JP2008199430A - Broadcast receiver - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a broadcast receiver capable of adjusting an amplification factor of a broadcasting signal according to goodness or badness of a receiving state. <P>SOLUTION: The broadcast receiver is provided with: a receiving part which receives digital broadcasting waves to be transmitted to a rear stage circuit as the broadcasting signal; an amplification part which amplifies the broadcasting signal; a judgment part which judges goodness/badness of the receiving state and an amplification factor adjustment part which adjusts the amplification factor in amplification according to results of judgment. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a broadcast receiving apparatus that receives a digital broadcast wave, and more particularly to an apparatus that amplifies a broadcast signal.

  With the development of communication technology and the generalization of digital broadcasts, development of portable digital broadcast receivers (hereinafter simply referred to as “broadcast receivers”) is also progressing. For example, Japanese Patent Application Laid-Open No. H10-228667 discloses a device that detects whether the reception status is good or not and adjusts the orientation of the antenna according to the detection result.

  Also, in a broadcast receiving apparatus, the quality of the reception state varies greatly depending on the distance from the broadcast station and the presence or absence of obstacles to the broadcast wave. In particular, when a broadcast receiving apparatus is incorporated in a mobile terminal, the reception state often changes with the movement of the apparatus itself.

On the other hand, in a broadcast receiving apparatus, when performing demodulation processing (such as binarization processing using a slice) on a received digital broadcast signal, if the amplitude level of the broadcast signal is too small, the processing may not be performed appropriately. Therefore, normally, received broadcast signals are amplified by an amplifier, and consideration is given to appropriate demodulation processing.
JP 2001-359003 A JP-A 64-32503

  As described above, since the quality of the reception status in the broadcast receiving apparatus varies depending on various factors, it may be assumed that the reception condition is bad (particularly when the electric field strength is small). In such a case, the amplitude of the broadcast signal becomes smaller than usual, and there is a risk that appropriate demodulation processing or the like may be hindered. However, even in such a case, if the amplification factor of the broadcast signal is set sufficiently high, there is a high possibility that such a problem can be avoided.

  However, in general, in the amplification processing of a broadcast signal, the power consumed increases as the amplification factor increases. Therefore, when the amplification factor is always set to a large value, a large amount of power is consumed even when the reception condition is relatively good (demodulation processing is possible even if the amplification factor of the broadcast signal is relatively small). Become. Such a situation leads to waste of power, and is a big problem especially when power saving is important as in a mobile terminal.

  In other words, since improvement in amplification factor (reception quality) and power saving are in a trade-off relationship, it is preferable to set the amplification factor so as not to be excessive or deficient as much as possible according to the quality of the reception state. In view of the above problems, an object of the present invention is to provide a broadcast receiving apparatus that can adjust the amplification factor of a broadcast signal according to whether the reception state is good or bad.

  In order to achieve the above object, a broadcast receiving apparatus according to the present invention includes a receiving unit that receives a broadcast wave of a digital broadcast and transmits it as a broadcast signal to a subsequent circuit, an amplifying unit that amplifies the broadcast signal, and the reception state. The configuration (first configuration) includes a determination unit that determines whether the quality is good and an amplification factor adjustment unit that adjusts the amplification factor in the amplification according to the result of the determination.

  According to this configuration, it is possible to adjust the amplification factor of the broadcast signal according to the quality of the reception state (for example, the strength of the electric field strength in the broadcast wave). For this reason, when the reception state is good, power saving is emphasized by making the amplification factor relatively small. Conversely, when the reception state is not good, the amplification factor is made relatively large to ensure signal quality. It becomes easy to attach importance.

  In the first configuration, the determination unit detects whether an amplitude state of the amplified broadcast signal is greater than a predetermined reference level, and determines whether the reception state is good or not based on the detection result. It is good also as a structure to perform (2nd structure).

  In general, when the reception state of the broadcast signal is good, the electric field strength of the broadcast wave is relatively high, so it is assumed that the amplitude of the received broadcast signal is also large. Conversely, when the reception state is poor, it is assumed that the amplitude of the broadcast signal is small. Therefore, according to this configuration, it is possible to determine whether the reception state is good or bad.

  Further, in this configuration, whether or not the reception state is good is determined based on whether or not the amplitude state of the amplified broadcast signal is larger than the reference level. For this reason, for example, when processing such as demodulation is performed on the amplified broadcast signal, by setting the boundary of whether or not this processing is appropriately performed as a reference level, whether the reception state is good or not corresponding to the availability of the processing is determined. It becomes possible to judge.

