KR20010054593A - Broadcasting detect circuit and method for repeater - Google Patents

Abstract

PURPOSE: A circuit for retrieving broadcasts each repeater is provided to retrieve whether new broadcasts of other repeaters are started or completed, and to notify a televiewer of a retrieved result. Therefore, it is possible to improve a capacity of a receiver, and to satisfy the televiewer. CONSTITUTION: A tuner(310) tunes channels each repeater from broadcast signals. A signal detector(320) detects whether an output signal of the tuner(310) is over a determined level. A controller(330) controls tuning frequencies of the tuner(310) of each repeater. The controller(330) retrieves an output signal of the signal detector(320), and decides whether broadcasts each repeater are started, then displays a decided result as an on-screen image.

Description

Broadcast search circuit and method by repeater {BROADCASTING DETECT CIRCUIT AND METHOD FOR REPEATER}

The present invention relates to broadcast reception, and in particular, to a broadcast search circuit and method for each repeater in a satellite broadcast receiver.

Advances in current broadcast technology have made it possible to watch satellite broadcasts.

In order to watch satellite broadcasts, a satellite broadcast receiver should be provided.

In general, the satellite broadcast receiver is configured as shown in the block diagram of FIG. 1 to perform the following operations.

The signal input from the antenna is tuned by the tuner 101 and then QPSK demodulated through the demodulator 102 and output as a transport stream of MPEG-2 standard.

At this time, the parser demultiplexer 103 separates video data, audio data, and additional service data from the MPEG-2 standard transport stream, and the A / V decoder 104 decodes each data.

Accordingly, the demultiplexer 103 outputs the signal decoded by the A / V decoder 104 to the NTSC encoder 105 and the audio D / A converter 106 so that the final video signal and the audio signal are output.

In satellite broadcasting, however, a plurality of repeaters are provided to transmit respective broadcast signals.

Accordingly, the frequencies of broadcast signals respectively transmitted by the plurality of repeaters are tuned by the tuner 101.

As shown in the circuit diagram of Fig. 2, the conventional tuner includes a high pass filter (HPF) 201 that passes only a predetermined high pass component of a broadcast signal in the 950 to 2050 MHz band, and the high pass of the high pass filter 201. A high frequency amplifier 202 for amplifying a component, a high frequency attenuator 203 for amplifying a high frequency component among the amplified components in the high frequency amplifier 202, and a predetermined low range of an output signal from the high frequency attenuator 203. The low pass filter 204 which passes only a component, and the tuning circuit 205 which outputs the signal of 479.5 MHz frequency as an input to the output signal from this low pass filter 204 are comprised.

The tuning circuit 205 inputs an oscillator 211 which oscillates at a frequency 479.5 MHz higher or lower than the center frequency of the repeater, and an oscillation frequency of the oscillator 211 as an input. PLL 212 which is fixed at a predetermined frequency by control signals SDA and SDL of the standard, and low pass filter 213 which outputs a DC voltage to the oscillator 211 by inputting the output frequency from this PLL 212. And a multiplier 214 for multiplying the oscillation frequency of the oscillator 211 by the output signal from the low pass filter 205 and outputting an intermediate frequency signal that is the difference, and amplifying the intermediate frequency signal in the multiplier 214. And an intermediate frequency amplifier 215 for outputting an intermediate frequency signal of 479.5 MHz.

Referring to the operation of the tuner in the prior art as follows.

When a broadcast signal of 950 to 2050 MHz is received by the antenna, only a predetermined high pass component is passed through the high pass filter 201, amplified by a high level by the high frequency amplifier 202, and then input to the high frequency attenuator 203.

At this time, when the high frequency attenuator 203 amplifies the high frequency component attenuated during transmission, only a predetermined low pass component is passed through the low pass filter 204 and input to the tuning circuit 205.

Accordingly, the tuning circuit 205 inputs the output signal of the low pass filter 204 into a microcomputer (not shown). The control signal (SDA, SDL) of the standard is to output the 479.5MHz intermediate frequency signal.

In other words, assuming that the center frequency of the repeater to be tuned for broadcast viewing is 'A', the tuning circuit 205 has a multiplier 214 oscillating frequency of the oscillator 211 to an output signal from the low pass filter 204. Multiply by to extract the difference frequency signal, and the intermediate frequency amplifier 215 amplifies the difference frequency signal to output an intermediate frequency signal of 479.5MHz.

At this time, the PLL 212 inputs the oscillation frequency of the oscillator 211 in a microcomputer (not shown). The control signal SDA, SDL of the standard is fixed at a predetermined frequency and input to the low pass filter 213.

Accordingly, the low pass filter 213 outputs the DC voltage corresponding to the frequency in the PLL 212 to the oscillator 211 so that the intermediate frequency signal of 479.5 MHz is output from the intermediate frequency amplifier 215. ) Generates an oscillation frequency of 479.5 MHz higher or lower than the center frequency A of the repeater to be tuned and outputs to the multiplier 214.

On the other hand, the satellite broadcasting satellite is provided with a plurality of repeaters, even if a commercial service is started, the broadcast signal may not be transmitted from any repeater.

