JP4651507B2 - Radio wave receiver - Google Patents

Description

  The present invention relates to a radio wave receiving apparatus that is mounted on a vehicle and includes a first receiving unit that receives a first broadcast and a second receiving unit that receives a second broadcast.

  Hybrid receivers have been developed that can receive two or more broadcasts, such as a fixed receiver digital broadcast and an analog broadcast, a fixed receiver digital broadcast, and a mobile digital broadcast. In digital broadcasting, received signals are subjected to processing such as error correction and data decoding, and then video and audio based on the received signals are output. Therefore, for digital broadcasting, when the power is turned on or when switching from analog broadcasting to digital broadcasting, video and audio are not immediately output, and the time until video and audio are output is connected by muting (for example, Patent Documents). 1).

JP 7-193767 A

  However, the user feels uncomfortable in a state in which no video and audio are output, particularly in a situation where the user tends to focus on the output unit, such as when the vehicle is parked or stopped. In addition, when the radio wave environment changes frequently due to changes in the surrounding environment, such as when a large vehicle passes in the vicinity of the vehicle, switching from digital broadcasting to analog broadcasting and from analog broadcasting to digital broadcasting occur continuously. However, there is a possibility that a state in which video and audio are not output to the output unit, a state in which video and audio are repeated, or a state in which video and audio are partially skipped may continue.

  An object of the present invention is to provide a radio wave receiver that can prevent a mute state or the like from continuing while a vehicle is parked or stopped.

The radio wave receiver according to claim 1 outputs video information and audio information based on a received signal received by a first receiving unit that receives a first broadcast or a second receiving unit that receives a second broadcast. In the radio wave receiving apparatus that is output to the unit and mounted on the vehicle , the radio wave environment between the first receiving unit and the second receiving unit is used as the first selection method in order to output video information and audio information to the output unit. Selecting means for selecting and selecting the better one, and when the traveling speed of the vehicle is determined to be equal to or lower than a predetermined speed, the selecting means selects the first receiving unit that is not easily affected by the radio wave environment. If the first receiving unit is selected, and the second receiving unit that is susceptible to the influence of the radio wave environment is selected by the first selecting method, the first selecting method selects the first receiving unit. Continue to select the first receiver after the first receiver is selected And changing the second selection method.

  According to the radio wave receiving apparatus of the first aspect, since the vehicle selection speed is changed from the normal selection method to the predetermined selection method when the traveling speed of the vehicle is determined to be equal to or lower than the predetermined speed, the broadcasting in which the reception state is stable By changing to the predetermined selection method of selecting the video information and audio information of the first broadcast or the second broadcast can be continuously output to the output unit. That is, it is possible to prevent the mute state in which broadcast video information and audio information are not output to the output unit from continuing.

Further , according to the radio wave receiving apparatus of the first aspect , when the traveling speed of the vehicle is determined to be equal to or lower than the predetermined speed, the first receiving unit that is not easily affected by the radio wave environment is continuously selected. It is possible to continue outputting the video information and audio information of the first broadcast that is not easily affected by the above-described effect, that is, not easily muted. That is, it is possible to prevent the mute state in which broadcast video information and audio information are not output to the output unit from continuing.

The radio wave receiving apparatus according to claim 2 is a video information and audio information based on a received signal received by a first receiving unit that receives a first broadcast or a second receiving unit that receives a second broadcast. In the radio wave receiver mounted on the vehicle,
The first measuring means for measuring the electric field strength of the radio wave received by the first receiving unit as the first electric field strength and the electric field strength of the radio wave received by the second receiving unit are measured as the second electric field strength. Comparing the second electric field strength measured by the second measuring means, the first electric field intensity measured by the first measuring means and the second electric field intensity measured by the second measuring means. Determining means for determining whether or not the electric field strength of 2 exceeds the first threshold value or a second threshold value set higher than the first threshold value; When it is determined that the second electric field strength is greater than the first threshold value than the first electric field strength, the second receiving unit that is easily affected by the radio wave environment is selected, and the first detection unit determines the first receiving unit. It is determined that the second electric field strength is not greater than the first threshold value than the electric field strength. And selecting means for selecting a first receiver that is not easily affected by the radio wave environment when the vehicle travel speed is determined to be equal to or lower than a predetermined speed. On the other hand, the first selection method is changed from the first selection method to the second selection method in which the first threshold value is replaced with the second threshold value, and the first reception unit or the second reception unit is selected based on the second threshold value. It is characterized by that.
According to a third aspect of the present invention, there is provided the radio wave receiving apparatus according to the first aspect of the present invention, wherein the video information and the audio information are based on the received signal received by the first receiver that receives the first broadcast or the second receiver that receives the second broadcast. In the radio wave receiver mounted on the vehicle,
A first measuring means for measuring a bit error rate of a digital signal received by the radio wave received by the first receiver as a first bit error rate; and a digital signal received by the radio wave received by the second receiver . a second measuring means for measuring the bit error rate as the second bit error rate, the second bit error measured by the first bit error rate and a second measuring means that is measured by the first measuring means comparing the rate, than the second bit error rate first bit error rate, a first threshold value or the second determining whether greater than a threshold value set higher than the first threshold value determination and determination means, and a first selection method, the first bit error rate than the second bit error rate by discriminating means greater than the first threshold value Selects the second receiver susceptible to radio wave environment when the, than the second bit error rate first bit error rate is judged to be not larger than the first threshold value by determining means Selecting means for selecting the first receiving unit that is not easily affected by the radio wave environment, and the selecting means determines whether the traveling speed of the vehicle is equal to or lower than a predetermined speed in response to the first selection method. the first threshold value is changed from the first selection method a second selection method instead of the second threshold value, select the first receiver or the second receiver based on the second threshold value and wherein a call.

