KR19990078457A - Position Control Device and Method of Satellite Antenna - Google Patents

Abstract

An apparatus and method for controlling position of a digital satellite antenna according to the present invention include a tuner for selectively receiving a signal of a specific satellite, a modulator for modulating a signal of a satellite selected by the tuner into a digital signal, and a modulator by the modulator. An error corrector for correcting a positional error of a satellite antenna through a signal of a satellite, a microprocessor for inputting a modulated signal and a signal for error correction, and driving the antenna according to the instructions of the microprocessor It includes an antenna driver to determine the identity of the satellite to be searched using the transponder information and channel information of the satellite input to the microprocessor, and by recognizing the satellite position information by the pulse generated from the antenna driver The location information of can be initialized correctly, and subsequent satellite broadcasting can be easily viewed.

Description

Position Control Device and Method of Satellite Antenna

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a set top box of digital satellite broadcasting. More particularly, the present invention relates to a position control device and a control method of a digital satellite antenna that automatically detects a satellite position when a satellite broadcasting viewer selects a satellite channel. .

The antenna must be in the best position and orientation with respect to the source of the signal for optimal signal reception.

Therefore, in order to watch various satellite broadcasts in the area where the satellite antenna is located with one satellite antenna, the direction of the satellite antenna must be changed in the direction of the satellite transmitting each satellite broadcast.

That is, when the user changes the channel to watch satellite B while watching satellite A, the satellite antenna must change the direction of the satellite transmitting satellite B. To do this, the satellite antenna needs to know the position of the satellite accurately.

In the conventional analog satellite antenna, the user must manually input the satellite position information at the time of initial use. That is, the user initializes the position control information of the satellite antenna by inputting the position information of the satellite when the screen of the satellite broadcast is optimal when the desired satellite broadcast appears on the screen. In this case, the user first initializes the position information of one satellite (reference satellite) and then initializes the position information of another satellite based on the position information of the reference satellite. Therefore, when watching satellite broadcasting after the initialization process, if the user inputs only a channel, the satellite antenna moves in the direction of the satellite of the channel selected by the user.

However, the conventional analog satellite antenna has a inconvenience that the user must initialize the position control information of the satellite antenna while watching the TV screen.

On the other hand, since the digital satellite antenna is not decoded in real time, the screen and sound cannot be viewed in real time. For this reason, it is difficult for a user to search the position of a satellite while watching a TV screen as compared to the case of an analog satellite antenna.

The present invention is to solve this problem, it is to automatically search the position information of the satellite in the digital satellite antenna, and to facilitate the satellite search of the satellite antenna even after the initial search.

1 shows a satellite antenna position control apparatus according to the present invention,

2 shows a circuit configuration of a satellite antenna drive motor,

3 is a flowchart of a satellite antenna position control method according to the present invention,

4 is a diagram illustrating a satellite detection method of a satellite antenna.

In order to achieve the above object, a position control apparatus for a digital satellite antenna according to the present invention includes a tuner for selecting a signal of a specific satellite, a modulator for modulating a signal of the satellite selected by the tuner into a digital signal, and An error corrector for correcting a positional error of a satellite antenna through a signal of a satellite modulated by a modulator, a microprocessor to which a modulated signal is input and a signal of an error corrector is input, And an antenna driver for driving an antenna according to an instruction, wherein the modulator includes an analog converter, a demodulator connected to the analog converter, and the antenna driver comprises a logic circuit for transmitting a signal of a microprocessor and an antenna. A motor driver for driving and a power supply for supplying power to the motor driver described above. The.

In addition, the position control method of the digital satellite antenna according to the present invention,

Setting a threshold reference value of the antenna direction angle, detecting a satellite by measuring a magnitude of a signal received by the antenna while changing the direction angle of the antenna from the threshold reference value of the direction angle, and recognition information of the target satellite; To determine the direction of the satellite antenna by error correction, to compare the detection satellite and the target satellite with the identification information, and to compare the satellite antenna if the detected satellite does not match the target satellite. Rotating and storing the detected satellite position and recognition information when the detected satellite matches the target satellite.

Detecting the satellite by measuring the magnitude of the signal received by the antenna,

It is characterized by detecting the satellite by measuring the magnitude of the AGC level or the noise (noise),

The step of setting the direction of the satellite antenna by the error correction, characterized in that the error correction by FEC demodulation,

Error correction by the FEC demodulation described above,

Comparing the detected satellite's FEC error rate with the target satellite's FEC error rate, changing the FEC rate if there is an error as a result of the comparison, comparing the same FEC rate, and comparing the FEC rate, Otherwise, changing the FEC rate; and if there is an error and the FEC rate does not match, moving the direction of the antenna.

