Portable GPS-receiver for a personal safety system

Details Portable GPS-receiver for a personal safety system Portable GPS-receiver for a personal safety system

2001-09-26

2002-11-12

Pham, Chi (Department: 2631)

Pulse or digital communications

Receivers

Interference or noise reduction

Reexamination Certificate

active

06480557

ABSTRACT:

FIELD OF THE INVENTION
The invention relates to the field of a radio navigation, and, more specifically, to technical systems of personal safety, which allow the position-fix based on signals of a satellite radio navigational system “GPS” and message passing about position along with the messages of an emergency situation to a base monitoring station.
DESCRIPTION OF THE RELATED ART
The systems of personal safety, considered here, are versions of systems of tracking of objects used in monitoring (tracking) or control. The development of this branch—the branch dealing with the observation of location of people, is justified by a prospect of development of receivers of GPS signals with such overall dimensions, weight and power consumption, that would allow construction of probable GPS receivers with personal means of mobile radio communication. Thus the task of minimization of overall dimensions, reduction of power consumption and simplification of receivers executing a position-fix on GPS signals, is one of most important.
The systems of tracking of objects, for example of vehicles (see application of Germany (DE) 3501035, Int. Cl. G08 G 1/00, publ. Jul. 17, 1986 [1], application EPO (EP) 0379198, Int. Cl. GO1 S 5/02, GO1 S 5/14, 30 publ. Jul. 25, 1990 [2], application EPO (EP) 0509775, Int. G01 S 5/14, publ. Apr. 15, 1992 [3]and patent of USA U.S. Pat. No. 5,319,374, Int. Cl. G01 S 1/24, G01 S 5/02, G01 S 3/02, G04 C 11/02, publ. Jun. 7, 1994 [4]), are known, in which the tracked object—a vehicle—is supplied with the unit for a position-fix on GPS signals and equipment for radio communication with a central station, which carries out monitoring of the position of transport.
The systems are known, which track vehicles on GPS signals and, in case of an extreme situation, transmit the data about position to a tracking station (see, for example, application of Germany (DE) 3839959, Int. Cl. G08 B 25/00, G08 G 1/123, B60 Q 9/00, H04 Q 7/00, publ. Apr. 12, 1990 [5], patent of USA U.S. Pat. No. 5,355,140, Int. Cl. G01 S 1/08, G01 S 5/02, publ. Oct. 11, 1994 [6] and application PCT (WO) 93/16452, Int. Cl. G08 G 1/123, publ. Aug. 19, 1993 [7]).
In the considered systems of tracking and scheduling of vehicles [1-7] for a position-fix the standard receivers of GPS signals, equipped by additional units ensuring data transmission about site, and also alarm signals of a radio channel on station of tracking are used. As a rule, in such systems the receivers of GPS signals are not supposed to perform with strict requirements to minimization of the equipment and the power saving, and the tasks of a position-fix in conditions of partial blocking of a signal reception GPS are overcome, for example, by an integration with elements of inertial systems.
In contrast to systems for tracking transport, in systems of personal safety to receivers of GPS signals, operating for a position-fix, additional requirements can exist. On the one hand, it is justified by the necessity of accommodation of the receiver of GPS signals in a body of a radiophone (see, for example, Application EPO (EP) 0528090, Int. Cl. G01 S 5/00, publ. Feb. 24, 1993 [8]. This results in necessity to minimize means of receiving GPS signals and their power consumption. On the other hand, the requirements may be specified on provision of a position-fix in conditions of partial blockage of GPS signals, for example in operation conditions “under foliage”, using thus only radio signals received from the air.
The receiver of GPS signals with communication channel for message passing about extreme situations (see application PCT (WO) 97/14057, Int. Cl. G01 S 5/14, G01 S 1/04, publ. Apr. 17, 1997) [9], is known in which the additional means ensuring a capability of a position-fix on GPS signals in conditions of their partial blockage are provided. The receiver described in [9], is selected as the prototype. The generalized skeleton diagram of the receiver adopted as the prototype, is shown on FIG.
1
.
The receiver—prototype, see
FIG. 1
, contains an input unit
1
of conventional receiver of GPS signals, including sequentially connected radio frequency signal converter
2
, whose input is also an input of the unit
1
, and unit
3
for analog-to-digital conversions of signals, whose output is also an output of the unit
1
, and also former
4
of signals of clock and heterodyne frequencies, whose control and reference inputs are control and reference inputs of the unit
1
, respectively; whereby heterodyne input of the radio frequency signal converter
2
and clock input of the unit
3
are connected respectively to heterodyne and clock outputs of the former
4
. The former
4
is supplied with means for formation of signal clock and heterodyne frequencies including, for example, synthesizers of frequencies, the pre-set inputs of which form a control input of the former
4
. The synthesizers of frequencies work from the reference generator which is included in a structure of the former
4
. In a case, where in the receiver the tuning of frequency of the reference generator by an external high-stable signal is provided, the reference generator is supplied with the appropriate tuning unit, for example unit PLLF, whose reference input forms a synchronization input (i.e., reference input) of former
4
.
The receiver—prototype contains also output unit
5
of the conventional receiver of GPS signals, whose signal input is connected to an output of the unit
3
via the switch
6
, and whose clock input is connected to a clock output of the former
4
.
To the second output of the switch
6
are connected sequentially joint memory unit
7
, for storage of calculated values of signals shaped by the unit
3
, and signal processor
8
. The clock input of the memory unit
7
is connected to a clock output of the former
4
.
Control input of the former
4
, control input of the switch
6
, and also the data inputs—outputs of the signal processor
8
and unit
5
are connected by the appropriate data buses to the decision-making unit
9
, whose structure includes a microprocessor for data processing, controller and memory unit for storage of programs and data.
The decision-making unit
9
is connected to the data input-output unit
10
and to the transceiver unit
11
, executing reception and transmission of signals and data through the communication channel linking the receiver to a base station
12
. In that case, when in the former
4
the tuning (synchronization) of the reference generator is performed using an external signal, the output of a reference signal (signal of synchronization) of transceiver unit
11
is supplied to the appropriate input of the former
4
(in
FIG. 1
, this connection is shown by a dotted line).
The data input-output unit
10
can be realized, for example, by an appropriate controller, keypad, and display supplied with an interface connector.
The transceiver unit
11
is realized as a modem and transceiver maintaining radio communication with a base station
12
.
The base station
12
is supplied with means for a signal reception of an alarm and locating information of the receiver, and also with its own means for formation of the ephemeral data, rough coordinate information on position of the receiver, data of Doppler shift and means for transmission of these data through a radio channel to the unit
11
. Besides, the base station
12
can be supplied with means for implementation of transmission of a reference signal for the said tuning of frequency of the reference generator of the receiver.
The receiver—prototype operates as follows. The GPS signals from an output of a receive antenna go to an input of the radio frequency converter
2
of the input unit
1
, where the signal conditioning with downturn of frequency takes place. The mixers, which are included in a structure of the converter
2
, working on heterodyne signals (Fr), coming from the appropriate outputs of the former
4
, are used.
The former
4
syn

Affiliated with

Also associated with

Rating

Portable GPS-receiver for a personal safety system does not yet have a rating. At this time, there are no reviews or comments for this patent.

If you have personal experience with Portable GPS-receiver for a personal safety system, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Portable GPS-receiver for a personal safety system will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFUS-PAI-O-2948120