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US 10,884,137 B2Granted
Position detection system, position detection device, position detection method, and sensor terminal
AssigneeFujitsu Limited
InventorsKouichi Kanda, Jun-ichi Nagata
Life of this patent
Estimating the term…
Abstract
A position detection system includes a GNSS sensor terminal that receives a satellite signal from a GNSS satellite as a snapshot, at least one relay device that receives the snapshot GNSS signal transmitted by the GNSS sensor terminal, and a calculation device that measures a position of the GNSS sensor terminal by using a code phase and a Doppler frequency of the GNSS satellite obtained from the snapshot GNSS signal, wherein the calculation device estimates an initial position of the GNSS sensor terminal by using position information of the relay device that has received the snapshot GNSS signal transmitted by the GNSS sensor terminal.
Claims10
A position detection system comprising:
- a Global Navigation Satellite System (GNSS) sensor terminal that receives a satellite signal from a GNSS satellite as a snapshot;
- at least one relay device that receives the snapshot GNSS signal transmitted by the GNSS sensor terminal;
- and
- a calculation device that measures a position of the GNSS sensor terminal by using a code phase and a Doppler frequency of the GNSS satellite obtained from the snapshot GNSS signal,
- wherein the calculation device estimates an initial position of the GNSS sensor terminal by using position information of the relay device that has received the snapshot GNSS signal transmitted by the GNSS sensor terminal,
- wherein one of the GNSS sensor terminal, the relay device, and the calculation device includes a baseband processing circuit that calculates the code phase and the Doppler frequency from the snapshot GNSS signal,
- wherein the baseband processing circuit searches for peaks of correlation values by dividing a search range into a plurality of subsets to search for a sampling point having a correlation value equal to or higher than a threshold in any of the subsets, and searching for a predetermined range before and after the sampling point having a correlation value equal to or higher than the threshold, when searching for the code phase from the correlation value obtained by performing correlation calculation on In-Phase/Quadrature-Phase (IQ) samples.
4 more elements
A position detection device comprising:
- a memory;
- and
- a circuitry coupled to the memory, the circuitry configured to:
- measure a position of a Global Navigation Satellite System (GNSS) sensor terminal by using a code phase and a Doppler frequency of a GNSS satellite obtained from a snapshot GNSS signal transmitted by the GNSS sensor terminal that receives the satellite signal from the GNSS satellite as a snapshot,
- estimate an initial position of the GNSS sensor terminal by using position information of a relay device that has received the snapshot GNSS signal transmitted by the GNSS sensor terminal, and
- calculate the code phase and the Doppler frequency from the snapshot GNSS signal in any one of the GNSS sensor terminal, the relay device, and the calculation device,
- wherein:
- a processing to calculate the code phase searches for peaks of correlation values by dividing a search range into a plurality of subsets to search for a sampling point having a correlation value equal to or higher than a threshold in any of the subsets, and searching for a predetermined range before and after the sampling point having the correlation value equal to or higher than the threshold, when searching for the code phase from the correlation value obtained by performing correlation calculation on In-Phase/Quadrature-Phase (IQ) samples.
5 more elements
A position detection method comprising:
- receiving a satellite signal from a Global Navigation Satellite System (GNSS) satellite as a snapshot by a GNSS sensor terminal;
- receiving the snapshot GNSS signal transmitted by the GNSS sensor terminal by at least one relay device;
- measuring a position of the GNSS sensor terminal by using a code phase and a Doppler frequency of the GNSS satellite obtained from the snapshot GNSS signal;
- estimating an initial position of the GNSS sensor terminal using position information of the relay device that has received the snapshot GNSS signal transmitted by the GNSS sensor terminal, when measuring the GNSS sensor terminal;
- and
- calculating the code phase and the Doppler frequency from the snapshot GNSS signal in any one of the GNSS sensor terminal, the relay device, and the calculation device,
- wherein:
- a processing of calculating the code phase searches for peaks of correlation values by dividing a search range into a plurality of subsets to search for a sampling point having a correlation value equal to or higher than a threshold in any of the subsets, and searching for a predetermined range before and after the sampling point having the correlation value equal to or higher than the threshold, when searching for the code phase from the correlation value obtained by performing correlation calculation on In-Phase/Quadrature-Phase (IQ) samples.
5 more elements
Dependencies are inferred from the claim text.