KR100518898B1 - Method for searching user terminal position using broadcasting satellite, gap filler And Dummy pilot gap filler for only searching user terminal position - Google Patents

Abstract

 The present invention relates to a method for tracking the position of a terminal in a broadcast satellite system.

The present invention provides a terminal using at least one or more broadcast satellites and at least two or more terrestrial repeaters, at least three or more terrestrial repeaters, or at least two or more broadcast satellites and at least one or more terrestrial repeaters. I'm implementing a way to track location. As a method, the GPS receiver is separately installed in the terrestrial repeater to synchronize the broadcast signal received by the terminal to obtain the position of the terminal using the relative distance between the points. Another method is to find the position of the terminal using the relative distance between the points from the terminal without installing a separate GPS receiver in the terrestrial repeater.

In addition, the present invention relates to a dummy pilot repeater consisting of a pilot channel and only one broadcast channel for data reception.

According to the present invention, when the position of the terminal is measured using a broadcast satellite and a terrestrial repeater, the distance is measured using a PN code, so that a very small error can be obtained. In addition, since the ground repeater is synchronized with the CDM signal as in the second embodiment, the GPS receiver does not need to be installed in the ground repeater, thereby reducing the cost. In addition, using a dummy pilot repeater can reduce hardware cost and minimize signal interference.

Description

Method for searching user terminal position using broadcast satellite and terrestrial repeater and dummy pilot repeater only for tracking terminal position {Method for searching user terminal position using broadcasting satellite, gap filler And Dummy pilot gap filler for only searching user terminal position}

The present invention relates to a method for tracking the location of a terminal in a broadcast system, and more particularly, to a system and a method for tracking the location of a terminal using a broadcast satellite and a terrestrial repeater.

In recent years, as mobile communication spreads around the world, it has become legal to provide a service for tracking the location of a terminal. In the United States, the Federal Communications Commission (FFC) provides location information services that guarantee a certain degree of accuracy, which is expected to be legislated in Korea soon.

As a method of tracking the location of a terminal in a mobile communication system, a method of determining a location using information received from a satellite by embedding a global positioning system (GPS) receiver in a terminal There is this. However, the location tracking method using GPS requires a separate receiver to be embedded in the terminal. Since the location is tracked using unidirectional communication, at least three phase satellites must be used. Since the location is tracked, there is a problem that the visual information between each satellite must be precisely adjusted. In addition, since the GPS network is intended for global service, the elevation angle between the satellite and the terminal is low and a large number of satellite signals must be received. Weakness may not be possible.

In addition, in the mobile communication system, a method of tracking the position of the terminal by calculating a signal arrival time difference when transmitting and receiving a signal between the base station and the terminal is used. In the case of a bidirectional communication system such as a mobile communication system, since the position is measured while the position and time of the base station are synchronized, it is possible to improve the measurement accuracy by using the reception angle data. Is advantageous. However, in the case of the urban area, the base station is very dense in consideration of the call volume of the base station, and there is a problem in that the measurement error of the system occurs when the equipment which generates a time delay such as an optical repeater is severe. . In addition, an accurate number of base stations and signal strengths that can be measured must be maintained for accurate measurement. In the case of a suburban area, a plurality of base stations do not exist.

Conventional terrestrial repeaters can use 64 Walsh codes. In general, however, 32 Walsh codes are used in consideration of interference between codes, and a broadcasting channel includes one pilot channel and 31 broadcasting channels. In the case of a mobile communication system, each finger must include actual effective data in order to perform a soft handoff. However, since there is no handoff in a broadcasting system, only one dominant signal Restoration is possible. Therefore, only one dominant transmitter is required to receive a broadcast channel, but in case of location service, there is a problem in that an unnecessary terrestrial repeater must be installed to provide a plurality of signals.

SUMMARY OF THE INVENTION The present invention has been made in an effort to provide a method for tracking the location of a terminal using a one-way broadcast satellite system and a terrestrial repeater.

Another object of the present invention is to provide a method of synchronizing the ground repeaters using a signal transmitted from a satellite rather than the ground repeater is synchronized with the GPS system in synchronizing the ground repeaters in the one-way broadcast system to position the terminal It is intended to provide a way to track.

