JP2011103515A - Digital broadcast receiving apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a digital broadcast receiving apparatus capable of downloading with higher success probability, even if a reception state is not proper for a service station in a given area. <P>SOLUTION: The digital broadcast receiving apparatus includes a channel selecting means 10 for selecting a service station to be received between service stations 300 and 310; a service station detection means 80 for detecting whether a plurality of service stations exist for receiving engineering services; a C/N (Carrier to Noise ratio) value acquisition means 90 for acquiring a C/N value of the engineering services transmitted from each of the service stations, when the plurality of service stations are detected by the service station detection means; a service station selection means 100 for comparing the C/N value for each service station acquired by the C/N value acquisition means, and selecting a service station having the highest C/N value; and a control means 60 for using an engineering stream broadcast transmitted from the service station selected by the service station selection means, and controls to download software. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a digital broadcast receiving apparatus, and more particularly to a digital broadcast receiving apparatus including software download means for downloading software using an engineering stream broadcast transmitted from a service station.

  Conventionally, when downloading program data via broadcast waves, the reception level of digital data multiplexed with the program is detected for a predetermined time to prevent the program from being incomplete due to poor reception. An average reception level is calculated, and if the average reception level is less than or equal to a predetermined level, digital data is not downloaded, and a data reception device that downloads only when the average reception level is greater than or equal to a predetermined value is known. (For example, refer to Patent Document 1).

JP 2000-217089 A

  However, in the configuration described in Patent Document 1 described above, downloading of content such as program data is performed only from an engineering service station in a defined area. For this reason, for users residing in prefectural borders, even if the reception status from the engineering service station outside the service area is better than that within the service jurisdiction area, content download from the service station in the service jurisdiction area where the reception condition is poor There was a problem that stable download could not be performed.

  Therefore, the present invention, for example, is a digital broadcast that has a high probability of successful content download even if it resides at a prefectural border as described above and the reception status from a service station in the service jurisdiction is not necessarily good. An object is to provide a receiving apparatus.

In order to achieve the above object, a digital broadcast receiving apparatus (200) according to the first aspect of the present invention includes a channel selection means (10) for selecting a service station (300, 310) to receive by changing a tuning frequency,
Service station detection means (80) for detecting whether there are a plurality of service stations (300, 310) capable of receiving the engineering service;
When a plurality of the service stations (300, 310) are detected by the service station detection means (80), the channel selection means (10) selects each service station (300, 310), and each service station C / N value acquisition means (90) for acquiring the C / N value of the engineering service transmitted from (300, 310);
The C / N values acquired by the C / N value acquisition means (90) are compared, the service station having the highest C / N value is selected, and the channel selection means (10) is selected. Service station selection means (100) for selecting a channel;
Control means (60) for performing control to download software using the engineering stream broadcast transmitted from the service station selected by the service station selection means (100).

  As a result, when digital broadcast signals can be received from a plurality of service stations, it is possible to download from a service station having the highest C / N value and good reception state, thereby improving the probability of successful download. Can be made.

A second invention is the digital broadcast receiving apparatus (200) according to the first invention, wherein:
The C / N value acquisition means (90) acquires a plurality of instantaneous C / N values of the digital broadcast signal from the same service station (300, 310), and calculates the average C / N value from a plurality of the instantaneous C / N values. The C / N value of each service station (300, 310) is calculated.

  Thereby, the accuracy of the C / N value to be acquired can be increased, and the service station to be downloaded can be appropriately selected based on the accurate C / N value.

A third invention is the digital broadcast receiver (200) according to the first or second invention, wherein
The service station detecting means (80) detects the service station that performs the engineering service from a service list (72) that lists channel information of each receivable service.

  Thereby, a service list can be utilized and a service station can be easily detected with a simple configuration.

A fourth invention is the digital broadcast receiving device (200) according to any one of the first to third inventions,
The selection of the service station by the service station selection means (80) is performed within a predetermined time before the engineering stream broadcast in which the software to be downloaded is transmitted.

