JP2014179731A - Digital broadcast receiving device, antenna switching method and program - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce waiting time until reception is made possible, thereby effectively receiving radio waves.SOLUTION: A mobile terminal device comprises: a plurality of antennas 100-1, 100-2 ... 100-n; an antenna switching unit 101 which switches over among the plurality of antennas 100-1 to 100-n; an in-range determination unit 102 which determines, based on a reception level or a reception error rate of each of the plurality of antennas 100-1 to 100-n, whether or not an antenna in question is in the range of reception radio waves; and a control unit 103 which obtains a determination result on each of the antennas by the in-range determination unit 102 while cyclically switching over among the plurality of antennas 100-1 to 100-n by the antenna switching unit 101, and controls the switching by the antenna switching unit 101 in such a manner that the determination by the in-range determination unit 102 is ended as soon as the antenna in question is determined to be within the range so that the radio waves are received by the antenna determined to be within the range.

Description

  The present invention relates to a digital broadcast receiver, an antenna switching method, and a program.

  In recent years, mobile terminal devices (mobile devices such as mobile phones, smartphones, and tablet terminals) with a digital broadcast receiving function have become widespread. In addition, multimedia broadcasting using the VHF-H band has been started, and its usage frequency is increasing. Due to the characteristics of mobile terminal devices, the frequency of outdoor use is also increasing. For example, the mobile terminal device may be viewed with a digital broadcasting function when moving, such as in a train, on a bus, in a car, on a walk, or in a bullet train.

  In mobile terminal devices that require miniaturization, not only fixed but also mobile reception is assumed. However, in a mobile terminal device that is required to be downsized, an installation space for increasing the number of antennas cannot be secured inside the terminal. Therefore, it is difficult to install a plurality of antennas as in a car navigation system with a digital broadcast reception function. Therefore, as one of the methods for improving the reception sensitivity, an external interface (for example, φ3.5 audio earphone jack or USB connector) to which an external antenna can be attached is provided on the mobile terminal device, and the external antenna is provided on the external interface. There is a method of attaching an antenna as necessary and switching between an antenna (hereinafter referred to as an internal antenna) installed in advance in the mobile terminal device and an external antenna according to the radio wave environment.

For example, in Patent Documents 1 to 5, in a device having a plurality of antennas, a technique for performing diversity reception such as maximum likelihood combining by a plurality of receiving antennas, a state of a received radio wave (a bit error rate (BER)) ) And packet error rate (PER: Packet Error)
There has been proposed a technique for efficiently receiving radio waves by switching a plurality of antennas in accordance with a rate), a carrier power to noise power ratio (C / N), and an antenna gain.

JP 2008-193384 A JP 2007-329715 A JP 2006-121707 A JP 2006-094360 A JP 2002-033688 A

  However, in Patent Documents 1 to 5 described above, when switching between a plurality of antennas, the bit error rate (BER), the packet error rate (PER), the antenna gain, and the like at each antenna are compared to obtain the highest reception rate. Since a high antenna is selected, there is a problem that the waiting time until it becomes a receivable state becomes long, and radio waves cannot be received efficiently.

  SUMMARY OF THE INVENTION An object of the present invention is to provide a digital broadcast receiving apparatus, an antenna switching method, and a program that can shorten the waiting time until the signal becomes receivable and can efficiently receive radio waves.

  Whether the mobile terminal apparatus according to the present invention is within a range of received radio waves based on a plurality of antennas, an antenna switching unit that switches between the plurality of antennas, a reception level for each of the plurality of antennas, or a reception error rate. A range determination unit for determining whether or not the plurality of antennas are cyclically switched by the antenna switching unit, the determination result for each antenna by the range determination unit is acquired, and the range determination unit determines that the range is within A control unit that controls the switching by the antenna switching unit so that the determination by the area determination unit is terminated at the time when the antenna is determined and the radio wave is received by the antenna determined to be within the area. Mobile terminal device.

  An antenna switching method according to the present invention is an antenna switching method in an electronic apparatus including a plurality of antennas, the antenna switching step for switching the plurality of antennas, and the reception level or reception error rate for each of the plurality of antennas. Based on the above, a range determination step for determining whether or not the received radio wave is within a range, and a determination result for each antenna in the range determination step is obtained while cyclically switching the plurality of antennas, A control step of controlling the switching of the plurality of antennas so as to receive the radio wave with the antenna determined to be within the range when the determination is completed, and the determination in the range determination step is terminated. This is an antenna switching method.

  The program of the present invention is based on an antenna switching function for switching the plurality of antennas to a computer of an electronic device having a plurality of antennas, a reception level for each of the plurality of antennas, or a reception error rate range. A determination result for each antenna by the range determination function is acquired while the plurality of antennas are cyclically switched by the range determination function for determining whether or not the range is within the range by the range determination function. The determination by the area determination function is terminated, and a control function for controlling switching of the plurality of antennas so as to receive radio waves by the antenna determined to be within the area is executed. It is a featured program.

  According to the present invention, it is possible to shorten the waiting time until the reception is possible and to efficiently receive radio waves.

It is a block diagram which shows the structure of the mobile terminal device 1 by embodiment of this invention. It is a figure which shows the determination content and determination result of reception level determination at the time of performing the antenna switching process by this embodiment, and the determination content and determination result of PER determination. It is a flowchart for demonstrating operation | movement of the antenna switching process at the time of viewing application starting and channel selection by this embodiment. It is a timing chart which shows the antenna state (switching operation | movement) in the antenna switching process at the time of viewing application starting and channel selection by this embodiment. It is a flowchart for demonstrating operation | movement of the antenna switching process at the time of the asynchronous by this embodiment. It is a timing chart which shows the operation | movement of the antenna switching process at the time of the asynchronous by this embodiment. It is a block diagram which shows the structure of Additional remark 1.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. The present invention is characterized in that, in a mobile terminal device with a digital broadcast reception function, an antenna automatic switching determination method is performed according to a digital broadcast reception state.

