KR100282586B1 - Virtual AFC Range Expansion Device and Control Method in Satellite Broadcasting Receiver - Google Patents

Abstract

The present invention relates to a virtual AF range expansion device and a control method thereof in a satellite broadcasting receiver, and in particular, a tuner unit 100 for receiving a satellite signal transmitted through an unspecified satellite through an antenna; QPSK demodulator 200 for demodulating the input satellite signal to output the original signal; An FEC unit 300 which automatically corrects an error of the original signal by the set FEC code, and transmits the error-corrected original signal to the MPEG decoding unit; If the frequency of the satellite signal transmitted via satellite is subtracted from the frequency generated by the LNB, the frequency is set in the tuner unit 100. If the satellite signal is not received due to an error in the frequency generator of the LNB mounted on the antenna, the virtual signal is virtual. By setting the frequency to the tuner unit 100 using an algorithm that extends the AFC range, and set the symbol rate and spectrum mode to the QPSK demodulator 200 to match the transmission rate of the satellite signal received through the tuner unit 100. And a CPU 400 that sets the FEC code to the FEC unit 300. The present invention is a satellite signal receiver due to an error in the frequency generator of the LNB mounted to the receiver antenna. If it is not received by the CPU, the CPU virtually sets an extended frequency that extends the AFC range to the tuner, indicating that satellite signals cannot be received due to errors. There is an effect that was not.

Description

Virtual AF range expansion device in satellite broadcasting receiver and its control method

The present invention relates to a satellite broadcasting receiver, and in particular, when a satellite signal cannot be received by a satellite broadcasting receiver due to a frequency generator error of a low noise block (LNB) mounted on a receiver antenna. LNB frequency generator by extending the AFC range by setting the center frequency to the tuner to virtually expand the range of automatic frequency control (AFC). The present invention relates to a virtual AF range expansion device and a method for controlling the same in a satellite broadcasting receiver that can prevent satellite signals from being received due to an error.

As is well known, the world is becoming a common area, and each country has launched various satellites in space to see the situation of each country at a glance.

In order to meet the globalization trend in Korea, various satellite broadcasting receivers are used in order to meet the global trend. When the channel is changed by the subscribers who listen to the satellite broadcasting, the satellite broadcasting receiver is installed inside the satellite broadcasting receiver. The installed satellite data receiver receives the changed channel through the satellite antenna.

In the conventional satellite broadcasting receiver, when the error in generating frequency of the LNB mounted on the receiver antenna is more than ± 1 MHz, and the AFC range of the satellite receiver is smaller than ± 1 MHz, the satellite receiver generates the frequency of the LNB mounted on the antenna. Satellite signal cannot be received due to the generator error. Therefore, if only the AFC range is actually extended to solve the above problem, the satellite is generated by outputting a false lock due to the expansion of the AFC range. There was a problem that the signal is broken.

The present invention is to solve the above conventional problems, when the satellite signal is not received by the satellite broadcasting receiver due to the error in the frequency generator of the LNB mounted on the receiver antenna, the CPU virtually extends the AFC range The present invention provides a virtual AF range expansion device and a control method of the satellite broadcasting receiver in which a satellite signal can be prevented from being received due to an error by setting an extension frequency in a tuner unit.

In order to achieve the above object, the virtual AF range expansion apparatus of the present invention for a satellite broadcasting receiver receives a satellite signal transmitted through an unspecified satellite through an antenna and passes only a signal of a frequency band to be used in the satellite broadcasting receiver. A tuner unit for inputting and outputting the input satellite signal; A quadrature phase modulation (QPSK) demodulation unit connected to the signal output terminal of the tuner unit and demodulating the satellite signal inputted through the tuner unit to output an original signal; Connected to the signal output terminal of the QPSK demodulator, automatically corrects an error of the original signal output from the QPSK demodulator by the set FEC code, and decodes the original signal of which the error is corrected to MPEG (Moving Picture coding image Experts Group) An FEC unit which transmits to a (Decoding) unit; A frequency generation device of the LNB connected to the tuner unit, the QPSK demodulation unit, and the FEC unit, and setting a frequency AFC range equal to the frequency of the satellite signal transmitted through the satellite unit to the tuner unit, and mounted on the antenna. If the satellite signal is not received due to an error, a symbol frequency and spectrum mode are set to adjust the transmission frequency of the satellite signal received through the tuner by setting an extended frequency that virtually extends the AFC range. And a CPU for setting (Spectrum Mode) to the QPSK demodulation unit and setting a FEC code to the FEC unit.

