KR20070061102A - Apparatus and method for deciding transmission route in terminal capable of two-way communication both gap filler and satellite - Google Patents

Abstract

An apparatus and a method for determining a transmission path by a terminal available for bi-directional communication with a gap filler and a satellite are provided to maintain a continuous communication state between a satellite and a terminal in a shadow area by comparing a signal transmitted from a satellite and that transmitted from a gap filler and selecting an optimum signal. A reception processing unit(305) measures the first SNR(Signal-to-Noise Ratio) of a signal directly received from a satellite. A reception processing unit(307) measures the second SNR of a signal received through a gap filler from the satellite. An SNR comparing unit(308) compares the first SNR and the second SNR. A transmission path determining unit determines a transmission path according to comparison result of the SNR comparing unit(308).

Description

Apparatus and method for deciding transmission route in terminal capable of two-way communication both gap filler and satellite}

1 is a configuration diagram of an embodiment of a bidirectional satellite system to which the present invention is applied;

2 is an embodiment configuration diagram for a repeater to which the present invention is applied;

3 is a configuration diagram of an apparatus for determining a transmission path in a terminal capable of bidirectional communication between a repeater and a satellite according to the present invention;

4 is a flowchart illustrating a method for determining a transmission path in a terminal capable of bidirectional communication with a repeater and a satellite according to the present invention.

* Explanation of symbols on the main parts of the drawing

301, 302; Duplexer 303; S band converter

304; Ku / Ka band converters 305 and 307; Receiving Processing Unit

306; A transmission processor 308; Signal to noise ratio comparison unit

The present invention relates to an apparatus and method for determining a transmission path in a terminal capable of two-way communication between a repeater and a satellite, and more particularly, a signal-to-noise ratio of a Ku / Ka band signal received from a satellite and an S-band signal received from a repeater. The present invention relates to an apparatus and a method for determining a transmission path in a terminal capable of bidirectional communication with a repeater and a satellite, by comparing a signal-to-noise ratio and determining a transmission path according to a comparison result of the signal-to-noise ratio.

In general, in satellite broadcasting and satellite communication using a stationary satellite, broadcasting and communication are possible only when a line of sight (LOS) with a satellite is guaranteed. That is, in the satellite broadcasting, satellite communication, and the like, data cannot be transmitted or received unless the antenna of the terminal faces the satellite direction.

For this reason, in the satellite broadcasting, satellite communication, etc., there is an area where a reception state is good and a service area is not available due to a feature.

In particular, an area in which the reception condition is poor is referred to as a "gap", and a system that relays a signal to the area to improve reception is referred to as a "gap filler".

In a conventional satellite broadcasting system, a satellite broadcaster uplinks a broadcast signal to a satellite and transmits the broadcast signal in one direction from the satellite.

The conventional satellite broadcasting system uses time division multiplexing (TDM) and cannot use such a repeater. Thus, since the conventional satellite broadcasting system does not have a separate repeater, the LOS of the receiving antenna for satellite broadcasting should always be guaranteed.

In particular, in the recently spotlighted satellite DMB system, the terminal receives a satellite signal directly from the satellite or a satellite signal from the satellite. That is, since the satellite DMB system must guarantee mobility while providing various information to a terminal through a satellite, the terminal is configured to simultaneously receive a satellite signal from a satellite and a repeater signal from a repeater.

As described above, in the conventional satellite broadcasting system, the repeater is limited to a unidirectional method of receiving a TDM signal from a satellite, converting it into a Code Division Multiplexing (CDM) signal, and transmitting the signal to a terminal. have.

In addition, in the conventional satellite broadcasting system, the terminal must distinguish between the satellite signal transmitted from the satellite and the repeater signal transmitted from the repeater for bidirectional satellite communication. That is, the terminal needs to select an optimal signal from the satellite signal and the repeater signal and transmit a signal through a transmission path of the corresponding signal in order to perform two-way satellite communication.

The present invention has been proposed to solve the above problems, and compares the signal-to-noise ratio (SNR) of the Ku-Ka band signal received from the satellite and the S-band signal received from the repeater, and transmits the signal according to the comparison result of the signal-to-noise ratio It is an object of the present invention to provide an apparatus and method for determining a transmission path in a terminal capable of two-way communication between a repeater and a satellite to determine a signal and to transmit a signal.

Other objects and advantages of the present invention can be understood by the following description, and will be more clearly understood by the embodiments of the present invention. Also, it will be readily appreciated that the objects and advantages of the present invention may be realized by the means and combinations thereof indicated in the claims.