  FIG. 1 is a block diagram showing a configuration of a mobile terminal device 1 according to an embodiment of the present invention. In FIG. 1, a mobile terminal device 1 includes a digital broadcast receiving antenna (hereinafter referred to as an internal antenna) 10, an antenna changeover switch 20, a digital broadcast receiving / demodulating unit (tuner) 30, a tuner control / video / audio reproducing unit (CPU). 40, a screen display unit 50, an audio output unit 60, and a memory 70. In addition to the digital broadcast receiving antenna (internal antenna) 10, the mobile terminal device 1 can be equipped with a detachable digital broadcast receiving antenna (hereinafter referred to as an external antenna) 11. The external antenna 11 may be plural instead of one.

  The internal antenna 10 receives digital broadcasting. Similarly, the external antenna 11 receives a digital broadcast. The antenna changeover switch 20 switches between the internal antenna 10 and the external antenna 11 according to a determination result described later. The digital broadcast receiving / demodulating unit (tuner) 30 demodulates the received digital broadcast by OFDM (Orthogonal Frequency Division Multiplexing), decodes the error correction code, and outputs the processed data (TS (Transport Stream) data). .

  A tuner control / video / audio reproduction unit (CPU) 40 takes in output data (TS data) of the digital broadcast reception / demodulation unit (tuner) 30 and reproduces video / audio, and also receives a digital broadcast reception / demodulation unit (CPU). Tuner) 30 is controlled. In particular, the tuner control / video / audio reproduction unit (CPU) 40 is configured to transmit transmission parameters (modulation method, coding rate), synchronization state (SYNC) information, and radio monitor information (bit error rate (BER), packet error rate). (PER), carrier power to noise power ratio (C / N)), and a function of reading an estimated Doppler frequency (referred to as Fd) and a moving speed. Note that the Doppler frequency of the mobile terminal device 1 and speed information during movement are acquired from the receiver itself, a device such as a GPS or a sensor of the receiver, or the outside of the mobile terminal device 1.

  The tuner control / video / audio playback unit (CPU) 40 receives the internal antenna 10 and one or more external antennas when the viewing application is activated and when the channel is not synchronized, in order to receive digital broadcasting in a better radio wave reception state. 11 (mounted / not mounted) is selectively switched. Note that the time when the viewing application is activated and the channel is selected is immediately after the application for viewing the digital broadcast is activated or when the channel to be viewed is selected. Also, the asynchronous time means that the determination result described later becomes “false” even when the antenna switching process is executed a predetermined number of times (number of trials N) at the time of starting / selecting the viewing application, or described later during viewing. This is when the determination result is “false”.

  The tuner control / video / audio reproduction unit (CPU) 40 determines which of the internal antenna 10 and one or more external antennas 11 (attached / not attached) is to be used, the reception level determination or the PER determination. Determine using. That is, either reception level determination or PER determination is used both when the viewing application is activated and selected, and when asynchronous (viewing). There are four combinations of determination methods as follows.

(First combination)
When viewing application is activated or selected: Reception level judgment Asynchronous: Reception level judgment

(Second combination)
Viewing application startup / channel selection: reception level determination asynchronous: PER determination

(Third combination)
Viewing application startup / channel selection: PER judgment Asynchronous: Reception level judgment

(Fourth combination)
Viewing application startup / channel selection: PER determination Asynchronous: PER determination

  In the reception level determination, the tuner control / video / audio reproduction unit (CPU) 40 first determines the reception level using the carrier power to noise power ratio signal (C / N) and the synchronization state signal (SYNC). When it is determined that the reception level is lower than the predetermined threshold (provisional determination), the reception level is further determined using the Doppler frequency (Fd) or moving speed and the packet error rate (PER) signal. . On the other hand, when it is determined that the reception level using the carrier power to noise power ratio signal (C / N) and the synchronization state signal (SYNC) is equal to or higher than a predetermined threshold (provisional determination), the bit error rate (BER) ) To determine the reception level.

  Then, the tuner control / video / audio reproduction unit (CPU) 40 determines that it is within the range (true) if the determined reception level is equal to or higher than the predetermined threshold, and out of range (if less than the predetermined threshold). False). As described above, in the reception level determination, it is possible to determine an appropriate digital broadcast reception level even in a fading environment by determining the reception level in two stages of provisional determination and final determination.

  The PER determination is a simpler method than the reception level determination, and is determined using a packet error rate (PER). That is, the tuner control / video / audio reproduction unit (CPU) 40 periodically acquires the packet error rate (PER) from the digital broadcast reception / demodulation unit (tuner) 30 and the value of the packet error rate (PER) is predetermined. When the number of consecutive times is less than the specified number of times, it is determined that the range is true (true) when the number of consecutive times is less than the specified number of times, and the number of continuous times when the packet error rate (PER) value is equal to or greater than the predetermined threshold value In some cases, it is determined to be out of range (false).

  As described above, the tuner control / video / audio reproduction unit (CPU) 40 is connected to the internal antenna 10 based on the determination result of the reception level determination or PER determination when the viewing application is activated / tuned asynchronously. Of the external antennas 11 that are not necessarily mounted / mounted or necessarily highly sensitive, an antenna switching process is performed so that an antenna capable of receiving a digital broadcast can be selected in a shorter time.

  The screen display unit 50 displays the video data processed by the tuner control / video / audio reproduction unit (CPU) 40 on a display device. The audio output unit 60 outputs the audio data processed by the tuner control / video / audio reproduction unit (CPU) 40.

  The memory 70 includes a transmission parameter, a synchronization state (SYNC), a bit error rate (BER), a packet error rate (read) read from the digital broadcast reception / demodulation unit (tuner) 30 by the tuner control / video / audio reproduction unit (CPU) 40. PER), carrier power to noise power ratio (C / N), estimated Doppler frequency (Fd), and moving speed are stored.

