JP5240033B2 - Mobile digital broadcast receiver and channel search method in mobile digital broadcast receiver - Google Patents

Description

  The present invention relates to a mobile digital broadcast receiver and a channel search method in the mobile digital broadcast receiver, and more specifically, a mobile digital broadcast receiver and a mobile digital broadcast receiver capable of speeding up channel search. Relates to a channel search method.

  2. Description of the Related Art Conventionally, in a mobile broadcast receiving apparatus, after searching for a channel of a basic station (master station), a channel search is performed for a relay station, and then a channel search is performed for an alternative station (affiliated station). Is detected, the detected broadcast channel is continuously received (see, for example, Patent Document 1).

Here, the relay station is an auxiliary broadcasting station provided in a different area from the parent station when the target area cannot be covered only by the parent station due to geographical influences. The relay station is the same broadcast station as the master station and is broadcasting the same program, and information on this relay station is transmitted to the mobile broadcast receiving apparatus as a relay station list of NIT (Network Information Table). By performing a channel search using the relay station list, if a broadcast cannot be received from a certain relay station, the broadcast can be received from another relay station and the same program from the same broadcast station can be continuously viewed. It becomes possible to be in a state.
On the other hand, there is a connection between broadcasters installed in each region, and broadcasters have a relationship between a parent station that sends a program and an affiliated station that receives and broadcasts the same program. Broadcasting companies that are affiliated with each other often spend the same time broadcasting the same program, but they are not necessarily the same. The information for identifying the affiliated station is transmitted to the mobile broadcast receiving apparatus as BIT (Broadcaster Information Table) sequence identification information. It can be regarded as an affiliated station if it has the same sequence identification information as the channel received before executing the channel search and the network identification information that can identify the broadcaster is different. . In addition, if the same affiliated station information and the same network identification information are the same, it can be regarded as a relay station because it is the same broadcasting station.

Japanese Patent Laid-Open No. 07-288446

In digital broadcasting, it takes about 500 msec to select a channel. For this reason, while searching for a relay station or affiliated station, the broadcast that has been received until then cannot be viewed for the time of channel search. That is, in the conventional mobile broadcast receiving apparatus, even when the original physical channel (previous viewing channel) that can no longer be received can be received during the channel search, the user can actually receive it. There was a problem that the channel could not be viewed until after the channel search was completed unless the previous viewing channel was selected.
Further, in the above-described conventional mobile broadcast receiving apparatus, the channel search of the relay station / affiliated station is executed based on the relay station list / sequence identification information transmitted as a broadcast signal. There was also a problem that the affiliated station could not receive.
The present invention has been made to solve the above-described problem, and can easily return to the broadcast channel that was viewed immediately before the channel search, and the channel search can be made inexpensively. It is an object of the present invention to provide a mobile digital broadcast receiving apparatus and a channel search method in the mobile digital broadcast receiving apparatus that can be realized quickly and accurately.

  The mobile digital broadcast receiving apparatus of the present invention receives a channel selection request, selects a physical channel designated by the channel selection request, and a reception level for measuring the electric field strength of the selected physical channel. Measurement unit, storage unit for storing last channel, relay station information and channel search list, search list creation unit for creating channel search list, and search for executing channel search processing based on the stored channel search list The search list creation unit creates a channel search list in which the last channel is inserted into the relay station information at an arbitrary interval based on the last channel and the relay station information, and outputs the channel search list to the storage unit. It is characterized by that.

  The channel search method in the mobile digital broadcast receiving apparatus of the present invention includes a step of acquiring a last channel, a step of acquiring relay station information, and a last channel inserted into the acquired relay station information at an arbitrary interval. The method includes the steps of creating a channel search list and executing a channel search process based on the created channel search list.

As described above, according to the present invention, during the channel search execution, the broadcast channel viewed before the channel search execution is inserted at an arbitrary interval, and the frequency of searching for the immediately preceding viewing channel is increased. Since all receivable broadcasting stations are channel searched, it is possible to easily return to the broadcasting channel that was viewed immediately before the channel search is being executed, and the channel search can be performed quickly and accurately with an inexpensive configuration. Can be realized.