  As a result, in accordance with the timing of each download, the service station with the best reception state can be selected in a state that appropriately matches the reception state at each time, and the download success probability can be improved to the maximum at each download. .

A fifth invention is the digital broadcast receiver (200) according to the fourth invention, wherein:
Storage means (71) for storing a download schedule (73) by the engineering stream broadcast in advance;
The service station is selected by the service station selection means (80) based on the download schedule (73) stored in the storage means (71).

  As a result, it is possible to reliably grasp in advance the time at which the download is started, and to select a service station having a good reception state at an appropriate timing immediately before the download is started.

  Note that the reference numerals in the parentheses are given for easy understanding, are merely examples, and are not limited to the illustrated modes.

  According to the present invention, it is possible to improve the probability of successful download in an area where digital broadcast signals can be received from a plurality of service stations.

It is explanatory drawing of an example of the usage condition of the digital broadcast receiver which concerns on a present Example. 1 is an example of an overall configuration block diagram of a digital broadcast receiving apparatus 200 according to the present embodiment. It is a figure for demonstrating a C / N value. 6 is a diagram showing an example of an electronic program guide stored in a flash memory 71. FIG. 5 is a diagram showing an example of specific contents of a service list 72. FIG. It is a processing flow figure of the digital broadcast receiver 200 concerning a present Example.

  DESCRIPTION OF EMBODIMENTS Hereinafter, embodiments for carrying out the present invention will be described with reference to the drawings.

  FIG. 1 is a diagram for explaining an example of a situation in which a digital broadcast receiving apparatus according to an embodiment to which the present invention is applied can be preferably used. In FIG. 1, a house 250 is located in Tokyo near the boundary between Tokyo and Chiba Prefecture, and the digital broadcast receiving apparatus 200 is installed in the house 250. The Tokyo Metropolitan Government and Chiba Prefecture each have a Tokyo Service Station 300 and a Chiba Prefecture Service Station 310, and the digital broadcast receiving apparatus 200 includes digital broadcast waves from the Tokyo Metropolitan Government Service Station 200 and Both digital broadcast waves can be received. In such a case, since the house 250 is located in the Tokyo Metropolitan area and is under the jurisdiction of the Tokyo service station 300, it is common to receive and use digital broadcast waves from the Tokyo service station 300.

  However, the digital broadcast receiving apparatus 200 can receive not only the digital signal wave transmitted from the Tokyo service station 300 but also the digital broadcast wave transmitted from the Chiba service station 310. In such a case, if the reception sensitivity of the broadcast wave from the Tokyo service station 300 is better, there is no problem in the setting for receiving the broadcast wave from the Tokyo service station 300 in the service area. Therefore, there may be a case where the reception state from the Chiba service station 310 is better. Under such circumstances, even if the Tokyo Metropolitan Government Service Station 300 is a service station in the jurisdiction, it is possible to enjoy better video and audio when receiving the broadcast wave from the Chiba Prefecture Service Station 310. In addition, when the service type to be received is normal video or audio content, even if there is a difference in the reception state between the service stations to receive, in many cases, in digital broadcasting, You may receive a service to download software from a service station. This is performed as part of an engineering service in a newly performed digital broadcast. By downloading software from an engineering stream broadcast broadcast from a service station, the digital broadcast receiving apparatus 200 operates normally. Software for modernization and optimization. Thereby, the reception state of the digital broadcast receiving apparatus 200 can be improved. However, when software is downloaded using broadcast waves, if the reception state is not good, the download is not performed properly, and there is a possibility that the software of the digital broadcast receiving device 200 is not correctly updated.