  In the present embodiment, the internal antenna 10 and the external antenna 11 are automatically switched and controlled without making the user aware of antenna switching. Due to the nature of the mobile terminal device 1 being a mobile terminal, a user does not necessarily have to attach the external antenna 11 and view a digital television. Therefore, whether the mobile terminal apparatus 1 is equipped with the external antenna 11 or not, the internal antenna can be used to shorten the waiting time until the mobile terminal apparatus 1 is ready for reception and to efficiently receive radio waves. Antenna switching processing for switching between 10 and the external antenna 11 is executed.

Therefore, in the present embodiment, the following items are preconditions.
A) Internal antenna 10 capable of efficiently receiving radio waves without the need for detecting means for detecting whether or not the external antenna 11 is attached (without requiring additional components). And external antenna 11 can be switched.
B) It is also effective when a plurality of external antennas 11 are connected.
C) The synchronization state of the digital broadcast receiving / demodulating unit (tuner) 30 is monitored, and whether or not the next antenna is to be monitored is determined depending on whether or not the synchronization is established.
D) Instead of simple loss of synchronization, the determination result of the reception level determination or PER determination is used as the antenna switching determination condition.

  The determination of the synchronization state of the digital broadcast receiving / demodulating unit (tuner) 30 can be made simply by determining whether or not the synchronization is lost, but because “the electric field intensity at which video and audio cannot be reproduced> the electric field intensity out of synchronization”. If the antenna is switched after the digital broadcast receiving / demodulating unit (tuner) 30 is out of synchronization, video and audio are interrupted. Therefore, in the present embodiment, by using the determination result of the reception level determination or PER determination, it is possible to switch the antenna without causing a video / audio interruption.

  2A and 2B are diagrams illustrating determination contents and determination results of reception level determination and determination contents and determination results of PER determination when performing antenna switching processing according to the present embodiment.

(1) Reception Level Determination As shown in FIG. 2A, reception level determination is a method for determining an appropriate digital broadcast reception level even under a fading environment, as described above. In the reception level determination, if the reception level finally determined and determined is greater than or equal to a predetermined threshold, it is determined that it is within the receivable range (true), the antenna switching process is interrupted, and the antenna setting at that time is held, Shift to digital TV broadcast viewing. On the other hand, if the finally determined reception level is lower than a predetermined threshold, it is determined that the signal cannot be received (false), and the process proceeds to switching to the next antenna.

(2) PER Determination As shown in FIG. 2B, the PER determination is a method that is simpler than the reception level determination and is determined using the packet error rate (PER). This makes it possible to increase the probability of viewing. The packet error rate (PER) is periodically acquired from the digital broadcast reception / demodulation unit (tuner) 30. If the PER value is equal to or greater than a predetermined threshold and the number of consecutive times is less than the specified number, the coverage is true (true) The antenna switching process is interrupted, the antenna setting at that time is maintained, and the process shifts to viewing digital TV broadcasting. On the other hand, if the number of consecutive times that the PER value is equal to or greater than a predetermined threshold is equal to or greater than the specified number, it is determined that the signal cannot be received (false), and the process proceeds to switching to the next antenna.

  However, if the acquired number of acquired PERs is less than the specified number of times, if the number of consecutive PER values is equal to or greater than a predetermined threshold value is less than the number of acquired PER data, it is determined to be within the range (true), and the antenna The switching process may be interrupted, the antenna setting at that time may be maintained, and the digital television broadcast may be viewed. For example, if the specified number of times is 5 and the number of acquired PERs is only 3 and the PER value is greater than or equal to a predetermined threshold, the number of consecutive times is less than 3 and the range is true. judge.

  In the present embodiment, as described above, it is necessary to set in advance whether to use the reception level determination or the PER determination when the viewing application is activated / tuned and when it is asynchronous. As described above, the reception level determination can detect a more accurate reception level than the PER determination, but the processing is relatively heavy. Moreover, the determination method of PER determination is simpler than the reception level determination.

  Therefore, for example, simpler PER determination may be used when the viewing application is activated and selected, and reception level determination that can detect a more accurate reception level may be used when asynchronous. Alternatively, when the mobile terminal device 1 is initially used, the PER determination is used both when the viewing application is activated, when the channel is selected, and when the mobile terminal device 1 is asynchronous. When a stable reception rate cannot be obtained, the mobile terminal device 1 is switched to the reception level determination. Good. Alternatively, as described above, the reception level determination is more effective when there is a lot of movement. Therefore, the speed information or the Doppler frequency during movement is periodically monitored. The reception level determination may be used both at the time of application activation / channel selection and at the time of asynchronous, and the PER determination may be used in the case of a usage mode with little movement.

  In the following, a case will be described as an example where reception level determination that can detect a more accurate reception level is used at the time of viewing application activation and channel selection, and simpler PER determination is used at the time of asynchronous.

Next, the operation of this embodiment will be described.
Here, the operation when mobile terminal apparatus 1 is provided with one internal antenna 10 and two external antennas 11 (hereinafter referred to as external antennas # 1 and # 2 when two external antennas are clearly shown) is mounted. Will be explained. In the present embodiment, the antenna switching process is performed under the circumstances of “viewing application activation / tuning” and “asynchronous”. First, antenna switching processing at the time of viewing application activation and channel selection will be described, and then antenna switching processing at the time of asynchronous will be described.

  FIG. 3 is a flowchart for explaining the operation of the antenna switching process when the viewing application is activated and selected according to the present embodiment. Note that times T1, T2, T3, and T7 used in the following description are standby times until the reception level of the antenna is determined when the antenna is switched. Time T1 is a standby time when switching to the internal antenna 10, time T2 is a standby time when switching to the external antenna # 1, time T3 is a standby time when switching to the external antenna # 2, and time T7 is This is the waiting time when switching to the internal antenna 10 again (in a round). By providing the standby time, frequent switching of the antenna is prevented. The initial values of these times T1, T2, T3, and T7 are set in advance, but may be changed according to the reception quality at the time of use. Details will be described later.

