KR101396363B1 - Apparatus and Method for Searching Broadcasting Channel - Google Patents

Abstract

The present invention relates to a method of searching for a broadcast channel, the method comprising: calculating weights of channel frequencies of at least one subchannel; Arranging only one subchannel of each subchannel included in each channel according to a calculated weight in accordance with a calculated weight; And sequentially searching for the sorted subchannels,

According to the present invention, a channel search can be completed within a short time by sorting and searching frequencies according to the priority of a channel and preferentially searching only one subchannel among subchannels of the channel.

DMB, channel search

Description

 [0001] Apparatus and Method for Searching Broadcast Channel [

1 is a flowchart showing a conventional channel search method,

2 is a diagram showing an application according to a frequency of a very high frequency (VHF) which is a frequency band of use of a terrestrial DMB (Digital Multimedia Broadcasting)

3 is a diagram showing a transmission frequency multiplex of a VHF-TV channel allocated to a metropolitan area,

FIG. 4 is a table showing availability of frequencies 7a to 13c channels allocated to DMB by region in Korea as of June 2006,

FIG. 5 is a map showing the availability of frequencies 7a to 13c channels allocated to DMB by region in Korea as of June 2006,

FIG. 6 is a flowchart illustrating a channel search method according to the present invention;

7 is a block diagram illustrating a channel search apparatus according to an embodiment of the present invention.

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a broadcasting channel, and more particularly, to a broadcasting channel searching apparatus and method.

Digital multimedia broadcasting (hereinafter referred to as DMB) is a mobile multimedia broadcasting that replaces the existing analog radio. It combines the advantages of MPEG and COFDM (Coded Orthogonal Frequency Division Multiplex) technology to provide a high-quality, high-quality multimedia signal Lt; / RTI > The 'multipath' interference, which is caused by the signal colliding with obstacles such as a building or a hill and bouncing off the FM reception, is small, and the digital multimedia receiver filters out such interference and corrects the signal error do. DMB is divided into terrestrial DMB and satellite DMB depending on satellite usage and service band.

The satellite DMB is a multimedia broadcasting service including audio, additional data, or moving picture in fixed and mobile portable receivers through satellites.

Terrestrial DMB is a mobile multimedia broadcasting service that can provide high quality voice and video service anytime and anywhere. Based on the excellent mobile reception characteristics, various contents such as music, text and video are transmitted through a portable terminal such as a small TV or PDA. In addition, it can establish a complementary relationship with digital terrestrial TV broadcasting that seeks high quality and high sound quality, and it can create an epoch-making demand of a mobile terminal through a service combined with a PDA and a mobile communication terminal. In terrestrial DMB broadcasting, a broadcasting service is provided using the VHF band.

VHF (very high frequency) is a frequency corresponding to microwave of the radio wave frequency band and belongs to the range of 30 to 300 MHz. At present, terrestrial DMB uses a bandwidth of 174 ~ 276 MHz corresponding to VHF TV channels 7 ~ 13 among very high frequency (VHF) terrestrial bands.

As of June 2006, the number of frequencies allocated to DMB in Korea is 21, ranging from Ch 7a to Ch 13c. One channel is divided into three multiplexes, and the data signal is transmitted. For example, channel 7 has three multiplexes 7a, 7b, and 7c, so the frequency assigned to one channel corresponds to three.

 Orthogonal Frequency Division Multiplexing (OFDM) is a technique for transmitting a narrow bandwidth having orthogonality, instead of a signal having a wide bandwidth, and is a technique used for high-speed transmission. Considering the OFDM time synchronization even when using this technique, it will take at least 2 seconds for searching for one channel. Therefore, it takes more than 40 seconds to search all channels. This amount of time is a tedious time for the user to wait, so it needs to be shortened.

