JP4463739B2 - Digital broadcast receiving apparatus and digital broadcast receiving method - Google Patents

Description

  The present invention relates to a digital broadcast receiving apparatus and a digital broadcast receiving method.

  In terrestrial digital broadcasting, in order to receive emergency warning broadcasts, the tuner is activated and the emergency information descriptor included in the digital broadcast signal is constantly monitored. If so, the receiver is activated to receive and play emergency alert broadcasts. As described above, in order to receive an emergency warning broadcast that requires temporary and immediateness, it is necessary to continuously receive the digital broadcast signal by operating the tuner.

However, in a battery-powered digital broadcast receiver such as a mobile phone having a digital broadcast receiving function or a PDA (Personal Digital Assistance), if the tuner is always operated to receive an emergency warning broadcast as described above, There is a problem in that power is increased and standby time for incoming calls and incoming mails is reduced. For this reason, a technique for shortening the operation time of the tuner and suppressing power consumption by periodically starting the tuner and intermittently receiving digital broadcast signals has been proposed. For example, although it is different from reception of a digital broadcast signal, Japanese Patent Laid-Open No. 2003-318807 discloses an intermittent reception operation for mobile communication in a mobile communication terminal having a short-range wireless data communication function such as Bluetooth (registered trademark). And a technique for reducing power consumption during standby by reducing the operation time during intermittent reception by synchronizing the intermittent reception operation with Bluetooth.
JP 2003-318807 A

 However, when the above prior art is applied to a digital broadcast receiving apparatus having a digital broadcast receiving function, that is, the intermittent reception operation of the notification signal transmitted from the mobile communication base station is synchronized with the intermittent reception operation of the digital broadcast signal. In this case, the series of operation time of starting the tuner, receiving the digital broadcast signal, and detecting the emergency information descriptor is longer than the intermittent reception operation time of the notification signal. There is a problem that the tuner always operates during the intermittent reception operation, and power consumption during standby increases.

 The present invention has been made in view of the above-described circumstances, and an object thereof is to reduce power consumption during standby of a digital broadcast receiving device having a digital broadcast receiving function.

To achieve the above object, a digital broadcast receiving apparatus according to the present invention includes a first receiving means for intermittently receiving a notification signal transmitted from a base station of a mobile communication network at a predetermined reception timing, and a digital broadcast signal. A second receiving means for intermittently receiving the signal , and determining whether or not the communication area is within a communication area based on a reception state of the notification signal by the first receiving means. characterized by comprising control means for controlling so as to perform the reception process, the.

Further, the control means controls the second receiving means so as to stop the receiving process of the second receiving means when it is determined that it is out of a communication area during the receiving process of the second receiving means. Features.

The digital broadcast receiving method according to the present invention intermittently receives a notification signal transmitted from a base station of a mobile communication network at a predetermined reception timing, and determines whether or not it is within a communication range based on a reception state of the notification signal. Then, as a result of the determination , control is performed so as to perform reception processing of the digital broadcast signal when the communication range is present.

In addition, the digital broadcast signal reception process is stopped when it is determined that it is out of a communication range during the digital broadcast signal reception process.

 According to the present invention, since the reception timing of the digital broadcast signal is dynamically controlled based on the reception state of the notification signal transmitted from the base station of the mobile communication network, the operation time of the tuner is shortened and the consumption during standby is reduced. It is possible to reduce power.

 Hereinafter, an embodiment of the present invention will be described with reference to the drawings. In the present embodiment, description will be made using a wireless communication terminal having a digital broadcast receiving function as an example of a digital broadcast receiving apparatus. FIG. 1 is a block diagram of a wireless communication terminal (for example, a mobile phone) having a digital broadcast receiving function according to an embodiment of the present invention. As shown in this figure, the wireless communication terminal includes a mobile communication antenna 1, an RF (wireless) communication unit 2, a digital broadcast antenna 3, a digital broadcast tuner unit 4, a control unit 5, and a broadcast reproduction unit 6. ing. Further, the control unit 5 includes a CPU (Central Processing Unit) 5a, a ROM (Read Only Memory) 5b, and a RAM (Random Access Memory) 5c as functional components, and the broadcast reproduction unit 6 includes a display unit 6a. And a speaker 6b. The mobile communication antenna 1 and the RF communication unit 2 constitute first receiving means, and the digital broadcast antenna 3 and the digital tuner part 4 constitute second receiving means.