This is because broadcast programs are not broadcasted 24 hours, but broadcasts may be interrupted or broadcasts may be newly started depending on broadcasting stations.

Conventional satellite broadcast receivers, however, do not have the ability to tell a viewer whether a new broadcast has started on another repeater or when the broadcast of another repeater has ended when the viewer is watching a program.

This is because, if the viewer is watching a program, the tuner of the receiver must be fixed to the channel of the repeater for receiving the program being viewed by the viewer.

Therefore, conventionally, when watching one broadcast program, it is not possible to know whether to start a new broadcast or terminate a broadcast on another repeater. You must bear the inconvenience of finding out if the broadcast is over.

Accordingly, the present invention provides a repeater-specific broadcast search circuit and method for informing a viewer whether or not another broadcaster is broadcasting even if the viewer is watching a broadcast program transmitted from an arbitrary repeater to improve the conventional inconvenience. There is a purpose.

1 is a block diagram of a typical satellite broadcast receiver.

2 is a circuit diagram of a tuner in the prior art.

3 is a block diagram of a circuit showing an embodiment of the invention.

4 is an exemplary view showing a repeater number and a center frequency for satellite broadcasting.

5 is a signal flow diagram for an embodiment of the invention.

Explanation of symbols on the main parts of the drawings

310: tuning circuit 311: oscillator

312: PLL 313: low pass filter

314: multiplier 315: intermediate frequency amplifier

320: signal detector 330: microcomputer

340: on-screen image display unit

The present invention provides a broadcast receiver for receiving a broadcast signal and reproducing a desired broadcast program, comprising: a tuning circuit for tuning a channel for each repeater from the broadcast signal, and detecting whether the output signal of the tuning circuit is above a predetermined level. And a microcomputer for determining whether to broadcast by the repeater by searching the output signal of the signal detector while adjusting the tuning frequency of the tuning circuit for each repeater and displaying the on-screen image. do.

In addition, the present invention is to determine whether the signal is detected after tuning the channel of any repeater to achieve the above object, and the flag value is changed after setting or resetting the flag value according to whether the signal detected in the above Determining whether a flag has been changed, and if the flag value is changed to a set, displaying the on-screen image that the broadcasting has been started in a certain repeater, and if the flag value has been changed to a reset, broadcasting has been terminated in any repeater. The step of displaying the on-screen image is repeated periodically for the remaining repeaters except for the repeater of the currently watching broadcast program.

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

Satellite broadcasting receiver for applying an embodiment of the present invention is the same as Figure 1 tuner 101, demodulator 102, demultiplexer 103, A / V decoder 104, NTSC encoder 105 and audio A It consists of the / D converter 106.

3 is a circuit diagram showing an embodiment of the present invention, as shown in FIG. 2, a high pass filter 201, a high frequency amplifier 202, a high frequency attenuator 203, a low pass filter 204, and a tuner as shown in FIG. A satellite broadcast receiver having a tuning circuit (205), comprising: a tuning circuit (310) for outputting a signal of 479.5 MHz frequency as an input of an output signal from the low pass filter (204); The signal detector 320 detects whether an intermediate frequency signal is output, and the output signal of the signal detector 320 is searched by adjusting the tuning frequency of the tuning circuit 310 for each repeater to determine whether to broadcast by the repeater. The microcomputer 330 displays the result on the on-screen image display unit 340.

The tuning circuit 310 inputs an oscillator 311 which oscillates at a frequency 479.5 MHz higher or lower than the center frequency of the repeater, and an oscillation frequency of the oscillator 311 as an input. PLL 312 for fixing at a predetermined frequency by control signals SDA and SDL of a standard, and a low pass filter 313 for outputting a DC voltage to the oscillator 311 with the output frequency from the PLL 312 as an input. A multiplier 314 for multiplying the oscillation frequency of the oscillator 311 by the output signal from the low pass filter 204 and outputting an intermediate frequency signal that is the difference, and amplifying the intermediate frequency signal in the multiplier 314. And an intermediate frequency amplifier 315 for outputting the 479.5 MHz intermediate frequency signal to the signal detector 320.

The signal detector 320 may include a filter, an integrator, and a level detector.

The circuit of the present invention can be built in the tuner 101.

The operation and the effect of the embodiment of the present invention configured as described above will be described with reference to the signal flowchart of FIG. 5.

Since the tuner 101 provided in the satellite broadcasting receiver to which the embodiment of the present invention is applied is configured in the same manner as in the prior art of FIG. 2, the operation for broadcasting viewing is performed in the same manner as in the prior art to output an intermediate frequency signal of 479.5 MHz. Done.

On the other hand, if a function for determining whether to broadcast other repeaters is set while watching an arbitrary broadcast program, the microcomputer 330 controls the tuning frequency of the tuning circuit 310 to determine whether to broadcast by repeater.

In this case, assuming that the repeater number and the center frequency are the same as those illustrated in FIG. 4 when six repeaters are provided, first, the microcomputer 330 sets the repeater number n to '2' to tune the circuit 310. This adjusts the tuning frequency of.

