JP2008017204A - Digital broadcast receiver for moving body - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To receive a digital broadcast continuously even in case of a decrease in reception sensitivity or movement from one broadcasting area to another. <P>SOLUTION: A digital broadcast receiving device for a moving body includes a control means (main control section 5) of monitoring a reception state of a broadcast and a continuous time of the reception state. If a fixed reception service which is currently channel-selected can not be received any more, the control means (main control part 5) switches the channel selection to partial reception service channel selection by a broadcasting station which is currently channel-selected when the broadcasting station which is currently channel-selected is providing the partial reception service and a channel selection switching condition wherein the reception state is less than a threshold and continues for a predetermined time is met, but selects a station in the same group with the currently channel-selected broadcasting station when the channel selection switching condition is not met. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a hierarchical switching channel selection function for a fixed reception service and a partial reception service, and a sequence broadcasting station switching function for selecting a channel in the same broadcast series as the broadcast that was being viewed until immediately before selecting a channel. The present invention relates to a mobile digital broadcast receiving apparatus.

  In terrestrial digital broadcasting, the frequency band of one channel is divided into 13 segments, and segments are allocated for fixed broadcasting, mobile broadcasting, and mobile broadcasting, and are transmitted hierarchically. For example, in the case of a high quality layer for fixed broadcasting (fixed reception service), a large amount of information is transmitted by 64QAM (Quadrature Amplitude Modulation) modulation, and in the case of complementary broadcasting for mobile and mobile (partial reception service), the frequency band is not much Transmission is performed by unoccupied QPSK (Quadrature Phase Shift Keying) modulation.

  When a mobile unit such as an in-vehicle TV receiver receives the above terrestrial digital broadcast, the broadcast program being received is continued by moving away from the broadcast area of the currently selected broadcast station. May not be received. Also, reception may not be possible due to deterioration of the reception environment. In this case, the user needs to manually select a receivable station, which is troublesome and has a problem that the broadcast cannot be received unless the channel selection is successful.

  Conventionally, in response to the above-described problem, a method of detecting the movement from the broadcast area to a broadcast area of another broadcast station by monitoring the signal intensity and automatically switching the channel (for example, see Patent Document 1). Alternatively, a method of switching to a high quality layer or a low quality layer depending on the reception state (for example, see Patent Documents 2 and 3) has been proposed.

JP 2001-53635 A (paragraphs “0009” to “0010”, FIG. 1) Japanese Patent Laying-Open No. 2005-277873 (paragraphs “0006” to “0011”, FIG. 1) JP 2004-166173 A (paragraphs “0005” to “0032”, FIG. 1)

However, according to the technique disclosed in Patent Document 1 described above, since a broadcast station cannot be automatically selected without position information, a current position detecting means such as GPS (Global Positioning System) is required. When the reception condition in the broadcast area deteriorates, it is possible that the affiliated broadcast station cannot be searched even if the channel selection is repeated.
On the other hand, according to the techniques disclosed in Patent Document 2 and Patent Document 3, high-quality broadcast content can be received as much as possible by switching between the high-quality layer and the low-quality layer. When it is out of the reception area, there is a problem that digital broadcasting cannot be continuously received at any level.

  This invention was made to solve the above-mentioned problem, and reception sensitivity deteriorates due to layer switching or channel switching when the channel selection condition for channel switching and channel switching is satisfied. Alternatively, it is an object of the present invention to obtain a mobile digital broadcast receiving apparatus that can continuously receive a digital broadcast even when moving across a broadcast area.

  The mobile digital broadcast receiving apparatus according to the present invention monitors the broadcast reception state and the duration of the reception state, and when the fixed reception service currently selected cannot be received, the currently selected broadcast If a channel selection switch condition is established that the partial reception service is operated in the station and the reception state is below the threshold and continues for a predetermined time, the channel is switched to the partial reception service channel selection by the currently selected broadcast station, and the channel selection switch condition Is not established, control means for selecting the same affiliated station of the currently selected broadcast station is provided.

