JP5196593B2 - Wireless terminal - Google Patents

Description

  The present invention relates to a wireless terminal such as a mobile phone having a failure diagnosis function for diagnosing internal component failures and malfunctions.

  In recent years, with the increase in the number of functions of mobile phones, inquiries from users regarding defects are increasing. However, due to the complexity of the internal configuration accompanying the multi-functionalization of the device, it is difficult to find out the detailed cause of the device failure in a short time, and in order to determine whether it is a hardware failure, It is necessary to make a judgment by analyzing the inside of the device for each function (IC). For this reason, a lot of man-hours (costs) are generated for the manufacturer in order to cope with the defect, and a disadvantage that the user cannot use the device during the analysis period occurs.

  In order to solve these problems, various mechanisms for detecting a failure by self-diagnosis have been proposed. In this self-diagnosis system, for example, a signal when the apparatus is operating is monitored and compared with a signal (expected value) acquired in advance and stored in a memory to determine whether or not a failure has occurred. Diagnoses and identifies the failure location. For example, Patent Document 1 discloses a method of detecting and predicting a failure by picking up noise generated from an apparatus with an antenna. Moreover, in patent document 2, the detector for detecting a voltage or an electric current is installed in a transmission line, the 3rd harmonic component and the 5th harmonic component are monitored, and this component becomes higher than a reference value. A method for determining an abnormal signal when a problem occurs is disclosed.

  In recent years, wireless terminals are equipped with reception functions such as wireless LAN, GPS (Global Positioning System), and 1Seg, in addition to digital functions such as cellular functions, cameras, music playback, and recording. Is progressing. Therefore, a lot of noise sources are mixed inside the wireless terminal, combined with demands for thinning and miniaturization, and the noise source and the antenna of the receiver are close to each other and interfere with each other, so that the cellular function, GPS, one segment, The reception sensitivity of a receiver such as an FM radio deteriorates. In addition, due to demands for thinning and miniaturization of wireless terminals, it is difficult to provide optimum shielding, and noise countermeasures adversely affect antenna characteristics, making it difficult to completely suppress noise.

  In order to solve these problems, in Patent Document 3, the noise received by the noise antenna that receives only the noise inside the wireless terminal and the noise received by the wireless communication antenna used for transmitting / receiving the desired wave are superimposed. A method (noise canceller) is disclosed in which noise is canceled out by taking a difference from a wave and only a desired wave is extracted to obtain a stable reception sensitivity. Patent Document 4 discloses a method of intentionally generating a signal having a phase opposite to that of assumed noise and suppressing an interference wave received by an antenna.

JP-A-6-102724 Japanese Patent Laid-Open No. 2000-1000079 JP 2004-260428 A US Pat. No. 7,123,676

However, the conventional techniques disclosed in the above-described patent documents have the following problems.
(1) The techniques disclosed in Patent Document 1 and Patent Document 2 require a dedicated sensor and a circuit therefor, which increases the cost and the circuit scale. In particular, the increase in circuit scale is fatal for portable devices.
(2) In the techniques disclosed in Patent Document 1 and Patent Document 2, when noise is detected in a high frequency and wide band range, a detector and frequency conversion means are expensive.
(3) In the techniques disclosed in Patent Documents 3 and 4, when measuring noise characteristics using a receiver equipped with a noise canceller to diagnose a failure, the noise from the main antenna and the noise from the noise detection antenna cancel each other. As a result, the noise level is reduced, so failure diagnosis cannot be performed with high accuracy.

  The present invention has been made in view of such circumstances, and an object of the present invention is to provide a wireless terminal capable of performing failure diagnosis with low cost and high accuracy.

A wireless terminal of the present invention includes a main antenna that receives a desired wave signal, a plurality of application circuit units that execute different applications, and a noise receiving antenna that receives noise caused by one of the plurality of application circuit units. an active noise canceller circuit for combining the previous SL desired wave signal to control said noise receiving antenna the noise of the phase received on such a phase and phase of the desired signal received by the main antenna, A noise level measuring unit for measuring a level of a noise component included in the combined output, and predetermined memory information corresponding to the plurality of application circuit units, provided in a receiving circuit unit for demodulating the combined output of the active noise canceler circuit unit; And the measurement result of the noise level measurement unit Out with a, a failure determination section for determining whether one of said plurality of application circuit at least two measurements in comparison with a predetermined memory information stored in the memory unit is faulty.