Another object of the present invention is to provide a dummy pilot repeater consisting of a pilot channel and only one broadcast channel to provide only location services.

Method for tracking the position of the terminal in a broadcasting system according to an aspect of the present invention for achieving the above object is

In a method for tracking the position of a terminal in a one-way broadcast satellite system including an earth station, a broadcast satellite, a terrestrial repeater, and a terminal,

(a) the broadcast satellite providing a signal and a first reference time to the terrestrial repeater and the terminal, and providing coordinates of a preset broadcast satellite to the terminal through a channel;

(b) setting, by the terrestrial repeater, a second reference time through a signal received from the broadcast satellite using a separate receiver;

(c) providing, by the terrestrial repeater, a terminal with a preset magnetic coordinate and the second reference time to the terminal using an idle channel;

(d) compensating for a signal transmitted from the terrestrial repeater by using the first and second reference times received by the terrestrial repeater and the broadcast satellite to obtain a time offset between the terrestrial repeater and the signal received by the broadcast satellite;

(e) determining, by the terminal, the relative distance difference from the terminal to the broadcast satellite and each terrestrial repeater using the time offset;

(f) tracking the location of the terminal using the relative distance difference and each coordinate.

In addition, a method for tracking the position of a terminal in a broadcasting system according to another aspect of the present invention

Claims [1] A method for tracking the position of a terminal in a one-way broadcast satellite system including a terrestrial repeater and a terminal that knows the distance from an earth station, a broadcast satellite, a broadcast satellite to a terrestrial repeater,

(a) providing a signal to the terrestrial repeater and the terminal by the broadcast satellite and providing a preset coordinate of the broadcast satellite to the terminal through a channel;

(b) obtaining a first time offset between the signal transmitted from the broadcast satellite and the signal transmitted by the terrestrial repeater to the terminal using the distance from the broadcast satellite to the terrestrial repeater and the signal received from the broadcast satellite;

(c) providing, by the terrestrial repeater, a terminal with a preset magnetic coordinate and the first time offset to the terminal using an idle channel;

(d) compensating for the signal received from the terrestrial repeater using the first time offset received from the terrestrial repeater to obtain a second time offset between the signal transmitted from the broadcast satellite and the signal transmitted from the terrestrial repeater;

(f) the terminal obtaining a relative distance difference from the terminal to the broadcast satellite and each terrestrial repeater using the second time offset;

(g) tracking the location of the terminal using the relative distance difference and each coordinate.

In addition, a dummy pilot repeater according to another feature of the present invention

A digital signal processing unit for processing time division multiplex (TDM) signals transmitted from broadcast satellites, a channel demultiplexer for dividing a time division multiplex (TDM) signal, which is a signal transmitted from the digital signal processing unit, into multiple channels, and each channel again. A serial-to-parallel converter that splits into two signals, a digital filter that filters the modulated signal of the serial-to-parallel converter, an amplifier that amplifies the output of the filter, and an adder that sums the amplified signals. It includes a D / A converter for converting a tree and a digital signal into an analog signal, and includes only a pilot channel for synchronization acquisition and one broadcast channel for data reception.

DETAILED DESCRIPTION Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings so that those skilled in the art may easily implement the present invention. As those skilled in the art would realize, the described embodiments may be modified in various different ways, all without departing from the spirit or scope of the present invention. In the drawings, parts irrelevant to the description are omitted in order to clearly describe the present invention. Like parts are designated by like reference numerals throughout the specification.

Hereinafter, with reference to the drawings will be described in detail an embodiment of the present invention.

1 is a diagram illustrating a schematic flow of a broadcasting system used in an embodiment of the present invention.

1 is a personal mobile service, which is another name of 'satellite DAB' which is a new concept broadcasting service that receives multiple channels of audio and video broadcasting using a satellite and can be watched anytime and anywhere by using a vehicle or a portable terminal. A personal mobile satellite broadcasting (hereinafter referred to as 'PMSB') system is shown.

As shown in FIG. 1, the PMSB system includes a content provider 10, an earth station 20, a broadcasting satellite 30, a ground filler 40, It consists of a user terminal 50.

