U.S. patent application number 09/234259 was filed with the patent office on 2001-05-24 for method for transmitting/receiving portions of an audio signal based on a priority of each portion.
Invention is credited to ITO, SEIGO.
Application Number | 20010001763 09/234259 |
Document ID | / |
Family ID | 16539693 |
Filed Date | 2001-05-24 |
United States Patent
Application |
20010001763 |
Kind Code |
A1 |
ITO, SEIGO |
May 24, 2001 |
METHOD FOR TRANSMITTING/RECEIVING PORTIONS OF AN AUDIO SIGNAL BASED
ON A PRIORITY OF EACH PORTION
Abstract
A position measuring apparatus according to the present
invention includes a first position measuring means for position
measuring a first position by receiving a first radio wave, a
second position measuring means for position measuring a second
position by receiving a second radio wave, an evaluating means for
evaluating uncertainty of data derived from the first position
measuring means and/or the second position measuring means, and a
selecting means for selecting data from the first position
measuring means or the second position measuring means based on an
output signal of the evaluating means.
Inventors: |
ITO, SEIGO; (TOKYO,
JP) |
Correspondence
Address: |
JAY H MAIOLI
COOPER & DUNHAM
1185 AVENUE OF THE AMERICAS
NEW YORK
NY
10036
|
Family ID: |
16539693 |
Appl. No.: |
09/234259 |
Filed: |
January 20, 1999 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
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09234259 |
Jan 20, 1999 |
|
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08897651 |
Jul 21, 1997 |
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Current U.S.
Class: |
455/512 ;
455/422.1; 455/521 |
Current CPC
Class: |
G01S 19/48 20130101;
G01C 21/28 20130101; G01S 2205/008 20130101; G01S 2205/002
20130101; G01S 19/36 20130101 |
Class at
Publication: |
455/512 ;
455/422; 455/521 |
International
Class: |
H04Q 007/20 |
Foreign Application Data
Date |
Code |
Application Number |
Aug 6, 1996 |
JP |
P08-207433 |
Claims
What is claimed is:
1. Position measuring apparatus comprising; a first position
measuring means for position measuring a first position by
receiving a first radio wave; a second position measuring means for
position measuring a second position by receiving a second radio
wave; an evaluating means for evaluating uncertainty of data
derived from said first position measuring means and/or said second
position measuring means; and a selecting means for selecting data
from said first position measuring means or said second position
measuring means based on an output signal of said evaluating
means.
2. Position measuring apparatus as claimed in claim 1 wherein said
first and second position measuring means receive radio wave
without transmitting a data request signal.
3. Position measuring apparatus as claimed fin claim 2, wherein
said first position measuring means receives a radio wave from a
satellite, and said second position measuring means receives a
radio wave not from a satellite.
4. Position measuring apparatus as claimed in claim 3, wherein said
first position measuring means receives a radio wave from a GPS
satellite, and said second position measuring means receives a
radio wave from a base station of mobile telephone network.
5. Position measuring apparatus as claimed in claim 4, wherein said
evaluating uncertainty of data is executed using a GDOP signal in a
GPS system.
6. Position measuring apparatus as claimed in claim 4, wherein said
evaluation uncertainty of data is executed using a position signal
from said base station of mobile telephone network.
7. Position measuring apparatus as claimed in claim 4, wherein said
second position measuring means determines a position by using one
and/or two and/or three radio wave(s).
8. Position measuring apparatus as claimed in claim 4, wherein said
second position measuring means determine a position by using a
decoded signal and a signal strength of a received signal.
9. Position measuring apparatus as claimed in claim 4, wherein said
first position measuring means is utilized only in a case that a
condition of a received signal form said second position measuring
mens is no satisfactory.
10. Position measuring apparatus as claimed in claim 4, wherein
said second position measuring means further comprises, for
enabling not only position measuring but also communicating, a
sound signal processing means for processing an audio signal to
communicate in a voice signal, and a transmitting means for
transmitting an RF signal modulated by an output signal of said
sound signal processing means.
11. Position measuring apparatus as claimed in claim 4, wherein
said second position measuring means further comprises a data
receiving means for receiving transmitted data which includes not
only an identification signal of a base station but also other data
signal, and a displaying means for displaying an output signal of
said data receiving means.
12. Position measuring apparatus from a position of plural
reference stations comprising; a receiving means for receiving
plural radio waves from plural reference stations, a position
measuring means for portioning by said received plural radio wave,
wherein said position measuring means determines a position by
using a decoded signal and a signal strength of a received
signal.
13. Navigation apparatus comprising: a first position measuring
means for position-measuring a first position by receiving a radio
wave from a GPS satellite; a second position measuring means for
portioning a second position by receiving a radio wave from a base
station of cellar telephone system without transmitting any request
signal for position-measuring to said base station; an evaluating
means for evaluating uncertainty of data derived from said first
position measuring means and/or said second position measuring
means; a selecting means for selecting data from said first
position measuring means or said second position measuring based on
an output signal of said evaluating means; a data storage means for
storing map data; a display signal generating means for generating
a display signal by composing an output signal from said selecting
means and output data from said data storage means; and a display
means for displaying said display signal.
14. Navigation apparatus as claimed in claim 13, wherein said
second position measuring means determines a position by using a
decoded signal and a signal strength of a received signal.
15. Navigation apparatus as claimed in claim 13, wherein said
second position measuring means further comprises, for enabling not
only position measuring but also communicating, a sound signal
processing means for processing an audio signal to communicate in a
voice signal, and a transmitting means for transmitting an RF
signal modulated by an output signal of said sound signal
processing means.
16. Navigation apparatus as claimed in claim 13, wherein said
second position measuring means further comprises a data receiving
means for receiving transmitted data which includes not only an
identification signal of a base station but also other data signal,
and a displaying means for displaying an output signal of said data
receiving means.
17. Navigation apparatus as claimed in claim 16, wherein said other
data signal and a signal which is displayed included traffic
information.
18. Navigation apparatus as claimed in claim 16, wherein said other
data signal and a signal which is displayed include weather
information.
19. Navigation apparatus claimed in claim 16, wherein said other
data signal and a signal which is displayed include news
information.
20. Navigation apparatus as claimed in claim 16, wherein said other
data signal and a signal which is displayed include advertisement
information.
21. Navigation apparatus as claimed in claim 16, wherein an image
of said displaying an output signal is overlapped to an image of
said map.
22. Navigation apparatus as claimed in claim 16, wherein an image
of said displaying an output signal is displayed to another region
from an image of said map.
