KR20080039595A - Method and apparatus for scanning channel in digital receiver - Google Patents

Abstract

A method and an apparatus for scanning a channel in a digital broadcasting receiver are provided to omit repetition of search time related to the same frequency band with a previously searched broadcasting channel. A process for scanning the first broadcasting type channel at an arbitrary frequency band is performed. When the broadcasting type channel signal is detected at the frequency band(S12), a process for moving the frequency band(S15) and scanning the first broadcasting type channel is performed. When the first broadcasting type channel signal is not detected at the frequency band, the second broadcasting type channel is scanned at the same frequency band. The channel information related to the first and second broadcasting type channels is stored. The channel scan process is performed at the frequency band adjacent to the initial frequency band.

Description

Method and apparatus for scanning channel of digital broadcasting receiver {Method and apparatus for scanning channel in digital receiver}

1 is a diagram illustrating an example of a channel in which a broadcast signal exists in a current broadcast in which digital broadcasting and analog broadcasting coexist.

2 is a flowchart illustrating an operation according to a channel scan in a conventional digital broadcasting receiver.

FIG. 3 illustrates an exemplary operation of performing a channel scan between an analog broadcast and a digital broadcast in a conventional digital broadcast receiver.

4 is a diagram illustrating a control configuration for channel scan control of a digital broadcasting receiver according to the present invention;

5 is a flowchart illustrating an operation according to a channel scan in a digital broadcast receiver according to the present invention;

6 is a diagram illustrating an operation of performing a channel scan between analog broadcasting and digital broadcasting in the digital broadcasting receiver according to the present invention.

Explanation of symbols on the main parts of the drawings

30: Tuner 31: Demux

32,33,34: Buffer 35: MPEG decoder

36: microcomputer 37: OSD generation unit

38: memory 40: HDR system

41: hard disk

The present invention relates to a channel scan method and apparatus for a digital broadcast receiver, and more particularly, to a channel scan method and apparatus for a digital broadcast receiver capable of shortening a channel search time in a digital broadcast receiver capable of receiving analog broadcast and digital broadcast. It is about.

Digital broadcast refers to a television broadcast that compresses and sends out a television signal in a digital form in which information signals are encoded and recorded. Conventional analogue television broadcasting can only carry one image in one radio wave, and voice has to be transmitted in another radio wave. On the other hand, since digital broadcasting can carry a plurality of video, audio, etc. in one radio wave and can compress information without degrading the quality, 4 to 8 channels in the frequency band of the conventional analog broadcasting channel Can be set. Accordingly, the digital broadcast can include various signals in addition to the television broadcast signal.

Modern broadcasting, on the other hand, is a transitional stage moving from analog broadcasting to digital broadcasting. Therefore, in the present broadcast, digital broadcast and analog broadcast coexist, and an analog channel and a digital channel are mixed also in a broadcast channel.

However, since analog broadcasting has been progressing for a long time, existing broadcast frequencies have been allocated as analog broadcasting standards. Therefore, the digital channel of the new digital broadcasting is allocated to the empty frequency band among the existing analog channels.

FIG. 1 shows an exemplary view in which such a state, that is, an analog channel and a digital channel coexist. That is, as shown in the illustration, analog broadcast channel "7" is assigned to 181.25MHz, analog broadcast channel "8" is assigned to 187.25MHz, and analog broadcast channel "12" is assigned to 205.25MHz. In this state, digital broadcast channel "10" exists in 195 MHz, which is an empty frequency band.

And analog broadcasting and digital broadcasting cannot coexist in one frequency band. Therefore, only one broadcast exists in one frequency band. In the example diagram shown, analog broadcast 181.25 MHz and digital broadcast 183 MHz are the same frequency band assigned to channel " 8. " Analog broadcast 187.25 MHz and digital broadcast 189 MHz are the same frequency bands assigned to channel "9". Analog broadcast 193.25 MHz and digital broadcast 195 MHz are the same frequency bands assigned to channel "10". The analog broadcast 205.25 MHz and the digital broadcast 207 MHz are the same frequency bands assigned to the channel "12". Therefore, only one of digital broadcasting and analog broadcasting exists in the same frequency band. Each of the frequencies (181.25MHz, 183MHz, 187MHz, ...) represents a center frequency included in each frequency band.