 The mobile communication antenna 1 receives and transmits signals such as reception of broadcast signals transmitted from a base station of a mobile communication network (not shown). The RF communication unit 2 performs frequency conversion and demodulation of each received signal such as a notification signal received by the mobile communication antenna 1 under the control of the CPU 5a, and outputs each demodulated received signal to the CPU 5a. Further, the RF communication unit 2 modulates and frequency-converts a transmission voice signal and data signal input from the CPU 5a, and transmits the modulated signal as a transmission signal to the base station of the mobile communication network via the mobile communication antenna 1. .

 The digital broadcast antenna 3 is a digital broadcast receiving antenna that receives a digital broadcast signal transmitted from a digital broadcast station (not shown). The digital broadcast tuner unit 4 is a digital broadcast tuner, performs frequency conversion and demodulation of the digital broadcast signal received by the digital broadcast antenna 3 under the control of the CPU 5a, and outputs the demodulated digital broadcast signal to the CPU 5a. In addition, tuning to each digital broadcast program (service) and emergency warning broadcast is performed.

 The CPU 5a of the control unit 5 controls the overall operation of the wireless communication terminal based on a predetermined control program stored in advance in the ROM 5b. Further, the control unit 5 displays the content of the e-mail on the display unit 6a or outputs the sound from the speaker 6b based on each received signal input from the RF communication unit 2. Further, the control unit 5 displays the video of the digital broadcast program on the display unit 6a based on the digital broadcast signal input from the digital broadcast tuner unit 4, and outputs the audio of the broadcast from the speaker 6b. The control unit 5 receives the digital broadcast signal by the digital broadcast tuner unit 4 based on the reception state of the notification signal transmitted from the base station of the mobile communication network as a characteristic control process based on the control program. Control processing. Details of such control processing will be described later.

 The ROM 5b stores a control program executed by the CPU 5a and other nonvolatile data. The RAM 5c is used as a working area for control processing by the CPU 5a. The display unit 6a is, for example, a liquid crystal display, an organic EL display, or the like, and displays e-mail content, video of a digital broadcast program, and the like under the control of the CPU 5a. The speaker 6b outputs sound as a telephone function and sound of a digital broadcast program to the outside under the control of the CPU 5a.

 Next, a characteristic control process of the control unit 5 in the wireless communication terminal configured as described above, that is, a digital broadcast signal reception process based on a reception state of a notification signal transmitted from a base station of a mobile communication network will be described. To do. As described below, this control process includes a first embodiment and a second embodiment. First, the first embodiment will be described. In both the first and second embodiments, it is assumed that the wireless communication terminal is in a standby state.

[First embodiment]
FIG. 2 is a flowchart in the first embodiment of the control process. First, the control unit 5 initially sets a tuner activation flag, which is a control parameter, to “0” (step S1). Subsequently, the control unit 5 determines whether the timer for measuring the predetermined time T _C expires (step S2). In this step S2, if “NO”, that is, the timer has not expired, the control unit 5 waits until the timer expires, and when the timer expires, that is, when the timing of intermittent reception of the notification signal is reached (“YES”). Then, the RF communication unit 2 is activated to receive a notification signal transmitted from the base station of the mobile communication network (step S3). And the control part 5 determines whether it is a communication range based on the electromagnetic wave intensity etc. of the alerting signal received by the RF communication part 2 (step S4).

  If it is determined as “YES” in step S4, that is, within the communication range, the control unit 5 sets the tuner activation flag to “1” (step S5). On the other hand, if it is determined as “NO” in step S4, that is, outside the communication range, the control unit 5 sets the tuner activation flag to “0” (step S6). Then, when the intermittent reception of the RF communication unit 2 is completed, the control unit 5 shifts to the sleep mode (step S7) and determines whether the tuner activation flag is “1” (step S8). If “YES” in this step S8, that is, if the tuner activation flag is “1”, the control unit 5 activates the digital broadcast tuner unit 4 (step S9). On the other hand, if “NO” in step S8, that is, if the tuner activation flag is “0”, the control unit 5 proceeds to the process of step S2.

 There is a high possibility that both the notification signal and the digital broadcast signal transmitted from the base station of the mobile communication network cannot be received when there is a similar shield such as in a tunnel or indoor. Therefore, when the wireless communication terminal is within the communication range as described above and is in a state where communication and call can be made and received, the digital broadcast tuner unit 4 is regarded as being capable of receiving a digital broadcast signal. If it is activated and it is out of the communication range, it is assumed that the digital broadcast signal cannot be received, and the digital broadcast tuner unit 4 is not activated.