  Further, in the second configuration, the amplified broadcast signal is demodulated, and video or audio is output based on the information obtained by the demodulation. The higher the amplification factor, the better. The reference level may be a configuration (third configuration) that is defined as the amplitude state when the quality of the video or audio becomes a predetermined level.

  According to this configuration, it is possible to perform video output or audio output (including the case of outputting both) of broadcast contents. Since the reference level is determined as an amplitude state when the quality of the video or audio reaches a predetermined level, the quality of the video or audio can be maintained at a predetermined level or higher. The predetermined level may be, for example, the lower limit of the range in which the user can view without feeling uncomfortable.

  In the second or third configuration, the amplification factor adjustment unit performs the adjustment (fourth configuration) so as to increase the amplification factor when the amplitude state is smaller than the reference level. Also good.

  According to this configuration, even when the amplitude state becomes smaller than the reference level due to the deterioration of the reception state, the amplitude state is adjusted to be equal to or higher than the reference level. Therefore, when it is necessary to maintain the amplitude state to be equal to or higher than the reference level, it is possible to meet such a request.

  Also, in the second or third configuration, the amplification factor adjustment unit performs the adjustment by applying any one of a plurality of modes having different amplification factors, and the amplitude state is A configuration (fifth configuration) may be adopted in which an optimization process is performed in which the mode having the smallest amplification factor within a range that is larger than the reference level is searched and the mode is applied to the amplification factor adjustment unit.

  According to this configuration, it is possible to suppress the power consumption related to the amplification process as much as possible while ensuring the amplitude state of the broadcast signal to a certain level or more by the optimization process.

  Further, in the fifth configuration, the optimization process includes a first process for provisionally applying the modes to the amplification factor adjustment unit in order from the smallest amplification factor, and each provisionally applied state. A second process for executing the detection; and a step in which the temporarily adopted mode is applied to the amplification factor adjustment unit when it is determined in the second process that the amplitude state is greater than the reference level. It is good also as a structure (6th structure) containing 3 processes.

  According to this configuration, when the optimization process is executed, the second process can be omitted for a mode in which the amplification factor is too large with respect to the current state. Therefore, the optimization process can be executed efficiently.

  The broadcast receiving device according to the fifth or sixth configuration, wherein power supply to an internal device is turned on / off or a channel in the broadcast signal is switched, wherein the optimization process includes at least the optimization process A configuration (seventh configuration) may be employed when the power supply is switched on or when the channel is switched.

  When the power supply is switched on or when the channel is switched, the reception state is highly likely to fluctuate greatly. However, according to this configuration, even when the reception state fluctuates in this way, the amplification factor is appropriately adjusted by the optimization process.

  In any one of the first to seventh configurations, the amplification factor may be adjusted based on an instruction from the outside (eighth configuration).

  According to this configuration, for example, even if it is desired to adjust the amplification factor to a specific value for some reason, such a request can be met by giving an instruction to do so from the outside.

  Further, in the eighth configuration, a configuration (9th configuration) may be provided in which a display unit that performs display according to the quality of the reception state is provided. According to this configuration, the user can give an instruction to adjust the amplification factor while referring to whether the reception state is good or bad.

  In addition, any mobile terminal having a configuration (tenth configuration) including the broadcast receiving apparatus according to any one of the first to ninth configurations can receive digital broadcasts, and any configuration described above You can enjoy the benefits of

  As described above, according to the broadcast receiving apparatus according to the present invention, it is possible to adjust the amplification factor of the broadcast signal according to the quality of the reception state. For this reason, when the reception state is good, power saving is emphasized by making the amplification factor relatively small. Conversely, when the reception state is not good, the amplification factor is made relatively large to ensure signal quality. It becomes easy to attach importance.

  As an embodiment of the present invention, a digital broadcast receiving apparatus (broadcast receiving apparatus) having the configuration shown in FIG. As shown in the figure, the broadcast receiving apparatus 1 includes an antenna 11, an RF circuit 12, a broadcast signal processing unit 13, an output unit 14, a power supply unit 15, an amplification factor adjustment unit 16, a control unit 17, an operation unit 18, and the like. Yes. The broadcast receiving apparatus 1 is used, for example, provided in a mobile terminal (such as a mobile phone).