  A mobile digital broadcast receiving apparatus according to the present invention includes a tuner that receives digital broadcast and extracts frequency components, demodulates the frequency components into digital signals, outputs them as transport streams, and receives the reception status for each layer. And a digital demodulator that outputs determination information, a data separator that separates the transport stream into a video stream, an audio stream, and service information, a video decoder that decodes the video stream, and an audio stream The reception status of the broadcast for each layer output by the audio decoding unit and the digital demodulation unit, and the duration of the reception status are monitored, and if the fixed reception service currently selected cannot be received, Channel selection is switched off when the partial reception service is operated at the selected broadcasting station and the reception status is below the threshold and continues for a predetermined time. Switch to partial reception service channel selection by the currently selected broadcast station, if the channel selection condition is not satisfied, select the same affiliated station of the currently selected broadcast station and separate the data Based on the service information output by the unit, obtains the packet identification information of the video stream and audio stream of the layer constituting the service to be provided, and sends the video corresponding to the packet identification information to the video decoding unit and the audio decoding unit A main control unit for instructing audio decoding, a video control unit for outputting a video stream decoded by the video decoding unit under control of the main control unit, and a decoding by the audio decoding unit under control of the main control unit And an audio control unit that outputs the audio stream thus output.

  According to the present invention, it is possible to continuously receive digital broadcasting even when reception sensitivity deteriorates or moves across broadcasting areas due to layer switching or channel switching when a channel selection condition is satisfied. .

Embodiment 1 FIG.
FIG. 1 is a block diagram showing the internal configuration of a mobile digital broadcast receiving apparatus according to Embodiment 1 of the present invention.
As shown in FIG. 1, the mobile digital broadcast receiving apparatus according to the first embodiment includes a broadcast antenna unit 1, a tuner unit 2, a digital demodulation unit 3, a data separation unit 4, and a main control unit 5. And a storage unit 6, a video decoding unit 7, an audio decoding unit 8, a video control unit 9, and an audio control unit 10.

The tuner unit 2 receives a digital broadcast via the broadcast antenna unit 1, extracts a frequency component, and outputs the frequency component to the digital demodulation unit 3. The digital demodulation unit 3 demodulates the frequency component input from the tuner unit 2 into a digital signal, and outputs the digital signal to the data separation unit 4 as a transport stream (TS). The digital demodulation unit 3 also determines the reception state for each layer and outputs the determination information to the main control unit 5.
The data separation unit 4 separates the transport stream (TS) input from the digital demodulation unit 3 into a video stream, an audio stream, and service information (SI: Service Information). Output to the voice decoding unit 8 and the main control unit 5.

The video decoding unit 7 decodes the video stream separated by the data separation unit 4 under the control of the main control unit 5, and the audio decoding unit 8 performs the main control on the audio stream separated by the data separation unit 4. Decoding is performed under the control of the unit 5 and output to the video control unit 9 and the audio control unit 10, respectively.
Under the control of the main control unit 5, the video control unit 9 outputs the video stream decoded by the video decoding unit 7 to a display monitor (not shown), and the audio control unit 10 controls the main control unit 5. Then, the audio stream decoded by the audio decoding unit 8 is output as audio to a speaker (not shown).

The main control unit 5 monitors the broadcast reception status for each layer output from the digital demodulation unit 3 and the duration of the reception status. If the fixed reception service currently selected cannot be received, the main control unit 5 When the partial reception service is operated at the broadcasting station in the station and the condition that the reception state is below the threshold value and continues for a predetermined time is established, switching to the partial reception service tuning by the currently selected broadcasting station, the above-mentioned conditions Is not established, the same affiliated station of the currently selected broadcasting station is selected, and packet identification of the video stream and audio stream of the layer that constitutes the service to be provided based on the service information output by the data separation unit 4 Information is acquired, and the video decoding unit 7 and the audio decoding unit 8 are instructed to decode video and audio corresponding to the packet identification information.
The storage unit 6 holds receivable broadcast station transmission frequencies, broadcast sequence identification information, transport stream identification information (TS_ID), service identification information (S_ID), and area identification information.

FIG. 2 is a block diagram showing an expanded function of the internal configuration of the main controller 5 shown in FIG. In terms of hardware, the main control unit 5 uses a microcomputer as a control center, sequentially reads a program recorded in a built-in memory (ROM), and controls the peripheral LSI using the memory (RAM). The reception status of the broadcast and the duration of the reception status are monitored, and if the fixed reception service currently selected cannot be received, the partial reception service is operated and received at the currently selected broadcast station. When the condition that the state is below the threshold value and continues for a predetermined time is satisfied, switching to the partial reception service channel selection by the currently selected broadcast station, and when the condition is not satisfied, the same affiliated station of the currently selected broadcast station is selected It functions as a control means.
Here, the peripheral LSI is a tuner unit 2, a data demodulating unit 3, a data separating unit 4, a storage unit 6, a video decoding unit 7, an audio decoding unit, which are connected via an internal bus of the microcomputer or an input / output port. 8 refers to at least one of the video control units 9.