According to the radio wave receiving apparatus according to claim 2 and claim 3, by changing the first threshold value to the second threshold value when the traveling speed of the vehicle is determined to be equal to or lower than the predetermined speed, It is possible to make it difficult to switch from the first receiving unit that is not easily affected to the second receiving unit that is susceptible to radio wave environment. Therefore, it is possible to continue outputting the video information and audio information of the first broadcast that is not easily affected by the radio wave environment, that is, not easily muted. That is, it is possible to prevent the mute state in which broadcast video information and audio information are not output to the output unit from continuing.

The radio wave receiving apparatus according to claim 4 further includes a canceling unit that cancels the second selection method changed by the selection unit , and the canceling unit is determined that the traveling speed of the vehicle is greater than a predetermined speed. If, or when instructed by instruction means for instructing a change release, it characterized that you change the second selection method has been changed by the selection means to the first selection method.

According to a fifth aspect of the present invention, there is provided a radio wave receiving apparatus comprising: a release unit that cancels the second selection method changed by the selection unit; and a measurement unit that measures the electric field strength of the radio wave received by the first reception unit. Further, the release means changes the second selection method changed by the selection means to the first selection method when the electric field intensity of the radio wave received by the first receiving unit is equal to or lower than a predetermined threshold value. It is characterized by that.

The radio wave receiving apparatus according to claim 6, wherein, further comprising, releasing means and release means for releasing the second selection method has been changed by the selection means, the first field strength is equal to or less than a predetermined threshold value In this case, the second selection method changed by the selection means is changed to the first selection method.

According to the radio wave receivers of the fourth to sixth aspects, since the release means for canceling the changed selection method is provided, when the traveling speed of the vehicle becomes higher than a predetermined speed, that is, the driving is resumed. When the user stops paying attention to the output unit, the broadcast selected by the first selection method can be output. Also, the broadcast selected by the first selection method can be output when the user gives an instruction to cancel the change or when the reception state by the first receiving unit that is not easily affected by the radio wave environment deteriorates.

  The radio wave receiver according to claim 7 is characterized in that the first broadcast is a mobile digital broadcast and the second broadcast is a fixed receiver digital broadcast.

  According to the radio wave receiving apparatus of the seventh aspect, the mobile digital broadcast that is less affected by the radio wave environment compared to the fixed reception digital broadcast as the second broadcast is used as the first broadcast. Thus, it is possible to continue outputting video information and audio information of the mobile digital broadcast that is less likely to be muted compared to the fixed receiver digital broadcast to the output unit.

  The radio wave receiver according to claim 8 is characterized in that the first broadcast is an analog broadcast and the second broadcast is a digital broadcast for a fixed receiving station.

  According to the radio wave receiving apparatus of the eighth aspect, the analog broadcast that is less affected by the radio wave environment as compared with the digital broadcast for the fixed receiving station as the second broadcast is used as the first broadcast. It is possible to continue to output video information and audio information in the digital direction for a moving body that is less likely to be in a mute state compared to digital broadcasting for a station.

According to the radio wave receiving apparatus of the present invention, when the traveling speed of the vehicle is determined to be equal to or lower than the predetermined speed, the first selection method is changed to the second selection method. By changing to the second selection method to be selected, video information and audio information of the first broadcast or the second broadcast can be continuously output to the output unit. That is, it is possible to prevent the mute state in which broadcast video information and audio information are not output to the output unit from continuing.

  A radio wave receiving apparatus according to a first embodiment of the present invention will be described below with reference to the drawings. The radio wave receiving apparatus according to the first embodiment is mounted on a vehicle. FIG. 1 is a block diagram showing the configuration of the radio wave receiving apparatus according to the first embodiment. As shown in FIG. 1, the radio wave receiving apparatus according to this embodiment includes a first antenna 1A and a second antenna 2A. The first antenna 1A is configured to receive radio waves for analog TV broadcasting (first broadcasting), and the second antenna 2A is digital TV broadcasting for fixed receiving stations (second broadcasting, hereinafter referred to as digital TV). It is configured to receive radio waves for broadcasting.) Note that the digital TV broadcast for fixed reception stations indicates, for example, CS, BS, terrestrial digital broadcast, and the like.

  Further, the radio wave receiving apparatus includes a first radio wave processing unit 1 and a second radio wave processing unit 2. The first radio wave processing unit (first receiving unit) 1 receives an analog TV broadcast radio wave from the first antenna 1A, and outputs video information and audio information. The second radio wave processing unit (second receiving unit) 2 receives radio waves of digital TV broadcast from the second antenna 2A and outputs video information and audio information. Here, as shown in FIG. 1, the first radio wave processing unit 1 includes a first channel selection unit 11 and a first demodulation unit 12. The first channel selection unit 11 selects and receives radio waves of a required channel for analog TV broadcasting from radio waves received by the first antenna 1A. The first demodulator 12 has a function of demodulating the received radio wave from the first channel selector 11 and outputting a video signal and an audio signal of analog TV broadcasting.