 Subsequently, when the digital broadcast tuner unit 4 is activated, the control unit 5 determines whether or not the digital broadcast tuner unit 4 can capture the digital broadcast signal (step S10), and when the digital broadcast signal cannot be captured (step S10). "NO"), the process proceeds to step S16, the digital broadcast tuner unit 4 is stopped (or the sleep mode), and the process returns to step S2. On the other hand, when the digital broadcast signal can be captured (“YES”), the control unit 5 causes the digital broadcast tuner unit 4 to receive the digital broadcast signal (step S11), and the digital broadcast signal is demodulated into stream data after demodulation. The included emergency information descriptor is confirmed (step S12). The channel of the digital broadcast signal to be received may be set in advance, or may be the channel of the digital broadcast program received before shifting to the standby state.

 And the control part 5 determines whether the emergency alert broadcast is performed from the content of the said emergency information descriptor (step S13). FIG. 3 is a schematic diagram showing the configuration of the emergency information descriptor. As shown in this figure, the emergency information descriptor includes a flag (start / end flag) indicating the start and end of emergency alert broadcasting, a region code indicating the broadcast area, and the like. That is, it is possible to determine whether or not emergency warning broadcasting is performed by checking the start / end flag. When the start / end flag is “1”, it indicates that the emergency alert broadcast is started or during emergency alert broadcast, and when the start / end flag is “0”, the end of the emergency alert broadcast is indicated. . Therefore, in step S13, the control unit 5 confirms whether the start / end flag is “1” or “0”. If the flag is “0”, the control unit 5 determines that the emergency warning broadcast is not performed and proceeds to step S16. Then, the digital broadcast tuner unit 4 is stopped, and the process returns to step S2. On the other hand, when the start / end flag is “1”, the control unit 5 determines that the emergency alert broadcast is being performed, and the digital broadcast tuner unit 4 so as to tune to the channel on which the emergency alert broadcast is performed. And an emergency warning broadcast signal is received (step S14).

 When the digital broadcast tuner unit 4 receives the emergency warning broadcast signal as described above, the control unit 5 displays video relating to the emergency warning broadcast on the display unit 6a and the speaker 6b based on the demodulated emergency warning broadcast signal. Audio is output (step S15). Then, when the emergency alert broadcast ends, the control unit 5 stops the digital broadcast tuner unit 4 (step S16), and proceeds to the process of step S2.

 FIG. 4 shows the control process of the control unit 5 as described above in a time chart. For example, if the communication area is determined at the timing of time T11 and it is determined that the wireless communication area is within the communication area (B11) (B11), the digital broadcast tuner unit 4 is activated and the emergency warning broadcast detection process is performed. Is performed (D11). When the intermittent reception timer expires and the communication range is determined at the next timing indicated by time T12, and it is determined that the communication range is out of range (NG) (B12), the digital broadcast tuner unit 4 is not activated (D12). . Further, since it is determined that it is out of communication range (NG) at the timing of the next intermittent time T13 (B13), similarly, the digital broadcast tuner unit 4 is not activated (D13). When it is determined that the communication range is within the next intermittent reception time T14 (B14) (B14), the digital broadcast tuner unit 4 is activated and emergency warning broadcast detection processing is performed (D14).

 As described above, according to the first embodiment, based on the reception state of the intermittent reception of the notification signal by the RF communication unit 2, the digital broadcast reception process, that is, whether to activate the digital broadcast tuner unit 4 is controlled. Therefore, the number of activations of the digital broadcast tuner unit 4 can be reduced, and as a result, the operation time for receiving the digital broadcast can be shortened and the power consumption of the wireless communication terminal can be reduced.

[Second Embodiment]
FIG. 5 is a flowchart of the second embodiment in the control process of the control unit 5. First, the control unit 5 initially sets a tuner activation flag, which is a control parameter, to “1” (step S20). Subsequently, the control unit 5 determines whether the timer for measuring the predetermined time T _C expires (step S21). If “NO” in step S21, that is, if the timer has not expired, the control unit 5 waits until the timer expires, and when the timer expires, that is, when the timing for intermittent reception of the notification signal is reached (“YES”). Then, it is determined whether or not the tuner activation flag is “1” (step S22). If “YES” in step S22, that is, if the tuner activation flag is “1”, the control unit 5 performs the out-of-service detection process and the emergency warning broadcast detection process at the same time (step S23). On the other hand, if “NO” in step S22, that is, if the tuner activation flag is “0”, the control unit 5 performs only out-of-communication detection processing (step S24).