  First, in the mobile terminal device 1, a digital broadcast viewing application (program) is activated in response to an operation by the user (step S10). Next, the digital broadcast receiving / demodulating unit (tuner) 30 performs channel selection (step S12). However, when selecting a channel while viewing the digital broadcast, step S10 for starting the digital broadcast viewing application (program) is skipped, and the channel selection starts at the next step S12.

  Next, the tuner control / video / audio reproduction unit (CPU) 40 resets the repetition count n (step S14), and switches the antenna setting to the internal antenna 10 by the antenna changeover switch 20 (step S16). Next, the tuner control / video / audio reproduction unit (CPU) 40 waits for a time T1 (seconds) (step S18), and determines whether the determination result of the reception level determination is “true” (step S20). If the determination result of the reception level determination is “true” (YES in step S20), the process ends with the internal antenna 10 remaining unchanged.

  On the other hand, if the determination result of the reception level determination is “false” (NO in step S20), the tuner control / video / audio reproduction unit (CPU) 40 sets the antenna setting to the external antenna # 1 by the antenna changeover switch 20. (Step S22), wait for time T2 (seconds) (step S24), and determine whether or not the determination result of the reception level determination is “true” (step S26). If the determination result of the reception level determination is “true” (YES in step S26), the process ends with the external antenna # 1 remaining.

  On the other hand, if the determination result of the reception level determination is “false” (NO in step S26), the tuner control / video / audio reproduction unit (CPU) 40 sets the antenna setting to the external antenna # 2 by the antenna changeover switch 20. (Step S28), waits for time T3 (seconds) (step S30), and determines whether the determination result of the reception level determination is “true” (step S32). If the determination result of the reception level determination is “true” (YES in step S32), the process ends with the external antenna # 2.

  On the other hand, if the determination result of the reception level determination is “false” (NO in step S32), the tuner control / video / audio reproduction unit (CPU) 40 sets the antenna setting to the internal antenna 10 by the antenna changeover switch 20. Return (step S34). That is, if the determination result of the reception level determination does not become “true” at this stage, the internal antenna 10 is selected assuming that the external antenna 11 is not attached. Alternatively, the external antenna 11 is attached, but switching to the internal antenna 10 is performed assuming that reception sensitivity is poor.

  Next, the tuner control / video / audio reproduction unit (CPU) 40 waits until the time T7 (second) elapses (step S36), increments the number of repetitions n (step S38), and the number of repetitions n is the number of trials N (for example, 5 times) is determined (step S40). If the number of repetitions n has not reached the number of trials N (NO in step S40), the process returns to step S18 and the above-described processing is repeated. On the other hand, when the number of repetitions n reaches the number of trials N (YES in step S40), if the determination result of the reception level determination is “true”, the process ends, while the determination result of the reception level determination When is false, the process shifts to an antenna switching process at the asynchronous time.

FIG. 4 is a timing chart showing the antenna state (switching operation) in the antenna switching process at the time of viewing application activation and channel selection according to the present embodiment.
a) First, the tuner control / video / audio reproduction unit (CPU) 40 switches to the internal antenna 10 (time t1), waits for time T1 (seconds), and determines whether the determination result of the reception level determination is “true”. Determine (time t2). When the determination result of the reception level determination is “true”, the internal antenna 10 remains as it is without switching.

b) When the determination result of the reception level determination is “false” in a) above, the tuner control / video / audio reproduction unit (CPU) 40 switches to the external antenna # 1 (time t2), and time T2 (seconds). ) Wait and determine whether or not the reception level determination result is “true” (time t3). If the determination result of the reception level determination is “true”, the external antenna # 1 is left and the process ends.

c) When the determination result of the reception level determination is “false” in the above b), the tuner control / video / audio reproduction unit (CPU) 40 switches to the external antenna # 2 (time t3) and waits for the time T3. Then, it is determined whether or not the determination result of the reception level determination is “true” (time t4). If the determination result of the reception level determination is “true”, the external antenna # 2 is left and the process ends.

d) When the determination result of the reception level determination is “false” in the above c), the tuner control / video / audio reproduction unit (CPU) 40 returns the antenna setting to the internal antenna 10 (time t4). That is, assuming that the external antenna 11 is not attached or that the external antenna 11 is attached but the reception sensitivity is poor, the internal antenna 10 is switched to.

e) The tuner control / video / audio reproduction unit (CPU) 40 stands by until the time T7 (seconds) elapses. During this time, the digital broadcast receiving / demodulating unit (tuner) 30 continues the receiving operation.

f) The tuner control / video / audio reproduction unit (CPU) 40 increments the number of repetitions n after the elapse of time T7 in e) (time t5), and whether the number of repetitions n has reached the number of trials N or not. Determine. If the number of repetitions n has not reached the number of trials N (for example, 5 times), the process returns to a) and the above-described processing is repeated. On the other hand, when the determination result of the reception level determination is “true” at the stage where the number of repetitions n reaches the number of trials N, the process ends, while the determination result of the reception level determination is “false” First, the process shifts to the antenna switching process at the asynchronous time.

  As described above, in this embodiment, when the viewing application is activated and selected, as shown in FIGS. 3 and 4, the internal antenna 10⇒external antenna # 1⇒external antenna without comparing the reception levels of the antennas. # 2⇒Circuit with internal antenna 10 ... and judge the reception level. (Reception level judgment or PER judgment) When the judgment result is "true", select that antenna and watch in a shorter time. It becomes possible to shift to operation.