As described above, the digital broadcast receiver for receiving the broadcast signal in which the analog broadcast channel and the digital broadcast channel are mixed is configured to receive both the analog broadcast and the digital broadcast. In addition, a channel scan has to be performed on existing analog and digital broadcasting channels.

2 is a flowchart illustrating an operation of scanning an analog broadcast channel and a digital broadcast channel in a conventional digital broadcast receiver.

In the channel scan of the conventional digital broadcast receiver shown, a channel scan is generally performed in such a manner that all analog bands are scanned for all frequency bands and then digital channels are scanned for all frequency bands. The process is described in more detail as follows.

First, in order to scan a channel for analog broadcast, the mobile station moves to the first frequency band (i = 0) and performs an investigation for the analog broadcast channel (S10 and S11).

Using the known analog broadcast frequency, the tuner receives the tuner and monitors whether the broadcast signal is caught, and stores the current frequency information in memory in association with the channel information when the analog broadcast signal is caught (S12). S13).

In the above process, it is checked whether or not an analog broadcast signal exists for all frequency bands, and the process of storing the confirmed analog broadcast channel in a memory is repeatedly performed (S14).

When the channel scan for all analog broadcasts is completed by the above process, the following channel scan is performed for digital broadcasts.

In order to scan a channel for digital broadcasting, the mobile station moves to the first frequency band (i = 0) (S15) and performs a survey on the digital broadcasting channel (S16).

Controls the tuner's receive frequency using a digital broadcast frequency that is already known, and monitors whether the broadcast signal is caught, and stores the current frequency information in memory in association with the digital channel information when the digital broadcast signal is caught (S17). (S18).

In the above process, it is checked whether or not a digital broadcast signal exists for all frequency bands, and the process of storing the checked digital broadcast channel in a memory is repeatedly performed (S19).

3 is an exemplary diagram illustrating a sequential channel scan process for an analog broadcast channel and a digital broadcast channel performed by the above process.

That is, the presence of analog broadcast signals is sequentially checked for all frequency bands, and if analog broadcast signals exist, corresponding analog broadcast channel information is stored in a memory.

When all the frequency bands have been investigated for the analog broadcast channel, the process returns to the first frequency band and examines the existence of the digital broadcast signal for all frequency bands again. Is stored in memory.

Therefore, as shown in the illustrated diagram, the channel scan process of the conventional digital broadcast receiver returns to the original frequency band again after the completion of the sequential channel scan process for the analog broadcast channel for all frequency bands and then all frequency bands. It is controlled to perform a sequential channel scan process for the digital broadcast channel.

The broadcast channel scanning process of the conventional digital broadcast receiver as described above exposes the following problems.

In the conventional broadcast channel scan of a digital broadcast receiver, the channel scan is sequentially performed on the analog broadcast channel, and then the channel scan is performed on all digital broadcast channels. In this case, in channel search, analog broadcast channel scan and digital broadcast channel scan are repeatedly performed for all frequency bands.

However, as mentioned above, analog broadcast and digital broadcast do not coexist in one frequency band. That is, only one of the analog broadcast and the digital broadcast exists. Therefore, the channel scan for both broadcasts for one frequency band causes a problem of consuming only channel scan time.

Therefore, the present invention was created to solve the above problems, and a channel scan method and apparatus for a digital broadcast receiver which can shorten a channel scan time by performing a channel scan on only one broadcast signal for one frequency band. To provide that purpose.

According to an aspect of the present invention, there is provided a channel scanning method of a digital broadcast receiver, comprising: a first step of scanning an analog broadcast channel (or a digital broadcast channel) in an arbitrary frequency band; A second step of scanning an analog broadcast channel (or a digital broadcast channel) by moving to another frequency band when an analog broadcast channel signal (or a digital broadcast channel signal) is detected in the frequency band of the first step; And a third step of scanning a digital broadcast channel (or an analog broadcast channel) in the same frequency band if no analog broadcast channel signal (or digital broadcast channel signal) is detected in the frequency band of the first step. It features.