Hereinafter, the out-of-service detection process and the emergency warning broadcast detection process illustrated in FIG. 5 will be described.
FIG. 6 is a flowchart showing the out-of-communication detection process shown in FIG. In the out-of-service detection process, the control unit 5 first activates the RF communication unit 2 and receives a notification signal transmitted from the base station of the mobile communication network (step S30). And the control part 5 determines whether it is a communication range based on the electromagnetic wave intensity etc. of the alerting signal received by the RF communication part 2 (step S31).

  If it is determined as “YES” in step S31, that is, within the communication range, the control unit 5 sets the tuner activation flag to “1” (step S32). On the other hand, if it is determined as “NO” in step S31, that is, outside the communication range, the control unit 5 cancels (suspends) the emergency warning broadcast detection process that has been started at the same time (step S33), and activates the tuner. The flag is set to “0” (step S34). That is, for example, when the out-of-communication detection process and the emergency warning broadcast detection process are performed simultaneously, and the reception state by the RF communication unit 2 is out of the communication range, the emergency warning broadcast detection process is forcibly stopped and terminated. It is.

 When the intermittent reception ends, the control unit 5 stops the processing of the RF communication unit 2 and shifts to the sleep mode (power saving mode) until the next intermittent reception timing (step S35). Then, the process returns to step S21 in FIG.

 FIG. 7 is a flowchart showing the emergency alert broadcast detection process shown in FIG. In the emergency warning broadcast detection process, the control unit 5 first activates the digital broadcast tuner unit 4 (step S40). Subsequently, the control unit 5 determines whether or not the digital broadcast tuner unit 4 can capture the digital broadcast signal (step S41). If the digital broadcast signal cannot be captured ("NO"), the control unit 5 proceeds to step S47. Then, the digital broadcast tuner unit 4 is stopped, the emergency alert broadcast detection process is terminated, and the process returns to the process of step S21 in FIG. On the other hand, when the digital broadcast signal can be captured (“YES”), the control unit 5 causes the digital broadcast tuner unit 4 to receive the digital broadcast signal (step S42), and the digital broadcast signal is converted into stream data after demodulation. The included emergency information descriptor is confirmed (step S43).

 And the control part 5 determines whether the emergency alert broadcast is performed from the content of the said emergency information descriptor (step S44). In step S44, the control unit 5 checks whether the start / end flag included in the emergency information descriptor is “1” or “0”. If the flag is “0”, the control unit 5 determines that the emergency warning broadcast is not performed. In step S47, the digital broadcast tuner unit 4 is stopped, the emergency warning broadcast detection process is terminated, and the process returns to step S21 in FIG. On the other hand, when the start / end flag is “1”, the control unit 5 determines that the emergency alert broadcast is being performed, and the digital broadcast tuner unit 4 so as to tune to the channel on which the emergency alert broadcast is performed. And an emergency warning broadcast signal is received (step S45).

 When the digital broadcast tuner unit 4 receives the emergency warning broadcast signal as described above, the control unit 5 displays the video and the sound related to the emergency warning broadcast on the display unit 6a and the speaker 6b based on the demodulated emergency warning broadcast signal. Is output (step S46). Then, when the emergency alert broadcast is completed, the control unit 5 stops the digital broadcast tuner unit 4 (step S47), ends the emergency alert broadcast detection process, and returns to the process of step S21 in FIG.