The content provider 10 sends the broadcast contents to the earth station 20. The earth station 20 transmits the contents to the equator in the form of code division multiplex (hereinafter referred to as 'CDM') or time division multiplex (hereinafter referred to as 'TDM') in the 11/14 GHz band. The stationary broadcast satellite 30 is supplied. The broadcast satellite 30 converts the supplied CDM and TDM signals into CDM signals in the 2.6 GHz band and supplies them to the ground, and also transmits a TDM signal in the 11 GHz band for the terrestrial repeater 40. The terrestrial repeater 40 converts the TDM signal supplied from the broadcast satellite into a CDM signal in the 2.6 GHz band and broadcasts it to the service area.

In this case, the 2.6 GHz CDM signal broadcast from the broadcast satellite 30 and the 2.6 GHz CDM signal broadcast from the terrestrial repeater 40 coexist in the service area in which the user terminal 50 exists. If the same frequency is mixed due to the characteristics of the broadcast, the broadcast can be demodulated using a signal having a strong reception strength. Hereinafter, a method of tracking the location of a terminal in the basic broadcasting system of FIG. 1 will be described.

2 is a diagram illustrating a method for tracking a terminal location using a terrestrial repeater synchronized with a broadcast satellite according to a first embodiment of the present invention.

As shown in FIG. 2, the method for tracking the location of a terminal according to the first embodiment of the present invention includes a terrestrial repeater 1 210, a terrestrial repeater 2 220, and a broadcast satellite 200 that are time synchronized with a broadcast satellite 200. And a user terminal 230.

In order to track the location of the terminal using a unidirectional broadcasting system, a reference time for measuring the absolute position (latitude and longitude) of each terrestrial repeater 210 and 220 and the signal arrival time is required. The absolute position (position and longitude) is set in advance when the terrestrial repeater and broadcast satellite are installed.

According to the first embodiment of the present invention, the broadcast satellite 200 is provided with a clock (CLOCK) provided from the earth station 20, as shown in FIG. Since 210 and 220 are not synchronized, the reference time for each signal can be set using the reference time received from the GPS system. This can be solved by installing a GPS receiver in each of the ground repeaters 210 and 220. have.

The ground repeaters 210 and 220 installed with the GPS receiver set the second reference time of the signal transmitted by the ground repeaters 210 and 220 to the user terminal 230 using the first reference time transmitted from the broadcast satellite 200. Each of the terrestrial repeaters 210 and 220 provides an absolute position and a second reference time to the user terminal 230 using a broadcast channel which is a reserved channel. The broadcast satellite 200 also provides the absolute position and the first reference time to the terrestrial terminal 230 through the broadcast channel. In this case, the user terminal 230 uses the absolute position (latitude and longitude) and the second reference time, the absolute position and the first reference time supplied from the terrestrial repeaters 210 and 220, respectively. Measure the position of the terminal. In this case, the terrestrial terminal 200 compensates the signals transmitted from the terrestrial repeaters by using the first and second reference times and the broadcast signals transmitted from the broadcast satellite 200 and the terrestrial repeaters 210 and 220. We can get time offset of. When the distance is obtained using the relationship of distance = speed * time, the value of the time offset can be used to measure the relative distance of the distance between the points 200, 210, and 220 from the ground terminal 230. Coordinates of the terrestrial terminal 230 may be obtained using the relative distances and the absolute positions of the points 200, 210, and 220. At this time, since each terrestrial repeater has a demuxing process of the TDM signal and a muxing structure for each code to the CDM signal, it is possible to adjust the time for the CDM channel using a buffer.

In addition, the method of tracking the position of the terrestrial terminal using three terrestrial repeaters may be performed in the same manner as in the second embodiment of the present invention, but each point from the terrestrial terminal using the reference time and absolute position received from the three terrestrial repeaters Find the relative distance between them. In addition, the above method is also used to track the location of the terrestrial terminal using two satellites and one broadcasting satellite to obtain a relative distance between the points from the terrestrial terminal.

The following describes a specific calculation method for the first embodiment of the present invention.

