JP2008241422A - Gps positioning device, electronic equipment, control method, program and storage medium - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To shorten the time necessary for positioning the present position at the time of positioning the present position by receiving the pseudo satellite signal transmitted from the pseudo satellite. <P>SOLUTION: A portable telephone 1 provided with a GPS function is able to measure the present position based on a GPS satellite signal emitted from a GPS satellite 3 and a pseudo satellite 5. In the positioning of the present position based on the pseudo satellite signal, if the arranged positional information corresponding to the PRN code of the captured pseudo satellite signal is stored, the present position is determined based on the arranged positional information. If not stored, the arranged positional information included in the captured pseudo satellite signal is acquired and determined as the present position, and stored while relating with the PRN code of the pseudo satellite signal. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a GPS positioning device, an electronic device, a control method, a program, and a storage medium.

  As a positioning system using an artificial satellite, a GPS (Global Positioning System) is widely known and used in a car navigation device or the like. In GPS, a GPS satellite signal is transmitted from each of a plurality of GPS satellites orbiting the earth orbit, and the GPS receiver calculates (positions) the current position based on the received GPS satellite signal.

  In recent years, portable electronic devices such as mobile phones and wristwatches have been equipped with a GPS function, and are not only used outdoors like car navigation devices, but also in various places such as in buildings and underground. in use. However, a new problem has arisen that it is difficult to receive GPS satellite signals in a building or underground, and it is difficult to calculate (measure) the current position.

Therefore, a technique for installing a pseudo-satellite is known as a technique for making it possible to acquire the current position even in a place where it is difficult to receive GPS satellite signals in a building or underground. The pseudo satellite periodically transmits (sends) a pseudo satellite signal simulating a GPS satellite signal. Specifically, the pseudo-satellite includes a PRN code other than the PRN code assigned to the GPS satellite (hereinafter referred to as “actual operation PRN code”) among the specified PRN codes (hereinafter referred to as “non-real operation”). A pseudo satellite signal obtained by modulating the information on the arrangement position of the pseudo satellite with the assigned PRN code is transmitted. In the GPS receiver, the pseudo satellite signal can be captured and the current position superimposed on the pseudo satellite signal can be acquired in the same manner as the GPS satellite signal. In this case, the transmission power and arrangement of the pseudo satellites are appropriately determined to eliminate the effects of multipath and to avoid receiving a plurality of pseudo satellite signals simultaneously in the GPS receiver. (For example, refer to Patent Document 1).
JP 2000-180527 A

  By the way, when using the pseudo satellite, there is a problem that it takes time to determine the current position in the GPS receiver. That is, a pseudo-satellite signal repeatedly transmits a signal having a predetermined length including arrangement position information. The GPS receiver receives the entire pseudo-satellite signal and then receives the current position information contained in the received signal. get. In other words, the positioning of the current position using the pseudo satellite signal requires at least a time corresponding to the signal length of the pseudo satellite signal. For this reason, positioning at a predetermined time interval such as an interval of 1 second may be impossible. Specifically, for example, when the transmission bit rate of the pseudo satellite signal is 50 [bit / s], if the signal length of the pseudo satellite signal exceeds 50 [bit], the GPS receiver receives the entire pseudo satellite signal. It takes 2 seconds or more, and positioning of the current position at 1 second intervals becomes impossible.

  The present invention has been made in view of the above circumstances, and an object thereof is to shorten the time required for positioning the current position when receiving the pseudo satellite signal transmitted from the pseudo satellite and positioning the current position. It is said.

  A first invention for solving the above-described problem is a GPS positioning apparatus that receives a GPS satellite signal and measures a current position, and simulates the GPS satellite signal and is assigned to an actually operated GPS satellite. The pseudo-satellite signal from the pseudo-satellite signal transmission device for transmitting a pseudo-satellite signal obtained by modulating predetermined data including arrangement position information with a non-actual operation PRN code other than the actual operation PRN code that is a PRN code, and A capture unit that captures a GPS satellite signal by performing a correlation operation using a PRN code, a storage unit that stores arrangement position information included in a pseudo satellite signal received for each non-actual PRN code, and the capture A pseudo-satellite signal acquisition detection unit that detects the acquisition of the pseudo-satellite signal by the unit, and the non-practical PRN that is the same as the detected pseudo-satellite signal according to the detection A determination unit that determines whether or not the location information of the pseudo satellite signal corresponding to the mode is stored in the storage unit, and when the detection is made and stored by the determination unit, Read-out position information of pseudo satellite signals corresponding to the same non-practical operation PRN code is read from the storage unit, and a current position determination unit at the time of re-reception that determines the current position from the position information, the detection is performed, and the determination If it is determined that the pseudo-satellite signal is not stored, the detected pseudo-satellite signal is tracked to obtain the placement position information included in the pseudo-satellite signal, and the obtained placement position information is obtained from the non-pseudo satellite signal. A GPS positioning apparatus comprising: a new reception current position determining unit that stores a current position in association with an actual operation PRN code and stores the current position in the storage unit A.