  The antenna 11 receives a broadcast wave from a broadcasting station related to digital broadcasting, and transmits it to a subsequent circuit as a broadcast signal.

  The RF circuit 12 performs amplification processing, conversion processing to an intermediate frequency signal, and the like on the broadcast signal transmitted from the antenna 11 side and transmits the broadcast signal to the broadcast signal processing unit 13 at the subsequent stage. The detailed configuration of the RF circuit 12 will be described with reference to FIG. As shown in this figure, the RF circuit 12 includes an RF variable amplifier circuit 21, a mixer circuit 22, a local oscillation circuit 23, and the like.

  With this configuration, the broadcast signal is amplified by the RF variable amplifier circuit 21, and then added to the local oscillation signal from the local oscillation circuit 23 in the mixer circuit 22 to be converted into an intermediate frequency signal. The RF variable amplifier circuit 21 receives amplification factor setting information described later, and the amplification factor in the amplification of the broadcast signal (hereinafter simply referred to as “amplification factor”) varies according to this information. It has become.

  More specifically, three modes, “mode A” in which the gain is the highest, “mode B” in which the gain is the next highest, and “mode C” in which the gain is the lowest These processing modes are prepared, and one of these is set. Hereinafter, the closer to mode A from mode C (the higher the amplification factor), the higher the rank.

  The amplification factor fluctuates when these modes are switched. The mixer circuit 22 and the local oscillation circuit 23 also receive amplification factor setting information, and perform appropriate processing according to this information. Thereby, even if the amplification factor in the RF variable amplifier circuit 21 fluctuates, the generation of the intermediate frequency signal is not hindered.

  Note that the RF circuit 12 is operated by electric power supplied from the power supply unit 15. As the amplification factor is increased, the power necessary for amplification increases, so that the power consumption necessary for operating the RF circuit 12 increases. Therefore, in the RF circuit 12, the power consumption increases as the amplification factor increases (from mode C to mode A), while the power consumption decreases as the amplification factor decreases (from mode A to mode C). It can be kept small. As power consumption is reduced, it is possible to extend the viewable time of broadcast content.

  Returning to FIG. 1, the broadcast signal processing unit 13 demodulates the intermediate frequency signal input from the RF circuit 12 and converts it into a baseband signal. Thereby, information related to digital broadcasting is acquired. Demodulation is performed through slice processing (a binary signal is obtained based on a comparison result between an input waveform and a slice level). Therefore, when the reception state of the broadcast wave is poor and the amplitude is small, errors may occur frequently in the demodulation process unless the broadcast signal is sufficiently amplified to compensate for this. The broadcast signal processing unit 13 monitors the amplitude of the broadcast signal amplified by the RF circuit 12 and continuously transmits the result as amplitude information to the amplification factor adjusting unit 16.

  The output unit 14 includes, for example, a sound generator (speaker), a video display device (display), and the like, and outputs broadcast contents (video and sound) based on the information obtained by the above-described demodulation. Therefore, the better the demodulation stability (for example, the lower the error frequency), the better the video and audio quality.

  The power supply unit 15 is composed of a rechargeable battery or the like, and supplies power to each device inside the broadcast receiving device 1. The power supply can be freely switched ON / OFF through the operation unit 18.

  The amplification factor adjustment unit 16 performs a predetermined amplitude determination, generates the amplification factor setting information described above based on this detection, and transmits it to the RF circuit 12. The amplitude determination and amplification factor setting information generation process will be described again.

  The control unit 17 controls each process performed in the broadcast receiving device 1. The operation unit 18 includes, for example, a button switch, a remote control signal reception unit, and the like, and functions as an interface for the user to give various instructions to the broadcast reception device 1. These various instructions include ON / OFF switching of power supply by the power supply unit 15, automatic / manual switching in amplification factor adjustment processing described later, setting of amplification factor at manual selection, switching of reception channel, and the like.

  With the configuration described above, the broadcast receiving device 1 can receive broadcast waves of digital broadcasting, further amplify / demodulate the broadcast signal, and output video and sound related to the broadcast content. Yes. In addition, during reception of a broadcast wave or the like, it is possible to perform processing (amplification factor adjustment processing) for adjusting the amplification factor for a broadcast signal according to whether the reception state is good or bad. Next, the contents of the amplification factor adjustment process will be described.

  The flow of the amplification factor adjustment process is shown in FIG. First, the control unit 17 determines whether the gain adjustment process is set to be performed automatically or manually in the operation unit 18 (step S11). If it is set to be performed manually (manual in step S11), the user can freely adjust the amplification factor.