  Therefore, when the digital broadcast receiving apparatus 200 can receive broadcast waves from a plurality of service stations, the service station with the best reception state is used regardless of the service stations in the service area of the digital broadcast receiving apparatus 200. If the software is downloaded by receiving the broadcast engineering stream broadcast, the probability of successful download can be increased. The digital broadcast receiving apparatus 200 according to the present embodiment selects the service station with the best reception state when the engineering stream broadcast can be received from a plurality of service stations, and increases the success probability of the software download. Even when the digital broadcast receiving apparatus 200 is used in an area where the reception state of the digital broadcast wave is not so good due to the prefectural border or the like, it can sufficiently cope.

  In addition, in FIG. 1, although the case where the digital broadcast wave from two Tokyo service stations 300 and the Chiba service station 310 can be received is mentioned as an example, for example, the prefectural border of three prefectures or four prefectures The digital broadcast receiving apparatus 200 according to the present embodiment can be suitably applied even when the house 250 is located in an area near the prefectural border and reception from three or more service stations is possible.

  FIG. 2 is an example of a block diagram showing an overall configuration of a digital broadcast receiving apparatus 200 according to an embodiment to which the present invention is applied. The digital broadcast receiving apparatus 200 according to the present embodiment includes a tuner 10, a demodulating unit 20, a control unit 60, a memory 70, a service station detecting unit 80, a C / N value acquiring unit 90, and a service station selecting unit. 100. In addition, the digital broadcast receiving apparatus 200 according to the present embodiment includes an encryption composite unit 30, an audio signal processing unit 40, a video signal processing unit 50, an audio signal conversion unit 41, a visual driver 51, as necessary. A PCI (Peripheral Component Interconnect) bus 110, a sub CPU (Central Processing Unit) 120, and a power supply unit 130 may be provided. Moreover, the antenna 11, the speaker 42, and the display part 52 may be provided as a related component of the digital broadcast receiving apparatus 200.

  The tuner 10 is a channel selection unit that selects a service station that receives a signal with a tuning frequency fixed to a predetermined frequency. The tuner 10 has a function of selecting a service station that provides an engineering service in the digital broadcast receiving apparatus 200 according to the present embodiment. In addition, the tuner 10 receives a program including a normal video signal and audio signal. It may be used as means for selecting a reception channel.

  The tuner 10 is applied with a channel selection means corresponding to digital broadcast capable of selecting a digital broadcast wave. This is because downloading of software using broadcast waves is possible by using digital broadcast waves. Note that the tuner 10 may constitute the receiving unit 15 together with the external antenna 11. The received signal output from the tuner 10 is output to the demodulator 20.

  The demodulator 20 is means for demodulating the received wave selected and received by the tuner 10 and restoring the signal before modulation of the digital broadcast wave. The demodulated signal is a digital signal before modulation on the service station side, and may include a video signal and an audio signal in addition to a data signal such as software.

  The demodulation unit 20 may include an error correction unit 21 as necessary. The error correction unit 21 corrects errors that occur during transmission using, for example, an error correction code such as a Reed-Solomon code and a convolutional code.

  The signal format output from the demodulator 20 may be a transport stream, for example.

  The encryption / decryption unit 30 decrypts the signal output from the demodulation unit 20 using a decryption key or the like. For example, when MULTI2 adopted as a standard encryption for digital terrestrial broadcasting in Japan is used, the encryption may be canceled by connecting a B-CAS card from the outside. When other encryption is used, an encryption / decryption unit 30 corresponding to the encryption used may be provided.

  The encryption / decryption unit 30 may include a separation unit 31. The separation unit 31 separates the decoded signal into an audio signal, a video signal, and additional information. The additional information is additional information including EPG (Electronic Program Guide). The audio signal separated in the separation unit 31 is output to the audio signal processing unit 40, and the video signal is output to the video signal processing unit 50. In addition, additional information including program information and the like is output to the control unit 60 and stored in the memory 70. When the signal is a transport stream signal, the encryption / decryption unit 30 separates each packet.