  In addition, as in the present embodiment, when the mobile terminal device 1 does not include a special means for detecting that the external antenna 11 is mounted, or depending on the usage status of the external antenna 11 or the surrounding environment When the reception rate of the external antenna 11 is not always better than that of the internal antenna 10, the synchronization is always performed from the external antenna 11, or both the internal antenna 10 and the external antenna 11 are synchronized. And comparing received levels is inefficient. This is because, as the number of processes increases, the waiting time until viewing is naturally increased = the reception rate is reduced. For this reason, as described above, it is effective to first synchronize with the internal antenna 10.

  FIG. 5 is a flowchart for explaining the operation of the antenna switching process at the time of asynchronous (viewing) according to the present embodiment. In the antenna switching process flow at the time of starting / selecting the viewing application shown in FIG. 3 described above, if the determination result of the reception level determination or PER determination ends with “false”, or the reception level determination during viewing, Alternatively, when the determination result of the PER determination is “false”, the asynchronous antenna switching process shown in FIG. 5 is executed. The flowchart shown in FIG. 5 is repeatedly executed until the determination result of the reception level determination or PER determination becomes “true”. As described above, a case where PER determination is used will be described below as an example.

  Note that the times T4, T5, T6, T8, and T9 used in the following description are standby until the reception level of the antenna is determined when the antenna is switched, similarly to the times T1, T2, and T3 described above. It's time. Time T4 is the standby time when switching to the internal antenna 10, time T5 is the standby time when switching to the external antenna # 1, time T6 is the standby time when switching to the external antenna # 2, and time T8 is This is the waiting time when switching to the internal antenna 10 again (in a round). The time T9 is a waiting time immediately after ending with “false” at the time of the above-described viewing application activation and channel selection, or immediately after being determined to be out of service at the time of viewing. By providing the times T4, T5, T6, T8, and T9, frequent switching of the antenna is prevented. The initial values of these times T4, T5, T6, T8, and T9 are set in advance, but may be changed according to the reception quality in use. Details will be described later.

  First, the tuner control / video / audio reproduction unit (CPU) 40 determines whether or not the determination result of the reception level determination is “false” in the flow at the time of viewing application activation and channel selection shown in FIG. (Step S50). If the determination result of the reception level determination is “false” (YES in step S50), the tuner control / video / audio reproduction unit (CPU) 40 holds the antenna setting, and time T9 (seconds) ( (First time) Waiting (step S52), it is determined whether the determination result of PER determination is “true” based on the current antenna setting (step S54). If it is determined that the determination result of the PER determination is “true” (YES in step S54), the antenna setting is retained and the process ends.

  On the other hand, if it is determined that the determination result of the PER determination is “false”, the tuner control / video / audio reproduction unit (CPU) 40 uses the antenna changeover switch 20 to rotate the antenna setting (internal antenna → external). Antenna # 1 → external antenna # 2 → ...) (step S56). That is, when the internal antenna 10 is currently selected, the external antenna # 1 is switched, and when the external antenna # 1 is selected, the external antenna # 2 is switched and the external antenna # 2 is selected. In this case, the internal antenna 10 is switched.

  Next, it waits for time T4 to T6 (seconds) (step S58), and it is determined whether the determination result of PER determination is “true” based on the current antenna setting (step S60). If it is determined that the determination result of the PER determination is “true” (YES in step S60), the antenna setting is retained and the process ends.

  On the other hand, when it is determined that the determination result of the PER determination is “false” (NO in step S60), the digital broadcast receiving / demodulating unit (tuner) 30 rotates the antenna setting by the antenna changeover switch 20 ( (Internal antenna → external antenna # 1 → external antenna # 2 →...)) (Step S62). That is, when the internal antenna 10 is currently selected, the external antenna # 1 is switched, and when the external antenna # 1 is selected, the external antenna # 2 is switched and the external antenna # 2 is selected. In this case, the internal antenna 10 is switched.

  Next, the system waits for time T4 to T6 (seconds) (step S64), and determines whether the determination result of PER determination is “true” based on the current antenna setting (step S66). If it is determined that the determination result of the PER determination is “true” (YES in step S66), the antenna setting is retained and the process ends.

  On the other hand, if it is determined that the determination result of the PER determination is “false” (NO in step S66), the tuner control / video / audio reproduction unit (CPU) 40 sets the antenna setting by the antenna changeover switch 20. Switching to the internal antenna 10 (step S68). Next, it waits until time T8 (second) passes (step S70), returns to step S52, and repeats the process mentioned above.

FIG. 6 is a timing chart showing the operation of the antenna switching process at the asynchronous time according to the present embodiment.
a) The antenna setting is maintained as it is (time t10). The tuner control / video / audio reproduction unit (CPU) 40 stands by for a time T9 (seconds) (first time), and determines whether the determination result of PER determination is “true” with the current antenna setting ( Time t11). If it is determined that the determination result of the PER determination is “true”, the antenna setting state is maintained and the process ends. The reason for waiting for time T9 (seconds) is that antenna switching is not performed immediately in consideration of the case where the reception state is improved immediately after the determination result is determined to be “false” at time t10 and the viewing returns.

b) The tuner control / video / audio reproduction unit (CPU) 40 rotates the antenna setting (internal antenna → external antenna) when the determination result of the PER determination is “false” in a) above. # 1 → external antenna # 2 →... (Time t11). That is, at the present time, the internal antenna 10 is switched to the external antenna # 1, the external antenna # 1 is switched to the external antenna # 2, and the external antenna # 2 is switched to the internal antenna 10.