  More specifically, the processing mode (or amplification factor) designated by the user through the operation unit 18 is detected, and the detection result is transmitted to the amplification factor adjustment unit 16. Then, the amplification factor adjustment unit 16 generates amplification factor setting information based on this result and transmits it to the RF circuit 12. In the RF circuit 12, a processing mode corresponding to a user instruction is set based on the gain setting information (step S12).

  On the other hand, if it is set to be performed automatically in the process of step S11 (automatic of step S11), the amplification factor is automatically set according to the quality of the reception state.

  More specifically, the amplification factor adjustment unit 16 first determines that the amplitude state of the broadcast signal (which has been amplified by the RF circuit 12) based on the amplitude information received from the broadcast signal processing unit 13 is a predetermined reference. A determination is made as to whether the level is greater than the level (hereinafter referred to as “amplitude determination”). This determination can be realized, for example, by detecting whether or not there is a time when the broadcast signal is larger than the reference value within the most recent predetermined time (if it is present, it is considered to be greater than the reference level).

  Note that this reference level is predetermined as the amplitude state of the broadcast signal when the quality of the output video and sound becomes a predetermined level (for example, the lower limit of the range in which the user can view without discomfort). It is. Therefore, when the amplitude state of the broadcast signal is smaller than the reference level, the video and audio quality is poor, and conversely, when the broadcast signal is large, the video and audio quality is improved.

  As a result of the processing in step S13, when it is determined that the level is lower than the reference level, amplification factor setting information is generated so as to raise the processing mode by one rank from the current level, and transmitted to the RF circuit 12. The RF circuit 12 receives this amplification factor setting information and updates the processing mode (step S14). Thereafter, the process returns to step S11 again.

  If it is determined as a result of the process in step S13 that it is greater than the reference level, it is determined whether or not the next timing for executing the optimization process has arrived (step S15). When it is determined that it has not arrived, the process returns to step S11. On the other hand, when it is determined that it has arrived, the optimization process is executed (step S16), and then the process returns to step S11.

  Here, the optimization process will be described. The optimization process is a process for searching for and setting a processing mode that is optimal for the current reception state. That is, it is possible to realize the application of a processing mode capable of reducing the power consumption in the RF circuit 12 as much as possible while ensuring the amplification factor to such an extent that the broadcast signal is in a certain amplitude or higher (greater than the reference level) amplitude state. . The flow of this optimization process will be described below with reference to FIG.

  First, a processing mode (here, mode C) having the lowest gain is provisionally applied (applied experimentally) to the RF circuit 12 (step S21). In this state, the amplitude determination described above is executed (step S22). As a result, if it is determined that the amplitude of the broadcast signal is smaller than the reference level, it is considered that the amplification factor needs to be further increased. Therefore, the processing mode that is one rank higher than the current level is temporarily applied (step S23), and the processing of step S22 is executed again.

  On the other hand, if it is determined in step S22 that the amplitude of the broadcast signal is larger than the reference level, the processing mode temporarily set at that stage is set as the formal processing mode (step S24), The optimization process ends. By the optimization processing described above, the most appropriate processing mode is applied according to the quality of the current reception state. For example, in the current reception state, when mode B or mode A (however, inferior to mode B in terms of power saving) can be supported, a situation in which mode C or mode A is applied can be avoided.

  As an optimization processing method, in addition to the above-described method, amplitude determination may be executed in order from the processing mode with the largest amplification factor. In addition, for example, all processing modes are provisionally applied and amplitude determination is performed on each of them. Based on the result, the processing mode in which the amplification factor is the minimum within the range where the amplitude state of the broadcast signal is larger than the reference level. May be detected and applied formally.

  Various timings such as a predetermined time interval can be adopted as the timing for executing the optimization process. In addition, when the power supply by the power supply unit 15 is switched ON or when the reception channel is switched, it is highly likely that the reception state has changed significantly. For this reason, it is preferable to execute the optimization process at least at these times.

  Moreover, it is preferable that the broadcast receiving apparatus 1 includes a display device for displaying the quality of the reception state of the digital broadcast to notify the user. In this way, manual gain adjustment (step S12) can be performed while referring to the display, and convenience is improved.