  The audio signal processing unit 40 is a means for decoding the audio signal, and performs signal processing necessary for decoding the audio signal. The output from the audio signal processing unit 40 is output to the audio conversion unit 41 as a digital audio signal.

  The audio conversion unit 41 is means for digital-analog conversion of the digital audio signal input from the audio signal processing unit 40 into an analog audio signal. The analog audio signal output from the audio conversion unit 41 is output to, for example, an externally connected speaker 42 and provides audio to the user from the speaker 42.

  The video signal processing unit 50 is a means for decoding the video signal, and performs signal processing necessary for decoding the video signal. The output from the video signal processing unit 50 is output to the visual driver 51 as a digital video signal.

  The visual driver 51 is a means for adjusting the ratio of the vertical and horizontal lengths of the display image of the video signal, the so-called angle of view. For example, the visual driver 51 converts and adjusts the display image to a predetermined angle of view such as 16: 9. The video signal adjusted by the visual driver 51 so that the angle of view is adapted to the external display unit 52 is output from the display unit 52 such as a display and provides video to the user. In addition to a normal cathode ray tube, a liquid crystal display panel, a plasma display panel, an organic EL (Electronic Luminescence), etc. may be applied to the display unit 52.

  The control unit 60 is a control unit that performs access to the memory 70 and various arithmetic processes. For example, the control unit 60 may be configured by a CPU in order to perform various arithmetic processes.

  When the additional information such as program information is output from the encryption / decryption unit 30, the control unit 60 writes the additional information in the memory 70 and stores the additional information. In addition, when downloading software by the engineering service, the control unit 60 performs control to write and store the software in the memory 70. Furthermore, the control unit 60 reads programs and information stored in the memory 70 and executes various arithmetic processes.

  The memory 70 is storage means for storing various information including software such as programs. The memory 70 includes a flash memory 71, a boot ROM (Read Only Memory) 74, and a RAM (Random Access memory) 75.

  The flash memory 71 is a rewritable nonvolatile memory, and stores additional information including program information and programs for various arithmetic processes. Accordingly, the software to be downloaded is finally stored in the flash memory 71. As shown in FIG. 1, the additional information includes information such as a service list 72 in which receivable service types are listed, a download schedule 73, and the like.

  The boot ROM 74 is a storage unit that stores a program used at startup, and a startup program is stored in a nonvolatile memory.

  The RAM 75 is a storage unit that uses a volatile memory, and is a storage unit that temporarily stores information and programs at the time of startup. For example, when software is downloaded, the software is temporarily stored in the RAM 75, developed by the control unit 60, and finally stored in the flash memory 71. Even when the power is turned off, the data is saved. Similarly, with respect to various additional information and programs, during the operation of the digital broadcast receiving apparatus 200, the information and programs are temporarily stored in the RAM 75, read by the control unit 60, and various arithmetic processing operations are executed.

  The service station detection unit 80 is a detection unit that detects whether there are a plurality of receivable service stations. The service station detection unit 80 can detect a service station that can be received by various methods. For example, as with the control unit 60, the service station detection unit 80 accesses the flash memory 71 and stores the service type 72. The number of service stations that can be received may be detected from this information. A specific method for detecting a service station from the service list 72 will be described later.

  Since the service station detection unit 80 accesses the flash memory 71 similarly to the control unit 60, the service station detection unit 80 may be configured as a CPU having an arithmetic processing function, for example. The detection result of the service station detection means 80 is output to the C / N value acquisition means 90.

  The C / N value acquisition means 90 is means for acquiring the C / N value of the digital broadcast wave received from the selected service station. When the service station detection unit 80 detects that the engineering service can be received from a plurality of service stations, the C / N value acquisition unit 90 allows the tuner 10 to select each service station and receive it. The C / N value of each service station is acquired. In this case, for example, as described with reference to FIG. 1, when two receivable service stations 300 and Chiba service stations 310 are detected, the C / N value acquisition unit 90 The C / N value of the engineering service from the Tokyo service station 300 and the C / N value from the Chiba service station 310 are acquired.