  Further, the second radio wave processing unit 2 includes a second channel selection unit 21, a second demodulation unit 22, a signal processing unit 23, and a decoding unit 24. The second channel selection unit 21 selects and receives radio waves of a required channel for digital TV broadcasting from the second antenna 2A. The second demodulator 22 has a function of demodulating the received radio wave from the radio wave received by the second channel selection unit 21 and outputting a digital signal. The signal processing unit 23 has a function of performing necessary digital signal processing such as interleaving and error correction. The decoding unit 24 has a function of decoding the digital signal processed by the signal processing unit 23.

  Further, this radio wave receiving apparatus includes a control unit 3 that performs overall control in the radio wave receiving apparatus. The control unit (selection unit) 3 measures the electric field strength that is the strength of the received radio wave processed by the first radio wave processing unit 1 and the second radio wave processing unit 2 and compares the measured electric field strength. The control unit 3 receives the received radio wave processed by the second radio wave processing unit 2 so that the electric field strength indicating the strength of the received radio wave processed by the first radio wave processing unit 1 (hereinafter referred to as the first electric field strength) is processed. If it is larger than the electric field strength indicating the strength of the electric field (hereinafter referred to as the second electric field strength), it is determined that the radio wave environment of the analog TV broadcast is better than the radio wave environment of the digital TV broadcast. Part 1) is selected. When the second electric field strength is greater than the first electric field strength, the control unit 3 determines that the radio wave environment of the digital TV broadcast is better than the radio wave environment of the analog TV broadcast, and the digital TV broadcast (second radio wave processing) Part 2) is selected. The control unit 3 outputs a selection result for selecting an analog TV broadcast or a digital TV broadcast to the switching unit 4.

  The switching unit 4 acquires video information and audio information from each of the first and second radio wave processing units 1 and 2. The switching unit 4 selects the first radio wave processing unit 1 or the second radio wave processing unit 2 based on the selection result of the analog TV broadcast or the digital TV broadcast by the control unit 3. That is, when the analog TV broadcast is selected by the control unit 3, the switching unit 4 outputs the video information from the first radio wave processing unit 1 to the display unit 6, and the first radio wave processing unit. The audio information from 1 is output to the speaker 7. When digital TV broadcasting is selected by the control unit 3, the switching unit 4 outputs the video information from the second radio wave processing unit 2 to the display unit 6, and the second radio wave processing unit. 2 is output to the speaker 7.

  Further, a vehicle speed sensor 8 is connected to the control unit 3, and the control unit 3 acquires the traveling speed of the vehicle from the vehicle speed sensor 8. When it is determined that the acquired traveling speed of the vehicle is equal to or lower than the predetermined speed, the control unit 3 selects an analog TV broadcast (first radio wave processing unit 1) or a digital TV broadcast (second radio wave processing unit 2). Change the selection method.

  In addition, the operation unit 5 is connected to the control unit 3, and when the control unit 3 obtains a signal for canceling the changed analog TV broadcast or digital TV broadcast selection method from the operation unit 5, for example, Cancel the changed selection method.

  Next, a selection method for selecting an analog TV broadcast or a digital TV broadcast in the radio wave receiving apparatus according to the first embodiment will be described with reference to a flowchart shown in FIG.

  First, the control unit 3 acquires the traveling speed of the vehicle from the vehicle speed sensor 8, and determines whether or not the acquired traveling speed of the vehicle is equal to or lower than a predetermined speed (step S10). Specifically, it is determined whether or not the vehicle is parked or stopped, or whether or not the vehicle is at a slow speed that allows the user to easily focus on the display unit 6 and the speaker 7. When it is determined that the traveling speed of the vehicle is equal to or lower than the predetermined speed, the control unit 3 performs analog TV broadcasting (first radio wave processing unit 1) or digital TV broadcasting (second radio wave processing unit 2). Change the selection method to select.

  In general, under the same radio wave environment, digital TV broadcasts have higher video and audio quality than analog TV broadcasts. However, in digital TV broadcasting, when the electric field strength becomes weak, the video stops and the sound is muted. On the other hand, analog TV broadcasts can continue to output video and audio, although the quality is not high when the electric field strength becomes weak. That is, the digital TV broadcast is easily affected by the radio wave environment, whereas the analog TV broadcast is not easily affected by the radio wave environment.

  In addition, since the digital TV broadcast performs error correction of the received digital signal in the signal processing unit 23 and decodes the digital signal in the decoding unit 24, the display unit 6 and the speaker 7 are compared with the analog TV broadcast. It takes time to output the video and audio, and the video and audio are not output until the video and audio are output. Therefore, when the radio wave environment around the vehicle is easily changed, when the analog TV broadcast is switched to the digital TV broadcast and the digital TV broadcast is continuously switched to the analog TV broadcast, the mute state continues, and the video and audio are There may be no output at all. When the user is driving the vehicle, the user is less likely to pay attention to the display unit 6 and the speaker 7, so the problem is small even if the mute state continues. However, when the user tends to focus on the display unit 6 and the speaker 7 such as when the vehicle is parked or stopped, the user feels uncomfortable with the continued mute state.

  Therefore, the control unit 3 determines whether or not the analog TV broadcast is selected in order to avoid the mute state continuing (step S11). If the analog TV broadcast is selected, the radio wave environment is determined. The analog TV broadcast that is not easily affected by the selection is continuously selected (step S12). And it returns to operation | movement of step S10, and repeats operation | movement of step S10-step S12 until it determines with the driving speed of a vehicle not being below predetermined speed.