  Then, the tuner control / video / audio reproduction unit (CPU) 40 waits for a time T4, T5, or T6 (seconds) according to the switched antenna, and the PER determination result is “true” with the current antenna setting. Is determined (time t12). That is, time T4 (seconds) corresponds to the standby time at the internal antenna 10, time T5 (seconds) corresponds to the standby time at the external antenna # 1, and time T6 (seconds) corresponds to the standby time at the external antenna # 2. To do. If it is determined that the determination result of the PER determination is “true”, the tuner control / video / audio reproduction unit (CPU) 40 ends with the antenna setting state maintained.

c) The tuner control / video / audio reproduction unit (CPU) 40 rotates the antenna setting (time t12) and switches when the determination result of PER determination is “false” in b) above. Depending on the antenna, it waits for time T4, T5, or T6 (seconds), and determines whether or not the determination result of PER determination is “true” with the current antenna setting (time t13). If it is determined that the determination result of the PER determination is “true”, the tuner control / video / audio reproduction unit (CPU) 40 ends with the antenna setting state maintained.

d) The tuner control / video / audio reproduction unit (CPU) 40 returns the antenna setting to the internal antenna 10 when the determination result of the PER determination is “false” in c) (time t13). ). That is, the tuner control / video / audio reproduction unit (CPU) 40 switches to the internal antenna 10 on the assumption that the external antenna 11 is not attached or the reception sensitivity of the external antenna 11 is poor. If the internal antenna 10 has already been selected, the antenna setting state is maintained.

e) Next, the tuner control / video / audio reproduction unit (CPU) 40 stands by until time T8 (seconds) elapses (time t14). During this time, the digital broadcast receiving / demodulating unit (tuner) 30 continues the receiving operation.

f) The tuner control / video / audio reproduction unit (CPU) 40 returns to a) after elapse of time T8 (seconds) in e). After the next process, time T9 (second) is not used, and time T4, T5, or T6 (second) according to the antenna setting is used.

  In the embodiment described above, a method for setting the times T4, T5, and T6 when the viewing application is activated and selected, and the times T4, T5, and T6 when asynchronous is described. In order to simply know the reception level, it is possible to compare the reception level by using the electric field strength (RSSI) in the reception frequency band, but there is also an interference wave other than the desired signal (here, the broadcast wave). This is not preferable because it is determined as a reception level. On the other hand, the carrier power to noise power ratio signal (C / N) is effective for use as a reception level. However, if the digital broadcast reception / demodulation unit (tuner) 30 does not synchronize with the broadcast wave, the C / N is I do not understand. Therefore, it takes too much time to synchronize with the internal antenna 10 / external antenna # 1 / external antenna # 2 and compare the C / N of each antenna to switch to the best antenna.

  In order to solve this problem, in the present embodiment, as described above, first, synchronization (reception level determination or PER determination) is attempted with the internal antenna 10. As long as the internal antenna 10 is not synchronized, the antenna setting is maintained. When the internal antenna 10 is out of synchronization, the external antenna 11 is tried to synchronize. However, the external antenna 11 may not be attached, and the external antenna 11 may be removed depending on the usage status of the external antenna 11. However, the reception sensitivity is not always better. Therefore, when the viewing application is activated and the channel is selected, it is necessary to optimize the times T2 and T3 to try to synchronize with the external antenna 11 so that the reception rate is maximized in any environment. Basically, by setting the time T1 at the internal antenna 10 to the time T2 at the external antenna 11 or the time T3, the standby time at the indeterminate external antenna 11 is shortened. For example, when T1 = T2 + T3 and the duty ratio is 50%, when time T1 = 3 seconds, time T2 = 1.5 seconds and time T3 = 1.5 seconds. The relationship between the times T4, T5, and T6 at the time of asynchronous is the same. That is, basically, the time T4 at the internal antenna 10 ≥ the time T5 at the external antenna 11 or the time T6.

  Specifically, before the mobile terminal device 1 is shipped, various reception environments (indoors, walking, building streets, trains, station platforms, close to transmitting stations, fringes far from transmitting stations, etc.) are assumed. The reception quality log when this system is executed while reproducing the radio wave environment with a signal generator and changing the time T1, T2, T3, T7 or the time T4, T5, T6, T8, T9 (Information such as BER, PER, C / N, RSSI, Fd) is analyzed, and the parameters (time T1, T2, T3, T7, or time T4, T5, T6, T8, T9 with few errors and high reception rate) Or PER determination value) is set as an initial value. Further, the parameter adjustment may be performed in the field as necessary.

  Eventually, the disturbance of the screen / sound that the user views occurs when a packet error rate (PER) occurs in the digital broadcasting system. Therefore, the simplest method is to record the occurrence frequency of the packet error rate (PER) as a reception quality log while changing the time T1, T2, T3, T7 or the time T4, T5, T6, T8, T9. Analyze the reception quality log and select the parameter (time T1, T2, T3, T7 or time T4, T5, T6, T8, T9, or PER judgment value) that minimizes the frequency of occurrence of packet error rate (PER) It is to be.

  Further, even in actual use, the reception quality log (BER, PER, C / N, RSSI, Fd, etc. information or packet error rate (PER) occurrence frequency) is recorded, and the reception quality log is analyzed to obtain a packet. A parameter (time T1, T2, T3, T7, or time T4, T5, T6, T8, T9, or PER determination value) that minimizes the occurrence rate of the error rate (PER) is selected (initial value is changed). It may be.

Further, for example, a weight value is stored in the nonvolatile memory in association with the occurrence frequency of the packet error rate (PER), and parameters (time T1, T2, T3, T7 are set according to the occurrence frequency of the packet error rate (PER). Alternatively, these parameters may be changed quickly by changing the weight value multiplied by the time T4, T5, T6, T8, T9 or the PER determination value).
Thus, in this embodiment, since it is not necessary to investigate the state of the external antenna 11 unnecessarily, there is an effect of power saving.

