Classifications

• • G—PHYSICS
  • G01—MEASURING; TESTING
  • G01S—RADIO DIRECTION-FINDING; RADIO NAVIGATION; DETERMINING DISTANCE OR VELOCITY BY USE OF RADIO WAVES; LOCATING OR PRESENCE-DETECTING BY USE OF THE REFLECTION OR RERADIATION OF RADIO WAVES; ANALOGOUS ARRANGEMENTS USING OTHER WAVES
  • G01S5/00—Position-fixing by co-ordinating two or more direction or position line determinations; Position-fixing by co-ordinating two or more distance determinations
  • G01S5/02—Position-fixing by co-ordinating two or more direction or position line determinations; Position-fixing by co-ordinating two or more distance determinations using radio waves
  • G01S5/0252—Radio frequency fingerprinting

Definitions

• the radio receiver determines whether the radio receiver has changed position. Thanks to the invention, it is possible to determine the presence or absence of at least one radio transmitter and to use this information in order to estimate a change in the position of a radio receiver, without this receiver needing to initiate a communication or even to request other terminals to retrieve useful information, such as the identifier of the transmitters and their location. Compared with existing solutions, the fact of not needing to initiate communication with other terminals optimizes the energy consumption of the radio receiver.
• the method refines its assessment of change in position to determine whether the receiver is moving slowly or is stationary. To do this, it searches for common transmitters between the last signal acquisition and each of the previous acquisitions. The evolution over time of the number of transmitters in common then allows the method to estimate whether the receiver is moving slowly or is finally stationary. Indeed, it is possible that the number of transmitters in common varies slowly but continuously over time, the determining method as well as the receiver moving slowly and therefore that it has changed position. Conversely, it is possible that the number of shared transmitters fell rapidly following a maintenance action on the transmitters which caused the displacement and replacement of two transmitters but that it was previously stable. This event is therefore analyzed as being one-off by the method and is therefore not linked to the movement of the receiver.
• the receiver has been stationary for some time (receiver stationary for several acquisitions of the signal) and, in this case, the method may decide to proceed to a next measurement within a long time since it is unlikely that the receiver will change position in a short delay,
• a specific scheduling in time of the phases of an alternative embodiment of the method according to the invention is defined, such an alternative mode being broken down into two phases: a first phase of initialization and a second phase of determining a change in position of the receiver.
• the initialization phase to be operational, requires that the receiver is stationary. The objective being to determine whether the receiver has changed position, the method therefore first of all seeks to identify the fixed transmitters in the surroundings of the receiver.
• the receiver performs periodic measurements of the radio signal in PI and, after processing, identifies in P2 and P3 the transmitter (s) common to all of these measurements.
• the method therefore defines a set of transmitters in common which are very probably fixed seen from the Euclidean frame of reference of the receiver because the transmitters are identified during all of the acquisitions made in P1.
• Steps PI, P2 and P3 can be reproduced on a period Dinit Ti so that the method calculates a set of invariable common emitter during each radio signal acquisition in this period.
• This set is called the reference set.
• the method carries out M acquisitions of radio signals at instants Ti-M, Ti- (Ml), ... Ti-j ..., Ti-1, Ti during the duration Dinit_Ti which must be as close as possible to a duration fixed by the method or for example a user of the receiver or an administrator of a fleet of receivers.
• the actions executed by the determination method are implemented partially by a server SERV.
• the SERV server is for example a network server equipped with a database solution.
• the SERV server has the conventional architecture of a computer and includes in particular a MEM_SERV memory, a UT_SERV processing unit, equipped for example with a PROC_SERV processor, and controlled by a computer program PG_SERV stored in MEM_SERV memory.
• the computer program PG_SERV comprises instructions for implementing the actions of the method for determining the change of position of the radio receiver as described above, when the program is executed by the processor PROC_SERV.

Landscapes

• Physics & Mathematics (AREA)
• Engineering & Computer Science (AREA)
• General Physics & Mathematics (AREA)
• Radar, Positioning & Navigation (AREA)
• Remote Sensing (AREA)
• Mobile Radio Communication Systems (AREA)
• Position Fixing By Use Of Radio Waves (AREA)

Applications Claiming Priority (2)

Publications (1)

Family

ID=67441387

Family Applications (1)

Country Status (3)

Family Cites Families (3)

• 2019
  • 2019-03-20 FR FR1902864A patent/FR3094094A1/fr not_active Ceased
• 2020
  • 2020-03-20 EP EP20731526.8A patent/EP3942320A1/de active Pending
  • 2020-03-20 WO PCT/FR2020/050605 patent/WO2020188227A1/fr unknown

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