JPH05501338A - satellite signal system - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed description of the invention] satellite signal system field of invention This invention provides a satellite signal system with signal coverage over a very wide area. related. The present invention is particularly, but not exclusively, applicable to satellite paging systems. Concerning satellite signal systems as may be used.

Background of the invention Today's state-of-the-art satellite paging systems are fixed paging systems mounted on satellites in synchronous orbit. Equipped with a positional antenna. Typically in such systems, the antenna and the beam pattern of the antenna are both fixed, so that the signal beam A spot or “footprint (footpr 1nt) J is a place that is “visible” to the satellite. The part of the sphere, that is, covers one-third of the earth's surface.

The ground level strength of the signal transmitted by the antenna is within the coverage area. Although fairly uniform throughout, the signal strength is very weak. This is the highest power synchronization Satellites also pose a problem, as the signal strength at ground level is limited by This is because it is too weak to allow for high-speed coverage. For example, 4 For a synchronous satellite with a radiated power of 0.00 watts, 512 bits per second State-of-the-art selective calling using POC8AG paging protocol at However, paging receivers only have a 2 dB signal margin, i.e. The average signal strength is 2 below the minimum level for activating the paging device. It's only dB higher. One solution is to reduce the bandwidth of the paging receiver. By using a low bit rate signal of 60 baud (baud) or less to be. However, this may not be serviced by the paging system. The paging system is extremely important in that the number of users who can Make it expensive and impractical. That is, a lower bit rate means a smaller capacity Can only support paging traffic.

It is therefore an object of the invention that the above-mentioned disadvantages are overcome or at least alleviated. The objective is to provide an improved satellite signal system.

Summary of the invention According to the invention, a satellite signal system is provided, which system is fixed to the earth. a ground station for receiving paging signals from a paging terminal; Uplink (uplink) for transmitting paging and control signals to the satellite -1ink) m-ray communications equipment and antennas, satellites in orbit around the earth, an uplink receiver on the satellite for receiving programming and control signals; downlink coupled to an antenna with a redirectable beam. n-14nk) The satellite is configured to control the beam position of the downlink antenna. and the beam of the antenna is configured such that when the paging signal is transmitted to the earth Directed to multiple locations on Earth in a predetermined sequence.

Since the antenna is configured to be movable in a predetermined sequence, the signal beam can be targeted sequentially to specific geographic areas, which results in tena scans a very large area and thus provides continental or global coverage. make it possible to provide

In another aspect of the invention, the paging receiver in the system is powered by a battery. a battery saver circuit, the battery saver circuit being configured so that the receiver beam is connected to the pager lock; “On” or fully operational only when being sent to the local area. Synchronize the on-off switching operation to the movement of the downlink beam .

The satellite signal system according to the invention will now be explained by way of example with reference to the accompanying drawings. Ru.

Brief description of the drawing FIG. 1 is an explanatory diagram of a prior art satellite paging system.

FIG. 2 is an explanatory diagram of a satellite paging system according to the present invention.

FIG. 3 is a block diagram for explaining the operation of the satellite paging system of the present invention. It is.

FIG. 4 is a flowchart illustrating the satellite beam operation.

Figures 5A to 5c are transmitted by the satellite paging system of the present invention. FIG. 2 is an explanatory diagram showing a batch of signals.

FIG. 6 shows a diagram suitable for use in conjunction with a satellite paging system according to the present invention. 1 is a block diagram of a typical paging receiver; FIG.

FIGS. 7A to 7B illustrate the buffer in the paging receiver shown in FIG. FIG. 3 is a timing diagram illustrating the operation of the Terisaver circuit.

8A to 8B are flowcharts explaining the operation of the pager in FIG. It is.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS Referring first to FIG. 1, the prior art satellite paging system 2 is A fixed antenna 4 is attached to a satellite 6 in a synchronous orbit. The antenna 4 The operation is performed by the satellite 6.

The antenna 4 was transmitted from the antenna 4 (its surroundings are indicated by dotted lines 9 and 11). The signal beam 10 (expressed as J is configured to have a beam area covering a portion of the plane of the earth. The bi The beam is generally a spot beam. As mentioned before, the satellite paging system Stem 2 is a page inside the building unless the data rate is reduced to approximately 60 baud or less. This is due to the signal strength at the earth surface. This is because the strength is very weak.

The paging signal from the ground-based terminal 31 is transmitted via antenna 33. and is transmitted to the receiving antenna 30 on the satellite 6. This is a radio frequency (RF) It is represented by plink 32.

Referring now also to FIG. A satellite paging system 20 according to an exemplary embodiment is in a synchronous orbit around the earth 26. It comprises a movable or redirectable antenna 22 mounted on a satellite 24. movable The movement and operation of antenna 22 is controlled by satellite 24.

