JP2001228233A - Gps receiver - Google Patents

Abstract

PROBLEM TO BE SOLVED: To determine time in a short time after a GPS receiver is turned on to start positioning. SOLUTION: Signals from GPS satellites are received to extract navigation message data. Parity checks are performed on the navigation message data by a parity check part 109 to detect the front of the words of a navigation message. The time of the detected front of the words is obtained by a 20-ms counter verifying part 111 through the use of the time of an RTC part 110 to verify a 20-ms counter part 112. A 6-sec counter part 113 is verified by a 6-sec counter verifying part 113 on the basis of the time of the RTC part 110. The transmission time of GPS data is speedily verified in this way to shorten rising time up to the start of positioning.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a GPS receiver, and more particularly to a GPS receiver capable of starting positioning in a short time after power-on.
It relates to an S receiver.

[0002]

2. Description of the Related Art A GPS (Global Positioning System) receiver simultaneously receives radio waves from a plurality of GPS satellites and
This system acquires orbit information and time information from navigation messages of PS satellites, and calculates the absolute position on the earth.

FIG. 13 shows the structure of a navigation message of a GPS satellite. The navigation message is data sent from a GPS satellite including orbit information of the satellite, and the like.
The transmission speed is 50 bps. Navigation messages consist of 25 mainframes. The mainframe consists of five subframes, and one subframe is
It is 300 bits (6 seconds). The subframe is composed of 10 words, and one word is 30 bits. Each word has a 6-bit parity. The first word of the subframe contains a preamble pattern (8 bits) indicating the beginning of the subframe, and the second word contains a Z counter indicating the time from the beginning of the week.

FIG. 14 is a functional block diagram showing a configuration of a conventional GPS receiver. In FIG. 14, a signal receiving section 1 is a means for receiving a signal from a GPS satellite. PRN
The code synchronizer 2 synchronizes the received signal with the PRN code and extracts data from the GPS satellite signal. The detailed time calculation unit 3 is a means for calculating a value of 1 ms or less of the signal transmission time from the phase of the synchronized PRN code. The bit edge detector 4 is a means for detecting an edge of a navigation message bit of a GPS satellite signal.
The 1 ms counter determining unit 5 is a means for determining a value of a signal transmission time in 1 ms units from a bit edge. The 1 ms counter section 6 is means for counting up from 0 ms to 19 ms cyclically in 1 ms units.

[0005] The bit data acquisition section 7 is means for acquiring a bit pattern of a GPS navigation message. The data storage unit 8 is means for storing the acquired bit data. The parity check unit 9 is a means for performing a parity check on bit data. The preamble pattern detector 10 is a means for detecting a preamble pattern of a navigation message. The RTC unit 11 is a unit that measures time. The Z count detector 12 calculates the Z count and R
This is a means for comparing TCs and confirming that a preamble pattern has been correctly detected. The 20 ms counter determination unit 13 is a means for determining the time in units of 20 ms based on the head of the word detected by the preamble pattern detection. The 20 ms counter section 14 is a means for counting the time in units of 20 ms. The 6-sec counter deciding section 15 is a means for deciding the time in units of 6 seconds based on the detected Z count value. The 6-sec counter 16 is a means for counting the time in units of 6 seconds.

[0006] The transmission time calculation unit 17 includes a detailed time calculation unit,
This is a means for calculating the transmission time from information of the 1 ms counter section, the 20 ms counter section, and the 6 sec counter section. The navigation message collecting unit 18 is a means for collecting navigation messages. The navigation message storage unit 19 is a means for storing a navigation message. The positioning calculation unit 20 is a means for performing a positioning calculation based on the transmission time and the navigation message.

[0007] The operation of the conventional GPS receiver configured as described above will be described. The signal receiving unit 1 receives a GPS satellite signal. The PRN code synchronization section 2 synchronizes the received signal with the PRN code and extracts data from the GPS satellite signal. The detailed time calculation unit 3 calculates a value of 1 ms or less of the signal transmission time from the phase of the synchronized PRN code. The bit edge detector 4 detects the edge of the navigation message bit of the GPS satellite signal. 1 ms
In the counter determination unit 5, based on the edge of the bit,
Determine the value of the signal transmission time in 1 ms units. The 1 ms counter section 6 cyclically counts up from 0 ms to 19 ms in 1 ms units.

The bit data acquisition section 7 acquires a bit pattern of a navigation message from a GPS satellite. The data storage unit 8 stores the acquired bit data. The parity check unit 9 performs a parity check on the stored bit data. The preamble pattern detector 10 detects the preamble pattern of the navigation message from the data that has passed the parity check, and detects the head of the subframe. The RTC unit 11 measures time. The Z count detector 12 compares the acquired Z count with the RTC, and confirms that the preamble pattern has been correctly detected. The 20 ms counter determination unit 13 determines the time in units of 20 ms with reference to the head of the word detected by the preamble pattern detection. 20ms
The counter unit 14 counts time in units of 20 ms. 6
The sec counter determining unit 15 determines the time in units of 6 seconds based on the detected Z count value. The 6-sec counter 16 counts time in units of 6 seconds.

[0009] The transmission time calculation unit 17 includes a detailed time calculation unit 3
, 1 ms counter section 6, 20 ms counter section 14, 6 sec
The transmission time is calculated from the information of the counter unit 16. The navigation message collection unit 18 collects navigation messages. The navigation message storage unit 19 stores the collected navigation messages. The positioning calculation unit 20 performs positioning calculation based on the transmission time and the navigation message.

[0010]

However, in the above-mentioned conventional GPS receiver, the time cannot be determined unless the preamble pattern is detected and the Z count is obtained. There was a problem that the rise time of the sphere became long.

The present invention solves such a conventional problem and detects the head of a word to determine the time without receiving a preamble pattern and a Z count from a GPS satellite. An object of the present invention is to reduce a rise time from when the power is turned on to when positioning is started.

