Positioning method, client and positioning system

• US 9,584,972 B2
• Filed: 06/27/2014
• Issued: 02/28/2017
• 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: Ding, Zhiming, Dong, Xiandong
• Primary Examiner(s): Magloire, Vladimir
• Assistant Examiner(s): Donado, Frank
• Application Number:
  US14/317,287
• Publication Number:
  US 20140315582A1
• Time in Patent Office: 977 Days
• Field of Search: None
• US Class Current: 1/1
• 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 and sends a radio signal flight time between itself and the client according to the corresponding measurement report message to a network side; and

receiving, by the client, a position estimation result from the 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 stored in a reference point database and measured in advance between each access point and each of multiple sampling points at sampling points located in area that includes each access point arranged in a non-collinear manner, and the position estimation result is an obtained coordinate location of a sampling point included in one of the sampling points whose corresponding sampling time that was stored in the reference point database has a minimum time difference between the radio signal flight time of each of the at least three access points and the stored sampling time of each of the multiple sampling points, and 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.

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 and sends 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 client, comprising:

a non-transitory computer readable medium having instructions stored thereon; and

a computer processor coupled to the non-transitory computer readable medium and configured to execute the instructions to;

send a position request instruction to at least three access points;

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

send a corresponding measurement report message to each access point such that each of the at least three access points obtains and sends a radio signal flight time between itself and the client according to the corresponding measurement report message to a network side; and

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 stored in a reference point database and measured in advance between each of the at least three access points and each of multiple sampling points at sampling points located in an area that includes each access point arranged in a non-collinear manner, and the position estimation result is an obtained coordinate location of a sampling point included in one of the sampling points whose corresponding sampling time that was stored in the reference point database has a minimum time difference between the radio signal flight time of each of the at least three access points and the stored sampling time of each of the multiple sampling points, and 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.

7. The client according to claim 6, wherein the computer processor is further configured to execute the instructions 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; and

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 wherein T4 is time when the first measurement report message arrives at the access point that sends the first response message.

8. The client according to claim 6, wherein the computer processor is further configured to execute the instructions 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

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.

9. 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 and sends 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 stored in a reference point database and measured in advance between each access point and each of multiple sampling points at sampling points located in an area that includes each access point arranged in a non-collinear manner, obtain a coordinate location of a sampling point included in the one of the sampling points whose corresponding sampling time has a minimum time difference between the radio signal flight time of each of the at least three access points and the stored sampling time of each of the multiple sampling points,

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.

10. The positioning system according to claim 9, 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.