In order to function as the above-described control means, the main control unit 5 internally includes a reception error management unit 51, an automatic channel selection management unit 52, a channel selection control unit 53, a channel information management unit 54, It is comprised with the GUI control part 55. FIG.
The reception error management unit 51 obtains the reception state for each layer from the digital demodulation unit 3, determines whether or not a predefined layer switching condition is satisfied, and if the condition is satisfied, the reception error management unit 51 notifies the automatic channel selection management unit 52. On the other hand, it has a function of outputting a hierarchy switching request. The reception error management unit 51 also has a function of outputting a sequence broadcast station switching request when a predefined sequence broadcast station switch condition is satisfied. The hierarchy switching condition and the affiliated broadcasting station switching condition described above will be described later.

Based on the layer switching request output from the reception error management unit 51, the automatic channel selection management unit 52 acquires the video and audio stream packet identification information (P_ID) in the layer to be switched from the data separation unit 4, and the video decoding unit 7 and the audio decoding unit 8 are instructed to decode video and audio based on the acquired packet identification information (P_ID).
The automatic channel selection management unit 52 also, based on the series broadcast station switching request output from the reception error management unit 51, from the SI information output from the data separation unit 4, the area identification information in the currently selected broadcast station and Series identification information is acquired, adjacent area information is acquired by referring to the built-in adjacent area table based on the acquired area identification information, and the same series broadcast of the adjacent area is referred to the storage unit 6 based on the sequence identification information The transmission frequency of the station, transport stream identification information (TS_ID), and service identification information (S_ID) are acquired, and the acquired transmission frequency is set in the tuner unit 2 via the channel selection control unit 53, and the channel selection operation is sequentially performed. If it is determined that the reception of the digital broadcast by the channel selection operation is good based on the output of the digital 3 demodulator, the transport acquired from the storage unit 6 is performed. Based on the identification information (TS_ID) and the service identification information (S_ID), the corresponding video stream and audio stream packet identification information (P_ID) is acquired from the data separation unit 4, and is sent to the video decoding unit 7 and the audio decoding unit 8. The video and audio corresponding to the packet identification information (P_ID) is instructed to be decoded, and the video and audio of the same broadcasting station are provided.

The channel selection control unit 53 causes the tuner unit 2 to sequentially set the transmission frequency under the control of the automatic channel selection management unit 52 to perform the channel selection operation, and the channel information management unit 54 includes a data separation unit. Packet identification information (P_ID) included in the service information is acquired from No. 4, and the automatic channel selection management unit 53 is instructed to decode video and audio by fixed reception or partial reception service based on the packet identification information (P_ID). In addition, it has a function of performing processing for matching with the packet identification information (P_ID) held in the storage unit 6 and maintaining the storage unit 6 in a new state at all times.
In addition, the GUI control unit 55 selects the automatic channel selection management 52 via the channel selection control unit 53 using the same series broadcast station outside the adjacent area when there is no same series broadcast station that can be received in the adjacent area. The station operation is performed. Here, when there is no corresponding broadcast station that can be received, the video control unit 9 is controlled to provide a GUI indicating that there is no same broadcast affiliated station that can be received.

In the above configuration, first, digital broadcast radio waves received by the broadcast antenna 1 are input to the tuner unit 2. The tuner unit 2 extracts a frequency component from the received broadcast radio wave and demodulates it into a digital signal by the digital demodulation unit 3.
Here, the demodulated digital signal is input to the data separation unit 4 as a transport stream (TS), and is separated into a video stream, an audio stream, and service (SI) information by the data separation unit 4.

The main control unit 5 acquires packet identification information (P_ID) of the video stream and audio stream of the layer constituting the service to be provided from the data separation unit 4, and packet identifications corresponding to the video decoder unit 7 and the audio decoder unit 8, respectively. Information (P_ID) is output and decoding is instructed.
The decoded video and audio are output to a display monitor and a speaker (both not shown) via the video control unit 9 and the audio control unit 10, respectively.
The digital demodulator 3 also determines the reception error rate (for example, PER: Packet Error Rate) and electric field strength for each layer when demodulating the frequency component output from the tuner unit 2 into a digital signal. The main control unit 5 constantly monitors the reception state. The storage unit 6 holds transmission frequencies, sequence identifications, transport identification information (TS_ID), service identification information (S_ID), and area identifications of all broadcasting stations. The SI information acquired by the data separation unit 4 If there is a difference, the main control unit 5 updates the information stored in the memory 6 to the latest state.