[0012]

According to the present invention, there is provided a signal receiving unit for receiving a GPS signal from a GPS satellite, synchronizing the GPS signal with a PRN code, and converting the GPS signal into a GPS data. PRN code synchronizing unit for extracting the GPS signal, a detailed time calculating unit for calculating a detailed time value of 1 ms or less of the GPS signal transmission time based on the phase of the PRN code, An edge detection unit, a 1 ms counter determination unit that determines a value of the transmission time in 1-ms units based on bit edges, a 1 ms counter unit that counts up from 0 ms to 19 ms in 1-ms units, and an R that measures time.
A TC section, a 6-sec counter section that measures time in 6-sec units, a 6-sec counter decision section that decides the 6-sec counter section, a bit data acquisition section that acquires bit data of a navigation message, and a data storage section that accumulates bit data. A parity check unit that performs a parity check of bit data, a 20 ms counter unit that measures time in units of 20 ms, a 20 ms counter determination unit that determines the 20 ms counter unit, and a value and a detailed time value of each counter unit. A transmission time calculation unit for calculating a transmission time, a navigation message collection unit for collecting navigation messages, a navigation message storage unit for storing navigation messages, and a positioning calculation unit for performing positioning calculation based on the navigation messages and the transmission time. G with
The parity check unit of the PS receiver is provided with a means for detecting the head of the word of the navigation message based on the parity check of the bit data, and the 20 ms counter determination unit obtains the head time of the word based on the time of the RTC unit. 20ms
Means for determining the counter section is provided, and the 6-sec counter determining section is provided with means for determining the 6-sec counter section based on the time of the RTC section.

With this configuration, determination of the 6-sec counter, detection of the head of a word, and determination of the 20-ms counter can be performed quickly, and the determination of the transmission time is speeded up to reduce the rise time. it can.

Further, a means for acquiring further 29 bits of data after detecting the head of the word in the 20 ms counter determining section and confirming that the portion other than the head of the first detected word does not pass the parity check, The time at the beginning of the word is determined based on the time of the RTC section in response to the confirmation, and is 20 ms.
Means for determining the counter section is provided. With this configuration, it is possible to suppress the erroneous detection of the head of the word, accurately determine the time, and suppress the positioning error.

[0015] Further, means for confirming that only one of the data of the past 59 bits of the navigation message passes the parity check in the 20 ms counter determination unit,
Means for determining the head time of the word in response to the confirmation based on the time of the RTC section and determining the 20 ms counter section. With this configuration, it is possible to suppress the erroneous detection of the head of the word, accurately determine the time, and suppress the positioning error.

A data comparing unit is provided for comparing the data stored in the navigation message storing unit with the data which has passed the parity check, and judging that the head of the word has been correctly detected when the data match. Was. With this configuration, it is possible to suppress erroneous detection of the head of a word, accurately determine the time, and suppress a positioning error.

Also, a data search unit for determining data transmission time by searching data passed in the parity check from the data stored in the navigation message storage unit is provided, and the determined data transmission time is stored in the 20 ms counter determination unit. Means for determining the 20 ms counter section based on the
With this configuration, the time at which data is to be transmitted is predicted, the time is determined, and the rise time can be reduced.

The 6-sec counter determining section uses a means for calculating the time in 12.5 minute units corresponding to one round of the navigation message from the RTC section and the time when the data retrieval section determines a fractional value of 12.5 minutes or less. And a means for determining the 6-sec counter based on the calculated time. With this configuration, even when the accuracy of the RTC unit is low, high-speed time determination can be accurately performed, and the rise time can be reduced.

Further, the data search unit is provided with means for limiting the search range according to the time of the RTC unit. With this configuration, it is possible to reduce the possibility that the acquired data coincides with a plurality of stored data, increase the probability that the time can be determined, enable quick time determination, and reduce the rise time.

In addition, a parity generation unit for generating and adding a parity to the data stored in the navigation message storage unit is provided, and a bit string including the parity stored in the data storage unit is stored in the data search unit. Means is provided for retrieving from the navigation message to which the parity is added by the parity generation unit and determining the time at which the data is transmitted. With this configuration, the time is determined in units of bits instead of words, so that the time can be determined more quickly and the rise time can be reduced.

[0021]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the present invention will be described below in detail with reference to FIGS.

(First Embodiment) In a first embodiment of the present invention, a head of a word of a navigation message is detected based on a parity check of bit data of a navigation message of a GPS satellite, and a head of the word is detected. Is determined based on the time of the RTC section, the 20 ms counter section is determined, and R
G for determining the 6-sec counter based on the time of the TC
It is a PS receiver.

FIG. 1 is a functional block diagram showing the configuration of the GPS receiver according to the first embodiment of the present invention. In FIG. 1, a signal receiving unit 101 is a unit that receives a signal from a GPS satellite. The PRN code synchronization section 102 is a means for synchronizing the received signal with the PRN code and extracting data from the GPS satellite signal. Detailed time calculation unit 103
Is means for calculating a value of 1 ms or less of the signal transmission time from the phase of the synchronized PRN code. The bit edge detection unit 104 is means for detecting an edge of a navigation message bit of a GPS satellite signal. 1ms counter decision section 10
Reference numeral 5 denotes a means for determining the value of the signal transmission time in 1 ms units from the bit edge. The 1 ms counter unit 106 has 0 ms
From 19 ms to 1 ms in a cyclic manner.

The bit data acquisition section 107 is means for acquiring a bit pattern of a navigation message of a GPS satellite. The data storage unit 108 is means for storing the acquired bit data. The parity check unit 109 is a unit that performs a parity check of the bit data and detects the head of the word of the navigation message. RTC unit 110
Is a means for measuring the time irrespective of ON / OFF of the power of the GPS receiver. 20 ms counter decision section 111
Is means for determining the head time of the detected word using the time of the RTC section, and determining the 20 ms counter. The 20 ms counter unit 112 is a unit that measures time in units of 20 ms. The 6-sec counter deciding unit 113 is means for deciding a 6-sec counter based on the time of the RTC unit. 6s
The ec counter unit 114 is a unit that measures time in units of 6 seconds.