  FIG. 3 is a diagram for explaining the C / N value. The C / N value is a value indicating a carrier to noise ratio, and is used to represent the quality of radio waves. In FIG. 3, the received power and noise are shown, but the margin of the received power with respect to the noise is the C / N value. Therefore, the larger the C / N value, the better the reception state. Here, the received power means the power of the received radio wave (desired wave) and represents the strength of the radio wave. As shown in FIG. 3, even when the received power is high, if the magnitude of noise is large, the C / N value may be low and the desired wave may not be received. Therefore, the digital broadcast receiving apparatus 200 according to the present embodiment acquires the C / N value and appropriately evaluates the reception state of the engineering service broadcast wave from each service station.

  The C / N value is expressed by the equation (1), and the unit is expressed in [dB].

図２に戻る。Ｃ／Ｎ値取得手段９０は、Ｃ／Ｎ値算出手段９１と、Ｃ／Ｎ値記憶手段９２を備えてよい。Ｃ／Ｎ値算出手段９１は、上述の（１）式を用いて、選局された各サービス局のＣ／Ｎ値を算出する手段である。なお、Ｃ／Ｎ値の算出は、１回だけでなく、所定期間内に複数回行い、複数の瞬間Ｃ／Ｎ値を算出し、瞬間Ｃ／Ｎ値の平均値を算出して行うようにしてよい。これにより、より精度の高いＣ／Ｎ値の算出を行うことができる。Ｃ／Ｎ値算出手段は、このような一連のＣ／Ｎ値の算出演算を行う。

Returning to FIG. The C / N value acquisition unit 90 may include a C / N value calculation unit 91 and a C / N value storage unit 92. The C / N value calculation means 91 is means for calculating the C / N value of each selected service station using the above-described equation (1). The C / N value is calculated not only once, but a plurality of times within a predetermined period, and a plurality of instantaneous C / N values are calculated and an average value of the instantaneous C / N values is calculated. It's okay. Thereby, it is possible to calculate the C / N value with higher accuracy. The C / N value calculation means performs such a series of C / N value calculation operations.

  The C / N value storage unit 92 is a unit for temporarily storing the C / N value of each service station calculated by the C / N value calculation unit 91. Since there are a plurality of service stations that calculate the C / N value, the calculated C / N value is temporarily stored, and a plurality of C / N values can be compared.

  The C / N value acquired by the C / N value acquisition unit 90 is output to the service station selection unit 100. Note that the C / N value acquisition unit 90 performs control for tuning each service station to the tuner 10 as described above, and arithmetic processing for calculating the C / N value. .

  The service station selection means 100 compares the C / N values of the service stations acquired by the C / N value acquisition means 90, selects the service station with the highest C / N value, and selects the tuner 10 for tuning. It is a means to make. The service station selection unit 100 may include, for example, a C / N value comparison unit 101 and a channel selection control unit 102.

  The C / N value comparison means 101 is for comparing the C / N values. For example, a comparison means such as a comparator may be applied, or the comparison is performed by a software calculation process. Also good. The channel selection control means 102 is a control means for receiving the comparison result of the C / N value comparison means 101, selecting the tuner 10 as the service station having the largest C / N value, and selecting and determining the reception service station. .

  By the final selection by the service station selection means 100, the tuner 10 can select the service station with the highest C / N value and download the software. The service station selection unit 100 may be configured with a predetermined electronic circuit or a CPU.

  Further, the control unit 60, the service station detection means 80, the C / N value acquisition means 90, and the service station selection means 100 are shown as separate components for each function, but of these, those configured as a CPU. May be configured in a single CPU. The hardware configuration of the control unit 60, the service station detection means 80, the C / N value acquisition means 90, and the service station selection means 100 can take various forms depending on the application.

