JP4931503B2 - Digital broadcast receiving apparatus and frequency list creation method - Google Patents

Description

  The present invention relates to a digital broadcast receiving apparatus and a frequency list creating method, and more particularly to a digital broadcast receiving apparatus and a frequency list creating method for creating and using a frequency list of receivable digital broadcast channels.

  In digital television broadcasting, the video / audio information of multiple programs and program arrangement information SI (Service Information) with the MPEG-2 TS (MPEG-2 Transport Stream) format as a logical format are multiplexed and transmitted, and the user receives them. A terminal receives a multiplexed signal and decodes and enjoys a desired program. That is, the broadcast station converts the program arrangement information SI, video streams and audio streams of a plurality of programs into MPEG-2 TS format packets, and multiplexes the obtained packets to form MPEG-2 TS transport streams. Send it on the carrier.

FIG. 4 is a configuration diagram of a terrestrial digital broadcasting station. The multiplexing unit 11 includes program arrangement information SI created by the SI creation unit 12 and video information generated by the plurality of program generation units 13a, 13b,. / Multiply audio information. The program arrangement information SI is a number of tables shown in FIG.
(1) PAT (Program Association Table),
(2) CAT (Conditional Access Table),
(3) PMT (Program Map Table),
(4) NIT (Network Information Table),
(5) SDT (Service Description Table),
(6) BAT (Bouquet Association Table),
(7) EIT (Event Information Table),
(8) TDT (Time Date Table),
(9) RST (Running Status Table),
(10) ST (Stuffing Table)
It is comprised by. The first four tables PAT, CAT, PMT, and NIT are called program specification information PSI (Program Specific Information). Based on the program sequence information SI, (1) the name of the organized channel (transport stream identification TS-ID) and (2) information on other channels that are carrying out digital broadcasting with the same TS-ID (same digital broadcasting) Etc. Furthermore, the program sequence information SI includes (3) information on the program such as the program name, broadcast date and time, description of the program content, (4) current date and time, (5) current progress of the program, etc. It is out.
The RS encoding unit 14 performs Reed-Solomon encoding processing on the multiplexed signal, and the convolutional encoding unit 15 further performs convolutional encoding processing and inputs the result to the OFDM modulation unit 14. The OFDM modulation unit 14 performs IFFT processing on N samples as N subcarrier signal components, adds a guard interval to the obtained time-series signal, performs DA conversion, and inputs the result to the transmission unit 17. The transmission unit 19 up-converts the input OFDM modulated signal to a transmission frequency (channel frequency) assigned to the own station and transmits the signal.

A digital TV broadcast receiving apparatus (not shown) appropriately creates and displays an electronic program guide (EPG) based on the received program arrangement information SI, and the user selects a program to be viewed. When a program to be viewed is selected, the digital broadcast receiving apparatus selects and demodulates the carrier on which the program is multiplexed, and MPEG-2 TS (Transport) in which a plurality of television broadcast program packets are multiplexed. After that, the video packet and audio packet of the target television broadcast program are extracted from the transport stream, and the extracted video packet and audio packet are decoded to output video and audio.
As another method for selecting a television broadcast program, there is a method using a frequency list (hereinafter referred to as a service list) of receivable digital broadcast channels. In this method, a service list is created in advance, and when a user presses a channel up key or a channel down key, a receivable channel is obtained from the service list and a desired television broadcast program is received. Alternatively, a service list is displayed, and a desired channel is selected from the list. Such a service list is conventionally created by the following procedure.

  First, an area where the digital TV broadcast receiving apparatus exists is set. Next, an instruction to start scanning is given. As a result, the system controller of the digital TV broadcast receiver creates a service list by scanning from 13CH to 62CH sequentially for channels in MFN (Multi Frequency Network) to obtain channels with good reception status. To do. At this time, the system controller, when a channel having the same organization series as a certain channel has already been registered in the service list, that is, the channel CH of the same TS-ID as the TS-ID of the channel of interest. If already registered, the broadcast contents are the same, so compare the C / N (Carrier / Noise) and BER (Bit Error Rate) to determine the channel with good reception status and register it in the service list. .