By the way, the above-mentioned mobile digital broadcast receiving apparatus has a hierarchical switching channel selection function of the fixed reception service and the partial reception service, and a broadcast station of the same broadcast series as that of the broadcast that has been sequentially selected and watched until immediately before. It is equipped with a broadcasting station switching function for channel selection, and characteristically, for automatic channel selection when reception sensitivity deteriorates, channel switching conditions for layer switching and channel switching are set. It is provided with a plurality of each, and it is to provide continuous digital broadcasting automatically even in the case of reception sensitivity deterioration or movement across broadcasting areas by layer switching when each channel selection switching condition is satisfied or affiliated broadcasting station switching. .
Hierarchy switching is based on video and audio that are established only in the high-quality hierarchy (fixed reception service) of the currently received broadcast, and video, audio that is established only in the low-quality hierarchy (partial reception service), or vice versa. This is a switching method that switches from hierarchies to high-quality hierarchies, and provides continuous video and audio even if the reception status deteriorates. Also, affiliated station switching is a switching method in which the same affiliated station in the adjacent area and the affiliated station other than the neighboring area are selected in order from the area information and affiliated information of the currently receiving broadcast station. Therefore, it is possible to switch to the same affiliated station that can be received in a short time without using the location information.

The channel selection switching condition described above consists of the reception state and the duration of the reception state. By having a plurality of these conditions, the duration until the switching and the recovery of the reception state can be achieved when the reception condition is relatively mild. By setting the confirmation duration time at a long time, it is possible to avoid a decrease in viewability due to continuous switching.
Also, when the reception condition is relatively severe, the duration until switching is set to a short time, so that video and audio can be provided quickly, or quickly from the state where video and audio cannot be provided. It is possible to provide video and audio of a low quality hierarchy or the same affiliated station.

FIG. 3 shows the above-described channel selection switching conditions in a table format. In the table, I is a hierarchical switching condition, here three of a to c, and II is an affiliated broadcasting station switching condition, and here, a and b are prepared.
In the hierarchical switching condition described above, a is a lapse of the duration A after the determination threshold A of the reception error rate (PER), b is a lapse of the duration A after the threshold A, and c is a lapse of the duration B after the threshold B. (Where no error <threshold A <threshold B, duration B <duration A). That is, a is a first layer switching condition in which a relatively mild deterioration of the reception state continues for a relatively long time, and b detects a recovery of the reception state, and the reception state is good and continues for a relatively long time. C is a second hierarchy switching condition in which a relatively severe deterioration of the reception state continues for a relatively short time.

On the other hand, in the affiliated broadcasting station switching condition, a is a threshold value C or more and the power value tends to decrease, and the duration C has elapsed, and b has two conditions that the threshold D or more has the duration D elapsed (provided that there is no error < Threshold C <threshold D, duration D <duration C).
In other words, when a reception state recovery is not detected and a reception error is detected by the partial reception service, a relatively mild deterioration of the reception state continues for a relatively long time, and the reception power value tends to decrease. The first affiliated broadcasting station switching condition b is a second affiliated broadcasting station switching condition in which a relatively severe reception state continues for a relatively short time.

4 to 6 are flowcharts cited for explaining the operation of the mobile digital broadcast receiving apparatus according to the first embodiment of the present invention. The processing during the fixed reception service selection (FIG. 4) and partial reception are shown. Each of the process during service selection (FIG. 5) and the process at the time of affiliated station switching (FIG. 6) is shown.
Hereinafter, the operation of the mobile digital broadcast receiving apparatus (mainly the main control unit 5) according to the first embodiment of the present invention shown in FIGS. 1 and 2 will be described with reference to the flowcharts shown in FIGS. This will be described in detail.