The detecting of the phase by the AGC level or the magnitude of the noise may include receiving a signal from a satellite during rotation, and determining whether the AGC level of the signal received from the satellite is maximum or minimum of noise. And stopping the direction of the antenna when the AGC level is the maximum or the noise is the minimum.

The storing of the position of the detected satellite is characterized in that it is stored as the number of pulses sent from the antenna driver until it moves from the threshold reference value of the direction angle to the detection satellite.

Hereinafter, an apparatus and method for controlling a position of a digital satellite antenna according to the present invention will be described in detail with reference to the accompanying drawings.

1 illustrates a position control apparatus of a digital satellite antenna according to the present invention.

As shown in Figure 1, the position control device of the digital satellite antenna according to the present invention,

A tuner 1 for receiving a signal of a desired channel among the signals of a plurality of channels, an A / D converter 2 for converting an analog signal received by the tuner into a digital signal, and the A / D converter 2 described above. Quadrature Phase Shift Keying (QPSK) demodulator (3) for demodulating the signal of the signal, Forward Error Correction (FEC) demodulator (4) for receiving the signal demodulated by the QPSK demodulator (3) and performing error correction, and the FEC demodulator signal. A demux (DEMULTIPLEXER) 6 for demultiplexing the signal, a microprocessor (5) receiving an input signal of the demultiplexer and a signal of a QPSK demodulator, an antenna driver (20) for driving an antenna according to a command of the microprocessor, And an MPEG decoder 11 for decoding the signal of the demultiplexer and converting the signal into a video signal.

The antenna driver 20 receives a control logic 7 which receives a signal of a microprocessor, a motor driver 8 which receives a signal of the control logic and drives a positioner 10 of the antenna, and supplies power to the motor driver. It consists of the power supply 9 which supplies.

2 shows the antenna driver 20 of FIG. 1 in detail.

The antenna driver 20 includes a power supply 9 for supplying power to the P-type MOSFETs P1 and P2, the N-type MOSFETs N1 and N2, each of the MOSFETs N1, N2, P1 and P2, and the buffer B1. And B2 and B3 and the gate drivers D1 and D2. A gate of each MOSFET is connected to a microprocessor 5 for applying a logic signal, and an antenna positioner 10 is connected between the common drain stages of MOSFETs P1 and N1 and MOSFETs P2 and N2.

The first signal from the first input terminal DIR1 of the microprocessor is input to a terminal jointly connected to the gates of the N-type MOSFET N1 and the P-type MOSFET P1 via the buffer B1 and the gate driver D1. do. The second signal from the second input terminal DIR2 of the microprocessor is input to a terminal jointly connected to the gates of the N-type MOSFET N2 and the P-type MOSFET P2 via the buffer B2 and the gate driver D2. do. The power supply 9 supplies power to a terminal to which the sources of the P-type MOSFETs P1 and P2 are jointly connected and a terminal to which the sources of the N-type MOSFETs N1 and N2 are jointly connected. The antenna positioner 10 is connected between the terminals (X, Y) jointly connected to the drains of the N-type MOSFETs (N1, N2) and the P-type MOSFET (P1.P2).

The operation of the MOSFET according to the input values of the first and second input terminals DIR1 and DIR2 of the microprocessor is shown in the following table.

DIR1 DIR2 P1 N1 P2 N2 LOW LOW ON OFF ON OFF LOW HIGH ON OFF OFF ON HIGH LOW OFF ON ON OFF HIGH HIGH OFF ON OFF ON

As shown in Table 1, when a low value is input to both the first input terminal DIR1 and the second input terminal DIR2 of the microprocessor, the MOSFETs P1 and P2 are turned on and the MOSFETs N1 and N2 are turned off. In this case, no potential difference occurs between the terminal X and the terminal Y, so that the antenna positioner is not driven.

In addition, when a high value is input to both the first input terminal DIR1 and the second input terminal DIR2 of the microprocessor, the MOSFETs N1 and N2 are turned on and the MOSFETs P1 and P2 are turned off. In this case as well, no potential difference occurs between the terminal X and the terminal Y, so that the antenna positioner is not driven.

When low and high values are input to the first input terminal DIR1 and the second input terminal DIR2 of the microprocessor, respectively, the MOSFETs P1 and N2 are turned on and the MOSFETs N1 and P2 are turned off. In this case, the potential of the terminal X becomes higher than the potential of the terminal Y, thereby causing a current to flow from the terminal X to the terminal Y direction.

On the other hand, when the high and low values are respectively input to the first input terminal DIR1 and the second input terminal DIR2 of the microprocessor, the MOSFETs N1 and P2 are turned on and the MOSFETs N2 and P1 are turned off. In this case, the potential of the terminal Y becomes higher than the potential of the terminal X, thereby causing a current to flow from the terminal Y to the terminal X direction.