  On the other hand, if it is determined in step S10 that the traveling speed of the vehicle is not lower than the predetermined speed, or if a digital TV broadcast that is easily affected by the radio wave environment is selected in step S11, the control unit 3 The electric field strength (first electric field strength) indicating the strength of the received radio wave processed by one radio wave processing unit 1 is measured (step S13). Next, the control unit 3 measures the electric field strength (second electric field strength) indicating the strength of the received radio wave processed by the second radio wave processing unit 2 (step S14).

  Next, the control unit 3 compares the first electric field strength measured in step S13 with the second electric field strength measured in step S14 (step S15). Specifically, the magnitudes of the first electric field strength and the second electric field strength are compared to determine whether or not the first electric field strength is greater than the second electric field strength. If the first electric field strength is greater than the second electric field strength, it is determined that the radio wave environment of the analog TV broadcast is better than the radio wave environment of the digital TV broadcast, and the analog TV broadcast (first radio wave processing unit 1) is selected ( Step S16). That is, an analog TV broadcast that can display video on the display unit 6 with higher quality than the digital TV broadcast and that can output audio on the speaker 7 with higher quality than the digital TV broadcast is selected.

  On the other hand, if the first electric field strength is smaller than the second electric field strength, it is determined that the digital TV broadcast radio wave environment is better than the analog TV broadcast radio wave environment, and the digital TV broadcast (second radio wave processing unit 2) is selected. (Step S17). That is, a digital TV broadcast that can display video on the display unit 6 with higher quality than the analog TV broadcast and that can output audio on the speaker 7 with higher quality than the analog TV broadcast is selected. When the first electric field strength and the second electric field strength are the same, it is determined that the radio wave environment of the analog TV broadcast and the digital TV broadcast are the same, and the currently selected broadcast is selected. select.

  Based on the selection result of the analog TV broadcast or the digital TV broadcast, the switching unit 4 outputs the video information of the analog TV broadcast or the digital TV broadcast to the display unit 6 and outputs the audio information to the speaker 7.

  The control unit 3 returns to the operation of Step S10 and repeats the operations of Step S10 and Steps S13 to S17 until it is determined that the traveling speed of the vehicle is equal to or lower than the predetermined speed.

  According to this selection method, when the traveling speed of the vehicle is determined to be equal to or lower than the predetermined speed, the first radio wave processing unit 1 that is not easily affected by the radio wave environment is continuously selected. That is, it is possible to continue outputting video information and audio information of an analog TV broadcast that are unlikely to be in the mute state to the display unit 6 and the speaker 7, and it is possible to prevent the mute state from continuing.

  Next, another selection method for selecting an analog TV broadcast or a digital TV broadcast in the radio wave receiving apparatus according to the first embodiment will be described with reference to a flowchart shown in FIG.

  First, the control unit 3 acquires the traveling speed of the vehicle from the vehicle speed sensor 8, and determines whether or not the acquired traveling speed of the vehicle is equal to or lower than a predetermined speed (step S20). When it is determined that the traveling speed of the vehicle is equal to or lower than the predetermined speed, the control unit 3 performs analog TV broadcasting (first radio wave processing unit 1) or digital TV broadcasting (second radio wave processing unit 2). Change the selection method to select.

  That is, the control unit 3 raises the first threshold value for selecting the analog TV broadcast or the digital TV broadcast to the second threshold value in order to avoid the mute state continuing (step S21). The first threshold is such that when the first threshold is exceeded, the radio wave environment of the digital TV broadcast is better than the radio wave environment of the analog TV broadcast. Set to improve the radio wave environment of TV broadcasting. The second threshold value is set so that the digital TV broadcast radio wave environment is much better than the analog TV broadcast radio wave environment when the second threshold value is exceeded.

  The first threshold value and the second threshold value are values indicating difficulty in switching from analog TV broadcasting to digital TV broadcasting, and are not easily influenced by the radio wave environment by raising the first threshold value to the second threshold value. It becomes difficult to switch from analog TV broadcasting to digital TV broadcasting that is easily affected by the radio wave environment.

  On the other hand, when it is determined that the traveling speed of the vehicle is not lower than the predetermined speed, the broadcast method is selected by the selection method using the first threshold without changing the selection method for selecting the analog TV broadcast or the digital TV broadcast. Make a selection.

  Next, the control unit 3 measures the received electric field strength (first electric field strength) indicating the strength of the received radio wave processed by the first radio wave processing unit 1 (step S22, first measuring means). Next, the control unit 3 measures the received electric field strength (second electric field strength) indicating the strength of the received radio wave processed by the second radio wave processing unit 2 (step S23, second measuring means).

  Next, the control unit 3 compares the first electric field strength measured in step S22 with the second electric field strength measured in step S23, and determines whether or not the comparison result exceeds a set threshold value. (Step S24). That is, in step S21, it is determined whether or not the second threshold value is exceeded if the first threshold value is raised to the second threshold value. Otherwise, the first threshold value is exceeded or not. Determine whether or not.

  When the comparison result between the first electric field strength and the second electric field strength exceeds the set threshold value, the control unit 3 determines that the radio wave environment of the digital TV broadcast is higher when the first threshold value is used. It is judged that the radio wave environment of analog TV broadcasting is better. When the second threshold value is used, it is determined that the radio wave environment of digital TV broadcast is much better than the radio wave environment of analog TV broadcast. As a result, a digital TV broadcast (second radio wave processing unit 2) is selected (step S25).