  In addition, the sixth aspect of the present invention simulates a GPS satellite signal and uses the non-practical PRN code that is a PRN code other than the PRN code that is a PRN code assigned to the GPS satellite that is actually operated to arrange the location information. A capture unit that captures the pseudo satellite signal and the GPS satellite signal from a pseudo satellite signal transmission device that transmits a pseudo satellite signal modulated with predetermined data including a PRN code by performing a correlation operation using a PRN code; A GPS positioning device control method for receiving a GPS satellite signal and positioning a current position including a storage unit for storing arrangement position information included in a pseudo satellite signal received for each operational PRN code, the acquisition A pseudo-satellite signal acquisition detecting step for detecting the acquisition of the pseudo-satellite signal by the unit, and in response to the detection, the same non-practical operation P as the detected pseudo-satellite signal A determination step of determining whether or not pseudo-satellite signal placement position information corresponding to an N code is stored in the storage unit; and when it is determined that the detection is performed and stored in the determination step, A re-reception current position determining step of reading out the position information of the pseudo satellite signals corresponding to the same non-actual operation PRN code from the storage unit and determining the current position from the position information, the detection is performed, and the determination If it is determined in the step that the information is not stored, the detected pseudo satellite signal is tracked to obtain the arrangement position information included in the pseudo satellite signal, and the acquired arrangement position information is obtained from the non-pseudo satellite signal. New reception current position that is stored in the storage unit in association with the actual operation PRN code and determines the current position from the acquired arrangement position information It is a control method comprising a determination step.

  According to the first or sixth aspect of the invention, in the GPS positioning device that receives the GPS satellite signal and measures the current position, when the pseudo satellite signal is captured, the same non-operational RRN code as the pseudo satellite signal is obtained. If the arrangement position information of the pseudo satellite signal corresponding to is already stored, the current position is determined from the stored arrangement position information. On the other hand, if not stored, the current position is determined from the arrangement position information included in the captured pseudo satellite signal, and this arrangement position information is associated with the non-actual PRN code of the pseudo satellite signal. Is memorized.

  That is, for example, when the GPS positioning device is not moving, the same pseudo satellite signal is continuously captured by the GPS positioning device. In such a case, the captured pseudo satellite signal is received and arranged. After acquiring the position information, it is not necessary to receive the same entire pseudo-satellite signal again to acquire the arrangement position information, and the current position can be quickly determined using the stored arrangement position information. As a result, the time required to determine the current position using the pseudo satellite can be shortened.

  The second invention is the GPS positioning device according to the first invention, wherein the out-of-use PRN code of the pseudo satellite signal not captured by the capturing unit out of the arrangement position information stored in the storage unit. It is a GPS positioning apparatus provided with an information erasure control unit for erasing arrangement position information stored in association with each other.

  The seventh invention is a control method according to the sixth invention, wherein, among the arrangement position information stored in the storage unit, a non-practical operation PRN code of a pseudo satellite signal not captured by the capture unit This is a control method including an information erasure control step of erasing the arrangement position information stored in association with the.

  According to the second or seventh aspect, the arrangement position information associated with the non-practical operation PRN code that is not captured is deleted from the arrangement position information stored for each non-operational PRN code. The That is, only the arrangement position information corresponding to the non-actual operation PRN code of the captured pseudo satellite signal is stored, and the arrangement position information corresponding to the other non-operational PRN code is erased and not stored. By the way, there is a limit to the non-practical PRN codes, and it is conceivable that the same PRN code is assigned to different pseudo satellites arranged at different locations. If the arrangement position information corresponding to the non-practical PRN code of the pseudo satellite signal that has not been captured is not erased, a pseudo satellite signal that has the same non-practical PRN code that was previously captured at a different location is captured. Then, a situation may occur in which the current position is determined from the arrangement position information included in the pseudo-satellite signal previously captured. However, as in the present invention, by erasing the arrangement position information corresponding to the PRN code of the pseudo-satellite signal that is no longer captured, a situation where a position different from the original current position is determined as the current position can be avoided. Can do.

  A third invention is the GPS positioning device of the first or second invention, wherein the pseudo satellite signal transmitting device repeatedly transmits one message data including the arrangement position information by the pseudo satellite signal. A ring buffer unit that updates and stores signals for a predetermined period of time captured by the capture unit as needed, and the new reception current position determination unit is already stored in the ring buffer unit of the message data. In this GPS positioning device, deficient data other than the existing data is compensated from the pseudo satellite signal obtained by the tracking to acquire one whole message data, and the arrangement position information is acquired from the acquired message data.

  The eighth invention is the control method of the sixth or seventh invention, wherein the pseudo satellite signal transmitting device repeatedly transmits one message data including the arrangement position information by the pseudo satellite signal. The GPS positioning device further includes a ring buffer unit that updates and stores signals for the past predetermined time captured by the capturing unit as needed, and the new reception current position determining step includes: In addition, the deficient data other than the data already stored in the ring buffer unit is supplemented from the pseudo satellite signal obtained by the tracking to obtain one whole message data, and the arrangement position information is obtained from the obtained message data. It is the control method which is a step which acquires.

  According to the third or eighth aspect of the invention, one message data including the arrangement position information is repeatedly transmitted as a pseudo satellite signal from the pseudo satellite signal transmission device. In the GPS positioning device, among the message data, One message data is obtained as a whole by supplementing the deficient data other than the data already stored in the ring buffer from the pseudo satellite signal. In the ring buffer unit, the captured signals for the past predetermined time are updated and stored as needed. That is, when acquiring one message data, it is not necessary to track the captured pseudo-satellite signal and acquire all of the message data of the pseudo-satellite signal, and a shortage other than the data stored in the ring buffer unit. It is sufficient to acquire only the data obtained by tracking the acquired pseudo satellite signal. As a result, the time required to acquire one message data is shortened, and the time required to determine the current position using the pseudo satellite is reduced.

  4th invention is the GPS positioning device of 3rd invention, Comprising: The said message data is data comprised by a predetermined number of unit data, The said current position determination part at the time of new reception is said ring buffer part Is extracted from the latest unit data in the unit data unit, and the unit data for the shortage is supplemented with the pseudo satellite signal obtained by the tracking to acquire one message data as a whole. It is a GPS positioning device.

