JP4204076B2 - Reception control method for data broadcasting receiver - Google Patents

Description

TECHNICAL FIELD OF THE INVENTION The present invention relates to reception control of a data broadcast receiver for receiving data broadcast in which data is transmitted in a frame having a plurality of packets and the data is interleaved and transmitted at the same bit position of each packet. Regarding the method. The invention also relates to a method for broadcasting data to such a receiver.
Background of the Invention At present, a TV data broadcasting system capable of receiving terrestrial data broadcasting is being studied in Japan. This system enables data reception by a mobile receiver, and uses data signal subcarriers 4.5 fH and 7.5 fH (fH = 15.73 kHz: horizontal synchronization pulse frequency) within the audio signal band of the television signal as a transmission path. Use. This terrestrial data broadcasting system provides the following programs.
E-mail service Newspapers, magazines, TV programs, news concerts, movies, restaurants, hotels, etc. Information on trains, buses, etc. Time, delay, seat availability, etc. Traffic jams, parking lots, gas stations, toilets, cars Information on shops, etc. Information on public facilities, hospitals, tourist information centers, etc. Shopping information on bargain sales, etc. Horse racing, information on entertainment and entertainment on bicycles, etc. Finance information on stock prices, MIDI data, games and other software groups, companies, schools, etc. So-called narrow cast for people
Live radio calls (pager) for disaster information sports such as earthquakes, tsunamis, and fires
However, the program is not limited to these, and it is considered that the program will be diversified in the future.
In this TV data broadcasting system, data is transmitted in the form of frames. An example of such a frame is shown in FIG. This frame consists of a total of 9232 bits containing a 16-bit framing code or frame synchronization signal (FC) and 32 data packets each having 288 bits. One data packet includes 16-bit mode control (MC), 14-bit prefix (PF), 176-bit service data (DAT), and error correction check code bit (CHC).
In the TV data broadcasting system, the data of all packets in a frame are interleaved at a depth of 32 in the vertical direction, as indicated by the dashed arrow 20 in FIG. That is, after the transmission of the frame synchronization signal FC, the most significant bit of the MC of the first row packet is transmitted, and then the most significant bit of the MC of the second row packet is transmitted. Similarly, after the most significant bit of MC of the 32nd row packet, the second bit of MC of the 1st row packet is transmitted. Therefore, in order to perform data decoding of each packet, it is necessary to receive data of all frames to which the packet belongs.
The MC, which is 16 bits, has 5 significant information bits and 11 error correction bits. FIG. 2 shows MC information bits b1 to b5 currently defined in the TV data broadcasting system, where b1 is the most significant bit. Five broadcast services are currently defined.
Some data broadcasting programs as described above have limited broadcast time or receivable time of the program. The operation of the receiver outside its program broadcast time consumes a lot of power and is therefore disadvantageous, especially in mobile receivers. Manually operating the receiver is a cumbersome operation.
Objects and Summary of the Invention The object of the present invention is to, when receiving a program whose broadcast time or receivable time is limited in the data broadcasting as described above, set the on time of the receiver for receiving the program. It is an object of the present invention to provide a reception control method for a data broadcasting receiver that can be automatically minimized.
For this reason, according to the first invention of the present application, the data broadcast is a data broadcast in which data is transmitted in a frame form having a plurality of packets including a frame identification section and at least a data section and a broadcast identification section transmitted prior to the data section. In the reception control method of a data broadcast receiver for receiving a data broadcast in which the data other than the frame identification unit is interleaved and transmitted at the same bit position of each packet, the receiver is under the control of the control device. When the frame identification unit of the frame is detected and frame synchronization is established, the data of the broadcast identification unit is deinterleaved and decoded, and when the decoded broadcast identification unit data has an identifier for identifying the reception control information broadcast, The program identification data and the time information data of the reception control information included in the data part are deinterleaved and decoded, and restored Based on the predetermined program identification data and the time information data related to the program identification data, the standby mode is entered from the time information data until the time specified, and the reception mode is entered when the specified time arrives. It is characterized by operating as follows.