When the reception state deteriorates during digital broadcast reception, the reception error management unit 51 determines the reception error rate (PER) for each layer acquired from the data demodulation unit 3 and the channel selection switching condition shown in FIG. The switching method is determined from the threshold and the duration of the reception state.
Specifically, as shown in the flowchart of FIG. 4, based on the output from the digital demodulation unit 3, the reception error management unit 51 of the main control unit 5 receives the high-quality layer during the digital broadcast reception by the fixed reception service. If an error is detected (step ST41 “YES” in FIG. 4) and the layer switching condition a or the layer switching condition c is satisfied (ST42 “YES”, ST43 “YES”), further, the affiliated station switching condition It is determined whether or not a and b are established (step ST44). Here, if the affiliated broadcasting station switching conditions a and b are not satisfied (step ST44 “NO”), the reception error management unit 51 outputs a hierarchy switching request to the automatic channel selection management unit 12. If established, the affiliated broadcasting station is switched (step ST45). Details of the affiliated station switching will be described later with reference to the flowchart of FIG.

  The automatic channel selection management unit 52 receives the above-described layer switching request and receives the packet identification information (P_ID) of the low-quality layer video and audio stream based on the partial reception service from the data separation unit 4 via the channel information management unit 54. And the video decoding unit 7 and the audio decoding unit 8 are instructed to decode with the packet identification information (P_ID) via the channel selection control unit 53, thereby providing video and audio of a low quality layer.

As described above, the digital demodulation unit 3 always monitors the reception state even after switching to the partial reception service based on the video and audio presentation of the low quality layer, and the reception error management unit 51 receives the reception output by the digital demodulation 3. When the recovery of the reception state by the fixed reception service is detected from the error rate (PER) (step ST51 in FIG. 5), the reception error management unit 51 then selects a hierarchy switching condition in which the reception state is good and continues for a relatively long time. It is determined whether or not b is established (step ST52).
When the layer switching condition b is satisfied (step ST52 “YES”), the automatic channel selection management unit 52 receives the high-quality layer video and audio based on the fixed reception service from the data separation unit 4 via the channel information management unit 54. By obtaining packet identification information (P_ID) of the stream and instructing the video decoding unit 7 and the audio decoding unit 8 to perform decoding using the packet identification information (P_ID) via the channel selection control unit 53, high-quality video Voice can be provided (step ST53).

On the other hand, when recovery of the reception state is not detected in the process of step ST52 (step ST52 “NO”) and a reception error due to the partial reception service is detected (step ST54 “YES”), a relatively mild deterioration of the reception state is performed. Is determined whether the broadcast station switching condition a in which the reception power value tends to decrease for a relatively long time or the broadcast station switching condition b in which the relatively severe reception state continues for a relatively short time is established. (Steps ST55 and ST56).
Here, when either of the affiliated broadcasting station switching conditions a and b is satisfied (steps ST55 “YES” and ST56 “YES”), the hierarchical switching tuning is switched to the affiliated broadcasting station tuning, and the broadcast program being viewed is selected. Continuous reception is performed (step ST57).

When the above-mentioned broadcast station switching condition is satisfied, the reception error management unit 51 requests the automatic channel selection management unit 52 to switch the broadcast station, and the automatic channel management unit 52 that has received this request Station switching is started (step ST61 in FIG. 6). That is, the automatic channel selection management unit 52 receives the area identification information of the currently selected broadcasting station from the NIT (Network Information Table) of the service information (SI) from the data separation unit 4 via the channel information management unit 54. Acquires the sequence identification information of the currently selected broadcasting station from (Broadcaster Information Table).
The automatic channel selection management unit 52 has a built-in adjacent area table (not shown), and acquires the adjacent area information by indexing the adjacent area table from the previously acquired area identification information (step S62). Based on the previously acquired sequence identification information, the transmission frequency information, transport identification information (TS-ID), and service identification information of the same series broadcasting station in the adjacent area are stored from the storage unit 6 via the channel information management unit 54. (S-ID) is acquired (step ST63).

The automatic channel selection management unit 52 notifies the acquired information to the channel selection control unit 53 when the broadcasting station in the adjacent area has the same affiliated station as described above (step ST64 “YES”), and acquires the acquired transmission frequency information. Based on this, frequency setting for tuning is performed in the tuner unit 2 (step ST65).
Subsequently, the automatic channel selection management unit 52 determines the presence / absence of a receivable station according to the above-described channel selection operation based on the output of the channel selection control unit 53 (step S66), and if reception is possible (step ST66 “YES”). ), The corresponding video and audio packet identification information (P_ID) is acquired from the data separator 4 based on the transport identification information (TS-ID) and the service identification information (S-ID). Then, by instructing the video decoding unit 7 and the audio decoding unit 8 to decode the corresponding packet identification information (P_ID), the video and audio of the same series broadcasting station are provided (step ST67).