The transmission time calculating section 115 is means for calculating the transmission time based on the value of each counter and the time of 1 ms or less. The navigation message collection unit 116 is a means for collecting navigation messages. The navigation message storage unit 117 is a means for storing a navigation message. Positioning calculation unit 118
Is a means for performing positioning calculation based on the navigation message and the transmission time.

The operation of the GPS receiver according to the first embodiment of the present invention configured as described above will be described. The signal receiving unit 101 receives a GPS satellite signal. The PRN code synchronization section 102 synchronizes the received signal with the PRN code and extracts data from the GPS satellite signal. The detailed time calculation unit 103 calculates a value of 1 ms or less of the signal transmission time from the phase of the synchronized PRN code.

The bit edge detector 104 detects the edge of the navigation message bit of the GPS satellite signal. 1 ms
The counter determination unit 105 determines the value of the signal transmission time in units of 1 ms based on the detected edge of the bit. 1
The ms counter 106 cyclically counts up from 0 ms to 19 ms in 1 ms units. Bit data acquisition unit
At 107, the bit pattern of the navigation message of the GPS satellite is acquired. The data storage unit 108 stores the acquired bit data. Up to this point, the operation is the same as that of the conventional GPS receiver.

The parity check unit 109 performs a parity check of the stored bit data, and detects the head of the word of the navigation message. In the RTC unit 110, the GP
The time is measured regardless of ON / OFF of the power of the S receiver. The 20 ms counter determination unit 111 obtains the head time of the detected word using the time of the RTC unit 110,
Determine the 20ms counter. At this time, the RTC unit 110 measures the head time of the detected word, and
The time is determined by quantizing in units of 0.6 seconds, which is the word length. Therefore, the RTC unit 110 needs an accuracy of less than ± 0.3 seconds.

The 20 ms counter 112 measures the time in units of 20 ms. In the 6-sec counter determination unit 113, the RTC unit 11
The 6-sec counter is determined based on the time of 0. At this time, the time of the RTC unit 110 is quantized in units of 6 seconds and determined. Therefore, here, the accuracy of the RTC unit 110 is:
It must be less than ± 3 seconds.

The 6-sec counter 114 measures time in units of 6 sec. The transmission time calculation unit 115 includes a detailed time calculation unit 103, a 1 ms counter unit 106, and a 20 ms counter unit 112.
Then, the transmission time is calculated based on the value of each counter of the 6-sec counter unit 114 and the time of 1 ms or less.

The navigation message collecting section 116 collects navigation messages. The navigation message storage unit 117 stores the collected navigation messages. The positioning calculation unit 118 performs a positioning calculation based on the navigation message stored in the navigation message storage unit 117 and the signal transmission time calculated by the transmission time calculation unit 115, calculates the position and time, and calculates the calculated time. To correct the time of the RTC unit 110.

As described above, in the first embodiment of the present invention, the GPS receiver detects the head of the word of the navigation message based on the parity check of the bit data,
Finding the time at the beginning of a word based on the time in the RTC section
Since the 20 ms counter section is determined and the 6-sec counter section is determined based on the time of the RTC section, 6 sec.
The determination of the counter, the detection of the head of the word, and the determination of the 20 ms counter can be performed quickly, the transmission time can be determined at high speed, and the rise time can be reduced.

(Second Embodiment) In a second embodiment of the present invention, after detecting the head of the word of the navigation message of the GPS satellite, 29-bit data is further acquired and the first detected word is detected. This is a GPS receiver which confirms that the parity check does not pass in the part other than the head, and thereafter obtains the head time of the word based on the time of the RTC part and determines the 20 ms counter part. The basic configuration of the second embodiment is the same as that of the first embodiment.
The second embodiment differs from the first embodiment in that a means for confirming that a part other than the head of the first detected word does not pass the parity check is provided in the 20 ms counter determining unit. It is.

FIG. 2 is a functional block diagram showing the configuration of the GPS receiver according to the second embodiment of the present invention. In FIG. 2, even after detecting the head of the word, the 20 ms counter determining unit 119 obtains an additional 29 bits of data, and after confirming that the part other than the head of the first detected word does not pass the parity check. , The RTC unit time is used to determine the head time of the detected word, and to determine the 20 ms counter.

The operation of the GPS receiver according to the second embodiment of the present invention configured as described above will be described. Signal receiving unit 101, PRN code synchronizing unit 102, detailed time calculating unit 10
3, bit edge detection unit 104, 1ms counter determination unit 105,
1 ms counter section 106, bit data acquisition section 107, data storage section 108, parity check section 109, RTC section 110, 20 ms
Counter 112, 6-sec counter determiner 113, 6-sec counter 114, transmission time calculator 115, navigation message collector 11
6. The navigation message storage unit 117 and the positioning calculation unit 118
The same operation as that of the embodiment is performed.

[0036] Even after detecting the beginning of a word, the 20 ms counter determination section 119 acquires 29-bit data further,
After confirming that the parity check does not pass in a part other than the head of the first detected word, the time of the RTC unit 110 is used to determine the head of the detected word using the time of the RTC unit 110 in the same manner as in the first embodiment. Obtain the time and determine the 20 ms counter.

As described above, in the second embodiment of the present invention, after detecting the head of a word, the GPS receiver obtains another 29 bits of data, and acquires data other than the head of the first detected word. In the part, it is confirmed that the parity check is not passed. Then, the time at the head of the word is obtained based on the time of the RTC section, and the 20 ms counter section is determined. In addition, the time can be accurately determined and the positioning error can be suppressed.

(Third Embodiment) In a third embodiment of the present invention, it is confirmed that only one place of the past 59 bits of data of the navigation message passes the parity check, and thereafter, This is a GPS receiver that determines the start time of a word based on the time of the RTC section and determines the 20 ms counter section. The basic configuration of the third embodiment is the same as that of the first embodiment. The difference between the third embodiment and the first embodiment is that the 20-ms counter determination unit confirms that only one of the past 59-bit data of the navigation message passes the parity check. This is the point that a means for performing this is provided.