In the second invention of the present application, the program identification data includes program number data, service number data, broadcast station identification data and / or broadcast channel data, and the time information data includes transmission time data, retransmission time data and / or Or it is comprised from intermittent transmission data.
The third invention of the present application is characterized in that the reception control of the receiver is performed by receiving the reception control information broadcast step by step based on a program category.
In a fourth aspect of the present invention, when the receiver recognizes the broadcast identifying unit that contains an identifier of a time signal broadcast in the receivable mode, the receiver uses the time information contained in the data portion of the packet. Thus, the time of the internal clock is calibrated.
The fifth invention of the present application is characterized in that the receiver enters the receivable mode again a little earlier than the specified time.
[Brief description of the drawings]
FIG. 1 is a diagram showing a frame structure in a TV data multiplex broadcast audio subcarrier system according to the present invention.
FIG. 2 is a diagram showing information bits defined by MC in the TV data multiplex broadcast audio subcarrier system.
FIG. 3 is a block diagram showing an example of a receiver that receives a data broadcast in the TV data multiplex broadcast audio subcarrier system.
FIG. 4 shows a data format for transmitting an electronic program guide according to the present invention.
FIG. 5 schematically shows a television receiver for receiving and presenting data of the electronic program guide EPG shown in FIG.
FIG. 6 shows a flowchart of operations performed by the microprocessor shown in FIG.
BEST MODE FOR CARRYING OUT THE INVENTION The method of the present invention will be described in detail below with respect to a reception control method of a receiver for the purpose of receiving a program whose broadcast time (or receivable time) is limited.
As is apparent from FIG. 2, in the TV data multiplex broadcast audio subcarrier system, five broadcasts are currently defined by related MCs. According to the present invention, reception control information data defining the broadcast time of a specific program is broadcast. As shown in FIG. 1, the reception control information data 21 is included in the data part DAT, and an identifier 29 for identifying the presence of the reception control information data is assigned to the MC of the data packet.
As long as the MC is different from the five bit patterns shown in FIG. 2, the pattern for identifying the reception control information broadcast may be any pattern. That is, the identifier may be “10111”, “10100”, or the like.
The reception control information data 21 includes, for example, a program number 22 (for example, 16 bits), a service number 23 (for example, 8 bits), a broadcast station identification 24 (for example, 12 bits), a broadcast channel 25 (for example, for each program). 10 bits), a transmission time 26 (for example, 24 bits), and a retransmission time 27 (for example, 16 bits). The transmission time data 26 indicates the time at which the program is broadcast, and the retransmission time data 27 indicates the time at which a program having the same content as the previous program is retransmitted. A plurality of retransmission times, for example, retransmission time 1 and retransmission time 2. . . Can also be specified. Here, it should be noted that the reception control information data of one program may be included in one data packet (DAT).
The present invention performs reception control of a receiver based on reception control information obtained by reception control information broadcasting as described above. Hereinafter, this control method will be described in detail.
FIG. 3 is a block diagram of an example of a receiver that receives a data broadcast in the TV data multiplex broadcast audio subcarrier system. This receiver is provided with a tuner 2 that performs frequency tuning of an audio signal of a television signal received via an antenna 1. The tuner 2 is connected to an FM detection unit 3 that performs FM detection of the output audio signal. The FM detector 3 is connected to a filter unit 4 for obtaining data signal subcarriers 4.5 fH and 7.5 fH from the FM detected signal. In the TV data multiplex broadcast audio subcarrier system, the data signal subcarrier is subjected to QPSK modulation. In view of this, a QPSK demodulator 5 for demodulating the subcarrier is connected to the filter unit 4. The QPSK demodulator 5 outputs interleaved frame data having a frame configuration composed of a plurality of packets.
A framing unit 6 that detects a frame code FC in order to establish frame synchronization of the frame data is connected to the QPSK demodulator 5. The framing unit 6 is a coincidence circuit having a timer and a comparison circuit. After recognizing the FC, the framing unit 6 counts the number of bits of the frame, that is, 9232 bits. The framing unit 6 is configured to detect that the next FC is input based on this count. The framing unit 6 is connected to a deinterleaving unit 7 for releasing the interleaving of the frame data. Connected to the deinterleave unit 7 is a decode unit 8 for performing data decoding of each packet of the deinterleaved frame. The data decoded by the decoding unit 8 is sent via an output 9 to a display device or the like (not shown).