According to the above configuration, an active noise canceller that generates a signal having the same amplitude and opposite phase as the noise superimposed on the desired wave signal received by the main antenna and cancels the noise is used on the reverse side to be superimposed on the desired wave signal. A signal with the same phase as the generated noise is generated and synthesized to increase the noise level, the level of the noise component contained in the synthesized output with the increased noise level is measured, and at least two of the measurement results are stored in the memory unit Whether or not one of the plurality of application circuit units is out of order is determined in comparison with the predetermined memory information stored in (1). Therefore, although it has a noise level measurement unit, a failure determination unit for determining a failure in the application circuit unit, and a memory unit, a dedicated sensor and a circuit for the same are not required, so that an increase in circuit scale can be suppressed low. it can. In addition, since the noise level is measured on the signal whose frequency after frequency conversion is low, an inexpensive detector can be used as the noise level measurement unit. In addition, the active noise canceller circuit unit is used at the time of failure diagnosis, and the noise level can be increased by use opposite to the original use, thereby enabling highly accurate failure diagnosis.
In addition, by making the phase of the noise in phase with the phase of the desired wave signal, the noise level can be maximized and a highly accurate failure diagnosis can be performed.

  The above configuration further includes an amplifying unit that amplifies the desired wave signal received by the main antenna, and adjusts a ratio between the gain of the active noise canceller circuit unit and the gain of the amplifying unit.

  According to the above configuration, since the ratio of the gain of the amplification unit that amplifies the desired wave and the gain of the active noise canceller circuit unit can be adjusted, noise can be detected with high quality.

  In the above configuration, the receiving circuit unit is a receiving circuit unit for receiving digital television broadcasts.

  According to the above configuration, since it is not necessary to provide a dedicated receiving circuit unit by using a receiving circuit unit for receiving digital television broadcasts for fault diagnosis of the application circuit unit, it is possible to perform fault diagnosis with low cost and high accuracy. A wireless terminal capable of being provided can be provided.

  INDUSTRIAL APPLICABILITY According to the present invention, it is possible to perform a diagnosis such as a failure or malfunction of an internal part of a wireless terminal such as a mobile phone with low cost and high accuracy.

1 is a block diagram showing a schematic configuration of a wireless terminal according to Embodiment 1 of the present invention. The figure which shows the characteristic of the noise which generate | occur | produces in the application circuit part which the radio | wireless terminal of FIG. 1 has The figure for demonstrating the method to measure the level of several frequencies in a narrow-band band in bandwidth 300MHz of DTV broadcasting. The figure which shows an example of the measurement result of the reception level measured in the failure judgment part of the radio | wireless terminal of FIG. 1, and stored in the memory part The figure which shows an example of the threshold value for failure determination previously stored in the memory part of the radio | wireless terminal of FIG. The figure which shows the noise characteristic when operating the Felica circuit The figure which expanded the band C which is a part of frequency band of FIG. The figure which shows the noise characteristic at the time of operating the DCDC converter circuit for liquid crystal displays The figure which shows the result of having detected a part of zone | band of FIG. The figure which shows the result of having detected a part of zone | band of FIG. The flowchart which shows the operation | movement at the time of the failure diagnosis mode of the radio | wireless terminal of FIG. The flowchart which shows the operation | movement at the time of the failure diagnosis mode of the radio | wireless terminal which concerns on Embodiment 2 of this invention.

  DESCRIPTION OF EXEMPLARY EMBODIMENTS Hereinafter, preferred embodiments for carrying out the invention will be described in detail with reference to the drawings.

(Embodiment 1)
FIG. 1 is a block diagram showing a schematic configuration of a radio terminal according to Embodiment 1 of the present invention. In the figure, a radio terminal 100 according to the present embodiment includes a main antenna 101 that receives a desired signal, a noise reception antenna 102 that receives noise, a low-noise amplification unit (LNA unit) 104 that can control gain, An ANC (Active Noise Canceller) circuit unit 105 that varies the phase and amplitude of the input noise signal, synthesizes and outputs the input desired signal, and a receiving circuit unit 106 that demodulates data from the input RF signal; The failure determination unit 107 that determines a failure from the noise measurement result by the detection unit (noise level measurement unit) 134 in the reception circuit unit 106 and the application control unit 140 that controls the two application circuit units 141 and 142 are input. An ANC control unit 108 for controlling the phase, gain (gain) and power supply of the ANC circuit unit 105 in accordance with the received signal; A mode setting unit 109 for setting the mode of the wireless terminal 100, and a memory unit 110 for recording a noise measurement result and a failure determination threshold level.