In addition, the control method of the virtual AFC range expansion apparatus in the satellite broadcasting receiver of the present invention, the AFC range of the frequency to be received through the antenna to the tuner unit, the symbol rate and spectrum mode for matching the transmission rate of the received satellite signal A setting step (S1) of setting the QPSK demodulation unit and the FEC code to the FEC unit; A first normal determination step (S2) of determining whether the received satellite signal operates normally in the demodulator and the FEC unit after the setting step (S1); After the first normal determination step (S2), if the received satellite signal does not operate normally in the demodulator and the FEC unit, the center frequency is 0.5 in order to double the AFC range of the frequency set in the tuner unit by -0.5M. A first expansion step S3 for moving in the negative (-) direction; A second normal determination step (S4) of determining whether the received satellite signal operates normally in the demodulator and the FEC unit after the first expansion step (S3); After the second normal determination step (S4), if the received satellite signal does not operate normally in the demodulator and the FEC unit, the center frequency is 0.5M to extend the AFC range of 0.5M set by the tuner unit. A second expansion step S5 for moving in the positive (+) direction by the expansion; A third normal determination step (S6) of determining whether the received satellite signal is operating normally in the demodulator and the FEC unit after the second expansion step (S5); After the third normal determination step (S6), if the received satellite signal does not operate normally in the demodulator and the FEC unit, the AFC range of the frequency set in the tuner unit is extended to -1M, and the center frequency is 1M. A third expansion step S7 for moving in the negative (-) direction; A fourth normal determination step (S8) of determining whether the received satellite signal is operating normally in the demodulator and the FEC unit after the third expansion step (S7); After the fourth normal determination step (S8), if the received satellite signal does not operate normally in the demodulator and the FEC unit, the center frequency is + 1M plus to quadruple the AFC range of the frequency set in the tuner unit four times. A fourth expansion step S9 for moving in the positive direction; After the fourth expansion step S9, it is determined whether the received satellite signal operates normally in the demodulator and the FEC unit, and if the received satellite signal does not operate normally in the demodulator and the FEC unit, -1.5M, Verify that both the demodulator and the FEC unit operate normally by increasing or decreasing the center frequency in the negative (-) / plus (+) direction in increments of + 1.5M, -2M, + 2M, -2.5M, and + 2.5M in 0.5M increments. And a fifth normal determination step (S10) of displaying the state of the satellite signal by determining that the satellite signal is absent or weak even when the demodulator and the FEC unit do not operate normally even when the center frequency is moved to the maximum; The received satellite after the first normal decision step S2, the second normal decision step S4, the third normal decision step S6, the fourth normal decision step S8, and the fifth normal decision step S10. When the signal performs the normal operation in the demodulator and the FEC unit, using the center frequency set in the tuner unit as an offset value, the frequency offset step of applying the offset value to the center frequency when receiving another satellite signal (S11). Characterized in that comprises a.

1 is a functional block diagram showing the configuration of a virtual AF range expansion apparatus in a satellite broadcasting receiver according to an embodiment of the present invention;

FIG. 2 is a control flowchart illustrating a control method of an apparatus for expanding a virtual AF range in a satellite broadcasting receiver according to FIG. 1.