The operations of the tuner 2, the FM detector 3, the filter 4, the QPSK demodulator 5, the framing unit 6, the deinterleaver 7 and the decoder 8 are all controlled by a central processing unit (CPU) 10. Further, a memory 11 and an internal clock 12 are connected to the CPU 10. The CPU 10 is also connected to a ROM 13 in which information of program identification data (program number data, service number data, broadcast station identification data, broadcast channel data, etc.) relating to programs that can be received by the receiver is stored. .
When the power supply of the receiver is turned on, all the elements constituting the receiver are turned on, and the receiver enters a frame FC detection mode under the control of the CPU 10. That is, the framing unit 6 detects an FC of a certain frame. In the case of frame synchronization, this frame data is subjected to deinterleaving in the deinterleaving unit 7, and the mode control unit MC of the packet of the frame is decoded in the decoding unit 8. If the MC does not have a bit pattern for identifying the reception control information data, the decoding process ends, and each element remains in the ON state until a reception control information broadcast is received.
When the MC includes a bit pattern for identifying the reception control information broadcast, the decoding unit 8 decodes the data portion DAT of the packet. Here, a table of reception control information is created in the memory 11. The CPU 10 compares this table with the program identification data information stored in the ROM 13 that identifies the program to be received. When the transmission of the program to be received is confirmed in the table, the transmission time of the program is extracted from the table, and the receiver enters the standby mode until this time arrives. In this way, the operation of each element constituting the receiver can be minimized.
Note that the CPU 10 continues to operate in power save mode to monitor the internal clock 12. When the above-described time is confirmed by the internal clock 12, each element of the receiver is turned on again under the control of the CPU 10, and a predetermined data broadcast program is received. It is preferable that the restart time of each element is slightly earlier than the stored time.
If the program is not received at the specified time for some reason, the time at which the program is retransmitted is extracted from the re-transmission time data of the associated reception control information data in the table, and re-reception of the program is attempted. That is, the operation of each element of the receiver is really minimized.
In this way, the data broadcast reception of the receiver can be automatically controlled based on the reception control information, and as a result, a significant reduction in power consumption of the receiver can be achieved.
Furthermore, it should be noted that the reception control information data itself may be specified as one program, and the program number may identify this reception control information broadcast. In this case, the transmission time and the retransmission time define the next broadcast time of the reception control information data.
As another application example, the data broadcasting does not identify all programs individually, but first reception control information for identifying a program category as a first stage, and a plurality of programs in each category as a second stage. The second reception control information for identifying the desired program may be transmitted. In the first reception control information, the program number data defines the first reception control information broadcast, the service number defines the category, and the transmission time defines the transmission time of the second reception control information broadcast related to this category. To do. In the second reception control information, the second reception control information of a category with a service number is defined, the program number identifies the program belonging to this category, and the transmission time defines the transmission time of this program. When receiving the first reception control information broadcast, the receiver recognizes the transmission time of the second reception control information broadcast of the desired category from the service number data and transmission time data of the desired reception control information data, The standby mode is entered until the time arrives. When the time of the second reception control information broadcast arrives, the receiver restarts, confirms the transmission time of the desired program from the reception control information data obtained by the second reception control information broadcast, and transmits this transmission time. Enter standby mode again until
It is important that the time of the receiver's internal clock 12 is accurate, and this time would preferably be calibrated by receiving a time signal broadcast when the receiver is ready to receive a given program. . For this reason, an MC pattern that is not the same as the identifier of the reception control information, for example, “10001” or “00001” may be assigned to the time signal broadcast containing the current time in the data portion DAT of the packet.
As another example, the reception control information data may define intermittent transmission data specifying a broadcast interval of a program such as every hour or every day, instead of a specific time. In this case, the operation of the receiver is controlled at intervals defined by the intermittent transmission data.
Furthermore, in the case of pay broadcasting, for example, the subscriber's personal ID may be set to receive a program depending on the situation. In the case of such a program, the reception control information data may include data related to the personal ID.