6 and 7 are explanatory diagrams for explaining the situation. As shown in FIG. 6, it is assumed that the TV transmission station TVBS1 of the physical channel CH13 and the TV transmission station TVBS2 of the physical channel CH16 existing in two adjacent areas AR1 and AR2 perform digital TV broadcasting of the same organization series. That is, both transmitting stations are assumed to be performing digital TV broadcasting with the same composition channel identifier TS-ID (= TS1). In such a case, the relationship between the organization channel (TS-ID) and the physical channel CH is as shown in FIG. 7, for example. The carrier frequency of each physical channel increases from 470 MHz in increments of 6 MHz. The carrier frequency of the physical channel CH13 is 470 MHz, the organization channel ID (TS-ID) is TS1, the carrier frequency of the physical channel CH16 is 488 MHz, and the organization channel ID (TS-ID) is TS1.
A digital TV broadcast receiver (not shown) of the vehicle CR1 existing at point B in the area AR1 receives TV radio waves from the transmission stations TVBS1 and TVBS2 of the physical channel 13 and the physical channel 16 when the service list is created. In such a case, the digital TV broadcast receiver of the vehicle CR1 needs to determine a physical channel with a good reception state and register it in the service list. Further, the digital TV broadcast receiving apparatus of the vehicle CR2 existing at the point A of the area AR2 receives TV radio waves from the transmission stations TVBS1 and TVBS2 of the physical channel 13 and the physical channel 16 when the service list is created. Even in such a case, the digital TV broadcast receiver of the vehicle CR2 needs to determine a physical channel with a good reception state and register it in the service list.

FIG. 8 is a process flow of the system controller when a channel having a good reception state is obtained in the service list creation process. If the C / N of the scanned predetermined channel CH is good, the system controller acquires the BER at the time of receiving the channel from the BER detection unit (step 101), and then included in the SI information separated from the received signal NIT (Network Information Table) is extracted (step 102), and another channel having the same NT-ID as that of the currently received channel is obtained from the NIT, and it is checked whether the other channel is registered in the service list. (Step 103). If not registered, the currently received channel is registered in the service list, and the BER acquired in step 101 is stored (step 104).
On the other hand, if another channel having the same NT-ID as the NT-ID of the currently receiving channel is registered in the service list in step 103, the BER of the currently receiving channel acquired in step 101 and the BER of the other channel are acquired. Are compared (step 105). If the BER of the other channel is small and the reception state of the other channel is better than the reception state of the currently receiving channel, the process is terminated. However, if the BER of the channel currently being received is smaller and the reception state is good, the registration of other channels is deleted from the service list and the channel currently being received is registered (step 106).

The home digital TV broadcast receiving apparatus does not need to update the service list once the service list creation process is performed once. However, the reception environment of the in-vehicle digital TV broadcast receiver changes due to movement. For this reason, when a service list created in one area becomes unusable in another area, the in-vehicle digital TV broadcast receiving apparatus recreates the service list in response to a request from the user. That is, when a user requests to create a service list, the in-vehicle digital TV broadcast receiving apparatus executes the service list creation process to create a new service list.
In a vehicle-mounted digital TV broadcast receiver, a creation request is frequently generated due to the movement of a car. Also, TV programs cannot be received while the service list is being created. For this reason, it is necessary to shorten the service list creation time. In the conventional service list creation method, as described above, when there are two or more channels having the same knitting sequence, the processing of FIG. 8 must be performed, and the service list creation time becomes long, which causes stress for the user. There's a problem. As described above, a method for reducing the service list creation time is required.
Information on other channels that are broadcasting digital broadcasting with the same TS-ID as the TS-ID of the channel of interest (channel information of the same series) is extracted from the NIT, and the channel search time in the destination area is calculated using this information. There is a technique of shortening or automatically selecting a program of an affiliated station that was being watched before moving after moving (Patent Document 1).
JP-A-2002-359825

However, the above prior art does not shorten the service list creation time.
Accordingly, an object of the present invention is to provide a digital broadcast receiving apparatus and a frequency list creation method that reduce the creation time of a service list.

A first aspect of the present invention is a digital broadcast receiving apparatus that creates and uses a frequency list of receivable digital broadcast channels, a list creation instruction unit for instructing the frequency list creation, and a good reception state of the digital broadcast channel A reception state detection unit that detects whether or not the channel is scanned according to the frequency list creation instruction, and when a channel having a good reception state is acquired, the frequency of the channel is registered in the frequency list. The information of other channels that are broadcasting the same digital broadcast as the channel is extracted and stored from the digital broadcast signal of the channel, and the frequency list is created by skipping the stored channel and scanning the channel. A control unit is provided.
A second aspect of the present invention is a frequency list creation method of a digital broadcast receiving apparatus for creating a frequency list of receivable digital broadcast channels. When the creation of a frequency list is instructed, a step of starting a channel scan, reception Determining whether the received state of the selected channel is good. If the received state is good, the frequency of the channel is registered in the frequency list, and the digital broadcast identical to the channel is transmitted from the digital broadcast signal of the channel. And extracting and storing information of the other channels being performed, and thereafter performing a channel scan by skipping the stored channels and creating the frequency list.