3 is a diagram showing a specific distance measuring method and a method of measuring a position according to the first embodiment of the present invention.

The G1 (1,5) 300, G2 (2.1) 310, and G3 (7,4) 320 shown in FIG. 3 respectively represent the respective terrestrial repeaters 200, 210 shown in FIG. Absolute position (latitude and longitude) and shows the coordinates of the absolute position of the broadcast satellite 120. Also, G1 (1,5) 300, G2 (2.1) 310, G3 (7,4) 320 may be replaced with coordinates representing three terrestrial repeaters or two broadcast satellites and one terrestrial repeater. Can be. T (x, y) is a coordinate of the terrestrial terminal 230 and its absolute position shown in FIG.

The distance measurement between G1 (1,5) 300, G2 (2.1) 310, G3 (7,4) 320 and T (x, y) is the absolute distance at T (x, y). Absolute distance cannot be measured because there is no standard for measurement. However, the actual position of T (x, y) can be measured using the relative distance between each terrestrial terminal. │AB│, │BC│, │AC│ which is the relative distance between G1 (1,5) 300, G2 (2.1) 310, G3 (7,4) 320 and T (x, y) Can be obtained. Where A, B, and C represent the absolute distances between G1 (1,5) 300, G2 (2.1) 310, G3 (7,4) 320 and T (x, y). Relative distance is a time offset between the two signals using the reference time of each terrestrial repeater received through a separate channel from each terrestrial repeater (200, 210) to the terrestrial terminal (220) and the reference time of the broadcast satellite. Measure The relative distance may be measured using the relationship of distance = velocity * time as the time offset. In the above description, the coordinates of T (x, y) are obtained using the following equation.

Here, the values of A-B, B-C, and A-C are arbitrarily determined for convenience of calculation. That is, since A-B, B-C, and A-C are the relative distances described above, this is a value that can be obtained using the time difference in the terrestrial terminal.

Solving the three equations above gives x and y.

Therefore, T (x, y) is obtained as T (5,2).

As described above, the terrestrial terminal tracking method described in FIG. 2 has to separately install a GPS receiver in the terrestrial repeater, and has a disadvantage in that a clock signal between an earth station and a broadcast satellite is also known correctly.

4 is a diagram illustrating a system related to a terrestrial terminal tracking method according to a second embodiment of the present invention having a method of synchronizing each terrestrial repeater through a signal transmitted from a broadcast satellite.

5A and 5B are diagrams illustrating a time offset between a CDM signal transmitted from the broadcast satellite 400 and a CDM signal transmitted from each terrestrial repeater 410 and 420 by the terminal 430. Δt1 and Δt2 shown in FIGS. 5A and 5B respectively represent time offsets, and the difference between the distance from the terminal to the broadcast satellite and the distance from the terminal to the terrestrial repeater is calculated using this. Hereinafter, a second embodiment of the present invention will be described with reference to FIGS. 4, 5A, and 5B.

As shown in FIG. 4, the system according to the second embodiment of the present invention includes one broadcast satellite 400, two terrestrial repeaters 410 and 420, and a terrestrial terminal 430.

As shown in FIG. 4, the broadcast satellite 400 transmits the TDM signal 440 and the CDM signal 450 to the terrestrial repeaters 410 and 420, and also transmits the CDM signal 450 to the terrestrial terminal 430. ). Each terrestrial repeater demodulates the TDM 440 signal transmitted from the broadcast satellite 400 and retransmits the CDM 460 to the terrestrial terminal 430. In FIG. 4, the distance between the broadcast satellite 400 and each of the ground repeaters 410 and 420 (hereinafter referred to as 'L1 and L2') is a value that can be known when the ground repeater is installed in advance. Remembered.

In FIG. 4, each of the terrestrial repeaters 410 and 420 is controlled from the broadcast satellite 400 by using the CDM 450 signal received from the broadcast satellite 400 and L1 and L2 stored in the respective terrestrial repeaters 410 and 420. The offset between the transmitted CDM signal 450 and the respective ground repeaters 410 and 420 demodulates the TDM signal into the CDM signal and transmits the CDM signal 460 transmitted to the ground terminal 430.