A standard for terrestrial DMB is the ETSI EN 300 401 document from the European Telecommunication Standardization Institute (ETSI), which is also called EUREKA-147. The EUREKA-147 system uses a new frequency band other than the FM band in which analog broadcasting is serviced. It can improve the reception performance in the mobile body due to the broadband transmission, and can efficiently utilize the frequency through the high-speed data transmission and single- It is known to be the most excellent digital audio broadcasting system developed so far.

Using the advantage of the DMB, the wireless network related service providers provide DMB broadcasting service to a user device having a DMB receiving function, for example, a portable terminal, so that users can search all channels available in the current area, To be received.

In order for the users to receive data on the channel even during the mobile communication, a channel search is performed by the service provider so that the user can receive channels at a frequency that can be received, so that the user can select a desired channel anytime and anywhere.

1 is a flowchart showing a conventional channel search method.

First, the user presses the channel search start button. The service provider must set the user's selectable local information (for example, the metropolitan area, the Kangwon area, the real estate, etc.) in advance, and at step 110, the user reads local information preset by the service provider. If the user determines whether the current area is a metropolitan area or not, and if the current area is a metropolitan area, or if the current area is a metropolitan area, a certain area, a right area, a right area, a chungcheong area, or a Jeju area, the service provider searches all frequencies of the corresponding receivable channel .

If it is a metropolitan area, it searches the six frequencies of 8a-8c and 12a-12c at step 130. If the set area is a non-metropolitan area, Of frequency.

However, such a conventional method has the inconvenience that the user of the user equipment must continue to select and set the current area when moving to another area. Further, when the user selects the current position, the frequency of the channel set by the service provider must be retrieved.

SUMMARY OF THE INVENTION Accordingly, it is an object of the present invention to provide an apparatus and method for searching for an audio channel, a video channel, a data channel, and the like in various types of terminals equipped with a broadcast receiving function, The present invention also provides a channel search apparatus and method for enabling a channel to be searched quickly even in a state where a channel is searched.

According to another aspect of the present invention, there is provided a method of searching for a broadcast channel in a broadcast receiving terminal, the method comprising: (a) calculating a weight of each channel frequency having at least one subchannel; (b) arranging only one of the subchannels included in each channel according to the calculated weight in accordance with the calculated weight value in order of priority; And (c) sequentially searching for the aligned subchannels.

In the step (c), if a data signal is received at the frequency of the searched subchannel, the step (c) may preferentially search the remaining subchannels of the corresponding channel of the subchannel receiving the data signal. Estimating an area where the corresponding channel may exist through the searched channel and a database stored in advance; And deleting channels that are not receivable in the predicted region from the sorted search frequency list and rearranging the frequencies.

If the data signal is not received in all the frequencies of the sequentially retrieved subchannels, the method may further include sequentially searching for the remaining subchannels that have not been searched.

According to another aspect of the present invention, there is provided a broadcast channel search apparatus for a broadcast receiving terminal, comprising: a data processing unit for calculating weights of channel frequencies and sorting the frequencies according to the calculated weights; A tuner for receiving a wireless broadcast signal; And a channel chip for receiving the information on the frequency priority from the data processor and controlling the tuner so that the tuner sequentially searches for the aligned channel frequency, Information is used to determine the frequency of the next channel to be searched.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Reference will now be made in detail to the preferred embodiments of the present invention, examples of which are illustrated in the accompanying drawings.

2 is a view showing an application according to a frequency of VHF (very high frequency) which is a frequency band of use of a terrestrial DMB. VHF is a frequency corresponding to microwave and belongs to the range of 30 to 300 MHz.

The frequencies corresponding to frequencies 54 to 72 MHz correspond to TV channels 2 to 4, and frequencies corresponding to frequencies 72 to 88 MHz correspond to TV channels 5 to 6. In the frequency band of 88 ~ 108MHz, FM broadcasting is transmitted. Currently, the terrestrial DMB uses a bandwidth of 174 ~ 276 MHz corresponding to the VHF TV channels 7 ~ 13 corresponding to the high band of the VHF band.