  The ninth invention is the control method according to the eighth invention, wherein the message data is data composed of a predetermined number of unit data, and the new reception current position determining step includes the ring buffer. The data is extracted from the latest unit data in the unit data unit among the data already stored in the unit, and the missing unit data is supplemented with the pseudo satellite signal obtained by the tracking to acquire one message data as a whole It is the control method which is a step to perform.

  According to the fourth or ninth invention, the message data is composed of a predetermined number of unit data, and in the GPS positioning device, the unit data unit from the latest unit data among the data already stored in the ring buffer unit. The data is extracted in the above manner, and the entire unit data is acquired by supplementing the deficient unit data from the pseudo satellite signal.

  A fifth invention is a portable electronic device including the GPS positioning device according to any one of the first to fourth inventions.

  According to the fifth aspect of the invention, a portable electronic device that achieves the same effect as any of the first to fourth aspects of the invention is realized.

  A tenth aspect of the present invention simulates a GPS satellite signal and includes arrangement position information with a non-operational PRN code that is a PRN code other than an actual operation PRN code that is a PRN code assigned to an actually operated GPS satellite. A capture unit that captures the pseudo satellite signal and the GPS satellite signal from the pseudo satellite signal transmission device that transmits a pseudo satellite signal modulated with predetermined data by performing a correlation operation using a PRN code; and the non-practical operation PRN A computer built in a GPS positioning device that receives a GPS satellite signal having a storage unit for storing arrangement position information included in the pseudo-satellite signal received for each code and measures the current position, A program for executing the control method according to any one of the inventions.

  By causing the computer to read the program of the tenth invention and executing the arithmetic processing, the same effects as any of the sixth to ninth inventions can be obtained.

  The eleventh invention is a computer-readable storage medium storing the program of the tenth invention.

  Here, the storage medium is a storage medium such as a hard disk, a CD-ROM, a DVD, a memory card, or an IC memory that can read stored information. Therefore, according to the eleventh aspect, the same effect as that of the tenth aspect can be obtained by causing the computer to read the information stored in the storage medium and executing the arithmetic processing.

  Preferred embodiments of the present invention will be described below with reference to the drawings. In the following, a case where the present invention is applied to a mobile phone having a GPS function will be described as a GPS positioning device of the present invention, but an applicable embodiment of the present invention is not limited to this.

[Positioning system]
FIG. 1 is a diagram showing a schematic configuration of the positioning system of the present embodiment. The positioning system includes a mobile phone 1 that is a GPS positioning device carried by a user, a GPS satellite 3, and a pseudo satellite 5 that is a pseudo satellite signal transmission device.

  The mobile phone 1 receives a GPS satellite signal transmitted (transmitted) from the GPS satellite 3 that is currently operated (actually operated), and GPS satellite orbit information (ephemeris data and data) superimposed on the received GPS satellite signal. Based on navigation data such as almanac data, satellite information such as the position, moving direction, and speed of the GPS satellite is calculated. Four or more GPS satellites 3 are arranged on each of the six orbiting surfaces of the earth, and in principle, four or more satellites are always operated from anywhere on the earth in a geometrical arrangement. .

  The mobile phone 1 transmits the captured GPS satellite signal based on the difference between the reception time of the GPS satellite signal specified by the built-in quartz clock and the transmission time of the GPS satellite 3 of the received GPS satellite signal. The radio wave propagation time from the original GPS satellite (hereinafter referred to as “captured GPS satellite”) to itself is calculated. Next, the distance (pseudo distance) from the captured GPS satellite to the own aircraft is calculated by multiplying the calculated radio wave propagation time by the speed of light. Then, the mobile phone 1 determines the values of the four parameters of the three-dimensional coordinate value indicating the position of the own device and the clock error, the satellite information of the plurality of captured GPS satellites, and the distance from each captured GPS satellite to the own device. By performing the positioning calculation calculated based on information such as (pseudo distance), the current position of the own device is determined.

  The mobile phone 1 is configured to be able to receive a pseudo satellite signal transmitted (transmitted) from a pseudo satellite 5 which is a pseudo satellite signal transmitter. The pseudo-satellite 5 is installed everywhere in a facility such as a building, and always transmits pseudo-satellite signals including information on the installation position (hereinafter referred to as “pseudo-satellite position information”). Here, the pseudo-satellite signal transmitted from the pseudo-satellite 5 is a weak signal, and the range in which each pseudo-satellite 5 can communicate with the mobile phone 1 is narrow (for example, a radius of 10 m around the pseudo-satellite 5). is there. The pseudo satellites 5 are installed with an interval corresponding to the communicable range, and the mobile phone 1 does not communicate with a plurality of pseudo satellites 5 in principle.

  The pseudo-satellite 5 has a storage unit (memory) that stores data including arrangement position information of the pseudo-satellite 5, and stores the stored data as an assigned PRN (Pseudo Random Noise) code (non-practical PRN). Code) modulated satellite signal is transmitted. That is, the modulation method of the GPS satellite signal and the pseudo satellite signal is the same. The PRN code is a unique sequence (Gold code) composed of “0” and “1”, and is originally a code assigned to identify each GPS satellite 3. 37 types of “1” to “37” are defined for the PRN code, and PRN codes of “1” to “32” are assigned to the currently operated GPS satellite 3. Then, among the PRN codes “33” to “37” other than the PRN codes assigned to these GPS satellites 3, four types of PRN codes “33” to “36” are included. Is assigned to the pseudolite 5. In the present embodiment, four types of PRN codes from “33” to “36” other than the PRN codes assigned to the currently operated GPS satellite 3 are assigned to the pseudo satellite 5. When the assignment of the PRN code to the GPS satellite 3 in operation is changed, the PRN code assigned to the pseudo satellite 5 may be changed in accordance with this change.