FIG. 3 is a functional block diagram showing the configuration of the GPS receiver according to the third embodiment of the present invention. In FIG. 3, the 20 ms counter determination unit 120 confirms that only one location of the past 59-bit data of the navigation message passes the parity check, detects the head of the word, and sets the RTC unit time. Is used to determine the head time of the detected word and to determine the 20 ms counter.

The operation of the GPS receiver according to the third embodiment of the present invention configured as described above will be described. Signal receiving unit 101, PRN code synchronizing unit 102, detailed time calculating unit 10
3, bit edge detection unit 104, 1ms counter determination unit 105,
1 ms counter section 106, bit data acquisition section 107, data storage section 108, parity check section 109, RTC section 110, 20 ms
Counter 112, 6-sec counter determiner 113, 6-sec counter 114, transmission time calculator 115, navigation message collector 11
6. The navigation message storage unit 117 and the positioning calculation unit 118
The same operation as that of the embodiment is performed.

The 20 ms counter determination unit 120 confirms that only one location of the past 59-bit data of the navigation message passes the parity check, detects the head of the word, and executes the first embodiment. In the same manner as in the embodiment, the time at the head of the detected word is obtained using the time of the RTC unit 110, and the 20 ms counter is determined.

As described above, in the third embodiment of the present invention, the GPS receiver confirms that only one of the data of the past 59 bits of the navigation message passes the parity check, After that, the time at the head of the word is obtained based on the time of the RTC section, and the 20 ms counter section is determined. Therefore, erroneous detection of the word head is suppressed, the time is accurately determined, and the positioning error is suppressed. It becomes possible to do.

(Fourth Embodiment) In the fourth embodiment of the present invention, the data stored in the navigation message storage unit is compared with the data that has passed the parity check, and they match. In this case, the GPS receiver determines that the head of the word has been correctly detected. The basic configuration of the fourth embodiment is the same as that of the first embodiment. 4th
Is different from the first embodiment in that
This is the point that a data comparison unit is provided.

FIG. 4 is a functional block diagram showing a configuration of a GPS receiver according to the fourth embodiment of the present invention. In FIG. 4, the data comparison unit 121 compares the data stored in the navigation message storage unit with the data that has passed the parity check, and when they match, determines that the head of the word has been correctly detected. It is a means to do.

The operation of the GPS receiver according to the fourth embodiment of the present invention configured as described above will be described. Signal receiving unit 101, PRN code synchronizing unit 102, detailed time calculating unit 10
3, bit edge detection unit 104, 1ms counter determination unit 105,
1 ms counter section 106, bit data acquisition section 107, data storage section 108, parity check section 109, RTC section 110, 20 ms
Counter determination unit 111, 20 ms counter unit 112, 6-sec counter determination unit 113, 6-sec counter unit 114, transmission time calculation unit 11
5, navigation message collection unit 116, navigation message storage unit 11
7. The positioning operation unit 118 performs the same operation as in the first embodiment.

The data comparing section 121 obtains the time from the RTC section 110, and compares the data stored in the navigation message storing section 117 to be transmitted at the corresponding time with the data that has passed the parity check. . If they match, it is determined that the beginning of the word has been correctly detected. In other cases, it is determined to be an erroneous detection.

As described above, in the fourth embodiment of the present invention, the GPS receiver compares the data stored in the navigation message storage with the data that has passed the parity check, and In such a case, the configuration is such that it is determined that the head of the word has been correctly detected, so that erroneous detection of the head of the word can be suppressed, time can be accurately determined, and positioning errors can be suppressed.

(Fifth Embodiment) In a fifth embodiment of the present invention, data which passed a parity check is searched from data stored in a navigation message storage unit.
This is a GPS receiver that determines a data transmission time and determines a 20 ms counter based on the determined data transmission time. The basic configuration of the fifth embodiment is similar to that of the fourth embodiment.
This is the same as the embodiment. The fifth embodiment is similar to the fourth embodiment.
The difference from the embodiment is that a data search unit is provided,
The 20 ms counter deciding section is provided with a means for deciding the 20 ms counter according to the data search result.

FIG. 5 is a functional block diagram showing a configuration of a GPS receiver according to the fifth embodiment of the present invention. In FIG. 5, a data search unit 122 is a means for searching data that has passed a parity check from data stored in a navigation message storage unit and determining the time at which the data was transmitted. The 20 ms counter determining unit 123 is means for determining the 20 ms counter based on the determined time.

The operation of the GPS receiver according to the fifth embodiment of the present invention configured as described above will be described. Signal receiving unit 101, PRN code synchronizing unit 102, detailed time calculating unit 10
3, bit edge detection unit 104, 1ms counter determination unit 105,
1 ms counter 106, bit data acquisition 107, data storage 108, parity check 109, RTC 110, 6 sec
The counter determination unit 113, the 6-sec counter unit 114, the transmission time calculation unit 115, the navigation message collection unit 116, the navigation message storage unit 117, and the positioning calculation unit 118 perform the same operations as in the fourth embodiment.

The data retrieving unit 122 retrieves the data that passed the parity check from the data stored in the navigation message storing unit 117, and obtains the time at which the data should be transmitted. The 20 ms counter determination unit 123 determines the 20 ms counter based on the determined time.

As described above, in the fifth embodiment of the present invention, the GPS receiver is searched for data that has passed the parity check from the data stored in the navigation message storage unit, and determines the data transmission time. Is determined, and the 20 ms counter section is determined based on the determined data transmission time. Therefore, the time can be determined from the transmission time of the acquired data, and the rise time can be reduced.

(Sixth Embodiment) According to a sixth embodiment of the present invention, a time in 12.5 minute units corresponding to one round of a navigation message is calculated by the RTC unit, and a fractional value of 12.5 minutes or less is calculated as a data value. A GP that calculates using the time determined by the search unit and determines the 6-sec counter based on the calculated time.
S receiver. The basic configuration of the sixth embodiment is as follows.
This is the same as the fifth embodiment. In a sixth embodiment,
The difference from the fifth embodiment is that a means for calculating the time in 12.5 minute units from the RTC unit is provided in the 6-sec counter determination unit.