23. Navigation apparatus comprising: a first position measuring
means for position measuring a first position by receiving a radio
wave from a GPS satellite; a second position measuring means for
position measuring a second position by receiving a radio wave from
a base station of cellar telephone system without transmitting any
request signal for position measuring to said base station; an
evaluating means for evaluating uncertainty of data derived from
said first position measuring means and/or said second position
measuring means; a selecting means for selecting data from said
first position measuring means or said second position measuring
means based on an output signal of said evaluating means; a data
storage means for storing map data; a display signal generating
means for generating a display signal by composing an output signal
from said selecting means and output data from said data storage
means; a display means for displaying said display signal; an input
means for entering a request from an user; a service request signal
transmitting means for transmitting a service request signal to a
request predetermined service except position measuring based on an
output signal of said input means; a service signal receiving means
for receiving a service information transmitted corresponding to
said service request signal; and an output means for making an
output signal from an output signal of said service signal
receiving means.
24. Navigation apparatus as claimed in claim 23, wherein said
service request signal is a route searching request signal, and
said output means is the same to said display means and a route is
shown overlapped to said map.
25. Navigation apparatus as claimed in claim 23, wherein said
service is a musical related service, and said output means
generates an audio signal.
26. Navigation apparatus as claimed in claim 25, wherein character
information is simultaneously displayed at the time when said audio
signal is generated.
27. Navigation apparatus as claimed in claim 23, wherein said
service is a connecting service to a computer network.
28. Navigation apparatus as claimed in claim 25, wherein said
output means generates an information at the time when a
predetermined time has passed even if a transferred information is
not enough.
29. Navigation apparatus as claimed in claim 28 wherein said output
means generates an information with priority.
30. Position measuring method comprising steps of: a first position
measuring step for position measuring a first position by receiving
a first radio wave; a second position measuring step for position
measuring a second position by receiving a second radio wave,
evaluating step for evaluating uncertainty of data derived from
said first position measuring step and/or said second position
measuring step; and a selecting step for selecting data from said
first position measuring step or said second position measuring
step based on an output signal of said evaluating step.
31. Position measuring method as claimed in claim 30, wherein said
first and second position measuring steps receive a radio wave
without transmitting a data request signal.
32. Position measuring method as claimed in claim 31, wherein in
said first position measuring step a radio wave from a satellite is
received, and in said second position measuring step a radio wave
not from a satellite is received.
33. Position measuring method as claimed in claim 32, wherein in
said first position measuring step a radio wave from GPS satellite
is received, and in said second position measuring step a radio
wave from a base station of mobile telephone network is
received.
34. Position measuring method from a position of plural reference
station comprising steps of: a receiving step for receiving plural
radio waves from plural reference stations; a position measuring
step for position measuring by said received plural radio wave,
wherein in said position measuring step a position is determined by
using a decoded signal and a signal strength of a received
signal.
35. Navigation method comprising steps of: a first position
measuring step for position measuring a first position by receiving
a radio wave from a GPS satellite; a second position measuring step
for position measuring a second position by receiving a radio wave
from a base station of cellar telephone system without transmitting
any request signal for position measuring to said base station; an
evaluating step for evaluating uncertainty of data derived from
said first position measuring step and/or said second position
measuring step; a selecting step for selecting data from said first
position measuring step or said second position measuring step
based on an output signal of said evaluating step; and a display
step for displaying a signal by composing an output signal from
said selecting step and map data.
36. Navigation method as claimed in claim 35, wherein in said
second position measuring step a position is determined by using a
decoded signal and a signal strength of a received signal.
37. Navigation method as claimed in claim 35 further comprising: a
step of communicating step for communicating, wherein said
communicating step comprises sound signal processing step for
processing an audio signal to communicate in a voice signal, and
transmitting step for transmitting an RF signal modulated by an
output signal of said sound signal processing step.
38. Navigation method as claimed in claim 35 further comprising a
step of; a data receiving step for receiving a transmitted data
which includes not only an identification signal of base station
but also other data signal; and a displaying step for displaying an
output signal of said data receiving step.
39. Navigation method comprising steps of: a first position
measuring step for position measuring a first position by receiving
a radio wave form a GPS satellite; a second position measuring step
for position measuring a second position by receiving a radio wave
from a base station of cellar telephone system without transmitting
any request signal for position measuring to said base station; an
evaluating step for evaluation uncertainty of data derived from
said first position measuring step and/or said second portioning
step; a selecting step for selecting data from said first position
measuring step or said second position measuring step based on an
output signal of said evaluating step; a display signal generating
step for generating a display signal by composing an output signal
from said selecting step and output map data from a data storage
means; a display step for displaying said display signal; an input
step for receiving an entering request from an user; a service
request signal transmitting step for transmitting a service request
signal to a request predetermined service except position measuring
based on an output signal of said input step; a service signal
receiving step for receiving service information transmitted
corresponding to said service request signal; and an output step
for making an output signal from an output signal of said service
signal receiving step.
40. Navigation method as claimed in claim 39, wherein said service
information is a musical related information, and said output step
generates an audio signal.
41. Navigation method as claimed in claim 40, wherein in said
output step there is generated an information at the time when a
predetermined time has passed even if a transferred information is
not enough.
42. Information distribution method comprising steps of: a request
signal receiving step for receiving a service request signal from a
user; a transmitting step for transmitting a musical related
information from a base station of mobile telephone network on a
predetermined cell by said service request signal; and an audio
signal generating step for generating an audio signal from said
musical related information at a subscriber side.
43. Car apparatus comprising; a first position measuring means for
position measuring a first position by receiving a radio wave from
a GPS satellite; a second position measuring means for position
measuring a second position by receiving a radio wave from a base
station of cellar telephone system without transmitting any request
signal for position measuring to said base station; an evaluating
means for evaluating uncertainty of data derived from said first
position measuring means and/or said second position measuring
means; a selecting means for selecting data from said first
position measuring means or said second position measuring means
based on an output signal of said evaluating means; a data storage
means for storing map data; a display signal generating means for
generating a display signal by composing an output signal from said
selecting means and an output data from said data storage means;
and a display means for displaying said display signal.
44. Car apparatus comprising: a first position measuring means for
position measuring a first position by receiving a radio wave from
a GPS satellite; a second position measuring means for portioning a
second position by receiving a radio wave from a base station of
cellar telephone system without transmitting any request signal for
position measuring to said base station; an evaluating means for
evaluating uncertainty of data derived from said first position
measuring means and/or said second position measuring means; a
selecting means for selecting data from said first position
measuring means or said second position measuring means based on an
output signal of said evaluating means; a data storage means for
storing map data; a display signal generating means for generating
a display signal by composing an output signal from said selecting
means and an output data from said data storage means; a display
means for displaying said display signal; an input means for
entering a request from an user; a service request signal
transmitting means for transmitting a service request signal to a
request predetermined service except position measuring based on an
output signal of said input means; a service signal receiving means
for receiving a service information transmitted corresponding to
said service request signal; and an output means for making an
output signal from an output signal of said service signal
receiving means.