[Pseudo satellite signal]
The pseudo satellite 5 repeatedly transmits message data including the arrangement position information of the pseudo satellite 5 as a pseudo satellite signal. FIG. 2 is a diagram showing a format of message data. According to the figure, one message data is composed of five consecutive words (Word) as unit data. One word is 30 bits (bits). That is, the message data is fixed-length data having a data length of 150 bits. The last 6 bits of each word are parity bits, so that the word delimiter is determined. In addition, the first 8 bits of the first word (“word 1”) are a preamble, whereby the head of the message data is determined. In each word, latitude, longitude, and altitude information is set as arrangement position information.

  FIG. 3 is a diagram for explaining message data acquisition in the mobile phone 1. FIG. 4A shows a conventional acquisition method, and FIG. 4B shows the acquisition method in the present embodiment. However, a pseudo satellite signal is transmitted from the pseudo satellite 5 at a bit rate of 50 [bit / s], and the mobile phone 1 receives 50 bits of data per second.

  According to FIG. 5A, conventionally, when a preamble is detected in received data, acquisition of each successive word starting from “word 1” including the preamble is started from the received data. When all of “word 1” to “word 5” are acquired, reception of one message data is completed. In this case, the time required to acquire one message data is the time from the start of reception to the detection of the preamble and the time required to acquire all five words from “word 1” to “word 5” from the detection of the preamble. And the sum.

  In FIG. 3A, the preamble in the received data is detected 3 seconds after the start of reception, and 3 seconds are required from the detection of the preamble to the completion of acquisition of all the words. Therefore, the time required from the start of reception to the completion of message data acquisition is 6 seconds. However, the time required to complete the acquisition of message data differs depending on at which point the preamble is detected.

  On the other hand, in the present embodiment, as shown in FIG. 5B, the mobile phone 1 includes a reception buffer that temporarily stores reception data, and the data stored in the reception buffer; One message data is acquired by combining the data acquired from the received data after detection of the preamble. The reception buffer is realized by, for example, a ring buffer, and is constantly updated and stored with the latest reception data. Here, it is assumed that the capacity of the reception buffer is “128 bits”. That is, when the preamble is detected in the received data, the data stored in the reception buffer is read in word units. Further, acquisition of each successive word starting from “word 1” including the detected preamble is started from the received data. When all of the deficient words other than the word read from the reception buffer are acquired from the reception data, the acquisition of one message data is completed.

  In FIG. 4B, a preamble in the received data is detected 3 seconds after the start. At this time, data including “word 3” to “word 5” received in the past is stored in the reception buffer. That is, as the message data, “word 1” and “word 2” are insufficient, and 2 from the detection of the preamble to the completion of acquisition from the received data of “word 1” and “word 2” for the shortage. It takes seconds. Therefore, the time required from the start of reception to the completion of acquisition of message data is 5 seconds, which is shortened by 1 second compared with the prior art shown in FIG.

[Mobile phone]
FIG. 4 is a block diagram showing a functional configuration of the mobile phone 1. The mobile phone 1 includes a GPS antenna 10, a TCXO (Temperature Compensated Crystal Oscillator) 20, a GPS receiving unit 30, a host CPU 60, an operation unit 61, a display unit 62, a ROM (Read Only Memory) 63, and a RAM. (Random Access Memory) 64, a cellular phone antenna 70, and a cellular phone wireless communication circuit unit 80.

  The GPS antenna 10 is an antenna that receives an RF signal including a GPS satellite signal transmitted from the GPS satellite 3 and a pseudo satellite signal transmitted from the pseudo satellite 5, and outputs the received signal to the GPS receiver 30. Note that the GPS satellite signal and the pseudo satellite signal are spread spectrum modulated by the PRN code, and are superimposed on the L1 band carrier wave having a carrier frequency of 1.57542 [GHz].

  The TCXO 20 is a temperature compensated crystal oscillator that generates an oscillation signal having a predetermined oscillation frequency, and outputs the generated oscillation signal to the RF reception circuit unit 40 and the baseband processing circuit unit 50.

  The GPS receiving unit 30 is a positioning unit that measures the current position of the mobile phone 1 based on a signal output from the GPS antenna 10, and corresponds to a so-called GPS receiver. The GPS receiving unit 30 includes an RF (Radio Frequency) receiving circuit unit 40 and a baseband processing circuit unit 50. The RF receiving circuit unit 40 and the baseband processing circuit unit 50 can be manufactured as separate LSIs (Large Scale Integration) or can be manufactured as one chip.

  The RF receiving circuit unit 40 is a circuit block of a high-frequency signal (RF signal), and generates an oscillation signal for RF signal multiplication by dividing or multiplying the oscillation signal generated by the TCXO 20. Then, by multiplying the generated oscillation signal by the RF signal output from the GPS antenna 10, the RF signal is down-converted to an intermediate frequency signal (hereinafter referred to as "IF (Intermediate Frequency) signal"), and IF After amplifying the signal, it is converted into a digital signal by an A / D converter and output to the baseband processing circuit unit 50.