  The PCI bus 110 is an external connection bus that enables connection to the outside when forming a LAN (Local Area Network) including the digital broadcast receiver 200 according to the present embodiment. May be provided.

  The sub CPU is an interface for signal processing when connecting to an analog device such as an external television, and may be provided as necessary.

  The power supply unit 130 is a unit for supplying power to the digital broadcast receiver 200 according to the present embodiment.

  Next, with reference to FIG. 2, an example of an operation related to software download of the digital broadcast receiving apparatus 200 according to the present embodiment having such a configuration will be described.

  First, a schedule for performing engineering streaming broadcast from a service station that provides an engineering service, that is, information regarding a schedule for performing a software download service, is stored as a download schedule 73 in the flash memory 71 as a part of additional information. Yes.

  FIG. 4 is a diagram showing an example of an electronic program guide (EPG) including software download notification information stored in the flash memory 71. FIG. 4 shows a download schedule SDTT, network ID information NIT, service information SDT, time lag information TOT, current time information TDT, program packet ID information PMT, program guide EIT, data broadcast information DATA, and the like.

  Among them, the download schedule SDTT is information relating to the software download schedule, and the software is distributed by the engineering stream broadcast of the engineering service according to this schedule. When downloading the software, the main power supply is not turned off and the digital broadcast wave for viewing is not received. The reception power supply is automatically turned on and tuning to the service station is automatically performed. Will be performed and software will be downloaded. At this time, with respect to the time, information TDT regarding the time lag of the specific area and the current time and date information TDT are referred to, and the download is performed according to the download schedule SDTT accurately.

  In the digital broadcast receiving apparatus 200 according to the present embodiment shown in FIG. 2, for example, the download schedule SDTT stored in the flash memory 71 is referred to, and the download operation is started a predetermined time before the download start time. You may do it. For example, if the download is scheduled to start at 10:00 am, the operation may be started at 9:55 five minutes before.

  First, the download schedule SDTT stored in the flash memory 71 is referred to, and when a predetermined time has passed, the service station detection means 80 detects whether or not there are a plurality of service stations that can receive the engineering service. . At this time, the service list 72 in the flash memory 71 is referred to.

  FIG. 5 is a diagram showing an example of specific contents of the service list 72. The service list 72 is a list in which information about receivable services is listed. For example, as shown in FIG. 5, a network ID, service ID, channel number, branch number, station name, C / N value, region The identification ID, service type, etc. are stored. Here, the item of “region identification” is assigned a number for each region. For example, a number is assigned for each region such as 1: Tokyo, 2: Chiba Prefecture, 3: Kanagawa Prefecture, etc. It is done. The item “service type” is an item for identifying the type of service, and an identification ID is assigned to each type of service. For example, if the service content is to transmit audio signals and video signals such as normal dramas and sports broadcasts, the flag “0X1C” is set, and if the service content is to transmit engineering service, the flag “0X1A” is set. In the case of FIG. 5, two stations, TBS and NTV, are shown as normal program receiving stations. In FIG. 5, there are two flags of the service type “0X1A” indicating the engineering service, and the receivable areas can receive engineering services in two different service areas in 1: Tokyo and 2: Chiba Prefecture. It turns out that it is.

  As described above, the service station detection unit 80 detects the flag of the engineering service from the service type item in the service list 72 stored in the flash memory 71, and then the services of a plurality of regions from the item of the region identification ID. By detecting whether or not there is a station, it is possible to detect whether or not there are a plurality of receivable service stations.

  Note that the service types include a television service, a radio service, a data service, and an engineering service. As described above, since each service has a flag, the service type can be determined by the flag. The setting of such a flag is regulated by ARIB (Association of Radio Industries and Broadcast).

  The service list 72 may be generated at the time of channel scanning in which the user purchases the digital broadcast receiving apparatus 200 and performs channel setting or the like. After the service list 72 is generated, based on the service list 72, tuning for normal viewing and software download by the engineering service are performed.