45. Audio signal transmitting method for an audio signal with a
first priority and an audio signal with an n-th priority (n is an
integer equal to or greater than 2.) comprising a step of: a
transmitting step for transmitting said audio signal with a
priority that said priority corresponds an audio signal to be
transmitted in a predetermined order.
46. Audio signal transmitting method as claimed in claim 45,
wherein said predetermined order is an order corresponding between
said priority and a frequency band of said audio signal.
47. Audio signal transmitting method as claimed in claim 45,
wherein said predetermined order is an order corresponding between
said priority and a kind of information whether main or sub
information related to said audio signal.
48. Audio signal transmitting method as claimed in claim 45,
wherein said predetermined order is an order corresponding between
said priority and a kind of information whether added or subtracted
component of said audio signal.
49. Audio signal receiving method comprising steps of: a receiving
step for receiving a signal; a detecting step for detection a
condition of a received signal; a utilizing step for utilizing
information which has higher priority than a predetermined level
based on a result of said detecting step.
50. Audio signal receiving method as claimed in claim 49, wherein
said information which has a higher priority than a predetermined
level corresponds to a frequency band of said audio signal.
51. Audio signal receiving method as claimed in claim 49, wherein
said information which has a higher priority than a predetermined
level is corresponded to a kind of information whether main or sub
information related to said audio signal.
52. Audio signal receiving method as claimed in claim 49, wherein
said information which has a higher priority than a predetermined
level is corresponded to a kind of information whether added or
subtracted component of said audio signal.
Description
BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] The present invention relates to a position measuring system
and/or a navigation system, and more particularly to a system using
a GPS. The present invention also relates to a navigation method,
an information service method, an automotive vehicle, and audio
information transmitting and receiving method.
[0003] 2. Description of the Related Art
[0004] Conventionally, a navigation system utilizing a position
measuring system using an artificial satellite called a GPS (Global
Positioning System) have been widely known and have already been
widespread considerably for use as a vehicle equipped system. In
addition, a so-called hybrid type navigation system for navigation
based on information from a gyro sensor or the like have also been
used extensively in tunnels, valleys between tall buildings in
town, and so on, where a GPS radio wave does not reach from the
satellite. A variety of receivers have been developed for position
measuring systems using satellite called a GPS other than a
vehicle.
[0005] However, while a conventional system demonstrates its
performance to some extent when it can receive a GPS radio wave, it
has a disadvantage in that data from a gyro sensor, generated at a
place where a GPS radio wave is not available, include so many
accumulative errors that they are not worth using. Also, while map
matching is frequently performed, this is a mere correction of data
so that an absolute measuring accuracy cannot be improved thereby.
If the matching leads to an erroneous road, a worse result is
introduced than without matching.
[0006] In addition, even when the GPS radio wave can be received,
it cannot straightforwardly said that a sufficient accuracy can be
always provided since there is a mode for intentionally degrading
the accuracy by the administrator of a system (the Department of
Defence of the United States), and since radio wave conditions may
be disturbed by a perturbed ionospheric layer or the like to
deteriorate the measuring accuracy.
SUMMARY OF THE INVENTION
[0007] The present invention is intended to solve the foregoing
problems and provides for absolute position measuring without
relying only on the GPS radio wave to achieve high performance at a
low cost.
[0008] According to a first aspect of the present invention, a
position measuring apparatus includes a first position measuring
means for position measuring a first position by receiving a first
radio wave, a second position measuring means for position
measuring a second position by receiving a second radio wave, an
evaluating means for evaluating uncertainty of data derived from
the first position measuring means and/or the second position
measuring means, and a selecting means for selecting data from the
first position measuring means or the second position measuring
means based on an output signal of the evaluating means.
[0009] According to a second aspect of the present invention, a
navigation apparatus includes a first position measuring means for
position-measuring a first position by receiving a radio wave from
a GPS satellite, a second position measuring means for portioning a
second position by receiving a radio wave from a base station of
cellar telephone system without transmitting any request signal for
position-measuring to the base station, an evaluating means for
evaluating uncertainty of data derived from the first position
measuring means and/or the second position measuring means, a
selecting means for selecting data from the first position
measuring means or the second position measuring based on an output
signal of the evaluating means, a data storage means for storing
map data, a display signal generating means for generating a
display signal by composing an output signal from the selecting
means and output data from the data storage means, and a display
means for displaying the display signal.
[0010] According to a third aspect of the present invention, a
position measuring method includes a first position measuring step
for position measuring a first position by receiving a first radio
wave, a second position measuring step for position measuring a
second position by receiving a second radio wave, evaluating step
for evaluating uncertainty of data derived from the first position
measuring step and/or the second position measuring step, and a
selecting step for selecting data from the first position measuring
step or the second position measuring step based on an output
signal of the evaluating step.
[0011] According to a fourth aspect of the present invention, a
navigation method includes a first position measuring step for
position measuring a first position by receiving a radio wave from
a GPS satellite, a second position measuring step for position
measuring a second position by receiving a radio wave from a base
station of cellar telephone system without transmitting any request
signal for position measuring to the base station, an evaluating
step for evaluating uncertainty of data derived from the first
position measuring step and/or the second position measuring step,
a selecting step for selecting data from the first position
measuring step or the second position measuring step based on an
output signal of the evaluating step, and a display step for
displaying a signal by composing an output signal from the
selecting step and map data.
[0012] According to a fifth aspect of the present invention, an
information distribution method includes a request signal receiving
step for receiving a service request signal from a user, a
transmitting step for transmitting a musical related information
from a base station of mobile telephone network on a predetermined
cell by the service request signal, and an audio signal generating
step for generating an audio signal from the musical related
information at a subscriber side.
[0013] According to a sixth aspect of the present invention, a car
apparatus includes a first position measuring means for position
measuring a first position by receiving a radio wave from a GPS
satellite, a second position measuring means for position measuring
a second position by receiving a radio wave from a base station of
cellar telephone system without transmitting any request signal for
position measuring to the base station, an evaluating means for
evaluating uncertainty of data derived from the first position
measuring means and/or the second position measuring means, a
selecting means for selecting data from the first position
measuring means or the second position measuring means based on an
output signal of the evaluating means, a data storage means for
storing map data, a display signal generating means for generating
a display signal by composing an output signal from the selecting
means and an output data from the data storage means, and a display
means for displaying the display signal.