When high, low, low and high are respectively input to the first input terminal DIR1 and the second input terminal DIR2 of the microprocessor, a potential difference in a different direction occurs between the terminal X and the terminal Y, and thus the terminal X and the terminal Y Since the direction of the current flowing in is changed, the rotation direction of the antenna positioner is changed.

Meanwhile, the MOSFET of the antenna driver may be implemented as another switching element such as a relay.

Satellites, which are usually used for satellite broadcasting, are geostationary satellites that rotate at the same angular velocity over the equator. For this reason, the satellite antenna does not need to move up and down, but needs to move from side to side. Therefore, the antenna driver of the present invention moves to the left and right of the antenna by the operation of the antenna positioner described above.

As described above, when the antenna positioner rotates, the positioner generates a pulse of a certain period. At this time, the microprocessor checks the rotation speed of the motor in the antenna positioner by the number of pulses, and through this, obtains the moving direction angle of the antenna. The pulse generated at the antenna positioner is sent to the microprocessor through the buffer B3.

The operation of the position control device of the digital satellite antenna according to the present invention will be described with reference to FIG.

First, as shown in FIG. 4, the limit values of the direction angles are set to the left and right of the satellite antenna. (S20, S20) The limit values of both directions are set regardless of whether the east or the west is preferred.

Then, the antenna moves from the limit direction angle in one direction (left or right) to another direction (S30). At this time, the direction movement of the antenna is driven by the antenna driver 20.

When the antenna changes direction, pulses are generated at a constant period from the motor in the positioner of the antenna driving unit as described above, so that the antenna is separated from the limit of the direction angle by a certain number of direction angles by counting the number of pulses of this constant period. (S40)

On the other hand, as the antenna moves, the microprocessor 5 checks the AGC (Automatic Gain Control) level or the noise level of the tuner 1. (S50) When the AGC level reaches the peak value or the noise level reaches the minimum value, Since it means that one satellite is found, the antenna is stopped to stop the antenna. If the AGC level is not the maximum or the noise level is not the minimum, the antenna is continuously moved and the above operation is repeated.

After finding one satellite whose AGC level is the maximum or the noise level is the minimum, the identification information of the target satellite is identified (S60). The satellite recognition information is based on the transponder information and the channel information. The satellite recognition information of the satellites in the area where the satellite antenna is located is already pre-programmed into the microprocessor or the recognition information of the satellite to be searched by the user is entered.

Next, if the AGC level reaches the maximum value or the noise reaches the minimum value, the QPSK demodulator demodulates the signal received by the antenna (S70).

The signal demodulated by the QPSK demodulator is used for fine adjustment of the antenna direction by the FEC (Forward Error Correction) demodulator.

After confirming the maximum AGC level and fine-tuning it again with the FEC demodulator, even if the AGC level reaches the maximum or the noise reaches the minimum, the signal may be undesired by the user. For adjustment.

Fine tuning of the antenna direction is by means of the FEC demodulator 4. That is, the direction of the antenna is finely adjusted until the error rate sent from the FEC demodulator reaches a minimum.

Next, fine adjustment of the antenna direction by the FEC demodulator 4 will be described in detail.

Each satellite has its own FEC rate. The FEC demodulator 4 compares the detected satellite's error rate with the target satellite's error rate (S80). If there is an error as a result of the comparison, the FEC demodulator 4 changes (S120) by comparing whether the FEC rates match. (S130) If it does not match, continue to change the FEC rate. The presence or absence of an error rate is determined by the changed FEC rate. If the error does not go away and the FEC rates do not match, then the process returns to the beginning of the satellite detection process.

If there is no error rate determination result (S80), the direction of the detected satellite is exactly found.

After finding the direction of the detection satellite, the demultiplexer decodes the recognition information of the detection satellite (S90). The recognition information of the satellite uses transponder information and channel information.

Recognition information unique to satellites is input to a memory of a microprocessor which is a component of a digital satellite antenna position control apparatus according to the present invention. Therefore, the microprocessor determines the authenticity of the satellite to be searched based on the unique recognition information of the satellites in the satellite antenna installation area.

In other words. The microprocessor compares the transponder information and channel information of the detection satellite decoded by the demultiplexer 6 with the transponder information and channel information of the destination satellite stored in the microprocessor. (S100) Transceiver information of the detection satellite and the destination satellite. If the channel information matches, the destination satellite to be found is found. If the transponder information and the channel information of the detection satellite and the target satellite do not match, the satellite antenna resumes movement and repeats the operation of the antenna driving and the satellite recognition information until the target satellite is found. By the above operation, the target satellite can be found until the satellite antenna reaches the limit of the direction angle.

After finding the target satellite, in order to facilitate the future viewing of satellite broadcasting, the detected satellite information and the satellite position information are stored in the memory. (S110) The satellite recognition information is a satellite transponder. ) And the position information of the satellite is stored as the number of pulses from the reference point of the direction angle (generally using the threshold value of the direction angle as the reference point).