  In the present embodiment, in order to avoid an increase in processing load due to frequent execution of optimization processing (which is considered to have a relatively large processing load), the processing in steps S13 to S15 (if the processing load is relatively small) (Conceivable) is executed constantly, while ensuring the signal quality as much as possible, the optimization process is executed only when a predetermined timing arrives. However, the optimization process may be executed constantly. In this case, even if the processes in steps S13 to S15 are omitted, substantially the same effect as in the present embodiment can be obtained.

  As described above, the broadcast receiving apparatus of this embodiment receives a digital broadcast wave and transmits it as a broadcast signal to a subsequent circuit, an antenna 11 and the like, an RF circuit 12 that amplifies the broadcast signal, and a reception state A gain adjustment unit 16 or the like is provided for determining pass / fail and adjusting the gain according to the result of the determination. Therefore, it is possible to adjust the amplification factor of the broadcast signal according to the quality of the reception state.

  In the present embodiment, the quality of the reception state is determined based on the amplitude state of the broadcast signal amplified by the RF circuit 12, but may be based on the amplitude state of the broadcast signal before being amplified, Other methods may be employed. For example, by monitoring the stability in demodulating a broadcast signal (the frequency of occurrence of errors) and detecting whether this stability is better than a predetermined reference level, the quality of the reception state is judged. You may make it do. Further, whether the reception state is good or not may be determined by detecting whether video / audio is output to such an extent that the user can view the broadcast content.

  The present invention is not limited to the above-described embodiments, and various modifications can be made without departing from the gist of the present invention.

  The present invention can be used in fields such as mobile digital broadcast receivers.

It is a block diagram of the broadcast receiving apparatus based on embodiment of this invention. It is a block diagram of RF circuit based on embodiment of this invention. It is a flowchart regarding an amplification factor adjustment process. It is a flowchart regarding an optimization process.

Explanation of symbols

11 Antenna 12 RF circuit (amplifier)
13 Signal processor (demodulator)
DESCRIPTION OF SYMBOLS 14 Output part 15 Power supply part 16 Amplification factor adjustment part 17 Control part 18 Operation part 21 RF variable amplification circuit 22 Mixer circuit 23 Local oscillation circuit

Claims (10)

A receiving unit that receives a broadcast wave of digital broadcasting and transmits it as a broadcast signal to a subsequent circuit;
An amplifier for amplifying the broadcast signal;
A determination unit for determining the quality of the reception state;
An amplification factor adjusting unit that adjusts the amplification factor in the amplification according to a result of the determination;
A broadcast receiving apparatus comprising: The determination unit
The broadcast according to claim 1, wherein whether or not the amplitude state of the amplified broadcast signal is larger than a predetermined reference level is detected, and whether or not the reception state is good is determined based on the detection result. Receiver device. The demodulated broadcast signal is demodulated, and video or audio is output based on the information obtained by the demodulation, and the quality of the video or audio is improved as the amplification factor increases. Because
The standard level is
The broadcast receiving apparatus according to claim 2, wherein the amplitude state when the quality of the video or audio is a predetermined level is defined. The amplification factor adjustment unit
4. The broadcast receiving apparatus according to claim 2, wherein the adjustment is performed to increase the amplification factor when the amplitude state is smaller than the reference level. 5. The amplification factor adjusting unit is adapted to perform the adjustment by applying any one of a plurality of modes having different amplification factors.
The optimization process is performed in which the mode in which the amplitude state is larger than the reference level and the amplification factor is the smallest is searched, and the mode is applied to the amplification factor adjustment unit. The broadcast receiving apparatus according to claim 2. The optimization process is as follows:
A first process of temporarily applying the mode to the amplification factor adjustment unit in order from the smallest amplification factor;
A second process for performing the detection for each of the temporarily applied states;
A third process of applying the temporarily adopted mode to the gain adjustment unit when the amplitude state is determined to be greater than the reference level in the second process;
The broadcast receiving apparatus according to claim 5, comprising: The broadcast receiving device according to claim 5 or 6, wherein power supply to an internal device is turned on or off, or a channel in the broadcast signal is switched.
The optimization process is as follows:
The broadcast receiving apparatus, which is performed at least when the power supply is switched on or when the channel is switched.   The broadcast receiving apparatus according to claim 1, wherein the amplification factor can be adjusted based on an instruction from the outside.   The broadcast receiving apparatus according to claim 8, further comprising a display unit that performs display according to whether the reception state is good or bad.   A mobile terminal comprising the broadcast receiving apparatus according to any one of claims 1 to 9.

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