[0014] According to a seventh aspect of the present invention, an
audio signal transmitting method for an audio signal with a first
priority and an audio signal with an n-th priority (n is an integer
equal to or greater than 2.) includes a transmitting step for
transmitting the audio signal with a priority that the priority
corresponds an audio signal to be transmitted in a predetermined
order.
BRIEF DESCRIPTION OF THE DRAWINGS
[0015] FIG. 1 is a block diagram illustrating the configuration of
a navigation apparatus of one embodiment according to the present
invention;
[0016] FIG. 2 is an explanatory diagram illustrating a position
measuring condition using the GPS in a suburb;
[0017] FIG. 3 is an explanatory diagram illustrating a radio wave
receiving situation in a city;
[0018] FIGS. 4A to 4C are explanatory diagrams illustrating formats
for an ID signal of a PHS base station;
[0019] FIG. 5 is a block diagram illustrating a GPS receiver unit
of one embodiment;
[0020] FIG. 6 is a block diagram illustrating a PHS receiver
unit/transmitter unit of one embodiment;
[0021] FIG. 7 is a block diagram illustrating a data receiver unit
of one embodiment and its peripherals;
[0022] FIG. 8 is a flowchart illustrating position determination
processing according to one embodiment;
[0023] FIG. 9 is a flowchart illustrating position determination
processing according to another embodiment;
[0024] FIG. 10 is a flowchart illustrating position measuring
processing by using radio waves of base stations according to one
embodiment;
[0025] FIGS. 11A to 11C are explanatory diagrams illustrating
conditions of the position measuring by using radio waves of base
stations according to one embodiment;
[0026] FIG. 12 is a flowchart illustrating display processing
according to one embodiment;
[0027] FIGS. 13A to 13D are explanatory diagrams illustrating
display examples according to one embodiment;
[0028] FIG. 14 is an explanatory diagram illustrating a display
example according to one embodiment;
[0029] FIGS. 15A and 15B are explanatory diagrams illustrating
display examples according to one embodiment;
[0030] FIG. 16 is an explanatory diagram illustrating a display
example according to one embodiment;
[0031] FIG. 17 is a flowchart illustrating data reception
processing according to one embodiment;
[0032] FIG. 18 is a perspective view illustrating an example of
arrangement of a navigation apparatus according to one embodiment
in an automotive vehicle; and
[0033] FIG. 19 is a perspective view illustrating an example of
arrangement of a navigation apparatus according to one embodiment
in an automotive vehicle.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0034] One embodiment of the present invention will hereinafter be
described with reference to the accompanying drawings.
[0035] First, prior to explaining a specific configuration of the
present invention, explanation will be given of a position
measuring system to which the present invention is applied. In the
present invention, position measuring is performed by a position
measuring system utilizing an artificial satellite called a GPS,
while position measuring is performed using a simplified mobile
telephone system called a PHS (Personal Handyphone System).
[0036] FIG. 2 is a diagram illustrating a situation of a position
measuring operation at a location where a GPS wave sufficiently
reaches, such as a suburb or the like. There are shown an
automotive vehicle or car 1 with a user therein, and GPS satellites
2a-2d, respectively. In this state, since radio waves from the four
GPS satellites 2a-2d sufficiently and favorably reach the location
of the user, position measuring at that location can be
satisfactorily carried out with data on three axis x, y, z and a
time axis t provided from the four satellites 2a-2d.
[0037] FIG. 3 is a diagram illustrating a situation of radio waves
in an urban area, where radio waves from the GPS satellites 2a, 2b,
and so on are blocked by tall buildings and high way built above
the ground or the like, so that they never reach the location of
the user or automobile 1. However, in recent years, a simplified
mobile telephone system adopting a digital cordless telephone
system has been gradually constructed in urban areas. In Japan,
such a system is called the PHS, as mentioned above. In the United
States, in turn, a similar system called personal communication
services (PCS) exists, and similar systems called CT2, DECT, and so
on also exist in Europe.
[0038] Explaining below the PHS in Japan, PHS base stations 3a-3c
illustrated in FIG. 3 are installed at intervals of about 100
meters and each form a cell of a narrow range. Further, due to the
nature of the PHS, if a line capacity becomes insufficient due to
excessive calls on the line in an urban area, this problem can be
immediately solved by fragmenting the cell. In this event, since
narrower cells are formed, it can be thought that separate cells be
positioned, for example, at intervals of 10 meters. While the PHS
base stations have been positioned closely in urban areas, few have
been installed in suburban areas.
[0039] Incidentally, a PHS base station transmits an ID signal
indicative of its own position and so on. FIG. 4A illustrates that
ID signal, where CS represents a PHS base station, and PS a PHS
terminal. Specifically, a company identifying code of 9 bits is
transmitted at first. Subsequently, an outdoor public additional ID
of 33 bits is transmitted, wherein a general call area number of np
bits is first transmitted, and then an additional ID of the
remaining 33-np bits is transmitted. Further, a PS call code of 28
bits is transmitted to call a particular terminal. FIG. 4B
illustrates a code transmitted from a PHS terminal to a PHS base
station, as opposed to the above, wherein the company identifying
code, the outdoor public additional ID, and the PS call code are
similar transmitted in the same format but in an opposite
identification relationship between transmission and reception.
FIG. 4C enlarges a portion of the codes, where the above-mentioned
np is 16. Specifically, an exchange unit in a ground public network
is specified with the general call area number, and a particular
PHS base station is specified with the additional ID.
[0040] Since such signals are communicated, a base station, from
which the signals have been transmitted, can be specified on a
receiving terminal side by reading the 33-bits outdoor public
additional ID. Further, if longitudes, latitudes, and so on
indicative of the positions of individual base stations have
previously been stored, the latitude and the longitude of each base
station can be known. Further, it is also possible to directly
transmit actual latitude and longitude informations from a base
station as well as the above-mentioned additional ID.
[0041] A technique applying such an idea is found in Japanese
patent publication No. 8-18501. This document exactly describes a
technique for performing the position measuring using the PHS.
Also, Japanese patent publication No. 6-311093 describes a
technique for detecting the position of a previously installed
portable telephone base station to identify its own current
position.
[0042] The above-mentioned techniques, however, have drawbacks.
Specifically, since Japanese patent publication No. 8-18501
performs the position measuring by the use of PHS base stations,
the position measuring cannot be performed in suburban areas where
no PHS base stations have been installed. As to Japanese patent
publication No. 6-311093, in turn, since a portable telephone base
station transmits a radio wave of large power at a low frequency, a
sufficient accuracy cannot be ensured for specifying a
position.
[0043] In addition, a technique for performing the position
measuring based on both the GPS position measuring and the
positions of cellular base stations is shown in Japanese patent
publication No. 6-148308. However, this technique presents a poor
position accuracy due to the use of portable telephone base
stations, and moreover, a transmission request must be issued from
a terminal side every time the position measuring is to be
performed.