 FIG. 8 shows the control processing in FIGS. 5 to 7 as described above in a time chart. For example, if the tuner activation flag is set to “1” at the timing of time T21, the out-of-communication detection process (B21) and the emergency warning broadcast detection process (D21) are performed in parallel at the same time, and the communication area of wireless communication is within the communication area ( If OK, the digital broadcast emergency alert broadcast detection process (D21) is not completed. Then, at the timing of the intermittent reception time T22 in the next wireless communication, the tuner activation flag remains “1” because it is determined as the communication range (OK) in the out-of-communication detection process (B21) in the previous wireless communication. Therefore, the out-of-service area detection process (B22) and the emergency warning broadcast detection process (D22) are performed in parallel. However, if it is determined that the communication area is out of communication range (NG) in the out-of-communication detection process (B22) performed in parallel at the same time, the emergency warning broadcast detection process (D22) performed in parallel at the same time is forced in the middle. End (stop). Subsequently, at the timing of the intermittent reception time T23 in the next wireless communication, the tuner activation flag has been changed to “0” because it was determined to be out of communication range (NG) in the previous out of communication detection process (B22). Only the out-of-communication detection process (B23) is performed, and the emergency warning broadcast detection process at this timing in digital broadcasting is not performed. Further, at this time, it is assumed that it is determined that the communication area is out of communication range (NG) in the communication area outside detection process (B23).

  Next, at the timing of intermittent reception time T24 in wireless communication, the tuner activation flag remains “0” in the previous out-of-communication detection process (B23), so the tuner activation flag remains “0”. Only the detection process (B24) is performed, and the emergency warning broadcast detection process at this timing in the digital broadcast is not performed. Also in this case, it is assumed that the communication range (OK) is determined in the out-of-communication detection process (B24). Then, at the timing of the intermittent reception time T25 in the wireless communication, the tuner activation flag is changed to “1” because it was determined as the communication range (OK) in the previous out-of-communication detection process (B24). The detection process (B25) and the emergency warning broadcast detection process (D25) are performed in parallel at the same time.

 As described above, according to the second embodiment, whether or not to activate the digital broadcast tuner unit 4 is controlled based on the reception state of the intermittent reception of the notification signal by the RF communication unit 2. Since it is possible to reduce the number of activations and to control whether or not to perform emergency broadcast detection processing for digital broadcasting based on the result of out-of-communication detection processing at the previous timing of intermittent reception timing in wireless communication, the first Compared to the embodiment, the operation time of the digital broadcast tuner unit 4 can be shortened, and the power consumption during standby of the wireless communication terminal can be further reduced.

 In addition, this invention is not limited to the said embodiment. For example, the wireless communication system may be a mobile phone communication network or a public broadband wireless communication network. Further, as long as the apparatus has both a wireless communication function and a digital broadcast receiving function, it may be configured by adding functions like a personal computer.

1 is a configuration block diagram of a mobile communication terminal according to an embodiment of the present invention. FIG. 3 is a flowchart showing a first embodiment of control processing by a control unit 5. It is a schematic diagram which shows the structure of an emergency information descriptor. It is a time chart regarding the first embodiment of the control processing by the control unit. It is a flowchart figure which shows the 2nd Example of the control processing by the control part. It is a flowchart figure which shows the out-of-service detection process in 2nd Example of the control process by the control part. It is a flowchart figure which shows the emergency alert broadcast detection process in 2nd Example of the control process by the control part. It is a time chart regarding the 2nd example of control processing by control part.

Explanation of symbols

 DESCRIPTION OF SYMBOLS 1 ... Mobile communication antenna, 2 ... RF communication part, 3 ... Digital broadcast antenna, 4 ... Digital broadcast tuner part, 5 ... Control part, 5a ... CPU (Central Processing Unit), 5b ... ROM (Read Only Memory), 5c ... Random Access Memory (RAM), 6 ... broadcast playback unit, 6a ... display unit, 6b ... speaker

Claims (4)

First receiving means for intermittently receiving a notification signal transmitted from a base station of a mobile communication network at a predetermined reception timing;
Second receiving means for intermittently receiving a digital broadcast signal;
Control means for determining whether or not the communication area is within a communication area based on a reception state of the notification signal by the first reception means , and for performing a reception process of the second reception means when the determination result indicates that the communication area is within the communication area ; ,
A digital broadcast receiver characterized by comprising: 2. The control unit according to claim 1, wherein the control unit performs control so as to stop the reception process of the second reception unit when it is determined that it is out of a communication range during the reception process of the second reception unit . Digital broadcast receiver. The broadcast signal transmitted from the base station of the mobile communication network is intermittently received at a predetermined reception timing,
It is determined whether or not the communication range based on the reception state of the notification signal ,
As a result of the determination, a digital broadcast receiving method is characterized in that control is performed so as to perform reception processing of a digital broadcast signal in the communication range . 4. The digital broadcast receiving method according to claim 3 , wherein the digital broadcast signal reception process is stopped when it is determined that the digital broadcast signal is out of communication range during the digital broadcast signal reception process.

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