On the other hand, when there is no same affiliated station in the broadcasting station in the adjacent area (step ST64 “NO”), the automatic channel selection management unit 52 selects the same affiliated station other than the adjacent area to the tuning control unit 53. (Step ST68), the channel selection control unit 53 determines the presence / absence of a receivable station based on this channel selection operation (step S69), and notifies the automatic channel selection management unit 52 of it.
If reception is possible (step ST69 “YES”), the automatic channel selection management unit 52 selects the corresponding video from the data separation unit 4 based on the transport identification information (TS-ID) and the service identification information (S-ID). By acquiring audio packet identification information (P_ID) and instructing the video decoding unit 7 and audio decoding unit 8 to decode the corresponding packet identification information (P_ID), the video of the same series broadcasting station other than the adjacent area The voice is provided (step ST67).

According to the above processing, by selecting a channel from the adjacent area acquired from the area identification of the currently selected broadcast station, a broadcast program by the same affiliated broadcast station that can be received rather than sequentially setting and selecting a frequency. It is possible to speed up the reception of.
If no receivable station is still found (step ST69 “NO”), the automatic channel selection management unit 52 notifies the GUI control unit 55 that there is no same receivable sequence, and via the video control unit 9. Present to the user (step ST70).

Note that, in the above-described sequence broadcasting station switching, switching is performed using the tendency of fluctuation of the power value in addition to the reception error rate (PER). This is because even if the reception error is relatively mild, if the power value is gradually decreasing, it is considered that the area boundary of the broadcasting station is approaching.
When this state continues for a certain period of time (affiliated broadcast station switching condition a), it is possible to avoid switching outside the broadcast area after video and audio are stopped by switching the affiliated broadcast station. It is possible to avoid unnecessary switching between affiliated broadcasting stations at locations where reception conditions deteriorate. In addition to the PER, the received error rate may be replaced with a C / N (Carrier to Noise Ratio) or a decoding error rate at the time of video and audio decoding.

FIG. 7 shows an example of channel selection associated with movement on the area map, and FIG. 8 is an operation conceptual diagram conceptually showing the channel selection switching operation at that time in a table format.
In FIG. 7, broadcast station A and broadcast station B are the same broadcast series, and the ranges where radio waves reach are shown as broadcast station area A and broadcast station area B, respectively. Moreover, af shows the point accompanying a movement and the area | region which attached | subjected hatching is made into a weak electric field area | region.
As shown in FIG. 8, by using two channel selection switching methods of hierarchical switching and affiliated broadcasting station switching, when receiving a digital broadcast with movement, a weak electric field area (points b and d in the broadcasting area). ), It is possible to provide video and audio of a low quality layer based on partial reception service by layer switching, and video and audio of a high quality layer of an affiliated broadcasting station by switching the affiliated broadcasting station near the boundary of the broadcasting station area. it can.

As described above, according to the first embodiment of the present invention, it is continued even when reception sensitivity deteriorates or moves across broadcasting areas due to hierarchical switching when switching conditions are satisfied or affiliated broadcasting station switching. It enables digital broadcast reception.
However, when layer switching or affiliated broadcasting station switching is performed with a relatively mild reception error, the video and audio to be provided are continuously switched, which reduces the user's viewability, Unless switching is performed until a relatively severe reception error occurs, a large amount of noise is superimposed on the video and audio, and there is a danger that the video and audio non-providing period lasts for a long time. According to Embodiment 1 of the present invention, as shown in FIG. 3, by setting a plurality of hierarchical switching conditions and affiliated broadcasting station switching conditions, when a relatively mild reception error occurs, it is generated for a long time. In addition, when a relatively severe reception error occurs, channel selection switching operation is performed by continuous occurrence for a short time, and layer switching from the low quality layer to the high quality layer has very few reception errors (error free) It is possible to avoid continuous switching by executing switching only when the state continues for a long time, so that viewability is not deteriorated, and a period in which noise is superimposed on video and audio is provided. Can be shortened.

  The embodiment of the present invention has been described in detail with reference to the drawings. However, the specific configuration is not limited to this embodiment, and includes design and the like within the scope not departing from the gist of the present invention.