  When the comparison result between the first electric field strength and the second electric field strength does not exceed the set first threshold value or the second threshold value, the control unit 3 determines that the radio wave environment of the analog TV broadcast is It is judged that the radio wave environment of digital TV broadcasting is better. As a result, an analog TV broadcast (first radio wave processing unit 1) is selected (step S26). When the comparison result between the first electric field strength and the second electric field strength is a set threshold value, the currently selected broadcast is selected.

  According to this selection method, when the traveling speed of the vehicle is determined to be equal to or lower than the predetermined speed, the first threshold value is raised to the second threshold value, so that the radio wave environment is not affected by the analog TV broadcast that is not easily affected by the radio wave environment. It is difficult to switch to a digital TV broadcast that is easy to receive. Therefore, it is possible to continue outputting the analog TV broadcast video information and audio information to the display unit 6 and the speaker 7 which are not easily affected by the radio wave environment, that is, not to be in the mute state, and avoiding the mute state continuing. it can.

  This radio wave receiving apparatus can cancel the selection method that is changed when it is determined that the traveling speed of the vehicle is equal to or lower than a predetermined speed. Hereinafter, a method for canceling the changed selection method in the radio wave receiving apparatus according to this embodiment will be described with reference to the flowchart shown in FIG.

  First, when the control unit 3 obtains a signal for canceling the changed selection method from the operation unit 5 (step S30), the control unit 3 cancels the changed selection method (step S33). That is, for example, when a release button for canceling the changed predetermined selection method included in the operation unit 5 is pressed, the changed predetermined selection method is switched to the normal selection method.

  Next, when the control unit 3 does not acquire a signal for canceling the changed selection method from the operation unit 5 (step S30), the control unit 3 acquires the travel speed of the vehicle from the vehicle speed sensor 8, and acquires the acquired travel speed of the vehicle. Is greater than a predetermined speed (step S31). If it is determined that the traveling speed of the vehicle is greater than the predetermined speed, the changed selection method is canceled (step S33). In addition, when it is determined that the traveling speed of the vehicle is equal to or lower than the predetermined speed (step S31), the control unit 3 measures the first electric field strength indicating the strength of the received radio wave of the analog TV broadcast, It is determined whether or not the electric field strength of 1 exceeds a predetermined threshold (step S32). The predetermined threshold value is set to a first electric field strength value at which the analog TV broadcast radio wave environment is extremely deteriorated and the video information and audio information of the analog TV broadcast cannot be output. When the predetermined threshold is not exceeded, that is, when the radio wave environment of the analog TV broadcast is extremely deteriorated, the changed predetermined selection method is canceled (step S33). On the other hand, when the predetermined threshold is exceeded, that is, when the radio wave environment of the analog TV broadcast is not extremely deteriorated, the operation returns to the operation of step S30 and the operations of steps S30 to S32 are repeated.

  According to this canceling method, the changed predetermined selection method can be cancelled. Therefore, when the traveling speed of the vehicle becomes higher than the predetermined speed, that is, when the operation is resumed, the user pays attention to the display unit 6 and the speaker 7. When the video is no longer directed, the video information and audio information of the broadcast selected by the normal selection method can be output. Also, when the user gives an instruction to cancel the change or when the reception status of the analog TV broadcast that is not easily affected by the radio wave environment deteriorates, the video information and audio information of the broadcast selected by the normal selection method can be output. Can do.

  According to the radio wave receiving apparatus according to the first embodiment, when the traveling speed of the vehicle is determined to be equal to or lower than the predetermined speed, the normal selection method is changed to the predetermined selection method. By changing to a predetermined selection method for selecting a broadcast that has been selected, video information and audio information of an analog TV broadcast or a digital TV broadcast for a fixed receiving station can be continuously output to the display unit and the speaker. That is, it is possible to prevent a mute state in which broadcast video information and audio information are not output to the display unit and the speaker from continuing.

  Next, a radio wave receiving apparatus according to a second embodiment of the present invention will be described with reference to the drawings. The radio wave receiving apparatus according to the second embodiment is mounted on a vehicle. FIG. 5 is a block diagram illustrating a configuration of a radio wave receiver according to the second embodiment. As shown in FIG. 5, in the radio wave receiver according to this embodiment, the antenna 100A is for digital TV broadcast for mobile (first broadcast) and digital TV broadcast for fixed reception stations (second broadcast). It is configured to receive radio waves. Note that mobile digital TV broadcast refers to mobile phone digital broadcast, for example.

  The radio wave receiving apparatus includes a radio wave processing unit 100. The radio wave processing unit (first and second receiving units) 100 includes a channel selection unit 111, a demodulation unit 112, a signal processing unit 113, and a decoding unit 114. Yes. The channel selection unit 111 selects and receives a radio wave of a required channel for the mobile digital TV broadcast and the fixed reception station digital TV broadcast from the antenna 100A. The demodulator 112 has a function of demodulating the received radio wave from the channel selector 111 and outputting a digital signal. The signal processing unit 113 has a function of performing necessary digital signal processing such as interleaving and error correction. The decoding unit 114 has a function of decoding the digital signal that has been digital signal processed by the signal processing unit 113.