And storing channel information on the analog broadcast channel or the digital broadcast channel detected in the second and third steps of the present invention.

In the second step of the present invention, the channel scan is performed by moving to a frequency band adjacent to the frequency band of the first step.

The present invention is characterized by repeating the first to third steps for all frequency bands.

The first step of the present invention is characterized by performing a channel scan from the first frequency band among all frequency bands.

The information on all the frequency bands of the present invention is characterized by using a pre-stored standard frequency band table.

In addition, a channel scan apparatus of a digital broadcast receiver according to the present invention for achieving the above object, the tuner for channel scanning; Check whether the analog broadcast channel (or digital broadcast channel) exists in any frequency band through the tuner, and whether the digital broadcast channel (or analog broadcast channel) exists only when no analog broadcast channel (or digital broadcast channel) exists. Control means for confirming; And a memory for storing channel information on the analog broadcast channel or the digital broadcast channel identified by the control means.

The control means of the present invention is characterized by checking the presence of any broadcast channel for any frequency band, and controls the channel scan of the tuner to a different frequency band.

The control means of the present invention is characterized by controlling the channel scan of the tuner to a frequency band adjacent to the frequency band confirming the presence of any broadcast channel.

The memory of the present invention stores a standard frequency band table, and the control means controls a channel scan of the tuner based on the standard frequency band table.

The control means of the present invention is characterized in that for controlling the channel scan in the initial operation of the product.

Any frequency band used in the present invention means any one of the frequency bands indicated by the standard frequency band table stored in the memory, and any broadcast channel used in the present invention is a digital broadcast channel or an analog broadcast channel. Indicates.

Hereinafter, a channel scan method and apparatus for a digital broadcast receiver according to the present invention will be described in detail with reference to the accompanying drawings.

4 is a control block diagram for channel scanning of a digital broadcast receiver according to the present invention.

The present invention can be applied to a digital broadcasting receiver such as a set top box (STB) or a digital television capable of receiving digital broadcasting, and a personal video recorder, a vehicle and a portable digital broadcasting receiver. will be.

As shown, the digital broadcast receiver according to the present invention includes a tuner 30 for receiving a broadcast signal and a demux for separating the MPEG transport stream of the broadcast program received through the tuner 30 into audio / video / data. (31), an audio buffer 32 for temporarily storing the audio output from the demux 31, a video buffer 33 for temporarily storing the video output from the demux 31, and the demux 31 A data buffer 34 for temporarily storing data output from the MPEG decoder; an MPEG decoder 35 for decoding the signals of the buffers 32, 33, and 34; an OSD generator 37 for generating OSD data; and a digital And a memory 38 for storing various data and programs necessary for the operation of the broadcast receiver.

The memory 38 stores an operation program for performing a channel scan operation in the digital broadcast receiver of the present invention and various data required during operation of the operation program. For example, the broadcast signal standard frequency data for each country is stored, and the standard frequency data includes a frequency band and a center frequency for each broadcast channel. Therefore, it is possible to read and use the standard frequency data corresponding to the region or country where the digital broadcasting receiver is used from the memory. The standard frequency data includes data for both analog broadcast and digital broadcast. In FIG. 6, 181.25 MHz represents the center frequency of analog broadcast in the frequency band allocated to channel "8", and 183 MHz represents the center of digital broadcast in the same frequency band as the frequency band assigned to channel "8." Indicates frequency. Therefore, the frequency value shown in the exemplary diagram of FIG. 6 represents the center frequency of each frequency band. The memory 38 stores, as channel information, a frequency value obtained after a channel scan and a channel number associated with the frequency value in the present invention. Thereafter, the channel information is used to control a user to view a broadcast signal of a requested channel.