If the above satellite detection operation is repeatedly performed, the location information of the satellites in the area where the satellite antenna is installed is input to the microprocessor.

Since location information of the satellites is input to the microprocessor, the satellite broadcaster only needs to input the channel of the satellite broadcast when he / she wants to watch the satellite broadcast later. The satellite antenna moves in the direction of the satellite corresponding to the input channel using the location information of the satellite stored in the microprocessor.

Therefore, when the digital satellite antenna is initially used, the satellite position information is stored in the digital satellite antenna without the user having to designate the position of the satellite while watching a TV screen. The antenna automatically moves in the desired satellite direction.

The apparatus and method for controlling a position of a digital satellite antenna according to the present invention facilitates initial recognition of position information of satellites of a satellite antenna and enables accurate satellite search of a satellite antenna.

Claims (16)

Setting a threshold reference value of the antenna direction angle; Detecting a satellite by measuring a magnitude of a signal received by the antenna while changing the direction angle of the antenna from the threshold reference value of the direction angle; Identifying recognition information of the target satellite; Setting a direction of the satellite antenna by error correction; Comparing the detection satellite and the destination satellite with the recognition information; Rotating a satellite antenna when the detected satellite and the target satellite do not match; And storing the position and recognition information of the detected satellite when the detected satellite matches the target satellite according to the comparison result. In claim 1, Detecting the satellite by measuring the magnitude of the signal received by the antenna, And detecting a satellite by measuring an AGC level or a noise level. In claim 2, Detecting satellites by measuring AGC levels or noise levels, Receiving a signal from a satellite during rotation of the antenna; Determining whether the AGC level of the signal received from the satellite is maximum or whether the noise level is minimum; Moving the direction of the antenna if the AGC level is not the maximum or the noise level is the minimum; Stopping the direction of the antenna if the AGC level is maximum or the noise level is minimum. In claim 1, Recognition information of the destination satellite and the detection satellite, A digital satellite antenna position control method using transponder information and channel information of a satellite. In claim 1, The step of setting the direction of the satellite antenna by the error correction, Error correction by the FEC demodulator position control method characterized in that the digital satellite antenna. In claim 5, Error correction by the FEC demodulator described above, Comparing the error rate of the detected satellite with the error rate of the target satellite; Changing the FEC rate if there is an error as a result of the comparison; Comparing the FEC rates to match; Changing the FEC rate if the FEC rates do not match; And moving the direction of the antenna if there is an error and the FEC rates do not match. In claim 1, Remembering the position of the detected satellite, A method of controlling the position of a digital satellite antenna, characterized in that the number of pulses sent from the antenna driver is stored in the microprocessor until it moves from the limit reference value of the direction angle to the detection satellite. In claim 1, The method of claim 1, further comprising detecting satellites by repeating the above steps. In claim 8, Determining position information of a satellite inputted to the microprocessor when a channel of satellite broadcasting is input; And searching for a destination satellite according to the input position information. A tuner that selectively receives signals of a specific satellite, A modulator for modulating a satellite signal selected by the tuner into a digital signal; An error corrector for correcting a positional error of the satellite antenna through a signal of the satellite modulated by the modulator; A microprocessor to which a modulated signal is input and a signal of error correction is input; And an antenna driver for driving the antenna according to the instructions of the microprocessor. In claim 10, The modulator, With analog to digital converter, Digital satellite antenna position control device comprising a demodulator connected to the analog-to-digital converter. In claim 10, The antenna drive unit, Digital satellite antenna positioning device characterized in that for generating a pulse of a certain period in the antenna positioner while driving the antenna. In claim 10, The antenna drive unit, A control logic that transmits a signal from a microprocessor, A motor driver for driving the antenna, Digital satellite antenna position control device including a power supply for supplying power to the motor driver. In claim 13, The control logic described above, A first buffer to which the first input signal of the microprocessor is input; A first gate driver connected to the first buffer to transfer a first input signal to a common terminal of a first switching element and a second switching element; A first switching device to which the signal of the first gate driver is input; A second switching element to which the signal of the first gate driver is input; A second buffer to which the second input signal of the microprocessor is input; A second gate driver connected to the second buffer to transfer a second input signal to a common terminal of a third switching device and a fourth switching device; A third switching device to which the signal of the second gate driver is input; And a fourth switching device to which the signal of the second gate driver is input. The method of claim 14, The first switching device is an N MOS transistor, The second switching element is a P MOS transistor, The third switching device is an N MOS transistor, And said fourth switching element is a P MOS transistor. The method of claim 13 or 14, The power supply is a digital satellite antenna position control device characterized in that to supply power to both ends of the common terminal of the second switching device and the fourth switching device and the common terminal of the first switching device and the third switching device.