A movable antenna 22 (represented by dotted lines 21 and 23 in FIG. 2) The transmitted signal beam 27 is located at a spot area 28 in this preferred embodiment. A construction site with a sufficiently small beam area to provide sufficient signal strength at the Earth's surface. configured to enable paging coverage within the object. ground level Since the signal strength of changes approximately according to the square of the radius of the beam on the earth, 12,8 Radius reduction by a factor of 10 from 74.52 kilometers to 1,287.452 The reduction is 100 times, or 20 dB, providing a larger ground level signal. for example , 400 watts effective radiated power (ERP) and 1,287.452 km A synchronous satellite with a spot beam diameter of generates a ground level signal strength that is 22 dB above the threshold. This is a good construction. sufficient to provide intra-product paging coverage.

The redirectable antenna 22 can be moved by the satellite 24, thereby The pot region 28 can be directed to a particular geographical location on the earth's surface, and thus The satellite 24 is capable of scanning all parts of the Earth's surface that are "visible" to the satellite 24. Ru. The movable or redirectable antenna 22 is arranged in a predetermined sequence and at a predetermined time. Scan the geographical location of the questions and answers in between. Implement electronically redirectable antennas This technology is well known in antenna technology and will not be explained again here. stomach. See, for example, U.S. Pat. reference.

A satellite paging system according to the invention operates as follows.

Referring to FIG. 3, a paging signal from a ground-based terminal 70 and control signals from the ground station satellite controller 74 are uplinks. applied to transmitter 76. paging data signal and then movable antenna 72. Uplink signals consist of the signals necessary to control the operation of the satellite. The signal is transmitted from uplink transmitter 76 via transmit antenna 80 and receive antenna 72. and is transmitted to uplink receiver 78. Uplink data is downlink that it can transmit at much higher data rates than those used for transmission. You should understand.

The output of uplink receiver 78 is sent to satellite control system 81 and satellite paging controller. controller 82 . Paging signal generator 84 is a satellite paging controller. receiving information and control signals from the controller 82 and paging of the type previously described; Paging information is received via downlink transmitter 86 and movable antenna 88 The information is transmitted to a pager user 90 who carries a device 92.

Movable antenna 88 is an antenna control device coupled to satellite paging controller 82. system 94 to locate a particular location on the Earth's surface in a predetermined sequence and for a predetermined time. Commanded to scan a geographic location. The beam of the movable antenna 22 is set at a specific position. When the downlink transmitter 86 is directed to of the timeslot assigned to a given location. During this time, a paging signal is transmitted via a paging signal generator 84.

The pager in this paging system uses the appropriate signal synchronization code, which will be explained later. the battery cells for appropriate batches in the signal transmission from the satellites. It works to synchronize the drivers. Once the pager is synchronized and addressed Then, it decodes the paging signal.

FIG. 4 is a flowchart illustrating the direction changing operation of the satellite beam. system After the beam is initialized (102), the next beam position is selected (104). Bee the beam is moved to the selected position (106) and the satellite beam is activated. (112). The paging signal that should be directed to that particular location is then transmitted (114) for a fixed period of time (116). As time passes, the satellite beam is turned off (118) and if the system is not disabled. If so (120), the next beam position is selected (104).

FIG. 5A is one exemplary representation of a signal transmitted from satellite antenna 22. . The signal 40 is a time division multiplexed binary paging signal and a series of batches 42-5. 0. Each of the batches 42-50 corresponds to a scan covered by the satellite 24. Corresponds to a specific geographic location within a region. For example, batch 42 is for New York. Accordingly, batch 44 is located in Boston, batch 46 is located in Chicago, and so on. Each batch is Sent on a sequential basis to the appropriate location. For illustration purposes, the POC8AG signal A protocol is used for the signal format in each batch.

FIG. 5B shows that each batch (e.g. 42) has a preamble 62 followed by N frames. It is shown that a frame 64 is provided.

Finally, FIG. 5C shows one exemplary representation 61 of the frame in FIG. 5A. . The frame 61 includes a synchronization code 63 followed by a unique area identification code 65. and the area identification code 65 indicates the geographical location covered by the batch transmission. corresponds to The identification hood 65 has an address for addressing a predetermined pager. A dress signal 66 follows.

The format of frame 61 controls the operation of the battery saver in the pager. By using the code 63, it is possible to synchronize with the scanning sequence of the movable antenna 24. and make it possible. A pager that operates within a particular geographic location is If the satellite 24 is transmitting to that geographic location, it will decode the paging signal. It only powers up to play. This gives a good pager battery life give.