In addition, the digital broadcast receiver 300 of the present invention includes an HDR (HDD Record) system 40, a hard disk 41, and the like for recording on a hard disk. The hard disk 41 stores a broadcast signal received through the tuner 30. For example, in the tuner 30, any of the digital satellite broadcasts received through the satellite broadcast antenna 200, desired by the user. Tunes into a broadcast channel. The demux 31 demultiplexes the digital broadcast data stream received through the broadcast channel, and outputs the demux to audio, video, and data streams, respectively. The audio and video data streams are temporarily stored in the audio buffer 32 and the video buffer 33 and then read and signaled by the MPEG decoder 35 and output as audio and video signals. The broadcast signal output from the MPEG decoder 35 is encoded by the HDR system 40 and then recorded on the hard disk 41. The data stream is temporarily stored in the data buffer 34. For example, the microcomputer described later reads and searches service information SI stored temporarily in the data buffer, and performs broadcast signal signal processing and various controls. It is used as reference information for

Accordingly, the digital broadcast receiver 300 of the present invention can receive digital broadcast programs through the tuner 30, record arbitrary broadcast programs on the hard disk 41, play back broadcast programs stored on the hard disk 41, and the like. The microcomputer 36 performs various controls required by the digital broadcasting receiver. The microcomputer 36 controls the tuning operation of the tuner 30 to control the channel scan operation. In particular, after detecting the analog broadcast (or digital broadcast signal) in a specific frequency band, the microcomputer 36 controls not to perform a signal search for digital broadcast (or analog broadcast) in the same frequency band. In the present invention, the microcomputer 36 controls to continuously search for digital broadcasting (or analog broadcasting) in the same frequency band when analog broadcasting (or digital broadcasting) is not searched in a specific frequency band. do.

The digital broadcast receiver according to the present invention having the above-described configuration controls the channel scan rate quickly by controlling only one channel scan for one broadcast signal for one frequency band, which will be described below. Explain in detail.

5 is an operation flowchart for channel scan control of a digital broadcast receiver according to the present invention.

The channel scan operation of the present invention is performed immediately after the user purchases the product or when the broadcast channel frequency needs to be changed according to the usage area. Therefore, the channel scan operation of the present invention is generally performed early in the use of the product. The channel scan result, which is performed once until a user's request is stored, is stored in the memory 38 and used repeatedly.

When the channel scan operation starts, the microcomputer 36 reads country-specific standard broadcast frequency information stored in the memory 38. The standard broadcast frequency table for the current country or region is set and stored.

The tuner 30 is set to receive a plurality of broadcast channel information stored in the standard broadcast frequency table corresponding to the read-out country, and to receive an analog broadcast signal included in the first frequency band (S20). . Typically, in the above process, the reception frequency of the tuner 30 is controlled to 175.25 MHz, which is the center frequency of the analog broadcast signal, and in addition, the tuning operation of the tuner is controlled to receive the analog broadcast signal in the frequency band. In addition, a process of controlling the signal received by the tuner 30 to enable signal processing by a signal processor including a microcomputer and a demux 31 is required.

Including all such operations, the tuning operation of the tuner 30 is controlled under the control of the microcomputer 36, and it is monitored whether the analog broadcast signal is detected from the tuner 30 in which the reception frequency is set as described above (S21). , S22).

As shown in the exemplary diagram of FIG. 6, there is no analog signal in the first frequency band.

Accordingly, when the microcomputer 36 does not detect the analog broadcast signal in the first frequency band, the microcomputer 36 controls the center frequency of the tuner 30 to receive the digital broadcast signal included in the first frequency band. At this time, the control frequency of the tuner 30 is controlled to be 177 MHz, which is the center frequency of the digital broadcast signal. In addition, the tuning operation of the tuner is controlled to receive the digital broadcast signal in the frequency band. In addition, the received signal of the tuner 30 controls the signal processing unit including a microcomputer and a demux 31 thereafter. Including all these operations, the tuning operation of the tuner 30 is controlled under the control of the microcomputer 36, and it is monitored whether the digital broadcast signal is detected from the tuner 30 (S24, S25, S26).

As shown in the exemplary diagram of FIG. 6, there is no digital signal in the first frequency band.

Therefore, the microcomputer 36 reads the frequency value of the frequency band adjacent to the value currently set as the tuning frequency of the tuner from the standard frequency table. After checking that the broadcast channel scan operation is not completed for all frequency bands (S27), the process returns to step S20 to scan the analog broadcast channel again.