Further, the reception control information data may include data related to the end time of the program, and the receiver may enter the standby mode again based on the end time. In this case, the standby mode may be continued until a related retransmission time or reception control information of a desired program is received again and a transmission time specified by the information.
The present invention is not applicable only to mobile data receivers. Reduction of power consumption is also desired in the standby state of the main power supply device. For example, television receivers are known that are configured to receive an electronic program guide (EPG) transmitted as teletext. The EPG is transmitted once a day or at most several times. In order to receive an EPG, the associated processing circuitry (tuner, teletext decoder, data memory) needs to operate even when the TV receiver is not used to watch the program. In the near future, international regulations are expected to prohibit power consumption of more than 1 watt when the TV receiver is off or in standby. This is difficult to implement with current hardware circuits, especially TV tuners.
In accordance with the present invention, the broadcaster includes a clock time for performing the next transmission in the transmission of an EPG (or other form of data). In this case, in the TV receiver, a related circuit is activated slightly earlier than a specified time. In other words, from the actual standby state (only the processor and TV real-time clocks are activated), the tuner, teletext decoder and data memory are activated during the transmission. Switch to “Standby” state. Only in this “data cast standby” state, power consumption exceeds 1 watt. Of course, all these operations are performed without any user intervention.
The broadcaster may further include whether the data transmission is a repeat of a previously transmitted EPG or may include new information. In the first case, the receiver may determine that an EPG is already stored and immediately switch to a normal standby state to further reduce power consumption. In the second case, the broadcaster may indicate whether the EPG is an incremental update or a completely new update. The additional update may identify which part of the EPG transmitted in the past is related to the update. This allows the TV to erase that part of the memory.
FIG. 4 shows an example of the transmission format of the electronic program guide 40. The guide includes a header 41, a section 42 having a plurality of program items that make up the guide, and an end-of-file (EOF) marker 43. The header includes an identifier 44 (EPG) that specifies that the data 42 represents an electronic program guide, a parameter 45 (CUR) that indicates the current clock time, and a parameter 46 (NXT) that specifies the time at which the data is transmitted again. ), And a parameter 47 (TYP) that specifies whether the EPG is simply a repeat of a previously transmitted version, or an update of all or part of this version. The parameter 46 (NXT) may have various formats. As the clock time at which the next transmission of the guide will be carried out (“4:00 AM tomorrow”), the time at which the guide will be repeatedly transmitted (“4:00 AM and 1:00 PM every day”), or as an offset with respect to the current time ( “This guide will be broadcast again in 12 hours”)).
FIG. 5 receives EPG data and assembles the data from the various channels to build and display a comprehensive TV guide that covers all channels that are available or desired by the user. 1 schematically shows a television receiver configured as shown in FIG. The receiver includes an antenna 50, a tuner 51, a video decoder 52, a display screen 53, a data decoder 54 (usually a teletext decoder), a control circuit 55 in the form of a microprocessor, a remote control receiver 56, and a remote control transmitter 57. , An EPG data memory 58, a real time clock circuit 59, and a power supply 60.
The tuner receives a broadcast TV signal and demodulates the signal to obtain a composite video and blanking (baseband) signal CVBS. The CVBS signal is further processed as known (52) and displayed (53). The CVBS signal is also supplied to the teletext decoder 54. The teletext decoder has a data slicer (not shown) for extracting a digital signal embedded in the vertical blanking period of the CVBS signal, and supplies the data to the microprocessor 55 via the communication bus 61. The teletext decoder 54 also has a display generator (not shown) that receives the video to be displayed from the microprocessor 55 via the bus 61. The video to be displayed is supplied to the display screen 53 via the video processing circuit 52 as an on-screen display signal OSD.
It should be understood that in the normal mode of operation, all the circuits of the TV receiver receive a power supply voltage. As is generally known, the microprocessor 55 and the remote control receiver 56 also receive a power supply voltage in a normal standby mode so that the receiver can be turned on in response to a remote control command. Standby power is further applied to the real time clock 59 so that the microprocessor can read the current time in standby mode.