  The ANC circuit unit 105 includes a synthesis unit 120, a variable phase unit 121, and a variable gain unit 122. The reception circuit unit 106 includes a frequency conversion unit 130, a filter 131, a variable gain unit 132, a demodulation unit (DEMOD) 133, a detection unit 134 that detects a signal input to the demodulation unit 133, and the frequency conversion unit 130. And a local frequency generator 135 for generating a local frequency input to.

  In this embodiment, the main antenna 101 and the receiving circuit unit 106 are for DTV (Digital Television). Incidentally, small wireless terminals such as mobile phones are generally configured to receive one-segment broadcasting.

  Each of the application circuit units 141 and 142 has a dedicated clock signal. In the present embodiment, the application circuit unit 141 is a Bluetooth (registered trademark) circuit, and the application circuit unit 142 is a Felica (registered trademark) circuit. The dedicated clock signals of these circuits are mixed to produce noise characteristics as shown in FIG. Note that Bluetooth is a short-range wireless communication standard for digital electronic devices, and is used for wireless communication between devices at a distance of several meters to several tens of meters. 2.4 GHz band radio waves are used. On the other hand, Felica is a non-contact IC card technology and is widely used in transportation tickets and electronic money systems. Radio waves in the 13.56 MHz band are used.

  In FIG. 2, the horizontal axis indicates the frequency, the vertical axis indicates the level, and the harmonic components of the clock signals A and B appear as noise. Such noise characteristics vary depending on the application used at the same time, and if there is a failure or malfunction in the Bluetooth circuit or Felica circuit, the noise characteristics change greatly, so fault diagnosis can be performed by measuring the noise characteristics. It becomes possible. In particular, since the harmonic level changes to the order of the basic clock level, the measurement of harmonics is effective for abnormality diagnosis based on the level.

  In order to detect the noise characteristics shown in FIG. 2 with high accuracy for each harmonic of the clock frequency, it is necessary to measure levels of a plurality of frequencies in a narrow band in a wide frequency range. Here, for example, as shown in FIG. 3, the bandwidth of one seg is about 430 kHz, and fault diagnosis is facilitated by measuring the noise level of the DTV broadcast bandwidth of 300 MHz (470 MHz to 770 MHz) at a local frequency of 430 kHz steps. It can be carried out.

  Next, the failure determination method for wireless terminal 100 according to the present embodiment will be specifically described. FIG. 4 is a diagram illustrating an example of a measurement result of the reception level measured by the failure determination unit 107 and stored in the memory unit 110. FIG. 5 is a diagram illustrating an example of failure determination threshold values (memory information) stored in the memory unit 110 in advance. The failure determination unit 107 compares the measured value shown in FIG. 4 with the threshold value shown in FIG. 5, and diagnoses the failure based on whether the measured value is within the threshold value. For example, the reception level at 473.999 MHz is −70 dBm, and the threshold value at the frequency is a lower limit of −75 dBm and an upper limit of −65 dBm. The reception level at 474.427 MHz is −55 dBm, and the threshold value at the frequency is −60 dBm at the lower limit and −50 dBm at the upper limit. The reception level at 474.855 MHz is -70 dBm, and the threshold value at the frequency is -75 dBm as the lower limit and -65 dBm as the upper limit. Diagnosis can be made in the same manner in other frequency bands (480.427, 480.855...). It should be noted that it is desirable to acquire the failure determination threshold for each device at the time of shipment without failure. A value obtained by adding a specified margin to the acquired measurement value is a threshold value.

  Here, the effectiveness of performing fault detection in comparison with at least two or more measured values, which is a feature of the present invention, will be described. FIG. 6 is a diagram showing noise characteristics when the Felica circuit is operated. FIG. 7 is an enlarged view of a part of the frequency band (band C) of FIG. It can be seen from the noise characteristics shown in FIGS. 6 and 7 that noise harmonics appear at regular frequency intervals. That is, in the case of the Felica circuit, since the frequency is 13.56 MHz, it can be seen that harmonic noise appears by multiplication of this 13.56 MHz.

  FIG. 8 is a diagram showing noise characteristics when a DCDC converter circuit (not shown) for a liquid crystal display is operated. It can be seen from the noise characteristics shown in the figure that the noise increases over the entire band. In other words, the liquid crystal noise is 13 kHz of the clock signal, and it can be seen that the noise spectrum appears to expand.