  The baseband processing circuit unit 50 performs correlation processing and the like on the IF signal input from the RF receiving circuit unit 40 to capture and extract GPS satellite signals and pseudo satellite signals, and performs demodulation to perform navigation messages and pseudo satellites. Information is taken out, and the current position of the mobile phone 1 is measured based on the information.

  FIG. 5 is a diagram illustrating an example of a circuit configuration of the baseband processing circuit unit 50. The baseband processing circuit unit 50 includes a reception channel 51 including first to eighth reception channels 51-1 to 51-8, a CPU 52, a ROM 53, and a RAM 54. Each reception channel 51 includes a signal capturing unit 511 that captures a GPS satellite signal and a pseudo satellite signal, a signal tracking unit 514 that tracks a change in the signal captured by the signal capturing unit 511, and a signal tracking unit 514. A reception buffer 515 for storing the tracked reception data.

  The signal acquisition unit 511 performs a correlation operation between the IF signal input from the RF reception circuit unit 40 and a pseudo PRN code generated by the PRN code generation unit 513 (hereinafter referred to as “replica PRN code”). A correlation processing unit 512 that tries to perform tuning and a PRN code generation unit 513 that generates a replica PRN code based on the control of the CPU 52 are configured.

  The signal tracking unit 514 includes circuits such as a code loop known as a delay locked loop (DLL (Delay Locked Loop)) and a carrier loop known as a phase locked loop (PLL (Phase Locked Loop)). By tracking the phase of the carrier wave, the signals captured by the signal capturing unit 511 are held in parallel.

  The reception buffer 515 is configured by a ring buffer of a predetermined size (for example, 128 bits), and the latest data of the reception data tracked by the signal tracking unit 514 is always temporarily stored.

  The CPU 52 comprehensively controls each unit of the baseband processing circuit unit 50 and the RF receiving circuit unit 40 and performs various arithmetic processes including a baseband process described later. Specifically, a PRN code is assigned to each reception channel 51. For example, when the mobile phone 1 is located outside the facility, the PRN code of the GPS satellite 3 is assigned to the seven reception channels 51 so that the GPS satellite signals are received with priority, and the remaining GPS satellite signals are received. The PRN code of the pseudo satellite 5 is assigned to one of the reception channels 51 so that the pseudo satellite signal is received. When the mobile phone 1 is present in the facility, the PRN codes of the pseudo satellites 5 are assigned to the four reception channels 51 so as to receive more pseudo satellite signals, and the remaining four reception channels 51 are assigned. Is assigned the PRN code of the GPS satellite 3.

  Then, for each reception channel 51, a PRN code replica PRN code assigned to the reception channel 51 is generated by the PRN code generation unit 513, and the satellite signal of the assigned PRN code is acquired by the signal acquisition unit 511. The satellite signal is tracked by the signal tracking unit 514. Note that the switching of the PRN code assignment to each reception channel 51 may be performed at a predetermined time interval, for example, or the type of satellite signal being captured (a GPS satellite signal or a pseudo satellite signal) You may switch according to.

  Here, the PRN code assignment to each reception channel 51 is stored in the PRN code assignment data 541. FIG. 6 shows an example of the data configuration of the PRN code assignment data 541. The PRN code assignment data 541 stores the assigned PRN code 541b and the satellite type 541c corresponding to the PRN code in association with each of the eight reception channels 541a.

  The CPU 52 performs GPS satellite positioning processing for calculating the current position based on the GPS satellite signal. That is, in each of the reception channels 51 to which the PRN code of the GPS satellite 3 is assigned, the current position is calculated by performing positioning calculation based on the received, captured and tracked GPS satellite signals. Then, the calculated current position is output to the host CPU 60 at the subsequent stage.

  Further, the CPU 52 performs a pseudo satellite positioning process for determining the current position based on the pseudo satellite signal. That is, it is determined whether or not a pseudo satellite signal has been acquired for each reception channel 51 to which the PRN code of the pseudo satellite 5 is assigned. When the pseudo satellite signal is acquired, it is determined whether the arrangement position information corresponding to the PRN code of the acquired pseudo satellite signal is stored in the pseudo satellite arrangement position data 543. If the corresponding arrangement position information is stored, the arrangement position information is output to the host CPU 60 at the subsequent stage as the current position.

  The pseudo satellite arrangement position data 543 is arrangement position information data included in the acquired pseudo satellite signal. FIG. 7 shows an example of the data configuration of the pseudo satellite arrangement position data 543. In the pseudo satellite arrangement position data 543, arrangement position information 543b acquired from the corresponding pseudo satellite signal is stored in association with each PRN code 543a assigned to the pseudo satellite 5.

  On the other hand, if the corresponding arrangement position information is not stored in the pseudo satellite arrangement position data 543, the CPU 52 acquires the arrangement position information included in the captured pseudo satellite signal, and uses the acquired arrangement position information as the current position. Is output to the host CPU 60 and the arrangement position information is stored in the pseudo satellite arrangement position data 543 in association with the PRN code of the captured pseudo satellite signal.

  Here, the acquisition of the arrangement position information from the captured pseudo satellite signal is performed as described with reference to FIG. That is, the presence or absence of a preamble included in the received data is monitored, and when the preamble is detected, the data stored in the reception buffer 515 is extracted in units of words and stored in the received message data 542 as data of the corresponding word. Further, acquisition of data of each successive word starting from “word 1” is started from the received data. The acquired data is stored in the received message data 542 as data of the corresponding word.

  The received message data 542 is message data acquired from the received data. FIG. 8 shows an example of the data structure of the received message data 542. According to the figure, the received message data 542 is formed with a data area for storing data of each of the five words “word 1” to “word 5” constituting the message data.