FIG. 6 is a functional block diagram showing a configuration of a GPS receiver according to the sixth embodiment of the present invention. In FIG. 6, the 6-sec counter determination unit 124 calculates the time in 12.5 minute units corresponding to one round of the navigation message by the RTC unit, and calculates the fractional value of 12.5 minutes or less using the time determined by the data search unit. Then, the 6-sec counter section is determined.

The operation of the GPS receiver according to the sixth embodiment of the present invention configured as described above will be described. Signal receiving unit 101, PRN code synchronizing unit 102, detailed time calculating unit 10
3, bit edge detection unit 104, 1ms counter determination unit 105,
1 ms counter 106, bit data acquisition 107, data storage 108, parity check 109, RTC 110, 6 sec
The counter determination unit 113, the 6-sec counter unit 114, the transmission time calculation unit 115, the navigation message collection unit 116, the navigation message storage unit 117, the positioning calculation unit 118, the data search unit 122, and the 20ms counter determination unit 123 are provided in the fifth embodiment. The same operation as in the embodiment is performed.

In the 6-sec counter determination section 124, the time in 12.5 minute units corresponding to one round of the navigation message is determined by the RTC section 110.
It is calculated from: The fractional value of 12.5 minutes or less is calculated using the time determined by the data search unit 122. Based on each calculated time, the 6-sec counter 114 is determined.

As described above, in the sixth embodiment of the present invention, the GPS receiver corresponds to one round of the navigation message.
A configuration in which a time in units of 12.5 minutes is calculated by the RTC unit, a value of a fraction of 12.5 minutes or less is calculated using the time determined by the data search unit, and the 6-sec counter unit is determined based on the calculated time. Therefore, even when the accuracy of the RTC unit is low, high-speed time determination can be performed with high accuracy, and the rise time can be reduced.

(Seventh Embodiment) In a seventh embodiment of the present invention, the search range is limited by the time of the RTC unit.
It is a PS receiver. The basic configuration of the seventh embodiment is the same as that of the fifth embodiment. The seventh embodiment differs from the fifth embodiment in that a means for limiting the search range is provided in the data search unit.

FIG. 7 is a functional block diagram showing a configuration of a GPS receiver according to the seventh embodiment of the present invention. In FIG. 7, a data search unit 125 is a unit that limits the search range by the time of the RTC unit, searches the stored data for acquired data, and determines the data transmission time.

The operation of the GPS receiver according to the seventh embodiment of the present invention configured as described above will be described. Signal receiving unit 101, PRN code synchronizing unit 102, detailed time calculating unit 10
3, bit edge detection unit 104, 1ms counter determination unit 105,
1 ms counter 106, bit data acquisition 107, data storage 108, parity check 109, RTC 110, 6 sec
The counter determination unit 113, the 6-sec counter unit 114, the transmission time calculation unit 115, the navigation message collection unit 116, the navigation message storage unit 117, the positioning calculation unit 118, and the 20ms counter determination unit 123
The same operation as in the fifth embodiment is performed.

When retrieving the corresponding data from the navigation message, the data retrieval section 125 acquires the time from the RTC section 110, performs a search with a limited search range, and determines the time.

As described above, in the seventh embodiment of the present invention, the search range is limited by the time of the RTC unit in the GPS receiver, so that the acquired data can match a plurality of stored data. The probability of being able to determine the time is increased by reducing the probability, and the time is quickly determined and the rise time can be reduced.

(Eighth Embodiment) In an eighth embodiment of the present invention, G is used to limit the search range by the time of the RTC unit.
It is a PS receiver. The basic configuration of the eighth embodiment is the same as that of the sixth embodiment. The eighth embodiment differs from the sixth embodiment in that a means for limiting the search range is provided in the data search unit.

FIG. 8 is a functional block diagram showing a configuration of a GPS receiver according to the eighth embodiment of the present invention. In FIG. 8, a data search unit 126 is a unit that limits the search range by the time of the RTC unit, searches the stored data for acquired data, and determines the data transmission time.

The operation of the GPS receiver according to the eighth embodiment of the present invention having the above configuration will be described. Signal receiving unit 101, PRN code synchronizing unit 102, detailed time calculating unit 10
3, bit edge detection unit 104, 1ms counter determination unit 105,
1 ms counter 106, bit data acquisition 107, data storage 108, parity check 109, RTC 110, 6 sec
Counter determination unit 113, 6-sec counter unit 114, transmission time calculation unit 115, navigation message collection unit 116, navigation message storage unit 117, positioning calculation unit 118, 20ms counter determination unit 123, 6s
The ec counter determination unit 124 performs the same operation as in the sixth embodiment.

When retrieving the corresponding data from the navigation message, the data retrieval unit 126 obtains the time from the RTC unit 110, performs a search within a limited search range, and determines the time.

As described above, in the eighth embodiment of the present invention, the search range is limited by the time of the RTC unit in the GPS receiver, so that the acquired data can match a plurality of stored data. The probability of being able to determine the time is increased, the time is quickly determined, and the rise time can be reduced.

(Ninth Embodiment) In a ninth embodiment of the present invention, a parity is generated and added to data stored in a navigation message storage unit, and the parity is stored in a data storage unit. This is a GPS receiver that searches for a bit string including a parity from the navigation message to which the parity is added, and determines the time at which the data was transmitted. Ninth
The basic configuration of this embodiment is the same as that of the fifth embodiment. The ninth embodiment is different from the fifth embodiment in that a parity generation unit and a means for determining a data transmission time by searching a bit string including parity from a navigation message are provided.