Since the terrestrial repeater knows L1 and L2 in advance, the offset time between the CDM signal 450 transmitted from the broadcast satellite and the CDM signal 460 transmitted by the terrestrial repeaters 410 and 420 to the terminal 430. (Hereinafter referred to as 'Δt1a and Δt2a', respectively). At this time, the terrestrial repeaters 410 and 420 are offset values between the CDM signal 450 received from the broadcast satellite 400 and the CDM signals 460 transmitted by the terrestrial repeaters 410 and 420 to the terrestrial terminal, that is, Δt 1a, The coordinate values of Δt2a and the ground repeaters 410 and 420 are transmitted to the ground terminal 430 through an idle channel.

The terrestrial terminal uses the offset values (Δt1a, Δt2a) transmitted from the terrestrial repeaters through an idle channel, and the CDM signal 450 transmitted from the broadcast satellite 400 and the terrestrial repeaters 410 and 420. From the CDM signal 460 transmitted from the time difference (Δt1, Δt2) can be obtained. This value is the difference between the distance between the ground terminal 430 and the ground repeaters 410 and 420 with respect to the distance between the ground terminal 430 and the broadcasting satellite 430. That is, the terminal compensates the CDM signal transmitted from the terrestrial repeater with the CDM signal transmitted from the broadcast satellite to the terminal using offset values Δt1a and Δt2a. 5A and 5B show the time difference between the CDM signal 450 transmitted from the broadcast satellite 400 and the CDM signal transmitted from each terrestrial repeater using the synchronized reference time, respectively.

The terminal uses the time offsets (ie, Δt1a, Δt2a) of the time offsets of the CDM signal sent from the terrestrial repeater 1 410 to the terminal and the CDM signal sent from the terrestrial repeater 2 420 to the terminal. Compensation to synchronize the reference time. Let this value be Δt3.

Coordinates of the user terminal can be obtained using the method shown in FIG. 3 by using the coordinate values of Δt1, Δt2, Δt3 and broadcast satellites and terrestrial repeaters. Assuming that G1 200, G2 210, and G3 220 shown in FIG. 3 are broadcast satellites 400, terrestrial repeaters 2 420, and terrestrial repeaters 1 410, the following relationship is established.

│A-C│ = Δt1 * constant

│A-B│ = Δt2 * constant

│B-C│ = Δt3 * constant

Here, the relationship of distance = time * speed is used. The velocity is a constant of 3.0 * E8 m / sec², which is the speed of light, and the right side of Equation 2 is constant because it knows Δt1, Δt2, and Δt3. Then, as in Equation 1, when Equation 2 is developed with the position of the terminal as T (x, y), the equation is as in Equation 1. Therefore, by solving the washing, it is possible to obtain the T (x, y) coordinate point which is the position of the user terminal. This value is the location of the user terminal.

In FIG. 4, the CDM signal among the signals is a CDM Pilot PN signal for synchronizing acquisition of a broadcast satellite without causing the GPS repeater to synchronize GPS time. The pilot PN channel allows the receiver to provide a pilot signal for synchronization acquisition and to transmit various control data of the system. In a digital system, the pilot channel has three functions. First, a unique word and a frame counter value are transmitted for frame synchronization. Second, a pilot symbol is transmitted for synchronization acquisition and phase compensation. Finally, control data is transmitted to provide the function of the receiver. The pilot symbols are composed of 32-bit length data, all of which are '1', and allow the receiver to perform path searching and channel estimation functions and to improve accuracy. In order to increase, it is necessary to transmit with more power than the broadcast channel, but it is suitable to transmit with twice the power of the broadcast channel.

As described above, in the terminal location tracking method according to the second embodiment of the present invention, since each terrestrial repeater obtains a time offset based on a 2.6 GHz CDM signal transmitted from a broadcast satellite without GPS time synchronization, a separate time synchronization is performed. It may provide a location value for a terminal within service coverage without assistance.