At this time, the frequency band where the channel scan is to be performed is moved to the second (i = 1), and the analog broadcast channel is examined in the second frequency band (S20 and S21).

Using the known analog broadcast frequency, the tuner 30 controls the reception frequency (181.25 MHz), monitors whether a broadcast signal is caught, and when the analog broadcast signal is caught (S22), the current frequency information is converted into channel information. It is stored in association with the memory (S23).

As shown in the exemplary diagram of FIG. 6, an analog broadcast signal exists in the second frequency band. Accordingly, in step S22, the analog broadcast channel is searched for in the second frequency band, and the channel information at this time is stored in the memory 38.

When the analog broadcast signal is detected in the second frequency band as described above, the microcomputer 36 omits the process of scanning the digital broadcast channel in the second frequency band. The microcomputer 36 performs a process of scanning the analog broadcast channel in the third frequency band.

That is, the frequency band for which the next channel scan is to be performed is moved to the third (i = 2), and the analog broadcast channel is examined in the third frequency band (S20 and S21).

Using the known analog broadcast frequency, the tuner 30 controls the reception frequency (187.25 MHz), monitors whether a broadcast signal is caught, and when the analog broadcast signal is caught (S22), the current frequency information is converted into channel information. It is stored in association with the memory (S23).

As shown in the exemplary diagram of FIG. 6, the analog broadcast signal exists in the third frequency band. Therefore, the analog broadcast channel is searched in the third frequency band in step S22, and the channel information at this time is stored in the memory 38 in step S23.

If the analog broadcast signal is detected in the third frequency band as described above, the microcomputer 36 omits the process of scanning the digital broadcast channel in the third frequency band. The microcomputer 36 performs a process of scanning the analog broadcast channel in the fourth frequency band.

That is, the frequency band where the channel scan is to be performed is moved to the fourth (i = 3), and the analog broadcast channel is examined in the fourth frequency band (S20 and S21).

The reception frequency (193.25 MHz) of the tuner 30 is controlled by using the known analog broadcast frequency, and the broadcast signal is monitored (S22).

However, as shown in the exemplary diagram of FIG. 6, no analog broadcast signal exists in the fourth frequency band.

Accordingly, if the microcomputer 36 does not detect the analog broadcast signal in the fourth frequency band, the microcomputer 36 controls the center frequency of the tuner 30 to receive the digital broadcast signal included in the fourth frequency band. At this time, the control frequency of the tuner 30 is controlled to 195 MHz, which is the center frequency of the digital broadcast signal, and in addition, the tuning operation of the tuner is controlled to receive the digital broadcast signal in the frequency band. In addition, the received signal of the tuner 30 controls the signal processing unit including a microcomputer and a demux 31 thereafter. Including all these operations, the tuning operation of the tuner 30 is controlled under the control of the microcomputer 36, and it is monitored whether the digital broadcast signal is detected from the tuner 30 (S24, S25, S26).

As shown in the exemplary diagram of FIG. 6, when a digital broadcast signal is detected in the fourth frequency band, the broadcast frequency of the current tuner and the digital channel information are stored in association with the memory 38.

The microcomputer 36 then controls the tuning operation of the tuner in the broadcast frequency band adjacent to the current broadcast frequency. Therefore, immediately after the detection of the digital broadcast signal in the fourth frequency band, the microcomputer 36 controls the tuner's reception frequency to 199.25 MHz to scan the analog broadcast channel. In this case, it is shifted to the next tuning frequency value closest to 195 MHz, which controlled the tuner frequency in the fourth frequency band, that is, 199.25 MHz in the fifth frequency band.

If the analog broadcast channel signal is not detected in the fifth frequency band, the microcomputer performs control to catch the digital broadcast channel signal in the same frequency band. That is, the tuner's receive frequency is controlled to 201 MHz in the fifth frequency band to monitor whether the digital broadcast channel signal is caught.

However, as illustrated in the exemplary diagram of FIG. 6, neither analog broadcast nor digital broadcast exists in the fifth frequency band. Therefore, the microcomputer controls the reception frequency of the tuner 30 to 205.25 MHz, which is the closest tuning frequency in the sixth frequency band.