According to an aspect of the present invention, there is provided an apparatus for determining a transmission path in a terminal capable of two-way communication between a repeater and a satellite, the apparatus comprising: first reception processing means for measuring a first signal to noise ratio of a signal directly received from the satellite; and; Second reception processing means for measuring a second signal-to-noise ratio of the signal received from the satellite via a repeater; Signal-to-noise ratio comparison means for comparing the first signal-to-noise ratio and the second signal-to-noise ratio; And transmission path determining means for determining a transmission path according to the comparison result of the signal-to-noise ratio comparison means.

The present invention also provides a method for determining a transmission path in a terminal capable of two-way communication between a repeater and a satellite, the method comprising: a first step of measuring a first signal-to-noise ratio of a signal directly received from the satellite; Measuring a second signal-to-noise ratio of the signal received from the satellite via a repeater; A third step of selecting a satellite as a transmission path when the first signal-to-noise ratio is large by comparing the first signal-to-noise ratio with the second signal-to-noise ratio; And comparing the first signal to noise ratio with the second signal to noise ratio, and if the second signal to noise ratio is large, selecting a repeater as a transmission path.

The above objects, features and advantages will become more apparent from the following detailed description taken in conjunction with the accompanying drawings, whereby those skilled in the art may easily implement the technical idea of the present invention. There will be. In addition, in describing the present invention, when it is determined that the detailed description of the known technology related to the present invention may unnecessarily obscure the gist of the present invention, the detailed description thereof will be omitted. Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings.

1 is a diagram illustrating an embodiment of a bidirectional satellite system to which the present invention is applied.

As shown in FIG. 1, the bidirectional satellite system to which the present invention is applied includes a satellite 100, a repeater 200, and a terminal 300.

The satellite 100 transmits the Ku / Ka band signal to the ground and receives the Ku / Ka band signal from the repeater 200 and the terminal 300.

The repeater 200 converts the Ku / Ka band signal received from the satellite 100 into an S-band signal and transmits it to the terminal 300, and receives the S-band signal from the terminal 300, thereby receiving a Ku / Ka band signal. Frequency conversion to transmit to the satellite (100).

The terminal 300 transmits and receives a Ku / Ka band signal from the satellite 100 and an S-band signal from the repeater 200. Here, the terminal 300 includes a mobile communication terminal such as a laptop, a personal digital assistant (PDA), a cellular phone, a PCS phone, a DMB phone, a vehicle terminal, and the like.

2 is a configuration diagram of an embodiment of a repeater 200 to which the present invention is applied.

As shown in FIG. 2, the repeater 200 to which the present invention is applied converts Ka / Ku band signals transmitted from satellites into S band signals or Ka / Ku band signals transmitted from the terminal 300. Frequency conversion to Ku band signal.

Hereinafter, in describing the components of the repeater 200, components that perform the same function will be described together with only the reference numerals.

The repeater 200 includes a duplexer 201 and 208, a low noise amplifier 202 and 209, a down converter 203, a filter 204 and 214, and a variable gain amplifier. variable gain amplifiers 205 and 210, detectors 206 and 211, gain regulators 207 and 212, up converter 213, high power amplifier 215, isolator 216 It includes.

The duplexers 201 and 208 are known antenna common apparatuses, which separate transmission and reception frequencies to prevent crosstalk of signals. That is, the duplexer 201 applies the Ku / Ka band signal received from the satellite 100 to the low noise amplifier 202 and transmits the Ku / Ka band signal applied from the isolation 216 to the satellite 100. . In addition, the duplexer 208 applies the S-band signal received from the terminal 300 to the low noise amplifier 209 and transmits the S-band signal applied from the variable gain amplifier 205 to the terminal 300.

In addition, the duplexers 201 and 208 also perform a function of selecting only a desired frequency band of signals of various channels received from an antenna.

The low noise amplifiers 202 and 209 eliminate noise included in the signals applied by the duplexers 201 and 208 as much as possible, and amplify only the desired signal.

The downlink frequency converter 203 downconverts the frequency of the Ku / Ka band low noise amplified signal applied from the low noise amplifier 202 to an S band intermediate frequency (IF).

In contrast, the up-frequency converter 213 up-converts the frequency (ie, intermediate frequency) of the S-band low noise amplified signal applied from the variable gain amplifier 210 to the Ku / Ka band frequency.

The filters 204 and 214 bandpass filter only the desired channel from among the channels included in the frequency conversion of the signal through the downlink converter 203 or the uplink converter 213.

The variable gain amplifiers 205 and 210 do not sufficiently amplify the desired signals by the low noise amplifiers 202 and 209 and thus amplify the signals after filtering by the filters 204 and 214.