For example, when one external antenna 11 is attached, there are the following antenna states.
(1) When setting is fixed to internal antenna 10 (2) When setting is fixed to external antenna 11 (3) Automatic switching between internal antenna 10 and external antenna 11 (external antenna 11 not attached)
(4) Automatic switching between internal antenna 10 and external antenna 11 (external antenna 11 mounted)

In the case of the present embodiment, when the sensitivity of the internal antenna 10 is equal to or less than the sensitivity of the external antenna 11, as a reception rate,
(4)> (2) ≧ (1) = (3)
Ideally.

  In particular, it is difficult to satisfy (1) = (3). If there is a restriction that the external antenna 11 cannot be detected, when synchronization can be established with the internal antenna 10, if the operation is performed to establish synchronization with the external antenna 11 that may not be attached, the operation time This is because the reception rate decreases.

  Therefore, as described above, the occurrence frequency of the packet error rate (PER) is saved as a reception quality log, and the reception quality log is analyzed, so that the packet error rate (PER) is minimized. By adjusting parameters such as T2, T3, T7 or time T4, T5, T6, T8, T9, and PER determination value, the reception sensitivity of the external antenna 11 tends to be low, or the mounting rate of the external antenna 11 And the reception sensitivity of the external antenna 11 tends to be high.

  In addition, according to the above-described embodiment, without comparing the reception levels of the antennas, the reception level is determined by circulating from internal antenna 10 ⇒ external antenna # 1 ⇒ external antenna # 2 ⇒ internal antenna 10. (Reception level determination or PER determination) When the determination result becomes “true” in the range, the antenna can be selected to shift to the viewing operation in a shorter time. That is, according to the present embodiment, the waiting time until the reception is possible is shortened, and radio waves can be received efficiently.

  Further, according to the above-described embodiment, since it is determined whether it is in the area or out of the area by the reception level determination or PER determination using parameters other than the electric field intensity, for example, a widely known reception level (electric field intensity: It is possible to solve the disadvantage that interference waves other than the desired signal (here, broadcast wave) are also determined as the reception level, which is caused by a method of constantly monitoring RSSI) and selecting an antenna having a high reception level.

  Further, according to the above-described embodiment, even if it is not possible to detect that the removable external antenna 11 is attached, the internal antenna 10 can be attached to and detached from the internal antenna 10 while maintaining a reception rate substantially equal to that when the external antenna 11 is fixed. The external antenna 11 can be switched and controlled.

  Further, according to the above-described embodiment, even when a plurality of external antennas are connected to the external interface of the mobile terminal device 1, it is possible to shift to a viewing operation in a shorter time and efficiently receive radio waves. Be able to.

  Further, according to the above-described embodiment, since “field strength incapable of reproducing video / audio> out-of-synchronization field strength”, the digital broadcast receiving / demodulating unit (tuner) 30 is out of synchronization and the antenna is disconnected. It is possible to solve the disadvantage that video / audio interruption occurs when switching.

  The embodiment of the present invention is an example applied to a mobile phone as a mobile terminal device, but is not limited to this, a television capable of receiving terrestrial digital broadcasting, a portable or stationary type with a terrestrial digital broadcast receiving function. Terminal devices such as game machines, tablet PCs, notebook PCs, TV receivers connected to PDAs (Personal Data Assistants), and the like, can be applied to OFDM modulation system-based broadcasting systems. In particular, the present invention can be applied to a portable terminal / digital broadcasting system to which an external antenna can be attached and a portable terminal / digital broadcasting system having a plurality of antennas.

The features of the present invention will be described below.
A part or all of the above-described embodiment can be described as in the following supplementary notes, but is not limited thereto.
(Appendix 1)
FIG. 7 is a configuration diagram of Supplementary Note 1. Here, the correspondence between FIG. 7 and FIG. 1 will be described. A plurality of antennas 100-1 to 100-n illustrated in FIG. 7 correspond to the internal antenna 10 and the external antenna 11 in FIG. 1, and the antenna switching unit 101 in FIG. 7 corresponds to the antenna switching switch 20 in FIG. 7 corresponds to the tuner control / video / audio reproduction unit (CPU) 40 in FIG.

As shown in this figure, the invention described in Appendix 1 is
A plurality of antennas 100-1, 100-2, ..., 100-n;
An antenna switching unit 101 for switching the plurality of antennas 100-1 to 100-n;
A coverage area determining unit 102 that determines whether or not the received signal is within a coverage area based on a reception level or a reception error rate for each of the plurality of antennas 100-1 to 100-n;
While the antenna switching unit 101 cyclically switches the plurality of antennas 100-1 to 100-n, the determination result for each antenna by the range determination unit 102 is acquired, and the range determination unit 102 determines that the range is within the range. The control unit 103 for controlling the switching by the antenna switching unit so as to terminate the determination by the area determination unit 102 and receive the radio wave with the antenna determined to be within the area at the time of being
A mobile terminal apparatus comprising:

(Appendix 2)
The range determination unit is a reception level determination unit that determines whether or not the range is within a received radio wave based on a reception level for each of the plurality of antennas.
The mobile terminal device according to Supplementary Note 1, wherein the mobile terminal device is characterized in that

(Appendix 3)
The reception level determination unit performs a first determination to determine a reception level using a carrier power to noise power ratio signal (C / N) and a synchronization state signal (SYNC), and the reception level is determined by the first determination. Is determined to be low, a first deterministic determination is further performed to determine a reception level using a Doppler frequency (Fd) or moving speed and a packet error rate (PER) signal. If it is determined that the reception level is high, the first determination determination or the second determination is performed by performing a second determination for determining the reception level using the bit error rate (BER). The mobile terminal apparatus according to appendix 2, wherein it is determined whether or not the received radio wave is within a range based on the reception level determined by the confirmation determination.

(Appendix 4)
The appendage range determination unit is an error rate determination unit that determines whether or not the received radio wave is within a range based on an error rate of reception for each of the plurality of antennas. It is a mobile terminal device.