Furthermore, the identification code 65 of frame 61 identifies the current operating position for the pager. Separate. Therefore, if the pager is outside of its normal operating area, the identification The code 65 can be displayed on the pager's display or can be displayed on a different pager. Locations that can be used to enable operating modes, e.g. "roaming" mode Provide information.

FIG. 6 shows a paging system suitable for use within the satellite paging system of the present invention. FIG. 2 is a block diagram of a receiver. It is a radio that receives signals via an antenna 120. Receiver 122 is a traditional selective call paging receiver. wireless receiver 1 The output of 22 is applied to a microcomputer decoder 124, which decodes the microcomputer. The putter decoder 1241 processes the information contained in the received signal. clearly, The microcomputer decoder 124 has an output annunciator 126 and a code plug address. the user with control over the space and optional memory 128, and pager. communicate with. The operation of a paging receiver of the type shown in Figure 6 is well known. May 2, 1985 entitled "Universal Paging Device with Power Savings" No. 4,518,916, issued on the 1st.

A microprocessor decoder for functioning within the satellite paging system of the present invention. 5A, 5B, and 5C. programmed to code. In particular, the decoder supports signals from satellites. and then synchronize its decoding operation to the timing of the beam movement. programmed.

To synchronize to the signal waveform, the decoder first decodes the downlink signal. stays on until It then uses well-known synchronization techniques to modify its decoding operation. Use to synchronize to the received signal. After this, the receiver then installs it's battery The operation of the programming circuit is stored in the program ROM of the microcomputer decoder. the code plug and the information that can be included in the optional memory. Synchronize with the predetermined timing of the star's downlink transmission. As a result, the receiver The battery saver is used during the period when the satellite is transmitting to the geographical area where the pager is located. It only activates the pager. For example, Figure 7A again shows batch 4 2 (FIG. 5A), the preamble 62 followed by the synchronization code 63, and then the The subsequent area identification portion 65 is shown.

Area identification portion 65 and address number 2, reference number 1301 are referred to as group 1. form what is possible. Each successive group consists of the first or second group as shown in Figure 7A. and a second address. Sync code 63 is repeated after the 8th group . Therefore, the receiver must be programmed to respond to group 4 addresses. For example, the receiver's battery saver circuit connects the pager while the receiver preamplifies the pager. During its search operation 132, which searches for the code 62 and synchronization code 63, the group During the period 134 during which 4 addresses are being transmitted, and then again each synchronization code Activates only during the code period 136. This is shown in Figure 7B.

Of course, the page has batches 44, 46, 48 and 50 corresponding to other geographical locations. It will not be activated during this time.

FIGS. 8A and 8B are flowcharts illustrating the operation of the receiver. initial After configuring, the receiver is turned on (140) and for a predetermined search period (144). ), then the receiver is turned off. (145). If bit synchronization is reached before the end of this predetermined search period (146) If so, the receiver begins its search for a synchronization code (148). Re and assuming that the synchronization code is detected before the predetermined search period (152). (150), and the location (loca t1on) code is decoded (154). and the battery saver timing circuit is synchronized (156). The receiver then A search for a response signal is started (158). If the address signal is detected (160 ), an alarm signal is generated (162).

If the address signal is not detected, the receiver will address (164) until the road indicates that it is time to save the battery. Continue searching for signals. If the end of batch is not detected (166), the timer The frame is set to wait for the next frame (168). If end of batch is detected If so, the timer is reset to wait for the next batch (170). either If so, the receiver is turned on (172) after an appropriate time (174).

By using a redirectable antenna, the claimed invention is highly can provide practical in-building paging coverage over large areas. moreover , with the scanning motion of the beam can be used to provide wide area coverage. When the pager's battery saver operation is synchronized to the beam movement, It can be used to extend the battery life of your mobile phone.

Additionally, the claimed invention provides a truly national or continental-wide paging network. It is understood that it can be used to provide coverage. Furthermore, it is also current Paging is used in conjunction with existing land-based paging systems. Provides true nationwide coverage if a subscriber leaves his usual geographic location be able to.