  Here, when there is only one service station capable of receiving the engineering service, it is only necessary to download the software from the engineering service, and therefore, a normal download operation may be performed. On the other hand, as shown in FIG. 5, when a plurality of receivable service stations are detected from the service list 72, the detection result of the service station detection unit 80 is output to the C / N value acquisition unit 90.

  Returning to FIG. 2, the operation of the C / N value acquisition means 90 will be described. When the service station detecting means 80 detects a plurality of receivable service stations, the tuner 10 first selects the first service station, for example, the Tokyo service station 300, and acquires the C / N value. To do. At this time, since the C / N value changes every moment depending on the reception state, a plurality of C / N values may be obtained instantaneously within a predetermined period. For example, if one instantaneous C / N value is acquired every 16 [ms], ten instantaneous C / N values can be acquired in only 160 [ms]. Here, for example, in order to increase the accuracy, if the C / N value is calculated by averaging the instantaneous C / N values for the center eight times, excluding the maximum value and the minimum value, a highly accurate C / N value is obtained. N values can be calculated. Such a calculation operation of the C / N value is performed by the C / N value calculation unit 91, and the calculated C / N value may be stored in the C / N value storage unit 92.

  Note that 16 [ms] is a unit of 1 [Tick], which is the same as the time interval at which the CPU outputs one command. In this way, the instantaneous C / N value may be acquired at a timing synchronized with the operation of the CPU.

  After acquiring the C / N value of the first receivable service station in this way, the second receivable service station, for example, the Chiba prefecture service station 310 is selected by the tuner 10, and the same If the C / N value is acquired by the method, the C / N values of the service stations 300 and 310 can be acquired in a time of only a few seconds.

  The C / N value of each service station acquired by the C / N value acquisition unit 90 is output to the service station selection unit 100.

  The operation of the service station selection means is the same as that performed when the components of the digital broadcast receiving apparatus 200 are described. That is, in the service station selection means 100, the C / N value comparison means 101 compares the C / N values of the service stations 300 and 310, selects the service station having the largest C / N value, and determines the result. Output to the tuning control means 102. The channel selection control unit 102 receives the result of the C / N value comparison unit 101 and causes the tuner 10 to select a service station having the largest C / N value. In this way, the service station with the largest C / N value is selected.

  After that, the engineering stream broadcast from the selected service station is received and the software is downloaded. With such an operation of the digital broadcast receiving apparatus 200 according to the present embodiment, software can be downloaded from the service station with the best reception state, and the success probability of downloading can be greatly improved.

  Next, the processing flow of the digital broadcast receiving apparatus 200 according to the present embodiment will be described with reference to FIG. FIG. 6 is a processing flowchart of the digital broadcast receiving apparatus 200 according to the present embodiment.

  In step 100, software download information is acquired from a digital broadcast wave. In FIG. 6, it is abbreviated as SWDL (Software Download). This step may be performed by storing the software download schedule 73 in the flash memory 71 when additional information is received by receiving a normal digital broadcast wave.

  In step 110, the service list detection unit 80 refers to the service list 72. The service list 72 may be referred to when the service station detection unit 80 accesses the service list 72 stored in the flash memory 71.

  Note that the timing at which step 110 is performed may be performed a predetermined time before the start of download based on the software download schedule 73 acquired at step 100. Specifically, a level several minutes before the download start time is sufficient.

  In step 120, the service station detection unit 80 detects a service whose service type corresponds to the engineering service from the service list 72. As described in FIG. 5, for example, by detecting the engineering service flag from the service type information in the service list 72 and further detecting from the area identification ID whether there are a plurality of receivable service stations. The service station may be detected.

  If the service station detection unit 80 detects a service station capable of receiving two or more engineering services in step 120, the process proceeds to step 130. On the other hand, if the service station detection unit 80 detects only one service station that can receive the engineering service, the process proceeds to step 160.