(Appendix 5)
The error rate determination unit determines that the packet error rate (PER) is within a range when the number of consecutive times when the value of the packet error rate (PER) is equal to or greater than a predetermined threshold is smaller than the specified number of times, and the value of the packet error rate (PER) is The mobile terminal device according to supplementary note 4, wherein the mobile terminal device is determined to be out of service when the number of consecutive times when the number is equal to or greater than a predetermined threshold is equal to or greater than a specified number.

(Appendix 6)
The plurality of antennas includes an internal antenna and a removable external antenna.
The mobile terminal device according to any one of appendices 1 to 5, characterized in that.

(Appendix 7)
The mobile terminal apparatus according to appendix 6, wherein the control unit preferentially switches the internal antenna when the antenna switching unit cyclically switches the plurality of antennas.

(Appendix 8)
Any one of appendices 1 to 7, wherein the control unit controls the timing for cyclically switching the plurality of antennas by the antenna switching unit based on the occurrence frequency of a past packet error rate (PER). The mobile terminal device according to claim 1.

(Appendix 9)
An antenna switching method in an electronic device including a plurality of antennas, wherein the antenna switching step for switching between the plurality of antennas and a reception radio wave range based on a reception level or a reception error rate for each of the plurality of antennas A range determination step for determining whether or not the antenna is within a range, and by obtaining a determination result for each antenna in the range determination step while cyclically switching the plurality of antennas, And a control step of controlling the switching of the plurality of antennas so as to receive radio waves with the antenna determined to be within the range.

(Appendix 10)
Based on the antenna switching function for switching the plurality of antennas, the reception level for each of the plurality of antennas, or the reception error rate, to a computer of an electronic device having a plurality of antennas The determination result for each antenna by the range determination function is acquired while the plurality of antennas are cyclically switched by the range determination function and the antenna switching function, and when it is determined that the range is within the range by the range determination function And a control function for controlling the switching of the plurality of antennas so as to receive radio waves with the antenna determined to be within the range, by terminating the determination by the range determination function. .

1 Mobile terminal device 10 Digital broadcast receiving antenna (internal antenna)
11 Digital broadcast receiving antenna (external antenna)
20 Antenna selector switch 30 Digital broadcast receiver / demodulator (tuner)
40 Tuner Control / Video / Audio Playback Unit (CPU)
DESCRIPTION OF SYMBOLS 50 Screen display part 60 Audio | voice output part 70 Memory 100-1, 100-2, ..., 100-n A plurality of antennas 101 Antenna switching part 102 Area determination part 103 Control part

Claims (10)

Multiple antennas,
An antenna switching unit for switching the plurality of antennas;
A range determination unit that determines whether or not it is within a received radio wave range based on a reception level for each of the plurality of antennas or a reception error rate;
While the antenna switching unit cyclically switches the plurality of antennas, the determination result for each antenna by the range determination unit is acquired, and when the range determination unit determines that the range is within range, the range determination unit A control unit that terminates the determination and controls switching by the antenna switching unit so as to receive radio waves with the antenna determined to be within the range;
A mobile terminal device comprising: The range determination unit is a reception level determination unit that determines whether or not the range is within a received radio wave based on a reception level for each of the plurality of antennas.
The mobile terminal apparatus according to claim 1. The reception level determination unit performs a first determination to determine a reception level using a carrier power to noise power ratio signal (C / N) and a synchronization state signal (SYNC), and the reception level is determined by the first determination. Is determined to be low, a first deterministic determination is further performed to determine a reception level using a Doppler frequency (Fd) or moving speed and a packet error rate (PER) signal. If it is determined that the reception level is high, the first determination determination or the second determination is performed by performing a second determination for determining the reception level using the bit error rate (BER). Based on the reception level determined by the final determination of whether or not it is within the received radio wave range,
The mobile terminal apparatus according to claim 2. The range determination unit is an error rate determination unit that determines whether or not a range of a received radio wave based on an error rate of reception for each of the plurality of antennas.
The mobile terminal apparatus according to claim 1. The error rate determination unit determines that the packet error rate (PER) is within a range when the number of consecutive times when the value of the packet error rate (PER) is equal to or greater than a predetermined threshold is smaller than the specified number of times, and the value of the packet error rate (PER) is When the number of consecutive times when it is equal to or greater than a predetermined threshold is equal to or greater than the specified number,
The mobile terminal apparatus according to claim 4. The plurality of antennas includes an internal antenna and a removable external antenna.
The mobile terminal device according to claim 1, wherein the mobile terminal device is a mobile terminal device. The control unit, when cyclically switching the plurality of antennas by the antenna switching unit, switches the internal antenna with priority.
The mobile terminal apparatus according to claim 6. The control unit controls the timing of cyclically switching the plurality of antennas by the antenna switching unit based on the occurrence frequency of the past packet error rate (PER).
The mobile terminal device according to claim 1, wherein the mobile terminal device is a mobile terminal device. An antenna switching method in an electronic device having a plurality of antennas,
An antenna switching step of switching the plurality of antennas;
A coverage area determining step for determining whether or not it is within a received radio wave range based on a reception level for each of the plurality of antennas or a reception error rate;
While cyclically switching the plurality of antennas, the determination result for each antenna in the range determination step is acquired, and when it is determined that it is within the range, the determination by the range determination step is terminated, A control step for controlling switching of the plurality of antennas so as to receive radio waves with the determined antenna;
An antenna switching method comprising: In the computer of electronic equipment with multiple antennas,
An antenna switching function for switching the plurality of antennas;
Within range determination function for determining whether or not within the range of the received radio wave based on the reception level for each of the plurality of antennas or the reception error rate,
While cyclically switching the plurality of antennas by the antenna switching function, the determination result for each antenna by the range determination function is acquired, and when the range determination function determines that the range is within range, the range determination function A control function for controlling the switching of the plurality of antennas so as to terminate the determination and receive radio waves with the antenna determined to be within the range;
A program characterized by having executed.

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