  In addition, this radio wave receiving apparatus includes a control unit 30 that performs overall control in the radio wave receiving apparatus. The control unit (selection unit) 30 measures the bit error rate (BER) of the received digital signal after being decoded by the decoding unit 114, and compares the measured BER. The control unit 30 is configured such that a BER (hereinafter referred to as a first BER) for a received digital signal for mobile digital TV broadcast is a BER (hereinafter referred to as a first BER) for a received digital signal for TV digital TV broadcast for a fixed receiving station. 2), the radio wave environment of the mobile digital TV broadcast is determined to be better than the radio wave environment of the fixed receiver digital TV broadcast, and the mobile digital TV broadcast is selected. In addition, when the first BER is larger than the second BER, the control unit 30 determines that the radio wave environment of the digital TV broadcast for the fixed reception station is better than the radio wave environment of the digital TV broadcast for the mobile unit. Select digital TV broadcast. The control unit 30 outputs a selection result for selecting the mobile digital TV broadcast or the fixed reception station digital TV broadcast to the switching unit 40 based on the BER comparison result.

  The switching unit 40 acquires video information and audio information of the fixed receiving station digital TV broadcast and the mobile digital TV broadcast from the radio wave processing unit 100. When the mobile digital TV broadcast is selected by the control unit 30, the switching unit 40 outputs video information of the mobile digital TV broadcast to the display unit 60, and the audio of the mobile digital TV broadcast is output. Information is output to the speaker 70. In addition, when the control unit 30 selects the fixed receiving station digital TV broadcast, the switching unit 40 outputs the video information of the fixed receiving station digital TV broadcast to the display unit 60, and the fixed receiving station The audio information of the digital TV broadcast is output to the speaker 70.

  In addition, a vehicle speed sensor 80 is connected to the control unit 30, and the control unit 30 acquires the traveling speed of the vehicle from the vehicle speed sensor 80, and if it is determined that the acquired traveling speed of the vehicle is equal to or lower than a predetermined speed, the movement is performed. The selection method for selecting the digital TV broadcast for the body or the digital TV broadcast for the fixed receiving station is changed.

  In addition, an operation unit 50 is connected to the control unit 30, and the control unit 30 cancels the method for selecting, for example, a changed mobile digital TV broadcast or fixed reception station digital TV broadcast from the operation unit 50. When the signal is acquired, the changed selection method is canceled.

  Next, a selection method for selecting a mobile digital TV broadcast or a fixed reception station digital TV broadcast in the radio wave receiver according to the second embodiment will be described. The operation of the selection method for selecting the mobile digital TV broadcast or the fixed receiver digital TV broadcast in the radio wave receiving apparatus according to the second embodiment is shown in the first embodiment shown in the flowchart of FIG. A detailed description of the same operation as the selection method for selecting an analog TV broadcast or a digital TV broadcast in the radio wave receiving apparatus according to the embodiment will be omitted.

  First, when it is determined that the vehicle traveling speed is equal to or lower than a predetermined speed, the control unit 30 determines whether or not the mobile digital TV broadcast is selected in order to avoid the mute state continuing. To do. When the mobile digital TV broadcast is selected, the radio wave of the mobile digital TV broadcast is less affected by the radio wave environment than the radio wave of the digital TV broadcast for the fixed receiving station. Continue to select TV broadcast. Note that the change of the selection method is the same as the operation in steps S10 to S12 shown in the flowchart of FIG.

  On the other hand, when the mobile digital TV broadcast is selected, or when it is determined that the traveling speed of the vehicle is not equal to or lower than the predetermined speed, the control unit 30 performs the mobile digital after decoding by the decoding unit 114. The BER (first BER) of the received digital signal for TV broadcasting is measured. Next, the control unit 30 measures the BER (second BER) of the received digital signal for the fixed receiving station digital TV broadcast after being decoded by the decoding unit 114.

  Next, the control unit 30 compares the first BER and the second BER. If the first BER is smaller than the second BER, it is determined that the radio environment of the mobile digital TV broadcast is better than the radio environment of the fixed reception station digital TV broadcast, and the mobile digital TV broadcast is selected. That is, a mobile digital TV broadcast that can display video on the display unit 60 with higher quality than the digital TV broadcast for fixed reception stations and that can output audio on the speaker 70 with higher quality than the digital TV broadcast for fixed reception stations is selected. To do.

  On the other hand, if the first BER is larger than the second BER, it is determined that the radio environment of the digital TV broadcast for the fixed reception station is better than the radio environment of the digital TV broadcast for the mobile unit, and the digital TV broadcast for the fixed reception station is selected. To do. That is, a digital TV broadcast for a fixed receiving station that can display video on the display unit 60 with higher quality than the digital TV broadcast for mobile bodies and that can output audio on the speaker 70 with higher quality than the digital TV broadcast for mobile bodies is selected. . When the first BER and the second BER are the same, it is determined that the radio wave environment of the mobile digital TV broadcast and the radio TV environment of the fixed receiver station are the same, and the currently selected radio wave broadcast is currently selected. Select a broadcast.

  According to this selection method, when the vehicle traveling speed is determined to be equal to or lower than a predetermined speed, the mobile digital TV broadcast that is not easily affected by the radio wave environment is continuously selected. The video information and audio information of the mobile digital TV broadcast that is unlikely to be in the mute state can be continuously output to the display unit 60 and the speaker 70, and the mute state can be prevented from continuing.