It is a block diagram which shows the internal structure of the digital broadcast receiver for mobile bodies concerning Embodiment 1 of this invention. FIG. 2 is a block diagram showing an expanded function of an internal configuration of a main control unit shown in FIG. 1. It is the figure which showed in a table form an example of the channel selection conditions used with the digital broadcast receiver for mobile bodies concerning Embodiment 1 of this invention. It is the flowchart quoted in order to demonstrate operation | movement of the digital broadcast receiver for mobile bodies concerning Embodiment 1 of this invention. It is the flowchart quoted in order to demonstrate operation | movement of the digital broadcast receiver for mobile bodies concerning Embodiment 1 of this invention. It is the flowchart quoted in order to demonstrate operation | movement of the digital broadcast receiver for mobile bodies concerning Embodiment 1 of this invention. It is the operation | movement conceptual diagram quoted in order to demonstrate operation | movement of the digital broadcast receiver for mobile bodies concerning Embodiment 1 of this invention. It is the operation | movement conceptual diagram quoted in order to demonstrate operation | movement of the digital broadcast receiver for mobile bodies concerning Embodiment 1 of this invention.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 Broadcasting antenna part, 2 Tuner part, 3 Digital demodulation part, 4 Data separation part, 5 Main control part (control means), 6 Storage part, 7 Video decoding part, 8 Audio decoding part, 9 Video control part, 10 Audio control Section, 51 reception error management section, 52 automatic channel selection management section, 53 channel selection control section, 54 channel information management section, 55 GUI control section.

Claims (9)