FIG. 9 is a functional block diagram showing a configuration of a GPS receiver according to the ninth embodiment of the present invention. In FIG. 9, a parity generation unit 127 is a unit that generates and adds a parity to data stored in the navigation message storage unit. The data search unit 128 is means for searching the bit string including the parity stored in the data storage unit from the navigation message to which the parity is added by the parity generation unit, and determining the time at which the data was transmitted.

The operation of the GPS receiver according to the ninth embodiment of the present invention configured as described above will be described. Signal receiving unit 101, PRN code synchronizing unit 102, detailed time calculating unit 10
3, bit edge detection unit 104, 1ms counter determination unit 105,
1 ms counter 106, bit data acquisition 107, data storage 108, parity check 109, RTC 110, 6 sec
The counter determination unit 113, the 6-sec counter unit 114, the transmission time calculation unit 115, the navigation message collection unit 116, the navigation message storage unit 117, the positioning calculation unit 118, and the 20ms counter determination unit 123
The same operation as in the fifth embodiment is performed.

The parity generation section 127 generates and adds a parity to the data stored in the navigation message storage section 117. In the data search unit 128, a bit string including the parity stored in the data storage unit 108 is searched from the navigation message to which the parity is added by the parity generation unit 127, and the time at which the data was transmitted is determined.

As described above, in the ninth embodiment of the present invention, the GPS receiver generates and adds a parity to the data stored in the navigation message storage, and stores the parity in the data storage. The bit string including the parity is also searched from the navigation message to which the parity is added, and the time at which the data is transmitted is determined. Therefore, the time is determined not by word but by bit, The time can be determined faster and the rise time can be reduced.

(Tenth Embodiment) In a tenth embodiment of the present invention, parity is generated and added to data stored in a navigation message storage unit, and the parity is stored in a data storage unit. This is a GPS receiver that searches for a bit string including a parity from the navigation message to which the parity is added, and determines the time at which the data was transmitted.
The basic configuration of the tenth embodiment is the same as that of the sixth embodiment. The tenth embodiment differs from the sixth embodiment in that a parity generation unit and a means for searching a bit string including parity from a navigation message to determine a data transmission time are provided.

FIG. 10 is a functional block diagram showing a configuration of a GPS receiver according to the tenth embodiment of the present invention. In FIG. 10, a parity generation unit 129 is means for generating and adding a parity to data stored in the navigation message storage unit. Data search unit 130
Is means for retrieving a bit string including parity stored in the data storage unit from the navigation message to which the parity is added by the parity generation unit and determining the time at which the data was transmitted.

The operation of the GPS receiver according to the tenth embodiment of the present invention configured as described above will be described. Signal receiving unit 101, PRN code synchronizing unit 102, detailed time calculating unit
103, bit edge detection unit 104, 1ms counter determination unit 10
5, 1 ms counter section 106, bit data acquisition section 107, data storage section 108, parity check section 109, RTC sections 110, 6
sec counter determination unit 113, 6-sec counter unit 114, transmission time calculation unit 115, navigation message collection unit 116, navigation message storage unit 117, positioning calculation unit 118, 20ms counter determination unit 123,
The 6-sec counter determination unit 124 performs the same operation as in the sixth embodiment.

The parity generation section 129 generates and adds a parity to the data stored in the navigation message storage section. In the data search unit 130, the data storage unit 1
The bit string including the parity stored in 08 is searched from the navigation message to which the parity is added by the parity generation unit 129, and the time at which the data is transmitted is determined.

As described above, in the tenth embodiment of the present invention, the GPS receiver generates and adds a parity to the data stored in the navigation message storage,
The bit string including the parity stored in the data storage unit is searched from the navigation message to which the parity has been added, and the time at which the data was transmitted is determined. By performing the determination, the time is determined more quickly, and the rise time can be reduced.

(Eleventh Embodiment) In an eleventh embodiment of the present invention, a parity is generated and added to the data stored in the navigation message storage unit, and is stored in the data storage unit. This is a GPS receiver that searches for a bit string including a parity from the navigation message to which the parity is added, and determines the time at which the data was transmitted.
The basic configuration of the eleventh embodiment is the same as that of the seventh embodiment. The eleventh embodiment differs from the seventh embodiment in that a parity generation unit and means for retrieving a bit string including parity from a navigation message to determine a data transmission time are provided.

FIG. 11 is a functional block diagram showing a configuration of a GPS receiver according to the eleventh embodiment of the present invention. In FIG. 11, a parity generation unit 131 is a means for generating and adding a parity to data stored in the navigation message storage unit. Data search unit 132
Is means for retrieving a bit string including parity stored in the data storage unit from the navigation message to which the parity is added by the parity generation unit and determining the time at which the data was transmitted.

The operation of the GPS receiver according to the eleventh embodiment of the present invention configured as described above will be described. Signal receiving unit 101, PRN code synchronizing unit 102, detailed time calculating unit 10
3, bit edge detection unit 104, 1ms counter determination unit 105,
1 ms counter 106, bit data acquisition 107, data storage 108, parity check 109, RTC 110, 6 sec
The counter determination unit 113, the 6-sec counter unit 114, the transmission time calculation unit 115, the navigation message collection unit 116, the navigation message storage unit 117, the positioning calculation unit 118, and the 20ms counter determination unit 123
The same operation as in the seventh embodiment is performed.

The parity generation unit 131 generates and adds a parity to the data stored in the navigation message storage unit 117. The data search unit 132 acquires the time from the RTC unit 110 when searching for the data with parity stored in the data storage unit 108 from the navigation message to which the parity is added by the parity generation unit 131, and sets the search range. A limited search is performed to determine the time.

As described above, in the eleventh embodiment of the present invention, the GPS receiver generates and adds a parity to the data stored in the navigation message storage,
The bit string including the parity stored in the data storage unit is searched from the navigation message to which the parity has been added, and the time at which the data was transmitted is determined. By performing the determination, the time is determined more quickly, and the rise time can be reduced.