  In step 130, the C / N value acquisition means 90 selects each service station that provides an engineering service using the tuner 10 and acquires the C / N value of each service station. At that time, for example, a plurality of instantaneous C / N values may be acquired for each service station, and an average value of the instantaneous C / N values may be calculated to acquire a more stable C / N value.

  In step 140, the service station selection means 90 compares the C / N values of the engineering services of each service station, selects the service station that provides the engineering service with the highest C / N value, and Adjust the tuning to the selected service station.

  In step 150, software is downloaded from the service station that broadcasts the engineering service with the highest C / N value selected in step 140, and the processing flow ends.

  On the other hand, if the process proceeds from step 120 to step 160, the software download is executed in one corresponding service station, and the process flow ends.

  Thus, according to the processing flow of the digital broadcast receiving apparatus 200 according to the present embodiment, when there are a plurality of service stations capable of receiving the engineering service, the download is performed from the service station with the best reception state at the time of downloading, You can increase the probability of successful downloads. When there is only one service station that can receive the engineering service, software can be downloaded from the service station in the service area as usual. Therefore, even when the digital broadcast receiving apparatus 200 is used in an area such as a prefectural border, it is particularly suitable not only in such an area but also in an area where a service station is clearly specified as one. Can be used.

  The preferred embodiments of the present invention have been described in detail above. However, the present invention is not limited to the above-described embodiments, and various modifications and substitutions can be made to the above-described embodiments without departing from the scope of the present invention. Can be added.

  The present invention can be used in a digital broadcast receiving apparatus including a set top box, a television receiver, and the like that receive digital broadcasts.

DESCRIPTION OF SYMBOLS 10 Tuner 11 Antenna 15 Receiving part 20 Demodulation part 21 Error correction part 30 Encryption / decryption part 31 Separation part 40 Audio signal processing part 41 Audio signal conversion means 42 Speaker 50 Video signal processing part 51 Visual driver 52 Display part 60 Control part 70, 71 , 72, 73 Memory 80 Service station detection means 90 C / N value acquisition means 91 C / N value calculation means 92 C / N value storage means 100 Service station selection means 101 C / N value comparison means 102 Channel selection control means 110 PCI Bus 120 Sub CPU
130 power supply unit 200 digital broadcasting receiver 250 house 300, 310 service station

Claims (5)

A tuning means for changing a tuning frequency and selecting a service station to receive;
Service station detection means for detecting whether there are a plurality of service stations capable of receiving the engineering service; and
When a plurality of service stations are detected by the service station detection unit, the channel selection unit selects each service station and acquires a C / N value of the engineering service transmitted from each service station. / N value acquisition means;
Service station selection that compares the C / N values of the service stations acquired by the C / N value acquisition means, selects the service station having the highest C / N value, and causes the channel selection means to select the service station Means,
A digital broadcast receiving apparatus comprising: control means for controlling software download using an engineering stream broadcast transmitted from a service station selected by the service station selecting means.   The C / N value acquisition means acquires a plurality of instantaneous C / N values of the digital broadcast signal from the same service station, and calculates the C / N value of each service station from an average value of the plurality of instantaneous C / N values. The digital broadcast receiving apparatus according to claim 1, wherein a value is calculated. Storing means for storing a service list that lists channel information of each receivable service;
The digital broadcast receiving apparatus according to claim 1, wherein the service station detection unit detects the service station that performs the engineering service from the service list.   The selection of the service station by the service station selection means is performed within a predetermined time before the engineering stream broadcast in which the software to be downloaded is transmitted. The digital broadcast receiver according to any one of the above. Storage means for storing a download schedule by the engineering stream broadcast in advance;
5. The digital broadcast receiving apparatus according to claim 4, wherein the service station is selected by the service station selection unit based on the download schedule stored in the storage unit.

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