1 is a block diagram showing the configuration of a mobile digital broadcast receiver according to a first embodiment of the present invention. Flowchart showing channel search processing according to the embodiment The figure which shows the structure of the channel search list concerning the embodiment

(Embodiment 1)
FIG. 1 is a block diagram showing a configuration of a mobile digital broadcast receiving apparatus according to Embodiment 1 of the present invention. The mobile digital broadcast receiving apparatus 100 is a digital broadcast receiving apparatus installed in a moving body such as a vehicle, for example, and includes a channel selection unit 101, a last channel storage unit 103, a search list creation unit 104, and a search processing unit 105. Consists of

  The channel selection unit 101 tunes to the instructed physical channel in response to a channel selection request from the search processing unit 105. In addition, the relay station list and sequence identification information are received as broadcast signals.

  The reception level measurement unit 102 measures the radio field intensity of the physical channel selected by the channel selection unit 101 and outputs the measured radio field intensity information to the search processing unit 105 as radio field intensity information.

  The storage unit 103 stores a physical channel (last channel) immediately before being selected before starting the channel search process. Further, the channel search list created by the search list creation unit 104 is stored. Further, the relay station list and sequence identification information acquired as a digital broadcast signal are stored.

  In response to a channel search list creation request from the search processing unit 105, the search list creation unit 104 acquires a relay station list from the storage unit 103 and creates a channel search list. Then, the created channel search list is output to the storage unit 103 and a channel search list creation completion notification is output to the search processing unit 105. The channel search list creation process will be described in detail later with reference to FIG.

  The search processing unit 105 outputs a channel search list creation request to the search list creation unit 104, triggered by a channel search instruction from the user or detection of a decrease in radio field intensity of the broadcast channel being viewed. Further, in response to the channel list creation completion notification from the search list creation unit 104, the channel search list is acquired from the storage unit 103, and the channel selection request is made to the channel selection unit 101 to sequentially select the physical channels described in the channel search list. Is output. Further, the radio wave intensity information is received from the reception level measuring unit 102, and it is determined whether or not the physical channel for which the channel selection instruction has been received is receivable. If the physical channel is a relay station or an affiliated station, reception of the physical channel for which a channel selection instruction has been issued is continued. The search process will be described in detail later with reference to FIG.

  Next, channel search processing executed by the search list creation unit 104 and the search processing unit 105 will be described with reference to FIGS. FIG. 2 is a flowchart showing channel search processing according to the first exemplary embodiment of the present invention. FIG. 3 is a diagram showing the structure of the channel search list. The channel search processing includes channel search list creation processing (step S201 to step S205) executed by the search list creation unit 104 and search processing (step S206 to step S208) executed by the search processing unit 105.

  First, the search list creation unit 104 receives a channel search list creation request from the search processing unit 105, and acquires the last channel and relay station list from the storage unit 103 (steps S201 and S202). Then, the acquired relay station list is arranged in order from the lowest frequency (step S203), and thereafter, the channel search list A (in FIG. 3) in which physical channels not included in the relay station list are arranged in order from the lowest frequency. (A)) is created (step S204). Further, the last channel is inserted into the channel search list A at an arbitrary interval to create a channel search list B ((b) in FIG. 3) (step S205). In the first embodiment, as shown in FIG. 3B, an arbitrary interval is set so as to be able to search alternately with the physical channels described in the channel search list A. The search list creation unit 104 outputs a channel search list creation completion notification to the search processing unit 105 after the processing of step S205 is completed.

  The search processing unit 105 receives a channel search list creation completion notification from the search list creation unit 104 and outputs a channel selection request to the channel selection unit 101 based on the channel search list B. The channel selection unit 101 selects a corresponding physical channel in response to the channel selection request (step S206). The reception level measurement unit 102 measures the electric field strength of the physical channel selected by the channel selection unit 101, and outputs the electric field strength information to the search processing unit 105. Based on the electric field strength information, the search processing unit 105 determines whether or not the physical channel for which the channel selection request has been made is at a receivable level, and determines that it is at a receivable level (in step S207). "YES"), the relay station / affiliated station is determined based on the sequence identification information and the network identification information (step S208). If it is a relay station or affiliated station (“YES” in step S208), reception of the detected physical channel is continued (step S209). If it is not a relay station or affiliated station (“NO” in step S208), the processing from step S206 to step S208 is repeated.