Through this process, it is determined whether analog broadcast or digital broadcast exists for all frequency bands, and the process of storing the confirmed broadcast channel in memory is repeatedly performed (S27).

As described above, the method and apparatus for scanning a channel of a digital broadcast receiver according to the present invention irradiates an analog broadcast channel (or a digital broadcast channel) for a specific frequency band, and if an analog broadcast channel (or a digital broadcast channel) exists, The existing analog broadcast channel (or digital broadcast channel) is stored in the memory. Then, other broadcast channel surveys are skipped in the same frequency band and moved to the next adjacent frequency band. However, if no analog broadcast channel (or digital broadcast channel) exists, it is checked whether another broadcast channel exists in the same frequency band. In this process, the present invention checks whether the analog broadcast channel and the digital broadcast channel exist for all frequency bands, but reduces the channel scan time by omitting the process of overlapping the same frequency band where the broadcast channel has already been detected.

5 illustrates an example of irradiating an analog broadcast signal for the first time and irradiating a digital broadcast signal with respect to a frequency band in which the analog broadcast signal does not exist, but the present invention is not limited thereto. It is also possible to control the first start to irradiate the digital broadcast signal and to irradiate the analog broadcast signal when there is no digital broadcast signal.

The above-described preferred embodiment of the present invention is disclosed for the purpose of illustration, and when the digital broadcast receiver controls the channel scan, the channel scan is prevented by overlapping the same frequency band where the broadcast channel is already detected. It can be applied to shorten the time. Therefore, those skilled in the art will be able to improve, change, substitute or add other embodiments within the technical spirit and scope of the present invention disclosed in the appended claims.

The channel scanning method and apparatus of the digital broadcast receiver according to the present invention described above, when the analog broadcast channel (or digital broadcast channel) is irradiated for a specific frequency band, and if there is an analog broadcast channel (or digital broadcast channel), The existing analog broadcast channel (or digital broadcast channel) is stored in the memory. Then, another broadcast channel survey is skipped in the same frequency band, and the next shift is made to the next frequency band. However, if no analog broadcast channel (or digital broadcast channel) exists, it is checked whether another broadcast channel exists in the same frequency band. In this process, the present invention checks whether the analog broadcast channel and the digital broadcast channel exist for all frequency bands, but the channel scan time can be shortened by omitting the process of overlapping the same frequency band where the broadcast channel has already been detected. You get an effect.

Claims (11)

A first step of scanning a first broadcast channel in an arbitrary frequency band; A second step of scanning a first broadcast channel by moving to another frequency band when a first broadcast channel signal is detected in the frequency band of the first step; And And if the first broadcast channel signal is not detected in the frequency band of the first step, scanning the second broadcast channel in the same frequency band. The method of claim 1, And storing the channel information on the first broadcast channel or the second broadcast channel detected in the second and third steps. The method of claim 1, The second step, the channel scan method of the digital broadcast receiver, characterized in that the channel scan is performed by moving to a frequency band adjacent to the frequency band of the first step. The method of claim 1, And repeating the first to third steps for all frequency bands. The method of claim 4, wherein The first step, the channel scan method of the digital broadcast receiver, characterized in that for performing a channel scan from the first frequency band of all frequency bands. The method of claim 5, wherein The information on all the frequency bands, the channel scan method of the digital broadcast receiver, characterized in that using the pre-stored standard frequency band table. A tuner for channel scan; Control means for checking whether a first broadcast channel exists in an arbitrary frequency band through the tuner and checking whether a second broadcast channel exists only when there is no first broadcast channel; And And a memory for storing channel information on the first broadcast channel or the second broadcast channel identified by the control means. The method of claim 7, wherein The control means checks the existence of any broadcast channel for any frequency band and controls the channel scan of the tuner in a different frequency band. The method of claim 8, And the control means controls the channel scan of the tuner to a frequency band adjacent to a frequency band which has confirmed the existence of any broadcast channel. The method of claim 7, wherein The memory stores a standard frequency band table, And the control means controls a channel scan of the tuner based on the standard frequency band table. The method of claim 7, wherein And the control means controls the channel scan in the early stage of operation of the product.

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