3 is a diagram showing a transmission frequency multiplex and a center frequency of a VHF TV channel allocated to a metropolitan area. A multiplex can be regarded as a subchannel for transmitting different broadcasting signals by dividing one channel into three multiplexes for each frequency band.

In the metropolitan area, channel 7 is allocated to KBS2, channel 9 is allocated to KBS1, channel 11 is allocated to MBC, channel 13 is allocated to EBS, and channels 8 and 12 are allocated to DMB among VHF-TV channels 7-13.

That is, the channels other than channels 8 and 12 are analog channels, and the DMB service is provided using the VHF-TV channel frequency band that does not use analog channels.

Instead of each radio station being assigned a different frequency, multiple broadcast channels in a DMB are provided in a multiplex. In the case of one 6 MHz VHF channel, it is divided into three multiplexes and can allocate a bandwidth of 1.54 MHz per multiplex. It is possible to implement 1 to 2 video channels, 3 to 4 audio, and data broadcasting per multiplex.

In the metropolitan area, 8 and 12 of the VHF-TV channels are allocated to the DMB channels. Channels 8 and 180 use frequencies in the range of 180 to 186 MHz and 204 to 210 MHz, respectively. In the case of the channel 12, for example, it is divided into multiplexes 12a, 12b and 12c for each frequency band. The center frequencies of each multiplex of VHF-TV channel 12 are 205.264 MHz, 207.008 MHz, and 208.736 MHz. For the current DMB channel 12 of the metropolitan area, the three multiplexers 12a, 12b and 12c transmit DMB broadcasting signals of KBS, MBC and SBS, respectively.

FIG. 4 is a chart showing the availability of frequencies 7a to 13c channels allocated to DMBs in the Republic of Korea as of June 2006 as a table.

In the metropolitan area, radio waves are generated at the transmission station of the Kwanak Mountain and provide DMB service. However, it is possible to use channel 13 for Kangwon area, channel 11 for Chungcheong area, channels 7, 8 and 12 for Jeolla area, channels 7, 9 and 12 for Kyungsang area, and channels 8 and 13 for Jeju area. That is, it can be seen that the DMB available channel and the transmitting station are different by region.

FIG. 5 is a map showing the availability of frequencies 7a to 13c channels allocated to DMB by region in Korea as of June 2006. FIG.

The range of the area where the data signal can be received at the frequency of each channel is shown. In other words, the circle on the map represents the reception range, and it is possible to receive the signal through the original channel including the area. For example, in the metropolitan area, channels 8 and 12 are available, and in Jeju, channels 8 and 13 are available.

According to FIG. 4 and FIG. 5, the service provider sets channels to be searched according to the region selected by the user, and when the user selects the region, the service provider can search for the corresponding channel frequency of the selected region and provide it to the user.

6 is a flowchart illustrating a channel search method according to the present invention.

In step 600, when a user of a user device such as a portable terminal desires to receive a DMB broadcast, channel-by-frequency channel search is started.

In step 610, a weight for each channel frequency is calculated. At this time, items that can be considered in weight calculation include the area set by the user, the number of viewers by frequency, the frequency at which the latest data signal is received, and the like. Even if the user does not set a region, the weight is calculated by the remaining elements. In order to be able to calculate the weights, the receiving terminal needs to store information on the past user's viewing history, the frequency at which the latest data signal was received, and information on past channels.

For the accuracy of the weights, the formula of the weights can be determined by the field test of the present invention. The field test is a test performed outside the laboratory to check the actual reception state using a receiver having a channel search apparatus according to the present invention in the process of developing a terminal. The field test allows the developer to arbitrarily adjust the weight based on reports such as the user's usage pattern and reception status.

In step 620, the channel frequencies are sorted in order of priority according to the calculated weights.