(Twelfth Embodiment) In a twelfth embodiment of the present invention, parity is generated and added to data stored in the navigation message storage unit, and the parity is stored in the data storage unit. This is a GPS receiver that searches for a bit string including a parity from the navigation message to which the parity is added, and determines the time at which the data was transmitted.
The basic configuration of the twelfth embodiment is the same as that of the eighth embodiment. The twelfth embodiment is different from the eighth embodiment in that a parity generation unit and means for determining a data transmission time by searching a bit string including a parity from a navigation message are provided.

FIG. 12 is a functional block diagram showing a configuration of a GPS receiver according to the twelfth embodiment of the present invention. In FIG. 12, a parity generation unit 133 is a unit that generates and adds a parity to data stored in the navigation message storage unit. Data search unit 134
Is means for retrieving a bit string including parity stored in the data storage unit from the navigation message to which the parity is added by the parity generation unit and determining the time at which the data was transmitted.

The operation of the GPS receiver according to the twelfth embodiment of the present invention configured as described above will be described. Signal receiving unit 101, PRN code synchronizing unit 102, detailed time calculating unit
103, bit edge detection unit 104, 1ms counter determination unit 10
5, 1 ms counter section 106, bit data acquisition section 107, data storage section 108, parity check section 109, RTC section 110,
6 sec counter deciding section 113, 6 sec counter section 114, transmission time calculating section 115, navigation message collecting section 116, navigation message storing section 117, positioning calculating section 118, 20ms counter deciding section 12
The 3, 6-sec counter determination unit 124 performs the same operation as in the eighth embodiment.

The parity generation unit 133 generates and adds a parity to the data stored in the navigation message storage unit 117. The data search unit 134 obtains the time from the RTC unit 110 when searching for the data with parity stored in the data storage unit 108 from the navigation message to which the parity is added by the parity generation unit 133, and sets the search range. A limited search is performed to determine the time.

As described above, in the twelfth embodiment of the present invention, the GPS receiver generates and adds a parity to data stored in the navigation message storage unit,
The bit string including the parity stored in the data storage unit is searched from the navigation message to which the parity has been added, and the time at which the data was transmitted is determined. By performing the determination, the time is determined more quickly, and the rise time can be reduced.

[0088]

As is apparent from the above description, according to the present invention, a signal receiving section for receiving a GPS signal from a GPS satellite, and a PRN for synchronizing the GPS signal with a PRN code and extracting GPS data from the GPS signal. A code synchronization section,
A detailed time calculating unit that calculates a detailed time value of 1 ms or less of the transmission time of the GPS signal based on the phase of the PRN code;
A bit edge detector for detecting a bit edge of a navigation message in the PS signal; a 1 ms counter determiner for determining a value of a 1 ms unit of the transmission time based on the bit edge;
a 1 ms counter section that cyclically counts up from 19 ms to 19 ms in 1 ms units, an RTC section that measures time,
a 6-sec counter for measuring the time in seconds, a 6-sec counter determining unit for determining the 6-sec counter, a bit data obtaining unit for obtaining bit data of the navigation message, a data storage unit for storing bit data, and a bit data Parity check unit that performs a parity check of 20 ms, a 20 ms counter unit that measures the time in 20 ms units, and 20 ms
20ms counter determination unit that determines the counter unit, transmission time calculation unit that calculates the transmission time based on the value of each counter unit and detailed time value, navigation message collection unit that collects navigation messages, and saves navigation messages A parity check unit of a GPS receiver including a navigation message storage unit for performing a positioning operation based on the navigation message and the transmission time, adds a head of a word of the navigation message based on a parity check of bit data. A means for detecting, a means for determining the head time of the word based on the time of the RTC section to determine the 20 ms counter section in the 20 ms counter determination section;
Since the means for determining the 6-sec counter section based on the time of the RTC section is provided, the 6-sec counter, the start of the word, and the 20-ms counter can be quickly performed, and the transmission time can be determined. This has the effect of speeding up the determination and shortening the rise time.

Further, a means for acquiring further 29 bits of data after detecting the head of the word in the 20 ms counter determination section and confirming that the portion other than the head of the first detected word does not pass the parity check, The time at the beginning of the word is determined based on the time of the RTC section in response to the confirmation, and is 20 ms.
Since the means for determining the counter section is provided, an effect is obtained in that erroneous detection of the head of a word is suppressed, time is accurately determined, and a positioning error can be suppressed.

A means for confirming that only one of the past 59-bit data of the navigation message passes the parity check in the 20 ms counter determining section,
Means for determining the head time of the word in response to the confirmation based on the time of the RTC section and determining the 20 ms counter section is provided. The effect that the error can be suppressed is obtained.

A data comparing unit is provided for comparing the data stored in the navigation message storing unit with the data which has passed the parity check, and judging that the head of the word has been correctly detected when they match. As a result, the time is correctly determined by suppressing erroneous detection at the beginning of the word,
The advantage is that the positioning error can be suppressed.

Further, a data search unit is provided for retrieving the data which passed the parity check from the data stored in the navigation message storage unit to determine the data transmission time, and the determined data transmission time is stored in the 20 ms counter determination unit. Since the means for determining the 20 ms counter section is provided on the basis of the above, an effect is obtained that the rise time can be reduced by predicting the time at which data is to be transmitted and determining the time.

Further, the means for calculating the time in 12.5 minute units corresponding to one round of the navigation message from the RTC unit and the time when the data retrieval unit determines the fractional value of 12.5 minutes or less are used for the 6-sec counter determining unit. And a means for determining the 6-sec counter section based on the calculated time are provided. Therefore, even when the accuracy of the RTC section is low, high-speed time determination can be accurately performed, and the rise time can be increased. The effect of shortening can be obtained.

Further, since the data search unit is provided with means for limiting the search range based on the time of the RTC unit, it is possible to reduce the possibility that the acquired data matches a plurality of stored data and reduce the probability that the time can be determined. As a result, it is possible to obtain the effect that the start-up time can be quickly determined and the rise time can be reduced.