In this case, the gain of the amplifier is finely adjusted through the detectors 206 and 211 and the gain regulators 207 and 212.

The high power amplifier 215 amplifies the power so that the signal of the channel selected by the filter 214 has sufficient power to transmit to the satellite 100.

The isolator 216 transmits the signal applied from the high power amplifier 215 to the satellite 100 and blocks the signal received from the satellite 100. Thus, the isolator 216 blocks the signal received from the satellite 100, thereby preventing the effect of the received signal on the high power amplifier 215.

Additionally, between the filter 204 and the variable gain amplifier 205, an optical to electric converter (O / E) and an electric to optic converter capable of long-distance transmission while minimizing signal loss. ; E / O). In addition, between the variable gain amplifier 210 and the uplink frequency converter 213 as an optical / electric converter (O / E) and an electrical / optical converter (E / O) capable of long-distance transmission while minimizing signal loss. Can connect

3 is a diagram illustrating an embodiment of an apparatus for determining a transmission path in a terminal 300 capable of bidirectional communication between a repeater 200 and a satellite according to the present invention.

As shown in FIG. 3, the apparatus for determining a transmission path in the terminal 300 according to the present invention selects a satellite signal from the satellite 100 and a repeater signal from the repeater 20 to receive and process a signal. The transmission path is determined according to the selection, and the signal is transmitted.

The apparatus includes duplexers 301 and 302, S band converter 303, Ku / Ka band converter 304, reception processing units 305 and 307, transmission processing unit 306, and signal to noise ratio comparison unit 308. .

3, components that perform the same function as in FIG. 2 will be described together with only reference numerals.

As mentioned above, the duplexers 301 and 302 separate the transmit / receive frequencies to prevent crosstalk of the signals. In this case, the duplexer 301 is connected to the Ku / Ka band antenna, and is connected to the S band converter 303 and the Ku / Ka band converter 304. In addition, the duplexer 302 is connected to the S band antenna, and is connected to the RF switch and the receiving processor 305.

The S band converter 303 converts the Ku / Ka band signal applied from the duplexer 301 into an S band signal. In this case, the S-band converter 303 applies the S-band signal to the reception processor 307.

The Ku / Ka band converter 304 converts the S-band signal applied through the transmission processor 306 and the RF switch into a Ku / Ka band signal for transmitting to the satellite 100. In this case, the Ku / Ka band converter 304 applies a Ku / Ka band signal to the duplexer 301.

When the S-band signal is applied from the duplexer 302, the reception processor 305 measures a signal-to-noise ratio (SNR) of the S-band signal. In this case, the reception processor 305 transmits the measured SNR to the signal to noise ratio comparison unit 308.

In addition, the reception processor 305 maintains a state in which the duplexer 302 can always receive the S-band signal.

Meanwhile, when the S band signal is applied from the S band converter 303, the reception processor 307 measures the SNR of the S band signal. In this case, the reception processor 307 transmits the measured SNR to the signal to noise ratio comparison unit 308.

In addition, the reception processing unit 307 maintains a state in which the S band converter 303 can always receive the S band signal.

In addition, it is preferable that the reception processing units 305 and 307 measure the SNR at regular intervals. As a result, the apparatus may determine an optimal signal among signals received from the satellite 100 and signals received from the satellite 100 through a repeater.

The signal-to-noise ratio comparison unit 308 compares and distinguishes the SNRs received from the reception processing units 305 and 307. That is, the signal-to-noise ratio comparison unit 308 compares and distinguishes between the SNR of the signal directly received from the satellite 100 and the SNR of the signal received from the repeater 200.

On the other hand, the signal-to-noise ratio comparison unit 308 compares the SNR of the two signals to select and output a signal with a high SNR. In this case, although the signal-to-noise ratio comparison unit 308 is not shown in FIG. 3, the signal-to-noise ratio comparison unit 308 is provided as a module (hereinafter, referred to as a “control module”) for processing a selected signal, and thus a detailed description thereof will be omitted.

The transmission processor 306 transmits a signal to be transmitted according to the transmission path selected by the RF switch.

In this case, the RF switch is controlled to determine a path having a high SNR as a transmission path according to the result of comparing the SNR in the signal-to-noise ratio comparison unit 308. That is, if the SNR of the signal received from the satellite 100 is greater than the SNR of the signal received from the repeater 200, the RF switch transmits the transmission processor 306 and the Ku / Ka band converter 304 by the RF switch control signal. Connect the transmission path between them. In addition, if the SNR of the signal received from the satellite 100 is smaller than the SNR of the signal received from the repeater 200, the RF switch transmits a transmission path between the transmission processor 306 and the duplexer 302 by an RF switch control signal. Connect it.