Currently, the VHF-TV channel utilized by terrestrial DMB is divided into three multiplexes or subchannels to provide data broadcasting services. The present invention is characterized by not only arranging all of these multiplexes but also arranging only one of the corresponding channels of each multiplex (hereinafter referred to as a first multiplex). Whether or not to search for the remaining multiplexes will be determined depending on whether the signal is received at the multiplex frequency. For example, the multiplexers 7a, 8a, 9a, 10a, 11a, 12a and 13a having the lowest frequency among the three multiplexes can be searched for first. Whether data signals are received at the frequency of the multiplex 8b, 9b, 10b, 11b, 12b, 13b, 7c, 8c, 9c, 10c, 11c, 12c, 13c. Of the three multiplexes, it is not always necessary to search from a which has a lower frequency, and it is possible to search for a, b, or c first.

In step 630, the multiplexer having the highest priority among the sorted first multiplexes is selected.

Step 640 retrieves the data signal at the frequency of the multiplex selected in step 630.

It is determined whether a data signal is received and not received at the frequency retrieved at step 650. If a data signal is received, the remaining multiplexes of the corresponding channel of the first multiplex are retrieved at step 660. When a data signal is received at a multiplexed frequency of one channel, it is highly probable that a data signal is also received at the remaining multiplexed frequency. Therefore, only one multiplex is searched for each channel for fast searching, But only at the remaining multiplex frequencies.

When the channel is searched, it is possible to predict an area where the frequency is output according to Fig. 4 or Fig. For example, if a weak data signal is received at step 650 as a result of performing a search at the frequency of one multiplex of channel 11, it is highly likely that the current location of the user is a reservoir, according to FIG. Also, as shown in FIG. 5, it is very unlikely that a signal can be caught except for channels 7, 8, and 12, which are available channels in a region within a range where the channel 11 provides signals or adjacent regions.

 In step 660, the remaining multiplexes of the corresponding channel of the searched frequency are searched. In step 670, it is determined whether the search of the desired frequency is completed. If the search is completed, the search is terminated.

However, if the search for the desired multiplex has not been completed, the procedure goes to step 680. 4 and 5 are stored in the receiving terminal so that the corresponding region and the searchable channel frequency can be predicted according to which multiplex is searched. If it is predicted, the multiplex of frequencies that are not receivable in the area is deleted from the sorted search list, and the remaining multiplexes are rearranged in step 680 to enable faster searching. In the above example, when the 11th channel is searched, the multiplexes of channels 6 and 13, which have a very low possibility of signal being caught, are deleted from the search list arranged in the order of search, and the remaining frequencies are rearranged do.

As another example, if MBC, KBS, and SBS are received in the search of channel 12, it means that the current user's location corresponds to the metropolitan area. Therefore, a frequency that is far from the metropolitan area and is expected to be unreceivable is deleted from the search list You can search by using the frequencies of the metropolitan area and its neighboring areas as the highest priority.

After the frequency is retrieved and the data signal is received, the unreceivable frequency is removed from the frequency search list and the frequencies are reordered accordingly in step 680, the multiplexer of the next rank in the order of priority of the reordered multiplexes in step 690 Select. Go to step 640 to retrieve the selected multiplex.

If the data signal is not received in step 650 in the process of searching the frequency of the first multiplex having the highest priority, the frequency of the first multiplex of the next priority is selected in step 690. If the data signal is received at the frequency of the first multiplex of the next rank, the process goes to step 660 to search for the remaining multiplex of the channel, and then to search for the desired frequency at step 670 Is completed. If it is completed, the search is terminated. Otherwise, the process goes to step 680 to delete a frequency that is not expected to be received from the search list. If, however, no signal is received at the frequency of the first multiplex of the next priority, the first multiplex is searched according to the priority (steps 690, 640, 650) until it finds the frequency at which the signal is received .