[0044] The present invention is intended to solve problems of these
previously proposed techniques, and the solution of the problems is
achieved by an apparatus having the configuration illustrated in
FIG. 1. Explaining below the configuration thereof, a GPS receiver
unit 5 connected to a GPS antenna 4 receives a GPS signal from a
GPS artificial satellite and decodes position data. A PHS antenna 9
for transmitting and receiving a PHS radio wave to and from a PHS
base station is also connected to a PHS receiver unit 6 and a PHS
transmitter unit 7 through an antenna sharing unit 10. The PHS
receiver unit 6 performs reception processing for extracting
position data of a base station from a PHS signal received by the
antenna 9. The PHS transmitter unit 7, in turn, performs
transmission processing for a variety of informations and transmits
the information from the antenna 9 to a base station (note that the
transmitter unit 7 may be omitted).
[0045] The GPS receiver unit 5 is connected to a GPS certainty
detector unit 8 which detects the certainty of a received GPS
signal. Specifically, the GPS signal has a coefficient signal
called a GDOP signal (Geometrical Dilution Of Precision signal),
added thereto, for indicating geometrical accuracy deterioration,
and the processing for detecting the certainty of the GPS signal is
performed by the detector unit 8 on the basis of this GDOP
signal.
[0046] A signal received by the GPS receiver unit 5, a signal
received by the PHS receiver unit 6, and a signal related to the
certainty detected by the GPS certainty detector unit 8 are
supplied to a control unit 12, serving as a system controller of
the apparatus, for coordinating a variety of informations supplied
thereto. The control unit 12 is connected with a position
calculation unit 11 which generates a specific position from the
respective received signals such as latitude and longitude data.
Alternatively, data indicative of a position such as a sheet number
of map may be generated in place of the latitude and longitude
data. In this case, if a signal for position measuring is available
from only one of the GPS receiver unit 5 and the PHS receiver unit
6, a position is calculated based on that signal. On the other
hand, when signals are available from both of them, a signal to be
used is selected with reference to the certainty detected by the
GPS certainty detector unit 8. More specifically, if the certainty
of the position measuring using the GPS, detected by the GPS
certainty detector unit 8 is low, the ID of a base station received
by the PHS receiver unit 6 is used to determine the position at
which the base station exists, and the determined position is
treated as the position derived by the position measuring. If the
certainty is high, a position measured signal by the GPS is used to
calculate the position. Incidentally, if data received by the PHS
receiver unit 6 includes map data and traffic information, the data
is stored in a map data storage unit 14 or the like.
[0047] The control unit 12 is also connected with a display unit 13
comprising a liquid crystal display unit or the like, on which
displayed are a map image generated by map data read from the map
data storage unit 14 and the position of the automotive vehicle
itself calculated by the position calculation unit 11. For the map
data storage unit 14, a large capacity storage means such as a
CD-ROM drive or the like may be used. In this case, in this
embodiment, absolute positional information on PHS base stations is
stored together with base station ID's in addition to the map
information on roads and so on.
[0048] Furthermore, the control unit 12 is connected with a key
input device 15 and a remote control signal receiver unit 16, so
that a variety of commands may be inputted from keys provided as
the key input device 15 and a separate remote control unit 17
through a remote control signal (electric wave signals and
infrared-ray signals).
[0049] The foregoing navigation apparatus of the configuration
illustrated in FIG. 1 is arranged in the automotive vehicle 1, for
example, as illustrated in FIG. 18 and FIG. 19. More specifically,
as illustrated in FIG. 19, the body of the apparatus comprising the
position calculation unit 11, the control unit 12, the map data
storage unit 14, and so on is disposed at a predetermined position
in an automotive vehicle 1, such as within its trunk or the like,
and the GPS antenna 4 and the PHS antenna 9 are attached at
corresponding positions on the vehicle body. Then, as illustrated
in FIG. 12, the display unit 13 comprising a liquid crystal display
unit or the like is positioned in front of a driver's seat 81 of
the automotive vehicle such that a driver, when seated at the
driver's seat 81, can view a display on the display unit 13. In
this case, the liquid crystal display unit constituting the display
unit 13 is also provided with the remote control signal receiver
unit 16 so as to receive infrared ray signals from the remote
control unit 17. Further, the key input device 15 comprising a joy
stick or the like is mounted beside a steering wheel 82.
Furthermore, speaker units 27L, 27R for outputting audio signals
generated from received radio broadcast and audio signals from a CD
player or the like (both not shown) are disposed at predetermined
positions, such as positions in front of left and right doors. A
microphone (microphone 58, later described) required as a telephone
set may also be disposed on the display unit 13 or the like. It
goes without saying that FIG. 18 and FIG. 19 illustrate an
exemplary arrangement and such components may be mounted at any
other positions within the automotive vehicle 1.
[0050] Next, the configuration of the GPS receiver unit 5 is
explained with reference to FIG. 5. The GPS antenna 4 is connected
to a down-convertor 31 for converting a signal at 1.57542 GHz from
a GPS satellite into an intermediate frequency signal, and this
intermediate frequency signal is supplied to a voltage comparator
32 for removing an analog noise included in the received signal.
Then, a received signal outputted by this voltage comparator 32 is
supplied to a multiplier 33 which multiplies the received signal by
a C/A code PN code outputted by a PN code generator 34
corresponding to a C/A code of a GPS to perform reverse spreading
for a GPS signal transmitted as a spread spectrum signal to decode
desired GPS data. Incidentally, a plurality of channels of the
multipliers 33 and the C/A code PN code generators 34 are provided
such that GPS data from a plurality of satellites can be decoded at
the same time.
[0051] Then, decoded data on the respective channels are sent onto
a bus line 35. This bus line 35 is connected with a central control
unit (CPU) 36 for controlling the operation of the GPS receiver
unit, with a ROM 37 having a decoding operation program stored
therein, with a RAM 38 for temporarily storing data upon decoding
or the like, with a clock generator 39 for generating a clock for
operations of respective circuits, and with an interface circuit
40, wherein decoding as the GPS is performed from decoded data on
the respective channels based on the control of the central control
unit 36 to produce position measured data. Then, the produced
position measured data is supplied to the control unit 12 (see FIG.
1) side connected through the interface circuit 40. Incidentally,
the GPS receiver unit 5 may utilize a card type one having all GPS
functions configured on a small-size substrate as a GPS receiver
board.