In the above, in the method for tracking the location of the user terminal according to the second embodiment of the present invention, a method of tracking the location of the user terminal using one satellite and two terrestrial repeaters has been described. As in the embodiment, the three terrestrial repeaters can track the position of the user terminal, and the two satellites and one terrestrial repeater can track the position of the user terminal. In tracking the position of the user terminal with three terrestrial repeaters, the user terminal, as in the method of the second embodiment of the present invention, is respectively Δt1a, Δt2a, Δt3a (where Δt3a is the third ground) from three terrestrial repeaters to synchronize the time. Compensation for synchronizing broadcast signal transmitted from each terrestrial repeater by using time offset value obtained from repeater). The user terminal can obtain the relative distance of each terrestrial relay period from the user terminal using the synchronized time reference. In the case of two broadcast satellites and one terrestrial repeater, the relative distance between two broadcast satellites and the terrestrial repeater can be obtained from the user terminal using Δt1a transmitted from one terrestrial repeater as in the second embodiment of the present invention. .

In the terminal location tracking method according to the first or second embodiment of the present invention, a map corresponding to the location coordinates of the terminal obtained by the first or second embodiment of the present invention is retrieved from the memory of the terminal. By providing a device for displaying the map on the terminal, the location can be displayed more clearly. In this case, the terminal may store the map in memory in advance or may receive the map through a broadcasting system.

In the terminal location tracking method according to the first or second embodiment of the present invention, the chip rate of the PN code used in the PMSB is 16.384 MHz, and the clock rate actually processes the data. Is 65.536 MHz. Therefore, the distance measurement using the Gap Filler has a resolution of about 4.6m. This is a very small error in measuring the position of the terrestrial terminal.

6 is a diagram illustrating a broadcast channel of a broadcast CDM of a terrestrial repeater. In FIG. 6, the broadcasting channel of the broadcasting CDM includes a TDM digital signal processor 610, a channel demultiplexer 620, a serial two parallel converter 630, and a root raised cosine filter. RR, a gain unit 650, an adder tree 660, and a digital-to-analog converter 670. The TDM digital signal processing unit 610 is a part for processing the TDM signal transmitted from the broadcast satellite, the channel demultiplexer 620 divides the TDM digital signal into several channels, and the serial to parallel 630 is each channel again Divide into two channels. In FIG. 6, the RRC 640 is a digital filter and the gain unit 650 amplifies the signal. The amplified signal is summed into an adder tree 660 to generate an analog signal using the D / A converter 670. In the broadcast CDM, 64 Walsh codes may be used, but as shown in FIG. 6, 32 Walsh codes are used in consideration of interference between codes, and one pilot channel is used as a broadcast channel. It consists of a pilot channel and 31 broadcasting channels. Since the pilot channel is involved in the synchronization acquisition process and the like, the pilot channel transmits at a higher power than the general broadcast channel. The output for each channel is determined by the setting of the gain block after the RRC filter (digital filter).

The dummy pilot repeater for the location information service according to the third embodiment of the present invention includes a pilot channel and only one broadcast channel among the broadcast channels shown in FIG. And, in order to prevent a malfunction of the terminal includes a tag (tag) indicating that the dummy data (Dummy data) in the broadcast channel. Since the broadcasting terminal simply compares the Ec / lo of the pilot signal, when the dummy pilot repeater signal is restored as the main signal, the reception performance of the system may be degraded. A tag indicating a dummy pilot repeater may be inserted into a channel to prevent a terminal from malfunctioning by a dummy pilot repeater. If the demodulated data of the terminal includes a tag indicating that the signal is transmitted from the dummy pilot repeater, the processor may add a reference signal or fading to the dummy pilot signal even if Ec / lo is good. It is not used as a binary signal but only for calculating distances to other reference signals.

As shown in the first and second embodiments of the present invention, three or more signals are required to track the taste of a terminal using a broadcast satellite and a terrestrial repeater. In the case of a mobile communication system, in order to perform a soft handoff, each finger of a signal transmitted from several repeaters must include actual effective data, but in a broadcasting system, there is no handoff function. Only one dominant signal can restore the signal. Only one dominant transmitter is needed to receive a broadcast channel, but for the location service, an unnecessary terrestrial repeater equipment should be installed to provide a plurality of signals. Therefore, when using the dummy pilot repeater according to the third embodiment of the present invention, the hardware configuration cost is reduced, and since the general broadcast channel is not transmitted, the feeding between the satellite signal and the signal for the other terrestrial repeater is reduced. In addition, since power for each broadcasting channel is not needed, a relatively large output signal can be transmitted by using a terminating amplifier with a small output, thereby ensuring wide coverage with low-cost equipment.