 For example, a case in which the terminal 300 performs bidirectional communication through the repeater 200 in an area where LOS with the satellite 100 is not guaranteed is described.

First, the signal-to-noise ratio comparison unit 308 determines that the SNR of the repeater signal measured by the reception processing unit 305 is higher than the SNR of the satellite signal measured by the reception processing unit 307. For this reason, the signal to noise ratio comparison unit 308 selects the repeater signal received through the reception processing unit 305 and outputs it to the control module.

Thereafter, the RF switch is controlled to allow bidirectional communication through the repeater 200 which is a high SNR path selected by the signal-to-noise ratio comparison unit 308. That is, the RF switch connects the transmission processor 306 and the duplexer 302.

4 is a flowchart illustrating a method for determining a transmission path in a terminal 300 capable of two-way communication between a repeater 200 and a satellite according to the present invention.

As shown in FIG. 4, the apparatus for determining a transmission path in the terminal 300 according to the present invention waits for receiving a Ku / Ka band signal from a satellite and waits for receiving an S band signal from a repeater (S400).

Thereafter, the device receives the Ku / Ka band signal from the satellite 100 through the Ku / Ka band antenna, and receives the S-band signal from the repeater 200 through the S-band antenna (S401). That is, the device processes the signal by receiving the Ku / Ka band signal and the S band signal through corresponding independent reception paths.

First, the apparatus converts a Ku / Ka band signal received through a Ku / Ka band antenna into an S band signal (S402), and measures an SNR of the S band signal (hereinafter, referred to as a “first SNR”). (S403).

Meanwhile, the apparatus measures SNR (hereinafter referred to as "second SNR") of the S band signal received through the S band antenna (S404).

Thereafter, the apparatus compares the magnitudes of the first SNR and the second SNR (S405).

If the first SNR is large as a result of the comparison, the apparatus converts the S band signal to be transmitted into a Ku / Ka band signal (S406). In addition, the device transmits the converted Ku / Ka band signal to the satellite 100 via the Ku / Ka band antenna (S407).

On the other hand, if the second SNR is large as a result of the comparison, the apparatus transmits the S band signal to be transmitted to the repeater 200 through the S band antenna (S408).

As described above, the method of the present invention may be implemented as a program and stored in a recording medium (CD-ROM, RAM, ROM, floppy disk, hard disk, magneto-optical disk, etc.) in a computer-readable form. Since this process can be easily implemented by those skilled in the art will not be described in more detail.

The present invention described above is capable of various substitutions, modifications, and changes without departing from the technical spirit of the present invention for those skilled in the art to which the present invention pertains. It is not limited by the drawings.

The present invention as described above has the effect that the two-way satellite communication between the terminal and the satellite in the shadow area.

In addition, the present invention by comparing the signal transmitted from the satellite and the signal transmitted from the repeater to select the optimum signal, there is an effect of maintaining a continuous communication state between the satellite and the terminal in the shadow area.

Claims (4)

An apparatus for determining a transmission path in a terminal capable of bidirectional communication between a repeater and a satellite, First reception processing means for measuring a first signal-to-noise ratio of a signal received directly from the satellite; Second reception processing means for measuring a second signal-to-noise ratio of the signal received from the satellite via a repeater; Signal-to-noise ratio comparison means for comparing the first signal-to-noise ratio and the second signal-to-noise ratio; And Transmission path determining means for determining a transmission path according to the comparison result of the signal to noise ratio comparison means Device for determining the transmission path in the terminal capable of two-way communication between the repeater and the satellite comprising a. According to claim 1, And an RF switch for switching the transmission path according to the control signal determined by the transmission path determining means. According to claim 1, And the first receiving processing means and the second receiving processing means measure a signal-to-noise ratio at regular intervals. A method for determining a transmission path in a terminal capable of bidirectional communication between a repeater and a satellite, A first step of measuring a first signal to noise ratio of a signal received directly from the satellite; Measuring a second signal-to-noise ratio of the signal received from the satellite via a repeater; A third step of selecting a satellite as a transmission path when the first signal-to-noise ratio is large by comparing the first signal-to-noise ratio with the second signal-to-noise ratio; And A fourth step of selecting a repeater for a transmission path when the second signal to noise ratio is large by comparing the first signal to noise ratio with the second signal to noise ratio; Method for determining a transmission path in a terminal capable of two-way communication between the repeater and the satellite comprising a.

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