  According to the present invention, when a frequency list of receivable digital broadcast channels is created, when a channel having a good reception state is acquired by channel scanning, the frequency of the channel is registered in the frequency list, and The information of other channels that are broadcasting the same digital broadcast is extracted from a digital broadcast signal (for example, NIT) and stored, and the frequency list is created by skipping the stored channel and scanning the channel. Therefore, it is possible to shorten the time for creating the frequency list and to avoid stress for the user.

(A) Digital Broadcast Receiver FIG. 1 is a block diagram of a digital broadcast receiver according to the present invention.
The tuner 51 receives the digital broadcast radio wave transmitted from each broadcast station, and inputs the digital broadcast signal (OFDM baseband signal) of the channel instructed by the system controller 52 to the OFDM demodulator 53. The OFDM demodulator 53 detects the OFDM synchronization timing from the OFDM baseband signal, deletes the guard interval, performs FFT processing for each N sample data, sequentially generates N subcarrier components, and parallelizes the subcarrier components The serial stream is demodulated and the transport stream is demodulated and output. An FEC (Forward Error Correction) unit 54 performs convolutional decoding (Viterbi decoding) and RS error detection / correction processing (Reed-Solomon decoding processing) on the input transport stream, and inputs it to the MPEG separation unit 55 as an MPEG data stream. If the OFDM demodulator 53 can detect the synchronization timing, the lock detector 56 inputs a lock detection signal to the system controller 52. The BER detection unit 57 detects a BER (Bit Error Rate) based on the decoding result of the FEC unit 54 and inputs it to the system controller 52. Similarly, the C / N detection unit 58 performs C / N ((Carrier to Noise Ratio) Is input to the system controller 52.

The MPEG separation unit 55 separates the program arrangement information SI and the MPEG video data VST and MPEG audio data AST of the selected program from the input MPEG data stream, and separates them into a system controller 52, an MPEG video decoder 59, and an MPEG audio decoder 60, respectively. To enter. The system controller 52 creates an electronic program guide EPG using the program sequence information SI and displays it on the display unit of the operation unit 61, or refers to the NIT when creating the service list, and receives the organization channel identifier of the digital broadcast Is extracted, and information on other channels that are performing digital broadcasting of the same TS-ID as the TS-ID is extracted.
The MPEG video decoder 59 decodes the MPEG video data VST and inputs the obtained video signal to the image output unit 62. The MPEG audio decoder 60 decodes the MPEG audio data AST into PCM audio data and converts it into an analog audio signal. To the audio output unit 63.
The operation unit 61 includes an operation display unit and a key unit. The key unit includes various operation keys for power on / off, channel selection, service list creation request, volume adjustment, and the like. The operation unit 61 can also be configured with a touch panel.
When the user selects a desired channel and program from the operation unit 61, the system controller 52 inputs a channel selection signal to the tuner 51, and the tuner 51 outputs a digital broadcast signal of the channel indicated by the channel selection signal. Thereafter, each unit operates as described above, the MPEG separation unit 55 separates the MPEG video data VST and the MPEG audio data AST of the selected program, and the image output unit 62 and the audio output unit 63 select the program selected by the user. The video is displayed on the monitor and the audio is output from the speaker.

(B) Service List Creation Processing An outline of service list creation processing in the present invention is as follows.
(1) When the creation of service list is instructed, channel scan starts,
(2) If the reception state of the received channel is good, register the frequency of the channel in the service list and information on other channels that are broadcasting the same digital broadcast as the channel from the NIT of the program sequence information SI Extract and
(3) Save the other channel as an interlaced channel,
(4) Thereafter, the saved interlaced channel is skipped and a channel scan is performed to create a service list.