FIG. 3 shows that the AFC range of the frequency set in the tuner of FIG. 1 is extended by -0.5M, and when the center frequency is shifted by -0.5M and set in the tuner, the 0.5M AFC range is extended in the negative direction. Graph shown,

FIG. 4 illustrates that the AFC range of the frequency set in the tuner of FIG. 1 is expanded by + 0.5M, and when the center frequency is shifted by + 0.5M and set in the tuner, the 0.5M AFC range is extended in the (+) direction. Graph shown,

FIG. 5 shows that in order to extend the AFC range of the frequency set in the tuner unit of FIG. 1 to -0.5M × 2, when the center frequency is shifted by -1M and set in the tuner unit, the 1M AFC range is extended in the negative direction. Graph shown,

FIG. 6 is a graph illustrating an extension of the 1M AFC range in the (+) direction when the center frequency is moved to + 1M and the tuner is set to the tuner unit to extend the AFC range of the frequency set to the tuner unit of FIG. 1 to 1M.

<Description of the code | symbol about the principal part of drawing>

100: tuner portion 200: QPSK demodulation portion

300: FEC unit 400: CPU

Hereinafter, the above-described contents will be described in detail through an embodiment according to the present invention.

As shown in FIG. 1, the tuner unit 100 receives a satellite signal transmitted through an unspecified satellite, passes only a signal of a frequency band to be used in a satellite broadcasting receiver, and inputs the input satellite signal. The QPSK demodulator 200 outputs the original signal to the FEC unit 300 by demodulating the satellite signal inputted through the tuner unit 100 and outputs the original signal to the FEC unit 300. Automatically corrects an error of the original signal output from the QPSK demodulator 200 according to the set FEC code, transmits the original signal with the error corrected to the MPEG decoding unit, and the CPU 400 transmits the satellite. A frequency AFC range equal to the frequency of the satellite signal to be set in the tuner unit 100, and when the satellite signal is not received due to an error in the frequency generator of the LNB mounted on the antenna, the center of virtually extending the AFC range Remind frequency And a symbol rate and spectrum mode for setting the transmission rate of the satellite signal received through the tuner unit 100 to the QPSK demodulator 200, and sets an FEC code to the FEC unit 300. The present embodiment is configured by setting the

Hereinafter, an operation process of the virtual AF range expansion apparatus in the satellite broadcasting receiver configured as described above will be described with reference to FIGS. 1, 2, 3, 4, 5, and 6.

First, the CPU 400 sets a ± 1 MHz frequency AFC range to the tuner unit 100, and sets the symbol rate and spectrum mode for matching the transmission rate of the satellite signal received through the tuner unit 100 to the QPSK. It is set in the demodulator 200, and the FEC code is set in the FEC unit 300 (S1).

The CPU 400 determines whether the satellite signal received through the antenna is operating normally in the tuner 100, the QPSK demodulator 200, and the FEC unit 300 (S2). When the signal performs normal operation in the tuner unit 100, the QPSK demodulator 200, and the FEC unit 300, the received satellite signals are all normal. When receiving, it is possible to receive by subtracting the offset frequency (S11).

At this time, the satellite signal received through the antenna determines whether the tuner unit 100, the QPSK demodulator 200 and the FEC unit 300 operates normally (S2), the received satellite signal is the tuner unit ( 100), when the QPSK demodulation unit 200 and the FEC unit 300 do not operate normally, as shown in FIG. 3, in order to extend the center frequency to the tuner unit 100 by -0.5MHz, By moving the frequency in the minus (-) direction by 0.5 MHz, the result is extended to the range of -1.53 MHz to +1 MHz AFC (S3), where the received satellite signal is again tuned to the tuner unit 100 and the QPSK demodulator ( 200 and the FEC unit 300 determines whether it operates normally (S4).

Meanwhile, as shown in FIG. 3, the CPU 400 extends the AFC range set in the tuner 100 by −0.5 MHz, and then moves the center frequency in the minus (−) direction by 0.5 MHz. As a result, even though the range of -1.5 MHz to +1 MHz AFC is extended (S3), the received satellite signal does not operate normally in the tuner unit 100, the QPSK demodulator 200 and the FEC unit 300. In this case, as shown in FIG. 4, when the CPU 400 shifts the center frequency set in the tuner 100 by +0.5 MHz, the range of ± 3 MHz AFC is expanded (S5). The received satellite signal determines whether the tuner 100, the QPSK demodulator 200, and the FEC unit 300 operate normally (S6).

3 and 4, even after the CPU 400 extends the AFC range from -1.5 MHz to +1.5 MHz, the received satellite signals are received in the tuner unit 100 and the QPSK demodulator 200. In the case where the FEC unit 300 does not operate normally, the CPU 400 extends the AFC range by -1 MHz to the tuner unit 100 as shown in FIG. 4. In order to further expand the ± 0.5MHz AFC range from the diagram shown in FIG. 4, the center frequency is moved in the minus (-) direction by -1MHz, resulting in the extension of the AFC range from -2MHz to + 1.5MHz (S7). In this case, it is determined whether the received satellite signal is normally operated by the tuner unit 100, the QPSK demodulator 200, and the FEC unit 300 (S8).

However, as shown in FIG. 5, the CPU 400 shifts the center frequency in the minus (-) direction by -1 MHz to extend the AFC range by -1 MHz, resulting in -25 MHz to +1.5. Even though the signal is extended to the MHz AFC range (S7), when the received satellite signal does not operate normally in the tuner unit 100, the QPSK demodulator 200 and the FEC unit 300, the CPU 400 As shown in FIG. 6, in order to extend the AFC range by +1 MHz to the tuner unit 100, the center frequency is shifted by +1 MHz in the positive direction, resulting in -2 MHz to +2 MHz. It extends the AFC range (S9), and it is determined whether the received satellite signal is normally operated by the tuner unit 100, the QPSK demodulator 200 and the FEC unit 300 (S10).

At this time, if the AFC range is extended to ± 2MHz in the tuner unit 100, most satellite signals are received.

In addition, when the AFC range is extended to ± 2MHz, the satellite signal does not operate normally in the tuner unit 100, the QPSK demodulator 200 and the FEC unit 300, 3, 4, 5, as shown in FIG. 6, the AFC range can be extended even more by shifting the center frequency in 0.5MHz steps. I can justify it.

On the other hand, when the CPU 400 virtually sequentially gives the AFC range, the CPU 400 receives the signal at a specific frequency shift (−0.5 MHz → + 0.5 MHz → −1 MHz → + 1 MHz → −1.5 MHz → + 1.5 MHz ……). When the satellite signal is operated normally in the tuner unit 100, the QPSK demodulator 200 and the FEC unit 300, the center frequency shift value is applied as a frequency offset value when receiving a satellite signal having a different center signal. By offsetting the frequency to the tuner unit 100 to receive another satellite signal (S11).

In addition, when the tuner 100 receives a satellite signal transmitted through an unspecified satellite, the tuner 100 passes only a signal of a frequency band to be used in a satellite broadcasting receiver, and inputs the input satellite signal to the QPSK demodulator 200. The QPSK demodulator 200 demodulates the satellite signal inputted through the tuner unit 100 to output the original signal to the FEC unit 300, and the FEC 300 is set to the set FEC code. By this, the error of the original signal output from the QPSK demodulator 200 is automatically corrected, and the original signal of which the error is corrected is transmitted to the MPEG decoding unit.

As described above, the apparatus for controlling the virtual AFC range of the satellite broadcasting receiver of the present invention and the control method thereof include a CPU when a satellite signal cannot be received by the satellite broadcasting receiver due to an error in the frequency generator of the LNB mounted to the receiver antenna. Virtually expands the AFC range, which prevents satellite signals from being received due to errors.

Claims (2)

A tuner unit for receiving a satellite signal transmitted through an unspecified satellite through an antenna, inputting only a signal of a frequency band to be used in the satellite broadcasting receiver, and outputting the input satellite signal; A QPSK demodulation unit connected to the signal output terminal of the tuner unit and demodulating the satellite signal inputted through the tuner unit to output an original signal; An FEC unit which is connected to the signal output terminal of the QPSK demodulator, automatically corrects an error of the original signal output from the QPSK demodulator by the set FEC code, and transmits the error corrected original signal to the MPEG decoding unit; Connected to the signal input / output terminals of the tuner section, the QPSK demodulation section and the FEC section, and sets a frequency equal to the frequency of the satellite signal transmitted through the satellite to the tuner section. If the satellite signal is not received due to this, virtually extend the main frequency to set the tuner unit to extend the AFC range, and check whether the satellite signal operates normally in the demodulator and the FEC unit at the shifted center frequency. And a CPU for setting a symbol rate and spectrum mode for matching the transmission rate of the satellite signal received through the tuner, and a CPU for setting an FEC code in the FEC unit. Virtual AF range extender at the receiver. A setting step of setting the AFC range of the frequency to be received through the antenna to the tuner unit, the symbol rate and spectrum mode to match the transmission rate of the received satellite signal to the QPSK demodulator, and the FEC code to the FEC unit (S1); A first normal determination step (S2) of determining whether the received satellite signal operates normally in the demodulator and the FEC unit after the setting step (S1); After the first normal determination step (S2), if the received satellite signal does not operate normally in the demodulator and the FEC unit, the center frequency is 0.5 in order to double the AFC range of the frequency set in the tuner unit by -0.5M. A first expansion step S3 for moving in the negative (-) direction; A second normal determination step (S4) of determining whether the received satellite signal operates normally in the demodulator and the FEC unit after the first expansion step (S3); After the second normal determination step (S4), if the received satellite signal does not operate normally in the demodulator and the FEC unit, the center frequency is 0.5M to extend the AFC range of 0.5M set by the tuner unit. A second expansion step S5 for moving in the positive (+) direction by the expansion; A third normal determination step (S6) of determining whether the received satellite signal is operating normally in the demodulator and the FEC unit after the second expansion step (S5); After the third normal determination step (S6), if the received satellite signal does not operate normally in the demodulator and the FEC unit, the AFC range of the frequency set in the tuner unit is extended to -1M, and the center frequency is 1M. A third expansion step S7 for moving in the negative (-) direction; A fourth normal determination step (S8) of determining whether the received satellite signal is operating normally in the demodulator and the FEC unit after the third expansion step (S7); After the fourth normal determination step (S8), if the received satellite signal does not operate normally in the demodulator and the FEC unit, the center frequency is + 1M plus to quadruple the AFC range of the frequency set in the tuner unit four times. A fourth expansion step S9 for moving in the positive direction; After the fourth expansion step S9, it is determined whether the received satellite signal operates normally in the demodulator and the FEC unit, and if the received satellite signal does not operate normally in the demodulator and the FEC unit, -1.5M, Verify that both the demodulator and the FEC unit operate normally by increasing or decreasing the center frequency in the negative (-) / plus (+) direction in increments of + 1.5M, -2M, + 2M, -2.5M, and + 2.5M in 0.5M increments. And a fifth normal determination step (S10) of displaying the state of the satellite signal by determining that the satellite signal is absent or weak even when the demodulator and the FEC unit do not operate normally even when the center frequency is moved to the maximum; The received satellite after the first normal decision step S2, the second normal decision step S4, the third normal decision step S6, the fourth normal decision step S8, and the fifth normal decision step S10. When the signal performs the normal operation in the demodulator and the FEC unit, using the center frequency set in the tuner unit as an offset value, the frequency offset step of applying the offset value to the center frequency when receiving another satellite signal (S11). Control method of the virtual AF range expansion apparatus in the satellite broadcasting receiver, characterized in that made.

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