Accordingly, the tuning circuit 310 receives the output signal of the low pass filter 204 as input from the microcomputer 330. The control signal (SDA, SDL) of the standard is to output the 479.5MHz intermediate frequency signal.

That is, since the repeater number to be tuned is '2' and the center frequency is 11746.66 MHz, the tuning circuit 310 uses the oscillation frequency of the oscillator 311 to input the oscillation frequency of the oscillator 311. It is fixed to a predetermined frequency by the control signals SDA and SDL of the standard and input to the low pass filter 313.

In this case, the low pass filter 313 outputs a DC voltage corresponding to the frequency in the PLL 312 to the oscillator 311 so that the intermediate frequency signal of 479.5 MHz is output from the intermediate frequency amplifier 315. The oscillator generates an oscillation frequency of 479.5 MHz higher or lower than the center frequency A of the repeater to be tuned and outputs to the multiplier 314.

Accordingly, the multiplier 314 multiplies the output signal of the low pass filter 204 by the oscillation frequency of the oscillator 311, extracts the difference frequency signal, and the intermediate frequency amplifier 315 amplifies the difference frequency signal so that it is 479.5. It outputs an intermediate frequency signal of MHz.

At this time, the signal detector 320 detects whether the signal is output by searching the output terminal of the tuning circuit 310.

Accordingly, the microcomputer 330 sets the flag [n] value to '1' when the signal detector 320 detects a signal, and sets the flag [n] value when the signal is not detected. After resetting to '0', it is determined whether the flag value is changed.

At this time, if it is determined that the flag flag [n] is changed, the microcomputer 330 determines whether the flag value is changed from '0' to '1'.

Therefore, if the flag [n] value is changed from '0' to '1', the microcomputer 330 determines that the broadcast signal, which is newly started by the repeater '2', is transmitted and the on-screen image display unit ( 340 to notify the viewer.

On the contrary, if the flag [n] value is changed from '1' to '0', the microcomputer 330 determines that all the broadcast signals transmitted from the repeater '2' are terminated and the on-screen image display unit ( 340 to notify the viewer.

Here, the on-screen image display unit 340 displays not only the broadcast start / stop but also the repeater number.

In addition, the above operation is repeatedly performed for each repeater. When the flag value is not changed when the flag value is set or reset according to whether the signal is detected, or the flag [flag [n]) is used. When the start / end of the broadcast is displayed on the on-screen image display unit 340 due to the change of the value, the microcomputer 330 increases the repeater number n by 2 and determines whether the value n is greater than 12. Done.

Therefore, if the newly set repeater number n is not greater than 12, the microcomputer 330 increases the repeater number n by 2, and then the signal detector 320 receives a signal from the tuning circuit 310. Determining whether the detection is to be repeated for each repeater.

On the contrary, if the newly set repeater number n is greater than '12', the microcomputer 330 sets the repeater number n to '2' to perform the same process as above.

The above operation may be performed when a broadcast search for each repeater is set by a user key input or automatically turned on to perform a broadcast search function for each repeater when the power is turned on.

As described in detail above, the present invention improves the performance of the receiver as well as satisfies the viewer by allowing the viewer to search for the presence or absence of a new broadcast start or stop of other repeaters even if the viewer is currently watching a broadcast program. It can be effective.

Claims (6)

A broadcast receiver for receiving a broadcast signal and reproducing a desired broadcast program, comprising: tuning means for tuning a channel for each repeater from the broadcast signal, signal detection means for detecting whether an output signal of the tuning means is above a predetermined level, and And a control means for searching for an output signal of the signal detecting means to adjust the tuning frequency for each repeater, determining whether to broadcast by the repeater, and displaying the same on-screen image. 2. The repeater broadcast search circuit according to claim 1, wherein the control means is configured to execute broadcast search by repeater when a broadcast search key for each repeater is input by a user or is turned on. Determining whether a broadcast signal is detected after tuning a channel of an arbitrary repeater, and if the broadcast signal is detected, displaying an on-screen image indicating that broadcasting has been started in an arbitrary repeater, and detecting the broadcast signal. If not, the repeater repeats the step of displaying on-screen video that the broadcast is terminated for all repeaters, characterized in that for repeating the repeater periodically. 4. The method of claim 3, further comprising determining a broadcast search setting for each repeater. The broadcast searching method according to claim 4, wherein the broadcast search setting is set automatically by a user's key input or upon power-on. Determining the broadcast search setting for each repeater; if the broadcast search for each repeater is set; determining whether a broadcast signal is detected after tuning a channel of an arbitrary repeater; and if the broadcast signal is detected, the flag value is determined. On the contrary, if the broadcast signal is not detected, resetting the flag value and then determining whether the flag value has been changed, and if the flag value has been changed to the set, displaying on-screen image that the broadcast has been started in any repeater. And repeating the step of periodically displaying the on-screen image that the broadcast is terminated in any repeater if the flag value is changed to the reset, for all the repeaters periodically.