2 and 3 are service list creation processing flows according to the present invention.
A service list creation is requested by operating a predetermined key on the operation unit 61 (step 201). As a result, the system controller 52 acquires vehicle current position information from a navigation unit (not shown), and starts channel scanning (step 202). The reason why the vehicle current position information is acquired is that it is necessary when receiving data broadcasts such as weather forecasts, traffic information, and news.
Next, the system controller 52 sets a scan channel (step 203). The first scan channel in the service list creation process is fixed at 13CH. The system controller checks whether the channel is an interlaced channel that does not require scanning (step 204). If it is an interlaced channel, in step 203, the channel is increased by one and the next channel is set.
If the set channel is not an interlaced channel, the system controller 52 inputs the channel selection signal of the channel to the tuner 51 to receive the channel (step 205). In such a channel reception state, the system controller 52 checks whether or not a synchronization-established front-end lock signal is input from the lock detector 56 (step 206), and if not input, determines that the reception state is bad. On the other hand, if the front-end lock signal is input, the C / N detector 58 checks whether the C / N is equal to or higher than the set value (step 207). .

If C / N is equal to or greater than the set value, the reception confirmation process of FIG. 3 is executed (step 208). That is, the system controller 52 acquires the BER from the BER detector (step 301), and then extracts the NIT constituting the program arrangement information SI (step 302). After that, the system controller 52 checks whether the BER acquired in step 301 is smaller than the set value and the reception state is good (step 303). If the BER is larger than the set value and the reception state is bad, the process is terminated. However, if the BER is smaller than the set value, the system controller 52 registers the channel currently being received in the service list SVLS (step 304).
Next, the system controller 52 refers to the NIT, extracts the TS-ID that is the organization channel identifier of the channel currently being received, and other channels that are performing digital broadcasting of the same TS-ID as the TS-ID. Ask for information. If there is another channel that performs digital broadcasting of the same TS-ID, the other channel is listed as an interlaced channel, and the process is terminated (step 305).
Returning to FIG. 2, when the processing of step 208 is completed, or if the reception state is bad in steps 206 and 207, it is checked whether the currently received channel is the last channel (62H) (step 209). If not, the process returns to step 203, the channel is increased, and the subsequent processing is continued. In this case, the interlaced channel is skipped.
On the other hand, if the channel scan is performed up to the final channel, “YES” is determined in the step 209, and the service list creation process is completed.
As described above, according to the present invention, when a channel having a good reception state is acquired by channel scanning, the frequency of the channel is registered in the service list, and other digital broadcasting is performed based on NIT information. Since the channel information is extracted and stored, and the service list is created by skipping the stored channel, the creation time of the service list can be shortened.

It is a block diagram of the digital broadcast receiver of the present invention. It is a first flow of service list creation processing of the present invention. It is a 2nd flow of the service list creation process of this invention. It is a block diagram of a terrestrial digital broadcasting station. It is explanatory drawing of the program arrangement | sequence information SI. It is explanatory drawing explaining a reception condition. It is TS-ID explaining a reception situation and a formation channel explanatory drawing. It is a conventional processing flow of the system controller when a channel having a good reception state is obtained in the service list creation processing.

Explanation of symbols

51 tuner 52 system controller 53 OFDM demodulation unit 54 FEC unit 55 MPEG separation unit 56 lock detection unit 57 BER detection unit 58 C / N detection unit 59 MPEG video decoder 60 MPEG audio decoder 61 operation unit 62 image output unit 63 audio output unit

Claims (2)

In a digital broadcast receiving apparatus that creates and uses a frequency list of receivable digital broadcast channels,
A list creation instruction unit for instructing the frequency list creation;
A reception state detection unit for detecting whether or not the reception state of the digital broadcast channel is good,
When a channel scan is started in response to the creation instruction of the frequency list and a channel having a good reception state is acquired, the frequency of the channel is registered in the frequency list and the same as the channel from the digital broadcast signal of the channel is registered. A controller that extracts and stores information of other channels that are performing digital broadcasting, skips the stored channels, scans the channels, and creates the frequency list;
A digital broadcast receiving apparatus comprising: In the frequency list creating method of the digital broadcast receiving apparatus for creating a frequency list of receivable digital broadcast channels,
When instructed to create a frequency list, start a channel scan,
Determine if the received channel is in good condition,
If the reception state is good, the frequency of the channel is registered in the frequency list, and the information of the other channel performing the same digital broadcast as the channel is extracted from the digital broadcast signal of the channel and stored,
Thereafter, the frequency list is created by skipping the saved channel and performing a channel scan.
A frequency list creation method characterized by the above.

Images