Although the preferred embodiment of the present invention has been described in detail above, the present invention is not limited thereto, and various other changes and modifications are possible.

For example, as mentioned above, in order to measure the position of the terminal in the first and second embodiments of the present invention, three or more reference points whose coordinate values are known are one broadcast satellite, two terrestrial repeaters, three terrestrial repeaters, It can be replaced by two satellites and one terrestrial repeater respectively.

As described above, according to the present invention, when the position of the terminal is measured using a broadcast satellite and a terrestrial repeater, the distance is measured using a PN code, thereby obtaining a very small error. In addition, since the ground repeater is synchronized with the CDM signal as in the second embodiment, the GPS receiver does not need to be installed in the ground repeater, thereby reducing the cost.

In addition, when using a dummy pilot repeater, the output power can be increased to reduce the noise of the channel and reduce the hardware configuration cost. In addition, since one broadcast channel is not transmitted, the amount of signal interference is reduced for satellite signals and other terrestrial repeaters.

1 is a diagram illustrating a schematic flow of a broadcasting system used in an embodiment of the present invention.

2 is a diagram illustrating a system relating to a method for tracking a terminal location using a terrestrial repeater synchronized with a broadcast satellite according to a first embodiment of the present invention.

3 is a diagram illustrating a specific distance measuring method and a method of measuring a position according to the first embodiment of the present invention.

4 is a diagram illustrating a system related to a ground terminal tracking method according to a second embodiment of the present invention.

5A and 5B are diagrams illustrating a time offset between the CDM signal transmitted from the broadcast satellite 400 and the CDM signals transmitted from the respective terrestrial repeaters 410 and 420 by the terminal 430.

6 is a diagram illustrating a broadcast channel of a broadcast CDM of a terrestrial repeater.

Claims (21)

