Positioning Method, Client and Positioning System

• US 20140315582A1
• Filed: 06/27/2014
• Published: 10/23/2014
• Est. Priority Date: 12/28/2011
• Status: Active Grant

• Current Assignee: DRNC Holdings, Inc. (InterDigital, Inc.)
• Original Assignee: Huawei Device Company Limited (Huawei Investment & Holding Co., Ltd.)
• Inventors: Dong, Xiandong, Ding, Zhiming
• Granted Patent: US 9,584,972 B2
• Time in Patent Office: Days
• US Class Current: 455/456.2
• CPC Class Codes: G01S 5/02521 using a radio-map
• CPC Class Codes: H04W 4/023 using mutual or relative location information between multiple location based services [LBS] targets or of distance thresholds
• CPC Class Codes: H04W 64/00 Locating users or terminals or network equipment for network management purposes, e.g. mobility management

Abstract

An indoor positioning method includes: sending, by a client, a position request instruction to at least three access points; receiving, by the client, a response message sent by each access point in response to the request instruction; sending, by the client, a corresponding measurement report message to each access point, so that each access point obtains a radio signal flight time between itself and the client; and receiving, by the client, a position estimation result from a network side, where the network side performs a comparative calculation on the radio signal flight time received from each access point and a sampling time measured in advance between each access point and each of multiple sampling points, and the position estimation result is an obtained coordinate location of a sampling point whose corresponding sampling time has a minimum time difference from the radio signal flight time received from each access point.

Claims

1. A positioning method, comprising:

sending, by a client, a position request instruction to at least three access points;

receiving, by the client, a response message sent by each of the at least three access points in response to the request instruction;

sending, by the client, a corresponding measurement report message to each of the at least three access points, such that each of the at least three access points obtains a radio signal flight time between itself and the client according to the corresponding measurement report message; and

receiving, by the client, a position estimation result from a network side, wherein the network side performs a comparative calculation on the radio signal flight time received from each of the at least three access points and a sampling time measured in advance between each access point and each of multiple sampling points, and the position estimation result is an obtained coordinate location of a sampling point whose corresponding sampling time has a minimum time difference from the radio signal flight time received from each access point, wherein the sampling time for each of the multiple sampling points includes a radio signal flight time between each of the multiple sampling points and each access point, and wherein the time difference is a difference between the radio signal flight time of each of the at least three access points and the sampling time of each of the multiple sampling points.

2. The positioning method according to claim 1, wherein before sending, by the client, the position request instruction to the at least three access points, the method further comprises:

storing coordinate values of the multiple sampling points on the network side;

receiving, by a sampling terminal located at the sampling points, a response message from each of the at least three access points, and sending a corresponding measurement report message to each access point such that each of the at least three access points obtains a radio signal flight time between itself and each sampling terminal; and

storing, by the network side, the radio signal flight time between each access point and each sampling terminal.

3. The positioning method according to claim 1, wherein receiving, by the client, the response message sent by each of the at least three access points in response to the request instruction, and sending, by the client, the corresponding measurement report message to each of the at least three access points such that each of the at least three access points obtains the radio signal flight time between itself and the client, comprises:

receiving, by the client, a first response message sent by a first access point, and recording a first response message arrival time T2;

sending, by the client, a first measurement report message to the first access point, and recording a measurement report message sending time T3, wherein the first measurement report message carries the first measurement report message sending time T3 and the first response message arrival time T2, or a difference between T3 and T2, namely, T3−

T2; and

obtaining, by the first access point, a radio signal flight time between the first access point and the client, namely, TOF=[(T4−

T1)−

(T3−

T2)]/2, wherein T1 is a first response message sending time, and T4 is time when the first measurement report message arrives at the first access point.

4. The positioning method according to claim 1, wherein before sending, by the client, the position request instruction to the at least three access points, the method further comprises:

receiving, by the client, a beacon frame from each of the at least three access points, wherein the beacon frame carries an identifier (ID) and channel information of each of the at least three access points, and

wherein sending, by the client, the position request instruction to the at least three access points comprises sending, by the client according to the ID and channel information of each of the at least three access points, the position request instruction to the at least three access points.

5. The positioning method according to claim 1, wherein the response message is an acknowledgement control frame for the position request instruction.

6. A positioning method, comprising:

sending, by a client, a position request instruction to at least three access points such that each access point sends a first measurement message to the client;

receiving, by the client, the first measurement message from each of the at least three access points;

sending, by the client, a response message to the first measurement message, to each access point, and receiving a second measurement message from each access point to obtain a radio signal flight time between each access point and the client; and

performing, by the client, a comparative calculation on the radio signal flight time between each access point and the client and a sampling time measured in advance between each of multiple sampling points and each access point, and using a coordinate location of a sampling point with a minimum time difference as positioning coordinates of the client, wherein the time difference is a difference between the radio signal flight time of each of the at least three access points and the sampling time of each of the multiple sampling points.

7. The positioning method according to claim 6, wherein sending, by the client, the response message to the first measurement message, to each access point, and receiving the second measurement message from each access point to obtain the radio signal flight time between each access point and the client comprises:

sending, by the client, a first response message to a first access point, and recording a first response message sending time T1;

receiving, by the client, the second measurement message sent by the first access point, wherein the second measurement message carries a second measurement message sending time T3 and time when the first response message arrives at the first access point, namely, T2, or a difference between T3 and T2, namely, T3−

T2;

receiving, by the client, the second measurement message, and recording a second measurement message arrival time T4; and

calculating, by the client, a radio signal flight time between the first access point and the client, namely, TOF=[(T4−

T1)−

(T3−

T2)]/2.