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Claims (14)

[Claims] 1. A satellite signal system, satellite orbiting the earth, An antenna coupled to the satellite to provide a signal beam, the signal beam comprising: With a data signal having a small beam area and multiple signal batches, said satellite is configured to control the position of said antenna, said signal beam; means for directing a plurality of terrestrial signals in a predetermined sequence to a plurality of locations on the earth, said The signal batches are arranged in a predetermined sequence, and each of the plurality of signal batches is arranged in a predetermined sequence. an identification code corresponding to a location and identifying a corresponding one of the plurality of locations; and located at one of the plurality of locations for receiving the signal beam. a portable selection signal receiver, the portable selection signal receiver including the plurality of batteries; the previous one of said plurality of batches; one of the plurality of positions corresponds to the one of the plurality of positions; stem. 2. The portable selection signal receiver comprises means for decoding the signal beam. and the decoding means determines the position of the receiver according to the identification code. A satellite signal system according to claim 1. 3. The small beam area is 800 square miles (approximately 2072 square kilometers) 2. A satellite signal system as claimed in claim 1, which is not larger than: 4. A satellite signal system, Antenna with redirectable beam, receives paging and control information a first receiver for coupled to the antenna and the first receiver and responsive to the paging information; a first transmitter for transmitting a paging signal; and coupled to the antenna and the first receiver in response to the control signal; controlling the antenna to sequentially direct the redirectable beam to a plurality of locations; control means for, A satellite signal system equipped with 5. further transmitting the paging information and control information to the first receiver; 5. The system of claim 4, comprising a second transmitter for. 6. The paging signal has a plurality of signal batches arranged in a predetermined sequence. a data signal corresponding to one of the positions, each of the batches corresponding to one of the positions; The stem further includes at least one selective call for receiving the paging signal. 5. The system of claim 4, comprising a receiver. 7. each of said batches has an identification code for identifying one of said locations and the at least one selective call receiver for decoding the identification code; 7. A system according to claim 6, comprising decoding means. 8. the at least one selective call receiver at one of the locations; as claimed in claim 6, in response to only one of said plurality of batches corresponding to system. 9. A satellite paging system comprising: a satellite; a first means for transmitting paging information to said satellite, arranged in a predetermined sequence; A paging signal comprising a plurality of signal batches arranged in a row is transmitted from the satellite to a plurality of positions. a second means for transmitting in a predetermined sequence to the batches, each of said batches comprising: corresponds to one of the plurality of positions, and is present in one of the plurality of positions at least one pager receiver, the at least one pager receiver selectively responds only to the batch corresponding to the location where said pager receiver is present. thing, Satellite paging system with. 10. Each of the batches corresponding to one of the plurality of positions is in front of the plurality of positions. The satellite page according to claim 9, comprising an identification code for identifying one of the satellite pages. ging system. 11. The second means is for providing a signal beam having a small beam area. a movable antenna, the antenna transmitting a signal beam according to said predetermined sequence; 10. The satellite of claim 9, wherein the satellite is positioned to point to said plurality of locations. paging system. 12. Receiving information from satellites that transmit signals sequentially to each of a plurality of predetermined areas. A selective calling radio receiver for there is a receiver section for receiving said signal, and said wireless receiver the receiver sensor when the satellite is transmitting information to one of the plurality of predetermined areas; activating an action, and said satellite is located in said one of said plurality of predetermined regions. said receiver section when transmitting to said plurality of predetermined area parts other than Battery saver circuit to deactivate, A selective calling radio receiver comprising: 13. A satellite paging system that includes a receiver identification code and a receiver location code. a receiving means for receiving a selective call message, the selective call message comprising: a receiving means for receiving a selective call message; An encoding means for encoding outbound messages into paging signal batches. Thus, each batch consists of selective call messages with the same receiver location code. What will become, uplink transmission for transmitting said paging signal batch and satellite control signals; means of trust, a ground station comprising; an uplink for receiving the paging signal batch and the satellite control signal; a paging signal batch receiving means for transmitting said paging signal batch to a geographical location; means of trust, coupled to the transmitting means and responsive to the satellite control signal to determine the geographic location; a satellite comprising control means for; and a receiving means for receiving the paging signal batch; and a receiving means for receiving the paging signal batch; a predetermined time indicating that the receiver is transmitting within the geographical area in which it is located; and power storage means for powering said receiver means between said plurality of selective calls. output receiver, Satellite paging system with. 14. Ground Station System Terminal to multiple locations on Earth A satellite signaling method for a communications receiver comprising: (a) Control information and communication information from the ground station system terminal; transmitting a signal with a batch, (b) receiving said signal at a first antenna coupled to a satellite orbiting the earth; the stage of (c) directing a second antenna coupled to the satellite to one of the plurality of locations; a floor, the one of the plurality of positions being determined according to the control information; , (d) providing a signal beam having a footprint from said second antenna. and the footprint is determined according to the control information; (e) some of the plurality of communication receivers located at the one of the plurality of locations; (f) a communication signal comprising said batch of communication information; from the antenna to the one of the plurality of locations; (g) transmitting said communication signal comprising said batch of communication information to said plurality of communication receivers; receiving by said one of; (h) deactivating said one of said plurality of communication receivers; ,and (i) repeating steps (a) to (h) for the next of said plurality of positions; the stage of A satellite signaling method comprising: