KR100235649B1 - Rssi detecting/displaying method of digital satellite-broadcast receiver - Google Patents

Abstract

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a digital satellite broadcasting system, and in particular, through a display device of a system that detects and listens to an electric field sensitivity level of a frequency received from a satellite located in a geostationary orbit above an equator spaced about 36,000 km from the earth. It is to display.

The present invention detects the level of the electric field sensitivity of the frequency received in the reception of satellite broadcasting through the power level of the I and Q signals extracted from the quadrature digitizer, and then processes the image processing means that supports the OSD, thereby causing screen shaking. This exclusion provides a clear image, and by detecting / displaying a continuous electric field sensitivity level at predetermined cycles, the electric field change according to the receiving environment can be visually recognized, thereby providing convenience for use.

Description

Receiving Sensitivity Detection / Display Method of Digital Satellite Broadcasting Receiver

1 is a schematic diagram of general digital satellite broadcasting reception.

2 is a schematic configuration diagram of a reception sensitivity detection / display device in a conventional analog receiver.

3 is a block diagram of a reception sensitivity detection / display apparatus in a digital satellite broadcasting receiver according to the present invention.

4 is a flowchart for realizing a reception sensitivity detection / display method in the present invention shown in FIG.

5 shows an example of the display of the reception sensitivity level.

* Explanation of symbols for main parts of the drawings

1: satellite 2: antenna

3: Satellite receiver 4, 4 ′: Audio and TV system

10: satellite tuner 11: gain detector

12 control unit 13 OSD IC

20: Satellite tuner 21: Band pass filter

22: Amplifier 23: Quadrature Digitizer

24: gain control unit 25: gain detection unit

26 microprocessor 27 video demodulator

28: video converter 29: carrier and clock recovery unit

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a digital satellite broadcasting system, and in particular, through a display device of a system that detects and listens to an electric field sensitivity level of a frequency received from a satellite located in a geostationary orbit above an equator spaced about 36,000 km from the earth. A reception sensitivity detection / display method of a digital satellite broadcasting receiver for displaying.

In general, as shown in FIG. 1 of the accompanying drawings, the satellite (1) launched from the ground for the purpose of communication, broadcasting, espionage, etc. is located at a stationary orbit above the equator spaced about 36,000 km from the earth. It acts as a relay station for retransmitting the radio wave compressed and applied from the terrestrial transmitting station to a predetermined state on the earth. The satellite receiver 3 is transmitted from the satellite 1 through a parabolic antenna installed on the earth. The electric field transmitted to the satellite receiver 3 is applied to the satellite receiver 3 due to the influence of the surroundings (for example, when the rain falls, the high frequency band attenuates the rainfall and the frequency is absorbed by the clouds). Is reached in a fairly weak state.

In the conventional analog receiver, the reception sensitivity detection / display apparatus includes a satellite reception tuner 10 for receiving and tuning a frequency retransmitted from a satellite, as shown in FIG. A gain detector 11 for detecting the gain of the received frequency signal and a clock having a predetermined period for detecting the gain of the received frequency signal and applying the clock to the gain detector 11 at a predetermined period of the detection clock. The control unit 12 controls the display of the received electric field gain applied from the gain detector 11, and the display unit displays the level of the received electric field sensitivity and the display of the image signal in accordance with the signal applied from the control unit 12, thereby predetermining the display means. OSD IC (On Screen Display Integrated Circuit: 13) is displayed.

In the conventional reception sensitivity detection / display device as described above, the gain detector 11 automatically gains and tunes the satellite reception tuner 10 which receives and tunes the frequency retransmitted and applied from the satellite located in the stationary orbit above the equator. After detecting the signal applied from the terminal of the control (Automatic Gain Control: AGC) through the internal amplification means and a resistor, the control unit 12 measures the gain of the received electric field according to the gain sensing clock signal applied from the control unit 12. Is applied to the side.

After controlling the gain of the detected electric field, the controller 12 sets the reception level together with the character signal, and then controls the OSD IC 13 to control the display of the reception electric field level.

At this time, the OSD IC 13 sets the position of the display means for displaying the received electric field level by calculating the number of scanning lines of the horizontal synchronizing signal and the vertical synchronizing signal of the input analog video signal, and then sets the character to the input video signal. To display visually on the monitor.

In the conventional analog satellite broadcasting receiver as described above, the detection / display device of the reception field level measures the intensity level of the signal received from the satellite, selects a character, and then calculates the scan line of the vertical synchronization and horizontal synchronization of the input analog image signal. Since the display position of the reception electric field level is selected and displayed, the image is shaken due to the influence of the video signal.

The present invention has been made in view of the above-described problems, and an object thereof is to detect an electric field level of a signal retransmitted from a satellite and display it through an image display means. It is to exclude the shaking of the electric field sensitivity level displayed by the signal processing, and to visually display the change in the reception environment of the radio channel using satellites by continuously detecting / displaying the predetermined period.

In order to achieve the above object, a feature of the present invention is a reception sensitivity detection / display method of a satellite broadcasting receiver which detects a level of a received electric field received from a satellite and displays it on a display by an OSD function. The process of separating the I signal and the Q signal from the QPSK type video signal after forming an intermediate frequency by tuning the frequency band of the channel selected by the user at the frequency, and the electric field level of the separated extracted I signal and the Q signal. And detecting the level of the received electric field based on the received electric field, and displaying the detected level of the received electric field on the display means.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings.

FIG. 3 is a block diagram of a reception sensitivity detection / display device in a digital satellite broadcasting receiver according to the present invention. FIG. 4 is a flowchart for realizing a reception sensitivity detection / display method in the present invention shown in FIG. Fig. 1 shows an example of the display of the reception sensitivity level.

As can be seen in FIG. 3, in the digital satellite broadcasting receiver according to the present invention, the reception sensitivity detection / display apparatus includes a satellite reception tuner 20, a band pass filter 21, an amplifier 22, and a quadrature digitizer 23. ), A gain control unit 24, a gain detection unit 25, a microprocessor 26, an image demodulator 27, an image converter 28, a carrier wave and a clock recovery unit 29, and a satellite reception tuner 20. ) Tunes to the frequency of the channel tuned by the user at the frequency applied by retransmission from the satellite located in the stationary orbit over the equator, and extracts and outputs the intermediate frequency (IF) from the tuned frequency.

The band fill filter 21 filters only an intermediate frequency (IF) signal applied from the satellite reception tuner 20 and extracts only a component of a predetermined band.

The amplifier 22 amplifies the intermediate frequency IF applied by filtering only components of a predetermined band to a predetermined predetermined level.

The quadrature digitizer 23 processes the modulated intermediate frequency (IF) in the form of quadrature phase shift keying (QPSK) to which the level is amplified and extracted into an I signal and a Q signal for image demodulation, and then to the sensitivity of the received signal. The power level PWR for the I signal and the power level PWR for the Q signal are output.

The gain control unit 24 detects a gain for phase-locking from the power level PWR for the I signal and the power level PWR for the Q signal applied from the quadrature digitizer 23 to automatically receive satellite broadcasting. The gain adjustment signal AGC is output to the quadrature digitizer 23 side.

The gain detector 25 detects the level of the electric field received from the satellite through the power level PWR for the I signal and the power level PWR for the Q signal applied from the quadrature digitizer 23, and the microprocessor. The level of the received electric field detected according to the gain detection clock signal applied from (26) is applied to the microprocessor 26 side.

The microprocessor 26 detects the received electric field level applied from the gain sensing unit 25 according to the gain detection clock signal, sets a character or a level bar for displaying the sensitivity of the electric field level, and processes the image signal. Handle the overall behavior for.

The video demodulator 27, as an MPEG-II video demodulation means, performs an operation for demodulation of a video signal received in accordance with a control signal applied from the microprocessor 26 and a process for displaying the received electric field level.

The image converter 28 is an NTSC image converter and processes the image signal applied from the image demodulator 27 and the signal of the received electric field level according to the signal applied from the microprocessor 26 to be output to the monitor side which is an image output means. do.

The carrier and clock recovery unit 29 restores a clock signal for receiving a carrier and a frequency in a frequency band received from the satellite and processing a received frequency.

In the present invention having the above-described function, an operation of detecting / displaying the reception electric field level will be described with reference to FIGS. 3 to 5 as follows.

When a broadcast frequency retransmitted and applied from a satellite located in a stationary orbit above the equator spaced 36,000 km from the ground is received by the satellite reception tuner 20 through a parabola antenna connected to each user terminal, the satellite reception tuner 20 In the received frequency band, the frequency band of the channel selected by the user is tuned to extract the intermediate frequency IF, and then the extracted intermediate frequency IF is applied to the band pass filter 21.

The band pass filter 21 extracts only components of a predetermined band set by filtering the applied intermediate frequency IF, and then amplifies the band pass filter 21 to a predetermined level through the amplifier 22 and applies the result to the quadrature digitizer 23. The digitizer 23 processes the modulated intermediate frequency IF of QPSK type from the amplifier 22, extracts the I signal and Q signal for image demodulation, and then provides the power level PWR for the I signal according to the sensitivity of the received signal. ) And outputs the power level PWR for the Q signal to the gain control unit 24 and the gain sensing unit 25, and the gain control unit 24 supplies the power level PWR and the Q signal of the applied I signal. After detecting the gain value for phase-locking the reception frequency from the power level (PWR) of the signal, the detected gain adjustment value is applied to the quadrature digitizer 23 to fix the phase with respect to the frequency of the received video signal. Gain detector 25 is a microphone According to the gain detection clock signal applied from the processor 26, the level of power received from the satellite is detected from the power level PWR of the I signal applied from the quadrature digitizer 23 and the power level PWR of the Q signal. The predetermined signal corresponding thereto is applied to the microprocessor 26 side.

The microprocessor 26 reads the level of the received electric field applied according to the clock signal, selects a character or level bar, selects a position for display, and applies it to the image demodulator 27 and the image converter 28.

The video demodulator 27, which is an MPEG-II video signal processing means, decodes the selected character or level bar signal to display the received electric field level in the video signal input according to the control signal applied from the microprocessor 26, and then the video. To the transducer 28 side.

The image converter 28 is a means for processing a video signal of the NTSC type image processing means for processing the image signal received and the level of the selected reception electric field and then display the image as can be seen in FIG. Displays the sensitivity of the received electric field level in the character (①) or level bar (②) format at the predetermined position of the user.

As described above, the present invention, the image processing means for supporting the OSD after detecting the level of the electric field sensitivity of the frequency received in the reception of the phase broadcast through the power level of the I signal and Q signal extracted from the quadrature digitizer It provides a clear image by eliminating screen shake, and detects / displays a continuous electric field sensitivity level at predetermined intervals, and provides convenience for use by visually recognizing changes in electric field according to the receiving environment. do.

Claims (1)

A reception sensitivity detection / display method of a satellite broadcasting receiver which detects a level of a received electric field received from a satellite and displays it on a display by an OSD function, the method comprising: tuning a frequency band of a channel tuned by a user at a frequency transmitted from the satellite; Forming an intermediate frequency and separating and extracting the I and Q signals from the QPSK type video signal, and detecting the level of the received electric field based on the electric field levels of the separated and extracted I and Q signals; And a step of reading the detected received electric field level and displaying the detected electric field level on the display means by an OSD function.