[0052] Next, the PHS receiver unit, the PHS transmitter unit, and
their peripheral configuration will be explained with reference to
FIG. 6. Explaining first the reception system, a signal received by
the antenna 9 is supplied to a reception amplifier 41 through the
antenna sharing unit 10 comprising a switch or the like, and an
output of this reception amplifier 41 is supplied to a mixer 43
through a high frequency filter (RF filter) 42. This mixer 43 is
supplied with a frequency signal generated by a frequency
synthesizer 44 corresponding to a transmission/reception frequency
(here, transmission and reception frequencies are the same and
allocated a 1/8GHz band) based on an oscillating output of a
temperature compensated type quartz oscillator (TCXO) 45. The
received signal and this frequency signal are mixed in the mixer 43
to produce a first intermediate frequency signal. Then, this first
intermediate frequency signal is supplied through a first
intermediate frequency signal filter 46 and an amplifier 47 to a
mixer 48, where mixing of the first intermediate frequency signal
with a frequency signal outputted from an oscillator 49 produces a
second intermediate frequency signal. Then, this second
intermediate frequency signal is supplied to a demodulator circuit
52 through an amplifier 51 to perform demodulation based on a
transmission scheme.
[0053] Here, a transmission signal of PHS conforms to a scheme
called a TDMA scheme (Time Division Multiple Access scheme: time
division multiple access scheme) which transmits and receives burst
data composed of slots in a time division manner. A demodulated
signal is supplied to a time-division multiplex circuit 53 for
extracting audio data and control data included in predetermined
slots. Then, the extracted audio data is supplied to an audio
processing unit 54 for performing processing to convert the audio
data into an analog audio signal, and the produced analog audio
signal is outputted from a speaker 55. Also, the extracted control
data is supplied to a data processing unit 56. In this data
processing unit 56, an ID signal of a PHS base station or a variety
of service signals, later described, and so on are extracted from
the received control data, and supplied to the control unit 12 (see
FIG. 1) side from a data output terminal 57.
[0054] As the configuration for the transmission system, an audio
signal picked up by a microphone 58 is supplied to the audio
processing unit 54 to be converted into digital audio data, and
this audio data is supplied to the time division multiplex circuit
53, and the audio data is placed in a predetermined position in
transmission slots. Also, data supplied from the control unit 12 is
supplied to the data processing unit 56 through a data input
terminal 59, and the data subjected to the transmission processing
is supplied to the time division multiplex circuit 53 and placed in
a predetermined position in the transmission slots.
[0055] Then, burst data configured as transmission slots, generated
by the time division multiplex circuit 53 is supplied to a
modulator circuit 60 for performing modulation processing for the
PHS, and a modulated signal is supplied to a mixer 61. In this
mixer 61, the modulated signal is mixed with a frequency signal
outputted from the frequency synthesizer 44 to produce a signal
with a transmitting frequency, and this transmission signal,
through a high frequency filter 62 and a transmission amplifier 63,
is transmitted in wireless fashion from the antenna 9 connected to
the antenna sharing unit 10 to a PHS base station.
[0056] Now, explaining a configuration connected to the data
processing unit 56 of the PHS terminal illustrated in FIG. 6 with
reference to FIG. 7, the data processing unit 56 is supplied with
data such as a service request signal or the like from the control
unit 12 side. Also, received packet data received by this terminal
from a base station side and supplied to the data processing unit
56 is supplied to a received packet processing unit 61. Then, data
for display within this received packet is supplied to the display
unit 13 through the control unit 12 and displayed thereon. Also,
audio data within the received packet is supplied to an audio
output unit 62, subjected to audio output processing therein, and
outputted from the left and right speakers 27L, 27R. Incidentally,
a service signal transmitted from the base station side may be
transmitted, for example, using a free portion within a control
channel (slot), or using a channel (slot) prepared for transmitting
communication signals.
[0057] Next, determination processing in the control unit 12 of the
apparatus of this embodiment when position of the automotive
vehicle 1 equipped with the apparatus is measured will be explained
with reference to a flow chart of FIG. 8.
[0058] First, the value of GDOP is evaluated on the basis of
detection in the GPS certainty detector unit 8 to judge whether or
not it is within a predetermined range (step 101), and it is
determined that a GPS receiving condition is satisfactory when it
is within the predetermined range. When it is determined to be
satisfactory, a signal received by the GPS receiver unit 5 is
fetched (step 102), and a position calculation is executed in the
position calculation unit 11 based on the fetched signal (step
103). Then, the calculated position is decided to be the current
position of the automotive vehicle 1 (step 104).
[0059] Conversely, if it is determined at step 101 that the value
of GDOP is not within the predetermined range, base station ID
information received by the PHS receiver unit 6 is fetched (step
105). Then, the position is calculated in the position calculation
unit 11 based on the base station ID (step 106). In this event, the
position calculation is performed with reference to position data
on each base station ID stored in the map data storage unit 14.
Then, the calculated position is decided to be the current position
of the automotive vehicle 1 (step 107).
[0060] Incidentally, the position determination processing may be
executed in the processing illustrated in a flow chart of FIG. 9.
In this example, the position measuring on the base station ID has
priority to the position measuring on the GPS. It is first judged
whether or not a PHS base station ID is satisfactorily received
(step 111). Then, if received satisfactorily, the base station ID
is fetched by the PHS receiver unit 6 (step 112). Then, the
position is obtained from information on the base station ID (step
113), and the obtained position is decided to be the current
position (step 114).
[0061] On the other hand, if it is judged at step 111 that the base
station ID is not satisfactorily received, the value of GDOP is
evaluated on the basis of detection in the GPS certainty detector
unit 8 to judge whether or not the value is within a predetermined
range (step 115), and it is determined that a receiving condition
of the GPS is satisfactory if it is within the predetermined range.
When it is determined to be satisfactory, a signal received by the
GPS receiver unit 5 is fetched (step 116), and a position
calculation is executed in the position calculation unit 11 based
on the fetched signal (step 117). Then, the calculated position is
determined to be the current position of the automotive vehicle 1
(step 114).
[0062] Conversely, if it is judged at step 115 that the value of
GDOP is not within the predetermined range, position measuring
information is not updated, and the previously measured position is
used again (step 118). Alternatively, instead of using the
previously measured position as it is, the current position may be
estimated from a position measuring history. Further, if no base
station ID is received, the position measuring calculation may be
executed even if the value of GDOP is not satisfactory. In this
case, a poor position measuring accuracy may be notified by a
display on the display unit 13 or the like when the value of GDOP
is not satisfactory.