  When the CPU 52 has acquired all the word data, the CPU 52 determines that acquisition of one message data has been completed, and acquires arrangement position information from the acquired message data. Then, the acquired arrangement position information is output to the host CPU 60 as the current position, and this arrangement position information is stored in the pseudo satellite arrangement position data 543 in association with the PRN code of the captured pseudo satellite signal.

  Returning to FIG. 5, the ROM 53 is a system program for the CPU 52 to control each unit of the baseband processing circuit unit 50 and the RF receiving circuit unit 40, various programs and data for realizing various processes including baseband processing, and the like. Is remembered. FIG. 9 shows an example of the configuration of the ROM 53. As shown in the figure, the ROM 53 stores a baseband processing program 531.

  The RAM 54 is used as a work area for the CPU 52, and temporarily stores programs and data read from the ROM 53, calculation results executed by the CPU 52 according to various programs, and the like. FIG. 10 shows an example of the configuration of the RAM 54. According to the figure, the RAM 54 stores PRN code assignment data 541, received message data 542, and pseudo satellite arrangement position data 543.

  Returning to FIG. 4, the host CPU 60 comprehensively controls each unit of the mobile phone 1 according to various programs such as a system program stored in the ROM 63. Specifically, the telephone function as a telephone is mainly realized, and a navigation screen in which the current position of the mobile phone 1 input from the baseband processing circuit unit 50 is plotted on a map is displayed on the display unit 62. Processing for realizing various functions including a navigation function is performed.

  The operation unit 61 is an input device including operation keys, button switches, and the like, and outputs an operation signal corresponding to an operation by a user to the host CPU 60. By operating the operation unit 61, various instructions such as a positioning start / end instruction are input. The display unit 62 is a display device configured by an LCD (Liquid Crystal Display) or the like, and displays a display screen (for example, a navigation screen or time information) based on a display signal input from the host CPU 60.

  The ROM 63 stores a system program for the host CPU 60 to control the mobile phone 1 and various programs and data for realizing a navigation function. The RAM 64 is used as a work area for the host CPU 60, and temporarily stores programs and data read from the ROM 63, data input from the operation unit 61, calculation results executed by the host CPU 60 according to various programs, and the like.

  The cellular phone antenna 70 is an antenna that transmits and receives cellular phone radio signals to and from a radio base station installed by a communication service provider of the cellular phone 1. The cellular phone wireless communication circuit unit 80 is a cellular phone communication circuit unit configured by an RF conversion circuit, a baseband processing circuit, and the like, and performs transmission and reception of radio signals under the control of the host CPU 60.

[Process flow]
FIG. 11 is a flowchart for explaining the flow of the baseband processing. This process is realized by the CPU 52 executing the baseband processing program 531 in the ROM 53. Prior to baseband processing, an IF signal digitized through reception of an RF signal by the GPS antenna 10 and down-conversion to an IF signal by the RF reception circuit unit 40 is input to the baseband processing circuit unit 50 as needed. Suppose that it is in a state.

  According to the figure, the CPU 52 first performs a loop A process for all the reception channels 51. In loop A, it is determined whether or not to change the PRN code assigned to the target reception channel 51. If the PRN code to be assigned is changed (step A1: YES), it is determined whether or not the currently assigned PRN code is a PRN code for pseudo satellites, and if it is a PRN code for pseudo satellites (step A3: YES), the arrangement information corresponding to the PRN code stored in the pseudo satellite arrangement position data 543 is deleted (step A5). Thereafter, a new PRN code is assigned to the target reception channel 51 (step A7), and the reception buffer 515 of the target reception channel is cleared (step A9). Loop A is performed in this way.

  Then, when the processing of the loop A for all the reception channels 51 is completed, the CPU 52 subsequently performs GPS satellite positioning processing. In the GPS satellite positioning processing, the current position is calculated by performing a positioning operation on the received channel 51 assigned with the PRN code for the GPS satellite signal among all the received channels 51, based on the captured GPS satellite signal. The calculated current position is output (step A11).

  Next, it is determined whether or not the positioning of the current position by the GPS satellite positioning process is successful. If the positioning is not successful (step A13: NO), then, the CPU 52, among all the receiving channels 51, Loop B processing is performed for each reception channel 51 to which a pseudo-satellite PRN code is assigned. In the loop B, first, pseudo-satellite positioning processing for determining the current position based on the pseudo-satellite signal captured by the target reception channel 51 is performed (step A15).

  FIG. 12 is a flowchart for explaining the flow of the pseudo satellite positioning process. According to the figure, the CPU 52 determines whether or not the pseudo satellite signal is captured in the target reception channel 51, and if not (step B1: NO), in the pseudo satellite arrangement position data 543, The arrangement position information associated with the PRN code assigned to the target reception channel 51 is deleted (step B3).

  On the other hand, if the pseudo satellite signal is captured (step B1: YES), in the pseudo satellite arrangement position data 543, the PRN code of the captured pseudo satellite signal (that is, the PRN code assigned to the reception channel 51) is set. It is determined whether corresponding arrangement position information is stored. If the arrangement position information is stored (step B5: YES), the stored arrangement position information is determined as the current position and output to the host CPU 60 (step B7).

  On the other hand, if the arrangement position information is not stored (step B5: NO), the CPU 52 clears the received message data 542 (step B9). Next, the preamble included in the received data is monitored (step B11), and if the preamble included in the received data is detected (step B13: YES), the data stored in the reception buffer 515 of the target reception channel is converted to a word. The data is extracted in units and stored in the received message data 542 as corresponding word data (step B15). Subsequently, the data is extracted from the received data in units of words, and stored in the received message data 542 as data of the corresponding word (step B17).