If no data signal is received until all of the frequencies of the first multiplex of the channel are received, the user is informed of the frequency and the frequencies of the remaining unmatched multiplexes are searched according to the priority order. At this time, the search for the remaining multiplexes goes through the same steps as those for the first multiplex. For example, if a is searched first, if the frequencies of the multiplexes of 7a, 8a, 9a, 10a, 11a, 12a and 13a are not all detected, then 7b, 8b, 9b, ..... 11c, 12c, 13c And so on, in order to search for the remaining multiplexed frequencies. It is possible to receive the signal at the frequency of the remaining multiplex even if the first multiplexed frequency can not be detected.

In the present embodiment, a channel search method in the DMB receiving terminal is exemplified, but the present invention is not limited to the DMB but can be applied to the broadcasting receiving terminal.

7 is a block diagram of a broadcast channel search apparatus of a digital multimedia broadcast receiving terminal according to the present invention.

The digital multimedia broadcasting receiving terminal includes an antenna 710, a tuner 720, a channel chip 730, a data processing unit 740, and a user interface unit 750.

The control unit 744 of the data processing unit 740 calculates a weight for each channel multiplex when the channel search starts and aligns the multiplex of the channels according to the calculated weight. A typical example of the data processing unit 740 is a CPU. The user can make a request for receiving the DMB through the user interface 750 connected to the data processing unit 740, thereby starting the search for the channel.

The memory unit 742 of the data processing unit 740 stores in advance a method of calculating a weight value. The weight can be calculated in consideration of the area set by the user, the weight of the viewer, the recent reception level, the preference of the channel, and the like. The channel chip 730 receives the multiplexed multiplexed information from the control unit 744 of the data processing unit 740 and provides it to the tuner 720.

When the DMB base station 700 transmits a data signal to the DMB receiving terminal, the tuner 720 receives a signal receivable in the current area of the user through the antenna 710 connected to the tuner 720. It is the channel chip 730 that the tuner 720 receives the signal from the base station and determines the frequency value of the channel to be searched. That is, the channel chip 730 receives information on the channel frequency to be searched from the control unit 744 of the data processing unit 740, and controls what tuner the tuner 720 tunes.

When the channel search is started, the control unit 742 of the data processing unit 740 sets priorities of frequencies of all channels in consideration of the weight. At this time, information on the weight is stored in the memory unit 742 of the data processing unit 740 as described above. When the user wishes to set the area, the area can be set through the user interface unit 750 connected to the data processing unit 740. However, even if the user does not set the region, the weight can be calculated by the remaining weight components stored in the memory unit 742 of the data processing unit 740. [ The memory unit 742 of the data processing unit 740 stores, for example, a user weight for each area, information on past searched channels, and the like. The control unit 744 of the data processing unit 740 calculates and arranges the frequency of the channel according to the priority, and transmits the frequency to the channel chip 730.

As described above, each of the VHF-TV channels is composed of three multiplexes, and only one multiplex (hereinafter referred to as a first multiplex) among the three multiplexes is sorted in order of priority, (740) to the channel chip (730), and the frequency search by the tuner (720) is performed.

The channel chip 730 controls the tuner in the frequency band of the aligned channel in the control unit 744 of the data processing unit 740 and the tuner 720 performs the frequency search of the first multiplex, And transmits information on whether or not the signal is received to the channel chip 730. The channel chip 730 converts the information received from the tuner into a language that can be processed by the data processor 740.

Then, the channel chip 730 transmits the data signal to the data receiving unit 746 of the data processing unit 740. Then, the control unit 744 of the data processing unit 740 determines the frequency of a next channel to be searched according to whether the data signal is received by the tuner, and transmits the channel frequency to the channel chip 730 again.

When the tuner 720 receives the data signal from the DMB base station at the frequency of the first multiplex, the control unit 744, which has been notified by the receiving unit 746 of the data processing unit 740, Thereby allowing the remaining multiplexes of the channel to preferentially search in the next order. For example, if the frequency of the 7a multiplex is received, the multiplexed frequencies 7b and 7c are searched first. Next, the control unit 744 deletes the multiplex which is expected to be impossible to receive based on the frequency of the received channel, and rearranges the remaining multiplexes to transmit to the channel chip 730.