[0063] Next, the processing performed for the position calculation
in the position calculation unit 11 based on the PHS base station
ID, during the foregoing determinations of positions, will be
explained with reference to a flow chart of FIG. 10 and a diagram
of FIG. 11 for explaining a position measuring condition. In this
embodiment, when ID's can be received from a plurality of base
stations, accurate position measuring is performed on the basis of
the plurality of base station ID's. Specifically, as illustrated in
FIG. 11A, when radio waves from three base stations, for example,
can be simultaneously received at a predetermined level or higher,
three regions exist as regions 1, 2, 3 in which radio waves from
the three base stations can be received, a region a1 in which the
three regions 1, 2, 3 overlap can be identified, and the region 1a
can be identified as the current position.
[0064] Similarly, when radio waves from two base stations can be
received at the predetermined level or higher, the position can be
identified to be in a region b2 in which regions 1, 2 overlap, as
illustrated in FIG. 11B, where radio waves from the respective base
stations can be received at the predetermined level or higher. In
this case, when regions in which data on ID's transmitted from the
respective base stations can be received and decoded at a
predetermined error rate or less are regions 1A, 2A, for example,
if either of the base station ID's can be decoded, the region b1 or
b2 can be identified, thereby making it possible to more accurately
identify the current position.
[0065] Further, when a radio wave from only one base station can be
received at the predetermined level or higher, it can be identified
to be a position within a region 1 determined by the base station.
Furthermore, if the ID of the base station can be decoded at the
predetermined error rate or less, the position can be identified to
be within a region c1 in which the ID can be decoded at the
predetermined error rate or less. If the ID cannot be decoded at
the predetermined error rate or less, the position can be
determined to be within the region 1 but out of the region c1 (for
example, at a position where c2 or c3 exists).
[0066] In this embodiment, the processing is performed for
identifying a position in accordance with the number of receivable
radio waves of base stations. As illustrated in the flow chart of
FIG. 10, it is first judged during the position calculation whether
or not n waves (for example, three waves) from PHS base stations
can be received at a predetermined level or higher at the same
position (step 121). Here, if n waves can be received, the position
measuring is performed with the n waves (the position measuring
illustrated in FIG. 11A if n is three, for example) (step 122).
Then, if n waves cannot be received, it is judged whether or not
n-1 waves (for example, two waves) can be received at the
predetermined level or higher (step 123). Here, if n-1 waves can be
received, the position measuring is performed with the n-1 waves
(the position measuring illustrated in FIG. 11B if n-1 is two, for
example) (step 124). Subsequently, the number of receivable radio
waves is decreased gradually and judgement is made in a similar
manner, and it is finally judged whether or not one wave can be
received at the predetermined level or higher (step 125). Then, if
one wave can be received, the position measuring is performed with
the one wave (the position measuring illustrated in FIG. 11C) (step
126). Additionally, if even one wave cannot be received, a flag
indicative of unsatisfactory ID receiving condition of a PHS base
station is set in a memory for judging in executing the processing
program judged by the control unit 12.
[0067] In this way, the position can be calculated from radio waves
of PHS base stations. Alternatively, a current position may be
estimated to some degree from a previous history. For example, if
only one wave from a base station can be received, for example, as
illustrated in FIG. 11C, when, after first determining the position
c2 (this determination may be made on the GPS side), c1 is
determined to be an area in which a base station ID can be decoded
at the predetermined error rate or less, and subsequently the base
station ID cannot be decoded at the predetermined error rate or
less, the current position may be estimated to be the position
c3.
[0068] Next, reception processing in the control unit 12 for a
service signal transmitted from a PHS base station in the apparatus
of this embodiment, will be explained with reference to a flow
chart of FIG. 12 and display examples of FIG. 13-FIG. 16. First, as
illustrated in the flow chart of FIG. 12, it is judged whether or
not a data signal other than an audio signal exists within PHS
received signals (step 131). Then, if no data signal other than the
audio signal is found, the service signal reception processing is
ended. Conversely, if any service signal is found, it is judged
whether or not the signal is traffic information such as traffic
jam information, closed street information, construction
information, or the like (step 132). Here, if it is traffic
information, a traffic information display operation is performed
(step 133). As this display processing, pertinent traffic
information 13b is displayed, for example, on the screen of the
display unit 13 in the form of characters or the like, as
illustrated in FIG. 13A. Alternatively, a traffic jam section 13a
or the like is demonstrated on a displayed road map. The
demonstration of a traffic jam section in this case indicates that
the currently forwarding direction only is in a jam. Alternatively,
the display of traffic information in the form of characters and a
map may be made only when a section indicated by the traffic
information is in the forwarding direction, instead of all
information being displayed any time on the display unit 13, when
received.
[0069] Turning back to the flow chart of FIG. 12, if it is
determined at step 132 that the signal is not traffic information,
it is next judged whether or not the signal is weather information
(step 134). Here, if it is determined to be weather information,
the weather information is displayed (step 135). As this display
processing, weather forecast 13c or the like is displayed in a
corner of a road map, as illustrated in FIG. 13B.
[0070] Conversely, if it Is determined at step 134 that the signal
is not weather information, it is next judged whether or not the
signal is a special news (step 136). Here, if it is determined to
be a special news, the received special news is displayed in the
form of characters 13d or the like in a corner of the screen on
which a map or the like is displayed, for example, as illustrated
in FIG. 13C (step 137).
[0071] Conversely, if it is determined at step 136 that it is not a
special news, it is next judged whether or not the signal is
information such as advertisements, events, or the like
(information on tourism, information on events at stores, and so on
near the current position) (step 138). Here, if it is determined to
be information such as advertisements, events or the like,
associated information is displayed in the form of characters 13e
in a corner of the screen on which a map or the like is displayed,
for example, as illustrated in FIG. 13D (step 139).
[0072] Conversely, if it is determined at step 138 that it is not
information such as advertisements, events, or the like, it is next
judged whether or not the signal is routing information (step 140).
Here, if it is routing information, processing such as displaying
the route or the like is performed (step 141). Incidentally, this
routing information is such that current position information and
destination information, for example, are transmitted from the
apparatus of this embodiment to a PHS base station side, a routing
computation is performed on a traffic information center (not
shown) connected to the base station side, and information on the
computed route is returned to the apparatus using a channel of the
PHS. In this way, appropriate routing information can be provided
for avoiding traffic jam based on latest information.
[0073] Incidentally, if audio signals are provided instead of
display signals as these service signals, the audio (a speech
indicating a traffic jam section or the like) may be outputted from
a speaker.
[0074] Alternatively, interactive communications may be performed
for providing information in response to a request from the
apparatus side so as to acquire necessary information. For example,
as illustrated in FIG. 14, a menu screen 13f is displayed in a
corner of a map or the like by a service signal transmitted from a
base station side, and a remote control signal (infrared ray
signal), serving as a selection signal, is transmitted from the
remote control unit 17 to the receiver unit 16 by predetermined key
manipulations on up and down selection keys, an enter key 17a and
so on disposed on the remote control unit 17. Incidentally, an item
selected within the menu screen 13f may be identified by giving it
a different size or color from other items or by blinking the item.