  Thereafter, referring to the received message data 542, it is determined whether or not the acquisition of the entire message data has been completed (that is, whether or not the data of all words has been acquired). : NO), it returns to step B17. On the other hand, if the acquisition of the entire message data is completed (step B19: YES), the arrangement position information included in the acquired message data is acquired (step B21), and the acquired arrangement position information is used as the captured pseudo satellite signal. Is stored in the pseudo-satellite arrangement position data 543 in association with the PRN code (that is, the PRN code assigned to the target reception channel 51) (step B23). Further, the acquired arrangement position information is determined as the current position, and is output to the host CPU 60 (step B25). When the above processing is performed, the CPU 52 ends the pseudo satellite positioning processing.

  When the pseudo satellite positioning process is completed, the CPU 52 determines whether or not the current position is determined as a result of the process. If the current position is determined (step A17: YES), the loop B is terminated. On the other hand, if the current position has not been determined (step A17: NO), the process of loop B targeting another reception channel 51 is subsequently performed. Loop B is performed in this way.

  When the loop B ends, the CPU 52 determines whether or not to end the positioning. If the positioning does not end (NO at Step A19), the CPU 52 returns to Step A1 and ends the positioning (Step A19: YES). The band process ends.

[Action / Effect]
Thus, according to the present embodiment, in the mobile phone 1 having a GPS function, the current position is determined based on the GPS satellite signal transmitted from the GPS satellite 3 and the pseudo satellite signal transmitted from the pseudo satellite 5. The In the positioning of the current position based on the pseudo satellite signal, if the arrangement position information associated with the PRN code of the acquired pseudo satellite signal is stored in the pseudo satellite arrangement position data 543, the stored arrangement position information is stored. Based on the current position is determined. On the other hand, if the corresponding arrangement position information is not stored, the arrangement position information included in the captured pseudo satellite signal is acquired and determined as the current position, and the pseudo position is correlated with the PRN code of the pseudo satellite signal. It is stored in the satellite arrangement position data 543. However, of the arrangement position information stored in the pseudo satellite arrangement position data 543, the arrangement position information corresponding to the PRN of the pseudo satellite signal that has not been captured is deleted.

  That is, for example, when the mobile phone 1 hardly moves in the facility or the like, the acquisition of the same pseudo satellite signal is continued. In such a case, the arrangement position included in the pseudo satellite signal once acquired After the information is acquired, it is necessary to receive the same pseudo satellite signal again and acquire the position information by using the stored position information while the acquisition of the same pseudo satellite signal is continued. No. Thereby, the time required for positioning the current position based on the pseudo satellite signal can be shortened.

  Further, when the arrangement position information is acquired from the captured pseudo satellite signal, the time required to acquire the arrangement position information is reduced by using the data stored in the reception buffer 515. That is, when the preamble indicating the head of the message data is detected in the received data, the data stored in the reception buffer 515 is extracted in units of words, and the data of insufficient words other than the extracted words is received data. Is received, one message data is completely received. In other words, unlike the prior art, after the preamble is detected, it is not necessary to acquire all word data from the received data, thereby shortening the time required to acquire the arrangement position information included in the pseudo satellite signal. .

[Modification]
It should be noted that embodiments to which the present invention can be applied are not limited to the above-described embodiments, and can of course be changed as appropriate without departing from the spirit of the present invention.

(A) Host CPU
For example, part or all of the processing performed by the CPU 52 of the baseband processing circuit unit 50 may be performed by the host CPU 60 in software.

(B) GPS positioning device In the above-described embodiment, the case where the GPS positioning device is applied to a mobile phone has been described. However, for example, a portable navigation device, an in-vehicle navigation device, a PDA (Personal Digital Assistants), a wristwatch, etc. The same can be applied to other electronic devices.

(C) Satellite Positioning System In the above-described embodiment, the case where GPS is used has been described, but it is needless to say that the present invention can be similarly applied to other satellite positioning systems such as GLONASS (GLObal Navigation Satellite System).

(D) Recording medium The baseband processing program 531 may be recorded on a recording medium such as a CD-ROM and installed in an electronic device such as a mobile phone.

The schematic diagram of a positioning system. Pseudo satellite signal format. Explanatory drawing of the acquisition method of the message data contained in a pseudo | simulation satellite signal. The internal block diagram of a portable telephone. The circuit block diagram of a baseband process circuit part. The data structural example of PRN code allocation data. The data structural example of pseudo satellite arrangement position data. An example of the data structure of received message data. The block diagram of ROM in a baseband processing circuit. The block diagram of RAM in a baseband processing circuit. The flowchart of a baseband process. The flowchart of the pseudo satellite positioning process performed during a baseband process.

