time point of the selected one of the plurality of first-second incoming samples is defined as the first-second time point,
a receiving time point of the selected one of the plurality of second-first incoming samples is defined as the second-first time point, and
a receiving time point of the selected one of the plurality of second-second incoming samples is defined as the second-second time point.
15 . A Wi-Fi system, comprising:
a first access point device, configured for transmitting at least a first-first Wi-Fi signal and a second-first Wi-Fi signal;
a second access point device, configured for transmitting at least a first-second Wi-Fi signal and a second-second Wi-Fi signal; and
a mobile station device, comprising:
a first antenna, configured for receiving a first-first Wi-Fi signal being transmitted along a first-first transmission path, and receiving a second-first Wi-Fi signal being transmitted along a second-first transmission path;
a second antenna, configured for receiving a first-second Wi-Fi signal being transmitted along a first-second transmission path, and receiving a second-second Wi-Fi signal being transmitted along a second-second transmission path, wherein
the first-first Wi-Fi signal and the first-second Wi-Fi signal originate from the first Wi-Fi signal, and the second-first Wi-Fi signal and the second-second Wi-Fi signal originate from the second Wi-Fi signal; and
a communication interface, electrically connected to the first antenna and the second antenna, configured for
calculating a first angle of arrival based on a separation distance between the first antenna and the second antenna and a first path difference between the first-first Wi-Fi signal and the first-second Wi-Fi signal, and calculating a second angle of arrival based on the separation distance between the first antenna and the second antenna and a second path difference between the second-first Wi-Fi signal and the second-second Wi-Fi signal; and
a control circuit, electrically connected to the communication interface, configured for performing a triangulation calculation to estimate a coordinate position of the mobile station device based on the first angle of arrival, the second angle of arrival, a coordinate position of the first access point device, and a coordinate position of the second access point device.
16 . The Wi-Fi system according to claim 15 , wherein
the communication interface performs a trigonometric function calculation to the first path difference and the separation distance between the first antenna and the second antenna to estimate the first angle of arrival, and
the communication interface performs another trigonometric function calculation to the second path difference and the separation distance between the first antenna and the second antenna to estimate the second angle of arrival.
17 . The Wi-Fi system according to claim 15 , wherein the first access point device comprises:
a third antenna; and
a fourth antenna, wherein at least one of the third antenna and the fourth antenna is configured for transmitting the first Wi-Fi signal.
18 . The Wi-Fi system according to claim 17 , wherein
one of the third antenna and the fourth antenna transmits the first Wi-Fi signal to carry a plurality of beacon packets when the mobile station device is not in communication with the first access point device.
19 . The Wi-Fi system according to claim 17 , wherein
both the third antenna and the fourth antenna transmit the first Wi-Fi signal to carry a plurality of data packets corresponding to the mobile station device when the mobile station device is in communication with the first access point device.
20 . A positioning method applied to a Wi-Fi system comprising a first access point device, a second access point device, and a mobile station device, wherein the positioning method comprises steps of:
the first access point device transmitting at least a first-first Wi-Fi signal and a second-first Wi-Fi signal;
the second access point device transmitting at least a first-second Wi-Fi signal and a second-second Wi-Fi signal;
through a first antenna, the mobile station device receiving a first-first Wi-Fi signal being transmitted along a first-first transmission path, and receiving a second-first Wi-Fi signal being transmitted along a second-first transmission path;
through a second antenna, the mobile station device receiving a first-second Wi-Fi signal being transmitted along a first-second transmission path, and receiving a second-second Wi-Fi signal being transmitted along a second-second transmission path,
wherein the first-first Wi-Fi signal and the first-second Wi-Fi signal originate from the first Wi-Fi signal, and the second-first Wi-Fi signal and the second-second Wi-Fi signal originate from the second Wi-Fi signal; and
the mobile station device calculating a first angle of arrival based on a separation distance between the first antenna and the second antenna and a first path difference between the first-first Wi-Fi signal and the first-second Wi-Fi signal;
the mobile station device calculating a second angle of arrival based on the separation distance between the first antenna and the second antenna and a second path difference between the second-first Wi-Fi signal and the second-second Wi-Fi signal; and
the mobile station device performs a triangulation calculation to estimate a coordinate position of the mobile station device based on the first angle of arrival, the second angle of arrival, a coordinate position of the first access point device, and a coordinate position of the second access point device.