The power supply 60 in FIG. 5 generates a power supply voltage V _SS for the tuner 51, the teletext decoder 54 and the data memory 58 in response to the power control signal PWR from the processor 55. This signal distinguishes between the normal standby mode as defined above and the “data cast standby” mode in which V _SS is applied to the tuner 51, teletext decoder 54 and data memory 58.
The operation of the receiver shown in FIG. 5 will be described below with reference to the flowchart of the operation executed by the microprocessor 55 shown in FIG. Assume that the receiver is in normal standby and has already received an electronic program guide as shown in FIG. 4 early. The guide is stored in the data memory 58. The clock time at which the EPG is transmitted again (parameter NXT in FIG. 4) is copied from the memory 58 (the memory itself cannot be accessed in this mode) to the processor 55 register.
In step 60, the processor checks whether a remote control command has been received. If so, the TV is switched on (including the application of the power supply voltage V _SS to the associated circuit) in step 61 and operates in a known manner. In step 62, the processor compares the current time T provided by the real time clock circuit 59 with the time NXT at which the EPG is to be transmitted. As long as there is a predetermined amount of time (e.g., 30 minutes or more) that elapses before the EPG is transmitted, the processor returns to step 60 described above. Thus, the TV remains in a normal standby state unless the receiver is turned on by the user.
If it is found in step 62 that the EPG transmission is due to reception, step 63 is performed to power the tuner, teletext decoder and data memory (or if the receiver is in normal operating mode). The microprocessor activates the power signal V _{SS (} to maintain power supply even when the user switches off the TV). The TV is now in the “data cast standby” state. In step 64, EPG data is acquired and stored in data memory 58. Thereby, the parameter TYP (47 in FIG. 4) is translated to identify which part of the already stored data can be updated and removed from the memory.
Then, in step 65, it is determined whether all transmitted EPG information has been processed. This is the case when the end-of-file marker EOF (43 in FIG. 4) is encountered or when the TYP parameter identifies that the received guide is identical to a previously transmitted and stored version. As long as not all EPG information has been processed, the processor continues the process described above at step 64. Otherwise, step 66 is performed and the next transmission time (defined by NXT and stored in the data memory) is copied to the processor's register, which deactivates the power control signal PWR. This suppresses further application of the power supply voltage VSS to the tuner, teletext decoder, and data memory.
In summary, the present invention relates to data reception by a data broadcast receiver, especially a mobile data receiver for Japanese TV data multiplex broadcast audio subcarrier system. The receiver is controlled to receive data in a desired format, such as weather forecasts, news, stock prices, and the like. The present invention provides the transmission of time information that defines for each data type when the data is transmitted or retransmitted. This allows the receiver to enter a standby mode where power consumption is reduced. At the same time or slightly earlier than the specified time, the receiver switches on and receives, decodes and displays the desired data.
The present invention is also applicable to television receivers that have the capability of receiving electronic program guides (EPG) or other services. The receiver is informed about the time when an updated version of the EPG can be expected. In order to reduce power consumption in the standby mode of the receiver, the hardware for receiving the EPG is not activated until the specified instant.

Claims (3)

A television receiver for receiving an EPG data signal representing an electronic program guide broadcast by a broadcaster,
Receiving and decoding means for receiving and decoding the EPG data signal;
A memory for storing the EPG data signal;
A television receiver having processing means for processing the EPG data signal and presenting the electronic program guide on a display screen;
The EPG data signal includes a parameter that indicates whether the EPG data signal represents a partial update or a total update of a program guide transmitted in the past,
The processing means is configured to replace only a portion corresponding to the portion in the memory when the EPG data signal represents a partial update of a program guide transmitted in the past. A receiver characterized by that. The parameter further represents whether the EPG data signal is a repetition of the same version as the electronic program guide transmitted in the past, and when it is the repetition of the same version, the standby mode is switched to a low power consumption. The receiver according to claim 1. It further has a real time clock circuit for generating the current time,
The processing means receives a packet transmitted by the broadcaster including a parameter for identifying a next transmission time of the EPG data signal, compares the current time with the next transmission time, and the current time is A receiver configured to deactivate the receiving and decoding means in a standby state of the receiver until substantially corresponding to a next transmission time.

Images