  Next, another selection method for selecting a mobile digital TV broadcast or a fixed reception station digital TV broadcast in the radio wave receiver according to the second embodiment will be described. The operation of another selection method for selecting a mobile digital TV broadcast or a fixed receiver digital TV broadcast in the radio wave receiving apparatus according to the second embodiment is shown in the flowchart of FIG. Detailed description of the same operation as the selection method for selecting analog TV broadcast or digital TV broadcast in the radio wave receiving apparatus according to the embodiment is omitted.

  First, when it is determined that the traveling speed of the vehicle is equal to or lower than a predetermined speed, the control unit 30 changes the selection method for selecting the mobile digital TV broadcast or the fixed reception station digital TV broadcast. That is, the control unit 30 raises the first threshold value for selecting the mobile digital TV broadcast or the fixed reception station digital TV broadcast to the second threshold value in order to avoid the mute state continuing. The first threshold value is moved when the first threshold value is below the first threshold value so that the radio wave environment of the digital TV broadcast for fixed reception stations is better than the radio wave environment of the digital TV broadcast for mobile objects when the first threshold value is exceeded. The radio wave environment of the body digital TV broadcast is set to be better than the radio wave environment of the fixed reception station digital TV broadcast. The second threshold value is set so that the radio wave environment of the fixed receiving station digital TV broadcast is much better than the radio wave environment of the mobile digital TV broadcast when the second threshold value is exceeded.

  Next, the control unit 30 receives the BER (first BER) for the received digital signal for mobile digital TV broadcasting after being decoded by the decoding unit 114 and the received digital signal for digital TV broadcasting for the fixed receiving station. The BER (second BER) of the signal is measured (first measuring means and second measuring means).

  Next, the control unit 30 compares the first BER and the second BER, and determines whether or not the comparison result exceeds a set threshold (first threshold or second threshold) ( Discrimination means). That is, if the first threshold value is raised to the second threshold value, it is determined whether or not the second threshold value is exceeded. Otherwise, it is determined whether or not the first threshold value is exceeded. Determine.

  When the comparison result between the first BER and the second BER exceeds the set threshold value, the control unit 30 uses the first threshold value, and the radio wave of the digital TV broadcast for the fixed receiving station is used. It is determined that the environment is better than the radio wave environment of mobile digital TV broadcasting. When the second threshold value is used, it is determined that the radio wave environment of the digital TV broadcast for fixed reception stations is much better than the radio wave environment of the digital TV broadcast for mobile objects. As a result, the digital TV broadcast for the fixed receiving station is selected. When the comparison result between the first BER and the second BER is a set threshold value, the currently selected broadcast is selected.

  According to this selection method, when the traveling speed of the vehicle is determined to be equal to or lower than a predetermined speed, the first threshold value is changed to the second threshold value, so that the digital TV broadcast for mobile objects that is not easily affected by the radio wave environment. It is possible to make it difficult to switch to a digital TV broadcast for a fixed receiving station that is easily affected by the radio wave environment. Therefore, it is possible to continue outputting video information and audio information of a mobile digital TV broadcast that is not easily affected by the radio wave environment, that is, not easily muted, to the display unit 60 and the speaker 70, thereby avoiding the muted state from continuing. be able to.

  This radio wave receiving apparatus has a selection method for selecting a mobile TV broadcast or a fixed receiver digital TV broadcast by the control unit 30, and a selection that is changed when the traveling speed of the vehicle is determined to be a predetermined speed or less. The method can be released. The method for canceling this selection method is the same as the method for canceling the selection method in the radio wave receiving apparatus according to the first embodiment shown in the flowchart of FIG.

  According to this canceling method, the changed selection method can be cancelled. Therefore, when the traveling speed of the vehicle becomes higher than a predetermined speed, that is, when the driving is resumed, the user pays attention to the display unit 60 and the speaker 70. When there is no longer available, it is possible to output video information and audio information of the broadcast selected by the normal selection method. In addition, even when the user gives an instruction to cancel the change or when the reception state of the mobile digital TV broadcast that is not easily affected by the radio wave environment deteriorates, the video information and audio information of the broadcast selected by the normal selection method are displayed. Can be output.

  According to the radio wave receiving apparatus according to the second embodiment, when the traveling speed of the vehicle is determined to be equal to or lower than the predetermined speed, the normal selection method is changed to the predetermined selection method. By changing to a predetermined selection method for selecting a broadcast that is currently being transmitted, video information and audio information of the mobile digital TV broadcast or the fixed receiver digital TV broadcast can be continuously output to the display unit and the speaker. That is, it is possible to prevent a mute state in which broadcast video information and audio information are not output to the display unit and the speaker from continuing.

  In the first embodiment and the second embodiment, the case where the mute state associated with switching in a situation where the radio wave environment around the vehicle is likely to change has been described as an example. It is possible to effectively solve the phenomenon in which the audio / video is rewound due to the switching to the TV broadcasting and the partial skipping phenomenon in which the audio / video jumps in accordance with the switching from the digital TV broadcasting to the analog TV broadcasting. .