In a method for tracking the position of a terminal in a one-way broadcast satellite system including an earth station, a broadcast satellite, a terrestrial repeater, and a terminal, (a) the broadcast satellite providing a signal and a first reference time to the terrestrial repeater and the terminal, and providing coordinates of a preset broadcast satellite to the terminal through a channel; (b) setting, by the terrestrial repeater, a second reference time through a signal received from the broadcast satellite using a separate receiver; (c) providing, by the terrestrial repeater, a terminal with a preset magnetic coordinate and the second reference time to the terminal using an idle channel; (d) compensating for a signal transmitted from the terrestrial repeater by using the first and second reference times received by the terrestrial repeater and the broadcast satellite to obtain a time offset between the terrestrial repeater and the signal received by the broadcast satellite; (e) determining, by the terminal, the relative distance difference from the terminal to the broadcast satellite and each terrestrial repeater using the time offset; And and (f) tracking the location of the terminal using the relative distance difference and each coordinate. The method of claim 1, Method of tracking the location of the terminal in a broadcast satellite system, characterized in that the separate receiver is a satellite receiver. The method of claim 1, The signal is a method of tracking the terminal position in a broadcast satellite system, characterized in that the pilot signal of the broadcast signal. The method of claim 1, Method of tracking the terminal position in a broadcast satellite system, characterized in that the channel is a broadcast channel. The method of claim 1, And a time offset between at least three signals using the first and second reference time and signals received from the at least two terrestrial repeaters and the at least one broadcasting satellite. How to track your terminal location on the phone. The method of claim 1, Wherein the terminal of step (d) using the first and second reference time and signals received from at least three terrestrial repeater to obtain a time offset between at least three signals to track the terminal position in a broadcast satellite system Way. The method of claim 1, In the broadcast satellite system, characterized in that the terminal of step (d) obtains a time offset between at least three signals using the first and second reference time and signals received from at least two satellites and at least one terrestrial repeater. How to track your terminal location. The method according to any one of claims 5 to 7, Step (e) is Obtaining a time difference between both signals using the time offset; And calculating the relative distance by using the time difference obtained in the above step by using a relationship of distance = speed * time. The method according to any one of claims 5 to 7, The terminal of step (f) is to obtain the three or more relative distances and coordinates to track the position of the terminal in the broadcast satellite system, characterized in that to track the position of the terminal using three simultaneous equations. The method of claim 1, Obtaining a location of the terminal and loading a map corresponding to the location from the memory built in the terminal to display the location of the terminal on the map further comprising the step of tracking the terminal location in the broadcast satellite system. Claims [1] A method for tracking the position of a terminal in a one-way broadcast satellite system including a terrestrial repeater and a terminal that knows in advance the distance from an earth station, a broadcast satellite, a broadcast satellite to a terrestrial repeater, (a) providing a signal to the terrestrial repeater and the terminal by the broadcast satellite and providing a preset coordinate of the broadcast satellite to the terminal through a channel; (b) obtaining a first time offset between the signal transmitted from the broadcast satellite and the signal transmitted by the terrestrial repeater to the terminal using the distance from the broadcast satellite to the terrestrial repeater and the signal received from the broadcast satellite; (c) providing, by the terrestrial repeater, a terminal with a preset magnetic coordinate and the first time offset to the terminal using an idle channel; (d) compensating for the signal received from the terrestrial repeater using the first time offset received from the terrestrial repeater to obtain a second time offset between the signal transmitted from the broadcast satellite and the signal transmitted from the terrestrial repeater; (e) determining, by the terminal, a relative distance difference from the terminal to the broadcast satellite and each terrestrial repeater using the second time offset; And and (f) tracking the location of the terminal using the relative distance difference and each coordinate. The method of claim 11, The signal is a method of tracking the terminal position in a broadcast satellite system, characterized in that the pilot signal of the broadcast signal. The method of claim 11, And said channel is a broadcast channel. The method of claim 11, Compensating for the signal transmitted from the terrestrial repeater to the terminal by using the at least two first time offsets received from the at least two terrestrial repeaters in step (d), and the terrestrial repeater and the signal transmitted from the at least one broadcast satellite. And obtaining at least three second time offsets between the signals transmitted from the mobile station. The method of claim 11, Compensating for the signal transmitted from the terrestrial repeater to the terminal by using the at least three first time offsets received by the terminal in at least three terrestrial repeaters; A method for tracking the position of a terminal in a broadcast satellite system, characterized by obtaining at least three time offsets. The method of claim 11, Compensating for the signal transmitted from the terrestrial repeater to the terminal using the at least one first time offset received by the terminal from the at least one terrestrial repeater, and the signal transmitted from the at least one terrestrial repeater And obtaining at least three second time offsets between signals transmitted from two satellites. The method according to any one of claims 14 to 16, Step (e) is Obtaining a time difference between both signals using the second time offset; And calculating the relative distance by using the time difference obtained in the above step by using a relationship of distance = speed * time. The method according to any one of claims 14 to 16, The terminal of step (f) is to obtain the three or more relative distances and coordinates to track the position of the terminal in the broadcast satellite system, characterized in that to track the position of the terminal using three simultaneous equations. The method of claim 11, Obtaining a location of the terminal and loading a map corresponding to the location from the memory built in the terminal to display the location of the terminal on the map further comprising the step of tracking the terminal location in the broadcast satellite system. A digital signal processing unit for processing time division multiplex (TDM) signals transmitted from broadcast satellites, a channel demultiplexer for dividing a time division multiplex (TDM) signal, which is a signal transmitted from the digital signal processing unit, into multiple channels, and each channel again. A serial-to-parallel converter that divides it into two signals, a digital filter that filters the modulated signal of the serial-to-parallel converter, an amplifier that amplifies the output of the filter, and an adder that sums the amplified signals. And a D / A converter for converting a digital signal into an analog signal, wherein the dummy pilot repeater includes only a pilot channel for synchronization acquisition and one broadcast channel for data reception. The method of claim 20, And a tag indicating that the broadcast channel is a dummy data signal in order to prevent a malfunction of the terminal.