Explanation of symbols

1 mobile phone, 30 GPS receiver, 40 RF receiver,
50 baseband processing circuit unit, 51 reception channel, 511 signal acquisition unit,
512 correlation processing unit, 513 PRN code generation unit, 514 signal tracking unit,
515 receive buffer, 52 CPU,
53 ROM, 531 Baseband processing program, 54 RAM,
541 PRN code assignment data, 542 received message data,
543 Pseudo satellite location data, 3 GPS satellites, 5 pseudo satellites

Claims (11)

A GPS positioning device that receives a GPS satellite signal and measures a current position,
Simulate GPS satellite signals, and modulate predetermined data including location information with non-actual PRN codes that are PRN codes other than actual PRN codes that are PRN codes assigned to actually operated GPS satellites A capture unit that captures the pseudo satellite signal and the GPS satellite signal from the pseudo satellite signal transmission device that transmits the pseudo satellite signal by performing a correlation operation using a PRN code;
A storage unit for storing arrangement position information included in the pseudo-satellite signal received for each non-practical operation PRN code;
A pseudo-satellite signal capture detection unit that detects capture of the pseudo-satellite signal by the capture unit;
In accordance with the detection, a determination unit that determines whether or not the location information of the pseudo satellite signal corresponding to the same non-practical operation PRN code as the detected pseudo satellite signal is stored in the storage unit;
When it is determined that the detection has been made and stored by the determination unit, the arrangement position information of the pseudo satellite signal corresponding to the same non-actual operation PRN code is read from the storage unit, and the current position is determined from the arrangement position information. Re-reception current position determination unit for determining
When it is determined that the detection is made and the determination unit does not store the acquired pseudo satellite signal, the arrangement position information included in the pseudo satellite signal is obtained by tracking the detected pseudo satellite signal, and the acquired arrangement position is acquired. Information is stored in the storage unit in association with the non-actual operation PRN code of the pseudo satellite signal, and a current position determination unit at the time of new reception that determines a current position from the acquired arrangement position information;
GPS positioning device equipped with.   The information deletion control part which erase | eliminates the arrangement position information memorize | stored in association with the non-actual operation | use PRN code | cord | chord which is not captured by the said capture | acquisition part among the arrangement | positioning position information memorize | stored in the said memory | storage part. The GPS positioning device according to 1. The pseudo satellite signal transmitting device repeatedly transmits one message data including the arrangement position information by the pseudo satellite signal,
A ring buffer unit that updates and stores the signal for the past predetermined time captured by the capturing unit as needed;
The new reception current position determination unit compensates a deficient data other than the data already stored in the ring buffer unit from the message data by compensating for a pseudo-satellite signal obtained by the tracking. Obtain the entire data, and obtain the location information from the obtained message data;
The GPS positioning apparatus according to claim 1 or 2. The message data is data composed of a predetermined number of unit data,
The new reception current position determination unit extracts data in unit data units from the latest unit data among the data already stored in the ring buffer unit, and obtains the deficient unit data by the tracking. Complement with satellite signal to get one message data whole,
The GPS positioning device according to claim 3.   The portable electronic device provided with the GPS positioning apparatus as described in any one of Claims 1-4. Simulate GPS satellite signals, and modulate predetermined data including location information with non-actual PRN codes that are PRN codes other than actual PRN codes that are PRN codes assigned to actually operated GPS satellites A capture unit that captures the pseudo-satellite signal and the GPS satellite signal from the pseudo-satellite signal transmission device that transmits the pseudo-satellite signal by performing a correlation operation using a PRN code, and a pseudo-satellite that is received for each non-operational PRN code. A GPS positioning device control method for receiving a GPS satellite signal including a storage unit for storing arrangement position information included in a signal and positioning a current position,
A pseudo satellite signal capture detection step for detecting capture of the pseudo satellite signal by the capture unit;
A determination step of determining whether or not arrangement position information of a pseudo satellite signal corresponding to the same non-practical operation PRN code as the detected pseudo satellite signal is stored in the storage unit in response to the detection;
When it is determined that the detection is made and stored in the determination step, the arrangement position information of the pseudo satellite signal corresponding to the same non-actual operation PRN code is read from the storage unit, and the current position is determined from the arrangement position information. Re-reception current position determination step for determining,
When it is determined that the detection has been made and the information is not stored in the determination step, the detected pseudo satellite signal is tracked to obtain arrangement position information included in the pseudo satellite signal, and the acquired arrangement position is acquired. Information is stored in the storage unit in association with the non-actual operation PRN code of the pseudo satellite signal, and a new reception current position determination step for determining a current position from the acquired arrangement position information;
Control method.   The information erasure control step of erasing the arrangement position information stored in association with the non-actual operation PRN code not captured by the capturing unit among the arrangement position information stored in the storage unit. The control method described in 1. The pseudo satellite signal transmitting device repeatedly transmits one message data including the arrangement position information by the pseudo satellite signal,
The GPS positioning device further includes a ring buffer unit that updates and stores signals for the past predetermined time captured by the capturing unit as needed,
In the new reception current position determining step, one of the message data is supplemented with deficient data other than the data already stored in the ring buffer unit from the pseudo satellite signal obtained by the tracking. The step of acquiring the entire data and acquiring the arrangement position information from the acquired message data.
The control method according to claim 6 or 7. The message data is data composed of a predetermined number of unit data,
The new reception current position determining step extracts data in unit data units from the latest unit data among the data already stored in the ring buffer unit, and obtains the deficient unit data by the tracking. It is a step of acquiring one whole message data by compensating with a satellite signal.
The control method according to claim 8.   Simulate GPS satellite signals, and modulate predetermined data including location information with non-actual PRN codes that are PRN codes other than actual PRN codes that are PRN codes assigned to actually operated GPS satellites A capture unit that captures the pseudo-satellite signal and the GPS satellite signal from the pseudo-satellite signal transmission device that transmits the pseudo-satellite signal by performing a correlation operation using a PRN code, and a pseudo-satellite that is received for each non-operational PRN code. A computer incorporated in a GPS positioning device that receives a GPS satellite signal and includes a storage unit for storing arrangement position information included in the signal and measures a current position, 10. A program for executing the control method described in 1.   A computer-readable storage medium storing the program according to claim 10.

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