8. The positioning method according to claim 6, wherein the response message is an acknowledgement control frame for the first measurement message.

9. A client, comprising:

a first sending unit configured to send a position request instruction to at least three access points;

a first receiving unit configured to receive a response message sent by each of the at least three access points in response to the request instruction;

a second sending unit configured to send a corresponding measurement report message to each access point such that each of the at least three access points obtains a radio signal flight time between itself and the client; and

a second receiving unit configured to receive a position estimation result from a network side, where the network side performs a comparative calculation on the radio signal flight time received from each of the at least three access points and a sampling time measured in advance between each of the at least three access points and each of multiple sampling points, and the position estimation result is an obtained coordinate location of a sampling point whose corresponding sampling time has a minimum time difference from the radio signal flight time received from each of the at least three access points, wherein the sampling time for each of the multiple sampling points includes a radio signal flight time between each of the multiple sampling points and each of the at least three access points, and wherein the time difference is a difference between the radio signal flight time of each of the at least three access points and the sampling time of each of the multiple sampling points.

10. The client according to claim 9, wherein the first receiving unit is specifically configured to receive, from each of the at least three access points, a first response message to the request instruction, and record a first response message arrival time T2, wherein the second sending unit is specifically configured to send, after the first response message is received, a first measurement report message to an access point that sends the first response message, and record a first measurement report message sending time T3, wherein the first measurement report message carries a difference between the first measurement report message sending time T3 and the first response message arrival time T2, namely, T3−

T2, such that the access point that sends the first response message obtains a radio signal flight time between the access point and the client, namely, TOF=[(T4−

T1)−

(T3−

T2)]/2, wherein T1 is a first response message sending time, and T4 is time when the first measurement report message arrives at the access point that sends the first response message.

11. The client according to claim 9, further comprising:

a third receiving unit configured to receive, before the position request instruction is sent to the at least three access points, a beacon frame from each access point, wherein the beacon frame carries an identifier (ID) and channel information of each of the at least three access points, and

wherein the first sending unit is specifically configured to send the position request instruction to the at least three access points according to the ID and channel information of each of the at least three access points.

12. A client, comprising:

a storing unit configured to store a radio signal flight time measured in advance between each of multiple sampling points and each access point;

a first sending unit configured to send a position request instruction to at least three access points such that each access point sends a first measurement message to the client;

a first receiving unit configured to receive the first measurement message from each of the at least three access points;

a second sending unit configured to send, to each access point, a response message to the first measurement message;

a second receiving unit configured to receive a second measurement message from each access point to obtain a radio signal flight time between each access point and the client; and

a processing unit configured to obtain a position estimation result, wherein the client performs a comparative calculation on the radio signal flight time between each access point and the client and a radio signal flight time measured in advance between each of the multiple sampling points and each access point, and uses a coordinate location of a sampling point with a minimum time difference as positioning coordinates of the client, and wherein the time difference is a difference between the radio signal flight time of each of the at least three access points and the sampling time of each of the multiple sampling points.

13. The client according to claim 12, wherein the second sending unit is specifically configured to record a first response message sending time T1 when sending to each access point a first response message to the first measurement message, wherein the second receiving unit is specifically configured to send, after receiving the first response message from each access point, the second measurement message, and record a second measurement message arrival time T4, wherein the second measurement message carries a second measurement message sending time T3 and time when the first response message arrives at each access point, namely, T2, or a difference between T3 and T2, namely, T3−

T2, and wherein the processing unit is specifically configured to calculate the radio flight time between each access point and the client, namely, TOF=[(T4−

T1)−

(T3−

T2)]/2.

14. A positioning system, comprising:

a client configured to receive, after sending a position request instruction to at least three access points, a response message sent by each access point in response to the request instruction, send a corresponding measurement report message to each access point such that each access point obtains a radio signal flight time between itself and the client, and receive a position estimation result from a network side;

the at least three access points configured to send, after receiving the position request instruction from the client, the response message to the client, and receive the corresponding measurement report message from the client to respectively obtain the radio signal flight time between each access point and the client, and send the obtained respective radio signal flight time between each access point and the client to the network side; and

the network side configured to perform a comparative calculation on the radio signal flight time received from each access point and a sampling time measured in advance between each access point and each of multiple sampling points, obtain a coordinate location of a sampling point whose corresponding sampling time has a minimum time difference from the radio signal flight time received from each access point, and send the coordinate location to the client, wherein the sampling time for each of the multiple sampling points includes a radio signal flight time between each of the multiple sampling points and each access point, and the time difference is a difference between the radio signal flight time of each of the at least three access points and the sampling time of each of the multiple sampling points.

15. The positioning system according to claim 14, wherein the network side is further configured to store coordinate values of the multiple sample points and the radio signal flight time between each access point and each sampling terminal.

16. A positioning system, comprising:

a client configured to send a position request instruction to at least three access points, receive a first measurement message from each of the at least three access points, send to each access point a response message to the first measurement message, receive a second measurement message from each access point to obtain a radio signal flight time between each access point and the client, and perform a comparative calculation on the radio signal flight time between each access point and the client and a radio signal flight time measured in advance between each of multiple sampling points and each access point, and use a coordinate location of a sampling point corresponding to a sampling time with a minimum time difference as positioning coordinates of the client, wherein the time difference is a difference between the radio signal flight time of each of the at least three access points and the sampling time of each of the multiple sampling points; and

the at least three access points configured to receive the position request instruction from the client, send the first measurement message to the client, receive from the client the response message to the first measurement message, and send the second measurement message to the client such that the client obtains the radio signal flight time between each access point and the client.