Further, a parity generation unit for generating and adding a parity to the data stored in the navigation message storage unit is provided, and a bit string including the parity stored in the data storage unit is stored in the data search unit. A means is provided to determine the time at which data was transmitted by searching from the navigation message to which the parity was added by the parity generation unit, so that the time was determined in bits instead of words, and the time was determined more quickly. And the rise time can be shortened.

[Brief description of the drawings]

FIG. 1 is a functional block diagram of a GPS receiver according to a first embodiment of the present invention;

FIG. 2 is a functional block diagram of a GPS receiver according to a second embodiment of the present invention;

FIG. 3 is a functional block diagram of a GPS receiver according to a third embodiment of the present invention;

FIG. 4 is a functional block diagram of a GPS receiver according to a fourth embodiment of the present invention;

FIG. 5 is a functional block diagram of a GPS receiver according to a fifth embodiment of the present invention;

FIG. 6 is a functional block diagram of a GPS receiver according to a sixth embodiment of the present invention;

FIG. 7 is a functional block diagram of a GPS receiver according to a seventh embodiment of the present invention;

FIG. 8 is a functional block diagram of a GPS receiver according to an eighth embodiment of the present invention;

FIG. 9 is a functional block diagram of a GPS receiver according to a ninth embodiment of the present invention;

FIG. 10 is a functional block diagram of a GPS receiver according to a tenth embodiment of the present invention;

FIG. 11 is a functional block diagram of a GPS receiver according to an eleventh embodiment of the present invention;

FIG. 12 is a functional block diagram of a GPS receiver according to a twelfth embodiment of the present invention;

FIG. 13 is an explanatory diagram showing a schematic configuration of a navigation message;

FIG. 14 is a functional block diagram of a conventional GPS receiver.

[Explanation of symbols]

 1, 101 signal receiving unit 2, 102 PRN code synchronizing unit 3, 103 detailed time calculating unit 4, 104 bit edge detecting unit 5, 105 1 ms counter determining unit 6, 106 1 ms counter unit 7, 107 bit data obtaining unit 8, 108 Data storage unit 9,109 Parity check unit 11,110 RTC unit 13,111,119,120,123 20ms counter decision unit 14,112 20ms counter unit 15,113,124 6sec counter decision unit 16,114 6sec counter unit 17, 115 Transmission time calculation unit 18, 116 Navigation message collection unit 19, 117 Navigation message storage unit 20, 118 Positioning calculation unit 121 Data comparison unit 122, 125, 126, 128, 130, 132, 134 Data search unit 127, 129, 131 , 133 Parity generator 10 Preamble pattern detector 12 Z count detector

Claims (8)

[Claims] 1. A signal receiving unit for receiving a GPS signal from a GPS satellite, and a PRN for synchronizing the GPS signal with a PRN code and extracting GPS data from the GPS signal.
A code synchronization unit, a detailed time calculation unit that calculates a detailed time value of 1 ms or less of the transmission time of the GPS signal based on the phase of the PRN code, and a bit edge that detects a bit edge of a navigation message in the GPS signal A detection unit;
A 1-ms counter determining unit that determines a value of the transmission time in 1-ms units based on the bit edge;
a 1 ms counter that counts up cyclically in units of ms, an RTC unit that measures time, a 6 sec counter that measures time in units of 6 sec, a 6 sec counter decision unit that decides the 6 sec counter, and the navigation message A bit data acquisition unit for acquiring the bit data, a data accumulation unit for accumulating the bit data, a parity check unit for performing a parity check of the bit data, a 20 ms counter unit for measuring time in units of 20 ms,
A 20ms counter determining section for determining the 20ms counter section,
A transmission time calculation unit that calculates a transmission time based on the value of each counter unit and the detailed time value, a navigation message collection unit that collects the navigation message, a navigation message storage unit that stores the navigation message, In a GPS receiver including a navigation message and a positioning operation unit that performs a positioning operation based on the transmission time, the parity check unit detects a head of a word of the navigation message based on a parity check of the bit data. Means for determining the leading time of the word in the 20 ms counter determining unit based on the time of the RTC unit.
A means for determining the 20 ms counter section is provided, and
A GPS receiver, wherein a counter determining unit is provided with means for determining the 6-sec counter unit based on the time of the RTC unit. 2. A means for acquiring, in the 20 ms counter determining section, 29 bits of data after detecting the head of the word and confirming that a portion other than the head of the first detected word does not pass the parity check. 2. The GPS receiver according to claim 1, further comprising: a means for determining a leading time of the word based on the time of the RTC unit in response to the confirmation and determining the 20 ms counter unit. . 3. A means for confirming that only one place of the past 59 bits of data of the navigation message passes the parity check in the 20ms counter determining section, and a head of the word in response to the confirmation. The time of R
2. The GPS receiver according to claim 1, further comprising means for determining the 20 ms counter section based on the time of the TC section. 4. A data comparing section for comparing data stored in the navigation message storing section with data that has passed a parity check, and determining that the head of the word has been correctly detected when the data match. The GPS receiver according to claim 1, further comprising: 5. A data search unit for searching data passed in a parity check from data stored in the navigation message storage unit and determining data transmission time in place of the data comparison unit, 5. The GPS receiver according to claim 4, wherein said counter determining unit is provided with means for determining said 20 ms counter unit based on the determined data transmission time. 6. A means for calculating, by the RTC section, a time in 12.5 minute units corresponding to one round of a navigation message in the 6-sec counter determining section, and a time in which the data search section determines a fractional value of 12.5 minutes or less. Means for calculating using
6. The GPS receiver according to claim 5, further comprising: means for determining the 6-sec counter based on the calculated time. 7. The GPS receiver according to claim 5, wherein said data search unit is provided with means for limiting a search range according to a time of said RTC unit. 8. A parity generation unit for generating and adding a parity to data stored in the navigation message storage unit, wherein the data search unit includes the parity stored in the data storage unit. 8. The GPS according to claim 5, further comprising means for retrieving the bit sequence from the navigation message to which the parity is added by the parity generation unit and determining the time at which the data was transmitted. Receiving machine.