Then, a signal for selecting a predetermined item within the menu
is transmitted from the transmitter unit 7 to the base station side
through the transmission of the selection signal, and detailed data
on the associated item is returned from the base station.
Information provided in this way may be other information such as
detailed news for supplementing the aforementioned special news,
sport news, or the like.
[0075] In addition, services related to music may also be provided
in the interactive services as mentioned above. For example, an
item displayed as "Best Ten of This Week" is selected on the menu
screen as illustrated in FIG. 14, and information on titles of
music of "Best Ten of This Week" is acquired as illustrated in FIG.
15A, and a display 13g of the information is provided. Then, by
further selecting a title from the titles displayed, information on
the selected music is received from the base station side, the
music is outputted from speakers, and its text 13h is displayed
within the screen as illustrated in FIG. 15B. In this event, the
output from the speakers may be instrumental music called "karaoke"
instead of the music including the song. Incidentally, the speakers
for outputting the music are preferably implemented by high
performance speakers for so-called high fidelity specification
prepared for car stereo (left and right speakers 27L, 27R
illustrated in FIG. 18 or the like) so as to reproduce the music in
a good sound quality. In this way, this service may be utilized to
always reproduce latest hit music only with menu manipulations,
whereas conventionally, medias (compact discs and so on) must be
purchased quite frequently for enjoying latest hit music, thereby
requiring a huge cost, a large number of steps, and a
depository.
[0076] Alternatively, by interactive communications through a base
station, so-called personal computer communications such as
Internet or the like may be performed to display acquired
information on the display unit 13 or the like. For example, as
illustrated in FIG. 16, a predetermined computer communication
center is linked by communications through a base station to
display acquired image information 13i together with a road map or
the like within the screen. Alternatively, in this case, the road
map may be erased to display information such as Internet or the
like over the entire screen.
[0077] Incidentally, when computer communications are performed
such as Internet or the like, the transmission speed may be
accidentally reduced due to a variety of causes. However, even in
such a case, if data to be received is music data, the music can be
transmitted without damaging its real time nature by generating a
data stream while a portion of the data is missing. As the
processing for this case, for example, as illustrated in FIG. 17, a
packet is received (step 151), and it is judged whether or not a
reception speed of the received packet is at a desired rate or
higher (step 152). If it is at the desired rate or higher,
communication reception processing is performed (step 153), and
data output processing is performed (step 154). Conversely, if it
is not at the desired rate or higher, a data stream is generated at
every predetermined time while a portion of data is missing (step
155), and the data output processing may be performed for the
generated stream.
[0078] By thus processing, the data transmission is divided, for
example, into reproducing frequency bands of the music signal and
its associated data (text data) as follows, and they are
transmitted with a definite priority from the above in the
following manner (1) to (7), thereby favorably reproducing the
music:
[0079] (1) L+R component at 3 kHz or lower;
[0080] (2) L-R component at 3 kHz or lower;
[0081] (3) text data;
[0082] (4) L+R component in a range of 3 to 6 kHz;
[0083] (5) L-R component in a range of 3 to 6 kHz;
[0084] (6) L+R component in a range of 6 to 15 kHz; and
[0085] (7) L-R component in a range of 6 to 15 kHz;
[0086] Incidentally, the L+R component is a signal (monaural
component) having a component generated by synthesizing left and
right signals of stereo music signals, and the L-R component is a
difference signal between the left and right stereo music
signals.
[0087] By thus transmitting the components with the definite
priority, for example, the music can be reproduced in monaural with
a minimum music quality when at least data of (1) can be received;
stereo reproduction is available when data up to (2) can be
received; the text can be displayed when data up to (3) can be
received; and the reproduced music quality is gradually improved as
data with lower priorities can be received. In this way, a
so-called graceful degradation can be realized.
[0088] Incidentally, in the foregoing embodiment, the GPS is used
as the position measuring using a signal received from a satellite
and the PHS is used as a mobile telephone system, however, it goes
without saying that other satellite position measuring system and
mobile telephone system may also be applied.
[0089] According to the present invention, since both the position
measuring by using satellites and the position measuring by using
radio waves of mobile telephone base stations are performed,
results of the position measuring by using satellites are used in a
area such as a suburban area or the like where radio waves from
satellites can be satisfactorily received, while results of the
position measuring by using radio waves of cellular mobile
telephone base stations are used in an urban area, a tunnel, or the
like, whereby highly accurate position measuring can be achieved at
any site.
[0090] Also, when the position measuring is performed by using
radio waves from mobile telephone base stations, the position
measuring with two waves from two stations, and the position
measuring with three waves from three stations can be performed in
addition to the position measuring with one wave from one station,
so that the position measuring can be achieved, while ensuring a
certain degree of accuracy, even if a small number of base station
radio waves can only be received.
[0091] Further, since the ID's of mobile telephone base stations
are utilized for the position measuring, positional information can
be provided without any transmission request from the user.
[0092] Further, since the position measuring by using satellites
and the position measuring by using radio waves of cellular mobile
telephone base stations are both in absolute positioning scheme, a
distance sensor and an azimuth sensor, as required by conventional
hybrid type navigation apparatuses, are eliminated, and error
accumulation, found in these relative position measuring schemes,
never occurs.
[0093] Further, since the position measuring is performed without
utilizing vehicle speed pulses on the vehicle side, the present
invention does not at all require complicated and difficult works
for dismounting internal parts of the automotive vehicle to make
the pulse available.
[0094] Further, since information such as traffic information,
weather information, and so on can be provided as data from
existing mobile telephone base stations, a dedicated
transmission/reception system for traffic information and so on is
not required. On the user side, it is not necessary to provide a
dedicated receiver for traffic information, while on the system
administration side, a dedicated infrastructure is not required,
thereby reducing facility investment.
[0095] Further, a portion for communicating with mobile telephone
base stations can also be used as a normal mobile telephone
terminal, so that its application is extended as a terminal. Also,
in the mobile telephone system called a PHS, since a telephone call
is difficult to make during high speed movements, the driver will
not call while driving, as is the case of ordinary portable
telephones, thus contributing also to safe driving.
[0096] Further, new services can also be provided by connecting a
variety of information services, music services, and so on such as
Internet or the like.
[0097] Having described preferred embodiments of the present
invention with reference to the accompanying drawings, it is to be
understood that the present invention is not limited to the
above-mentioned embodiments and that various changes and
modifications can be effected therein by one skilled in the art
without departing from the spirit or scope of the present invention
as defined in the appended claims.
* * * * *