  On the other hand, when the search processing unit 105 determines that the physical channel for which the channel selection request has been made is not at a receivable level (“NO” in step S207), the channel selection of the next physical channel described in the channel search list B is performed. The request is output to the channel selection unit 101, and the processing from step S206 to step S208 is repeated until a receivable level physical channel is detected.

  In the first embodiment of the present invention, a channel search list creation request is made to the search list creation unit 104 by using a channel search instruction from the user or detection of a decrease in radio field intensity of the broadcast channel being viewed as a trigger. The channel search list B is created, but the channel search list A is created in advance at any timing such as when the area is changed, and the channel search instruction from the user or the radio wave of the broadcast channel being viewed Only the channel search list B may be created with the intensity decrease detection as a trigger.

  According to the present invention, the channel search time can be obtained by inserting the last channel whose reception level is deteriorated but highly detectable in the next channel search process into the channel search list at an arbitrary interval and repeating the channel search preferentially. Can be shortened.

  In addition, it is not necessary to add a new configuration (for example, providing a separate dedicated tuner) for speeding up the channel search process, and the channel search processing can be speeded up with the conventional one tuner configuration. Can do.

  Furthermore, since all physical channels not listed in the relay station list are also channel-searched, receivable physical channels can be extracted accurately.

  According to the present invention, even during the channel search execution, it is possible to easily return to the broadcast channel that was viewed immediately before, and the channel search can be realized quickly and accurately with an inexpensive configuration. It is useful for all mobile digital broadcast receivers such as in-vehicle digital broadcast receivers and portable digital broadcast receivers.

DESCRIPTION OF SYMBOLS 100 Mobile digital broadcast receiver 101 Channel selection part 102 Reception level measurement part 103 Storage part 104 Search list creation part 105 Search processing part

Claims (6)

A channel selection unit that receives a channel selection request and selects a physical channel instructed by the channel selection request;
A reception level measurement unit that measures the electric field strength of the selected physical channel;
A storage unit for storing a last channel, relay station information, and a channel search list;
A search list creation unit for creating the channel search list;
A search processing unit for executing a channel search process based on the stored channel search list,
The search list creation unit creates a channel search list in which the last channel is inserted into the relay station information at an arbitrary interval based on the last channel and the relay station information, and outputs the channel search list to the storage unit. A mobile digital broadcast receiver characterized by the above. 2. The mobile digital broadcast receiving apparatus according to claim 1, wherein the search list creating unit creates a channel search list so that the relay station information and the last channel are searched alternately. The search list creation unit creates a first channel search list by adding all remaining receivable physical channel information other than the physical channel described in the relay station information after the relay station information. Creating a second channel list in which the last channel is inserted into the first channel search list at an arbitrary interval and outputting the second channel list to the storage unit;
The mobile digital broadcast receiving apparatus according to claim 1, wherein the search processing unit performs a channel search process based on the second channel search list. Whether the search processing unit is a relay station or an affiliated station based on the network identification information and the sequence identification information of the physical channel when the electric field strength measured by the reception level measuring unit is a receivable level. 4. The mobile digital broadcast receiving apparatus according to claim 1, wherein the mobile digital broadcast receiving apparatus is configured to determine whether or not to continue the reception of the physical channel only when it is a relay station or an affiliated station. Obtaining a last channel;
Obtaining relay station information;
Creating a channel search list in which the last channel is inserted at an arbitrary interval in the acquired relay station information;
Executing channel search processing based on the created channel search list;
A channel search method characterized by comprising: Obtaining a last channel;
Obtaining relay station information;
Acquiring all remaining receivable physical channel information other than the physical channel described in the relay station information to create a first channel search list;
Creating a second channel search list in which the last channel is inserted into the first channel search list at an arbitrary interval;
Executing a channel search process based on the created second channel search list;
A channel search method characterized by comprising:

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