When the tuner 720 fails to receive the data signal at the frequency of the first multiplex, the control unit 744 of the data processing unit 740 receives the data signal to search for the first multiplex of the next priority, 730 control the tuner 720. If the tuner 720 can not retrieve the frequencies of all the first multiplexes, the data processor 740 arranges the multiplexed multiplexers in the order of priority to search for the remaining multiplexes, . For example, if the multiplex frequencies of 7a, 8a, 9a, 10a, 11a, 12a and 13a are not all detected, the remaining multiplex frequencies of 7b, 8b, 9b, ..... 11c, 12c, It is prioritized to be transmitted and transmitted to the channel chip.

The above-described embodiments of the present invention can be embodied in a general-purpose digital computer that can be embodied as a program that can be executed by a computer and operates the program using a computer-readable recording medium.

The computer readable recording medium may be a magnetic storage medium such as a ROM, a floppy disk, a hard disk, etc., an optical reading medium such as a CD-ROM or a DVD and a carrier wave such as the Internet Lt; / RTI > transmission).

The present invention has been described with reference to the preferred embodiments. It will be understood by those skilled in the art that various changes in form and details may be made therein without departing from the spirit and scope of the invention as defined by the appended claims. Therefore, the disclosed embodiments should be considered in an illustrative rather than a restrictive sense. The scope of the present invention is defined by the appended claims rather than by the foregoing description, and all differences within the scope of equivalents thereof should be construed as being included in the present invention.

As described above, according to the present invention, even if the user of the broadcast receiving terminal does not accurately select the current region, the subchannel frequencies of the respective channels are sorted according to the priorities of the channels with weighting, The receivable channel search can be completed.

In addition, the best result can be obtained by preferentially and selectively searching one subchannel among the subchannels of one channel rather than searching the frequencies of all the subchannels of each channel.

Claims (5)

A method for searching a broadcast channel in a broadcast receiving terminal, (a) calculating weights of respective channel frequencies of at least one sub-channel; (b) arranging only one of the subchannels included in each channel according to the calculated weight in accordance with the calculated weight value in order of priority; And (c) sequentially searching for the aligned subchannels, The step (c) If the data signal is received at the frequency of the searched subchannel, searching for the remaining subchannels of the corresponding channel of the subchannel receiving the data signal preferentially; Estimating an area where the corresponding channel may exist through the searched channel and a database stored in advance; Further comprising the step of reordering the remaining subchannels except for subchannels that are not receivable in the predicted region. delete The method according to claim 1, And sequentially searching for the remaining subchannel frequencies that have not been searched according to a priority order when a data signal is not received in all of the frequencies of the sequentially retrieved subchannels. An apparatus for searching a broadcast channel of a broadcast receiving terminal, A data processor for calculating a weight of each channel frequency having at least one subchannel and sorting one of the subchannels of the channel according to the calculated weight in order of priority; A tuner for receiving a wireless broadcast signal; And Receives the information on the subchannel frequency priorities from the data processor, controls the tuner to sequentially search the aligned subchannels, receives information on the subchannels retrieved from the tuner, and transmits the information to the data processor A channel chip for transmitting, Wherein the data processor determines a subchannel frequency to be searched next using subchannel information transmitted from the channel chip, Wherein the channel chip controls the tuner to preferentially search the remaining subchannels of the corresponding channel of the subchannel on which the data signal is received when a data signal is received at the frequency of the searched subchannel, Wherein the data processing unit predicts an area where the corresponding channel can exist through the searched channel and a previously stored database and excludes subchannels that are not receivable in the predicted area and reorders the remaining channels. . A computer-readable recording medium storing a program for causing a computer to execute the method according to any one of claims 1 to 3.

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