It is a block diagram which shows the structure of the electromagnetic wave receiver concerning 1st Embodiment. It is a flowchart for demonstrating the selection method in the electromagnetic wave receiver concerning 1st Embodiment. It is a flowchart for demonstrating the other selection method in the electromagnetic wave receiver concerning 1st Embodiment. It is a flowchart for demonstrating the method to cancel | release the selection method in the electromagnetic wave receiver concerning 1st Embodiment. It is a block diagram which shows the structure of the electromagnetic wave receiver concerning 2nd Embodiment.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 ... 1st radio wave process part, 2 ... 2nd radio wave process part, 1A ... 1st antenna, 2A ... 2nd antenna, 3,30 ... Control part, 4,40 ... Switching part, 5,50 ... Operation unit 6, 60 ... display unit, 7, 70 ... speaker, 8, 80 ... vehicle speed sensor, 11 ... first channel selection unit, 12 ... first demodulation unit, 21 ... second channel selection unit, 22 ... first 2 demodulation units, 23, 113 ... signal processing unit, 24, 114 ... decoding unit, 100 ... radio wave processing unit, 100A ... antenna, 111 ... channel selection unit, 112 ... demodulation unit.

Claims (8)

Video information and audio information based on the received signal received by the first receiving unit that receives the first broadcast or the second receiving unit that receives the second broadcast is output to the output unit and mounted on the vehicle. In the radio wave receiver,
In order to output the video information and the audio information to the output unit, as a first selection method, a selection is made by discriminating and selecting the better radio wave environment between the first receiving unit and the second receiving unit With means,
The selection means, when it is determined that the traveling speed of the vehicle is equal to or lower than a predetermined speed, the first reception unit is selected when the first reception unit that is not easily affected by the radio wave environment is selected. If the second receiving unit that is susceptible to the influence of the radio wave environment is selected by the first selection method, the first receiving unit is selected by the first selection method. The radio wave receiving apparatus is changed to a second selection method that continues to select the first receiving unit after being selected . Video information and audio information based on the received signal received by the first receiving unit that receives the first broadcast or the second receiving unit that receives the second broadcast is output to the output unit and mounted on the vehicle. In the radio wave receiver,
First measuring means for measuring the electric field intensity of the radio wave received by the first receiving unit as a first electric field intensity;
Second measuring means for measuring the electric field intensity of the radio wave received by the second receiving unit as the second electric field intensity;
The first electric field strength measured by the first measuring means is compared with the second electric field strength measured by the second measuring means, and the second electric field strength is more than the first electric field strength. Determining means for determining whether or not is greater than a first threshold or a second threshold set higher than the first threshold;
As a first selection method, when the determination unit determines that the second electric field strength is greater than the first threshold value than the first electric field strength, the determination unit is easily affected by the radio wave environment. When the second receiving unit is selected and it is determined by the determination unit that the second electric field strength is not greater than the first threshold value than the first electric field strength, Selecting means for selecting the first receiving unit which is not easily affected,
When the traveling speed of the vehicle is determined to be equal to or lower than a predetermined speed, the selection unit is configured to use a second selection method in which the first threshold is replaced with a second threshold with respect to the first selection method. A radio wave receiving apparatus that is changed from the first selection method and selects the first reception unit or the second reception unit based on the second threshold value. Video information and audio information based on the received signal received by the first receiving unit that receives the first broadcast or the second receiving unit that receives the second broadcast is output to the output unit and mounted on the vehicle. In the radio wave receiver,
First measuring means for measuring a bit error rate of a digital signal received by the radio wave received by the first receiver as a first bit error rate ;
Second measuring means for measuring a bit error rate of a digital signal received by the radio wave received by the second receiving unit as a second bit error rate ;
The first bit error rate measured by the first measuring unit is compared with the second bit error rate measured by the second measuring unit, and the first bit error rate is compared with the first bit error rate. and a bit error rate, a first threshold value or determination means for determining whether greater or not greater than the second threshold value set higher than the first threshold value,
As a first selection method, when the determination unit determines that the first bit error rate is greater than the second threshold than the second bit error rate, the determination unit is easily affected by the radio wave environment. The radio wave environment when the second receiving unit is selected and the determining unit determines that the first bit error rate is not greater than the first threshold value than the second bit error rate. Selecting means for selecting the first receiving unit that is not easily affected by
It said selecting means, when the traveling speed of the vehicle is determined to be below a predetermined speed, a second selection method for changing the first threshold value to the first selection method in the second threshold value the first change from the selection process, the radio wave reception device comprising a benzalkonium select the first receiver or the second receiver based on the second threshold. A release means for releasing the second selection method changed by the selection means ;
The release means is configured to change the second changed by the selection means when it is determined that the traveling speed of the vehicle is higher than a predetermined speed, or when there is an instruction by an instruction means for instructing release of change. radio wave receiving apparatus according to any one of claims 1 to 3, wherein that you change the selection method in the first selection method. Cancellation means for releasing the second selection method changed by the selection means;
Measuring means for measuring the electric field strength of the radio wave received by the first receiving unit,
The release means changes the second selection method changed by the selection means to the first selection method when the electric field intensity of the radio wave received by the first reception unit becomes a predetermined threshold value or less. The radio wave receiving apparatus according to claim 1 , wherein the radio wave receiving apparatus is changed. Release means for canceling the second selection method changed by the selection means,
It said releasing means, if the previous SL first field strength is equal to or less than a predetermined threshold value, and changing the modified second selection method by the selecting means to the first selection method The radio wave receiver according to claim 2. The radio wave receiver according to claim 1 or 3 , wherein the first broadcast is a mobile digital broadcast, and the second broadcast is a fixed receiver digital broadcast. The radio wave receiver according to claim 1 or 2 , wherein the first broadcast is an analog broadcast, and the second broadcast is a digital broadcast for a fixed receiving station.

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