Equipped with a hierarchical switching channel selection function for fixed reception service and partial reception service, and an affiliate broadcasting station switching function that selects channels in sequence and selects a broadcasting station of the same broadcasting series as the broadcast that was being viewed until immediately before. A mobile digital broadcast receiver,
The broadcast reception status and the duration of the reception status are monitored, and when the fixed reception service currently selected cannot be received, the partial reception service is operated at the currently selected broadcast station, and When the channel selection condition that the reception status is below the threshold and continues for a predetermined time is satisfied, the channel is switched to the partial reception service channel selection by the currently selected broadcasting station, and when the channel selection condition is not satisfied, the currently selected channel broadcasting Control means for selecting the same affiliated station,
A digital broadcast receiving apparatus for a mobile unit comprising: The control means includes
When a relatively mild reception state deteriorated by comparing with two or more threshold values, the duration based on the reception state until the layer switching, and the reception state for confirming that the reception state has recovered Is set to a first value, and when a relatively severe reception state deteriorates, the duration time until the layer switching is set shorter than the first value. The digital broadcast receiver for mobile bodies according to claim 1. The control means includes
A first layer switching condition in which a reception error due to the fixed reception service is detected and a relatively mild reception state continues for a relatively long time, or a relatively severe reception state deterioration continues for a relatively short time. In the case where any one of the hierarchical switching conditions is satisfied, a first mild broadcasting station switching condition in which a relatively mild deterioration of the reception state continues for a relatively long time and the received power value tends to decrease, and It is determined whether or not the second affiliated broadcasting station switching condition that the severe reception state continues for a relatively short time is satisfied, and when the first and second affiliated broadcasting station switching conditions are satisfied, 3. The mobile digital broadcast receiving apparatus according to claim 1, wherein in the case of switching or failure, video and audio based on hierarchical switching by partial reception service are provided. The control means includes
When the recovery of the reception state by the fixed reception service is detected and the third layer switching condition that the reception state is good and continues for a relatively long time is satisfied, the layer switching from the partial reception service to the fixed reception service is performed, Present video and audio based on hierarchy switching,
When the reception status recovery is not detected and a reception error is detected by the partial reception service, the first sequence in which the reception power value tends to decrease due to a relatively mild deterioration of the reception status continues for a relatively long time. It is determined whether or not a broadcasting station switching condition or a second affiliate broadcasting station switching condition in which a relatively severe reception state continues for a relatively short time is satisfied, and either of the first and second affiliate broadcasting station switching conditions 4. The mobile digital broadcast receiving apparatus according to claim 3, wherein, when the above is established, switching from hierarchical switching channel selection to affiliated channel tuning is performed. The control means includes
In selecting the affiliated broadcast station, the adjacent area information is obtained from the area identification information of the selected broadcast station to obtain broadcast station information based on the adjacent area, and the broadcast station in the adjacent area has the same broadcast affiliated station. If there is a broadcasting station in the adjacent area and the same affiliate broadcasting station, the same affiliate broadcasting station in the neighboring area is selected, and when it is a receivable station, the receivable video and If the same affiliated station other than the neighboring area is selected when the neighboring station broadcast station does not have the same affiliated station, the video and audio of the receivable station are selected. The mobile digital broadcast receiving apparatus according to claim 3 or 4, wherein when the reception is impossible, the fact that there is no same affiliated station is output by a GUI (Graphical User Interface). Equipped with a hierarchical switching channel selection function for fixed reception service and partial reception service, and an affiliate broadcasting station switching function that selects channels in sequence and selects a broadcasting station of the same broadcasting series as the broadcast that was being viewed until immediately before. A mobile digital broadcast receiver,
A tuner for receiving digital broadcasts and extracting frequency components;
A digital demodulator that demodulates the frequency component into a digital signal and outputs it as a transport stream, determines a reception state for each layer, and outputs the determination information;
A data separator that separates the transport stream into a video stream, an audio stream, and service information;
A video decoding unit for decoding the video stream separated by the data separation unit;
An audio decoding unit for decoding the audio stream separated by the data separation unit;
The broadcast reception status for each layer output by the digital demodulator and the duration of the reception status are monitored, and when the fixed reception service currently selected cannot be received, the currently selected broadcast station When the partial reception service is operated and the channel selection switching condition that the reception state is below a threshold value and continues for a predetermined time is satisfied, the channel selection is switched to the partial reception service channel selection by the currently selected broadcasting station, and the channel selection switching is performed. If the condition is not satisfied, the same affiliated station of the currently selected broadcasting station is selected, and the video stream and audio stream packets of the layers constituting the service to be provided based on the service information output by the data separation unit A main control unit that obtains identification information and instructs the video decoding unit and the audio decoding unit to decode video and audio corresponding to the packet identification information;
A video control unit that outputs a video stream decoded by the video decoding unit under the control of the main control unit;
An audio control unit that outputs the audio stream decoded by the audio decoding unit under the control of the main control unit;
A digital broadcast receiving apparatus for mobile objects characterized by comprising: The main control unit
Obtaining the reception status for each layer from the digital demodulator, determining whether or not a predefined layer switching condition is satisfied, a reception state management unit that outputs a layer switching request when the condition is satisfied,
Based on the layer switching request, the packet identification information of the video and audio stream in the layer to be switched from the data separation unit is acquired, and the video and audio decoding units and the audio decoding unit are notified of the video and audio based on the acquired packet identification information. An automatic tuning manager that instructs decoding;
The mobile digital broadcast receiver according to claim 6. A storage unit in which transmission frequencies of broadcast stations that can be received, broadcast sequence identification information, transport stream identification information, service identification information, and area identification information are held,
The main control unit
A tuning control unit for sequentially setting a transmission frequency in the tuner unit and performing a tuning operation;
A reception state management unit that outputs a sequence broadcast station switching request when the predefined broadcast station switch condition is satisfied;
Based on the affiliated station switching request, from the service information output from the data separation unit, the area identification information and the series identification information in the currently selected broadcasting station are acquired, and built-in based on the acquired area identification information The adjacent area information is obtained by referring to the adjacent area table, and referring to the storage unit based on the sequence identification information, each of the transmission frequency, transport stream identification information, and service identification information of the same series broadcasting station in the adjacent area Get
Via the channel selection control unit, the acquired transmission frequency is set in the tuner unit so that channel selection operations are performed sequentially, and reception of digital broadcast by the channel selection operation is good based on the output of the digital demodulation unit. If it is determined that the packet identification information of the corresponding video stream and audio stream is acquired from the data separation unit based on the transport identification information and service identification information acquired from the storage unit, the video decoding unit, the audio decoding An automatic channel selection management unit that instructs the unit to decode video and audio corresponding to the packet identification information, and presents video and audio of the same series broadcast station;
The mobile digital broadcast receiver according to claim 6. The automatic tuning manager is
When there is no same series broadcast station that can be received in the adjacent area, the channel selection operation is performed using the same series broadcast station outside the adjacent area, and when there is no corresponding broadcast station that can be received, the video control unit is controlled. 9. The mobile digital broadcast receiving apparatus according to claim 8, wherein a GUI indicating that there is no same broadcast affiliated station that can be received is provided.

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