  In the characteristics shown in FIGS. 6 and 8, when a failure is determined only with one band level, it cannot be determined whether the noise is a constant frequency interval noise or the entire band noise. That is, it is not possible to accurately determine the circuit that has failed. The noise level of the band C shown in FIGS. 6 and 8 is the same. That is, the noise separation of FIGS. 6 and 8 cannot be performed only by the level value of only the fixed band. When strictly determining a failure, it is necessary to compare two or more points (level max, level min). By comparing the levels of two or more points, it is possible to determine whether the Felica circuit is faulty or the DCDC converter circuit for the liquid crystal display is faulty. In addition, since these inspections can be performed simultaneously, the speed of failure diagnosis can be increased. In addition, noise has a characteristic frequency characteristic, and it becomes easy to locate a faulty part by determining the frequency characteristic. Needless to say, failure diagnosis of the Bluetooth circuit can also be performed.

  In the present embodiment, noise characteristics are determined in advance, and a failure is determined based on at least two points: a frequency point with a high noise level and a frequency point with a low noise level, thereby enabling a highly accurate failure diagnosis.

  FIG. 9 shows the result of detecting a part of the band in FIG. The noise in FIG. 7 is characterized by having a harmonic of 13.56 MHz by using the 13.56 MHz clock of the Felica circuit. By comparing at least two of the level of 474.427 MHz which is a frequency band of this harmonic and the level of 480.427 MHz which is a low level band, it is possible to accurately determine the failure of the Felica circuit. The level of 474.427 MHz (= 13.56 × 35) is high, and the level of the band in the vicinity (for example, 6 MHz separation) is low. This is a feature of noise when the Felica circuit is operating normally, and it can be determined that the Felica circuit is operating normally.

  On the other hand, the result of detecting a part of the band of FIG. 8 is shown in FIG. The noise of the DCDC converter circuit for the liquid crystal display of FIG. 8 is a clock signal of 13 kHz, and the noise spectrum appears to spread. The failure of the DCDC converter circuit for the liquid crystal display can be accurately determined by comparing at least two of the level 470.575 MHz of the level max that is a frequency band of this harmonic and the level of 769.711 MHz of the level min. Is possible. From the measurement result, it can be seen that the level is high over the entire band. It is difficult to determine whether or not there is a failure only with information in the 470 MHz band, and failure determination is performed after confirming that noise in the 770 MHz band has dropped.

  It is desirable that the failure diagnosis is performed in an environment that can block external radio waves such as an anechoic box. Further, the wireless terminal 100 may periodically perform a self check and leave the result as a log. As a result, the service company confirms the log, so that it is possible to grasp the failure time.

Next, the operation of the wireless terminal 100 when measuring noise will be described.
FIG. 11 is a flowchart showing the operation of the radio terminal 100 in the failure diagnosis mode. In this figure, when an external failure diagnosis command (not shown) is input to the mode setting unit 109, the mode setting unit 109 sets the failure diagnosis mode. In the failure diagnosis mode, the user selects a function (application) to be diagnosed, and the mode setting unit 109 that has obtained the information determines an application for failure diagnosis (step 1). Next, the mode setting unit 109 gives a command to the application control unit 140 so that the application setting is optimized for the diagnostic measurement. The application control unit 140 performs ON / OFF control of the application according to the setting mode (step 2).

  Next, the receiving circuit unit 106 sets the frequency of the local frequency generating unit 135 (step 3). Next, the ANC circuit unit 105 sets a gain and phase suitable for the local frequency set by the receiving circuit unit 106 (step 4). Here, it is desirable that the noise received by the noise receiving antenna 102 is in phase with the so-called self-addicted noise received by the main antenna 101. In particular, when the optimum phase setting during operation of the ANC circuit unit 105 is known, the phase setting is set by adding 180 ° (inverted) to the ANC setting value at the time of failure diagnosis.

  After the ANC circuit unit 105 sets the optimum gain and phase, the detection unit 134 of the reception circuit unit 106 measures the reception level (for example, RSSI (Received Signal Strength Indicator)) (step 5). In this case, the reception level is measured repeatedly at designated frequency points (two or more locations) (step 6). For example, the reception level is measured at a frequency step of 430 kHz with a bandwidth of 430 kHz in the range of detectable bands shown in FIG.

  After completing the measurement at the specified frequency point, the failure determination unit 107 compares the measured value with the threshold value stored in the memory unit 110 (step 7), and if the measured value is within the normal operating range. If the measured value is out of the normal range, a fault application name is displayed on the display unit (step 9).

  As described above, according to the wireless terminal 100 of the present embodiment, the main antenna 101 that receives the desired wave signal, the plurality of application circuit units 141 and 142 that execute different applications, and the application circuit units 141 and 142 A noise receiving antenna 102 that receives noise caused by the noise, an ANC circuit unit 105 that controls the phase and amplitude of the noise received by the noise receiving antenna 102 and synthesizes the desired wave signal received by the main antenna 101; Predetermined memory information corresponding to the application circuit units 141 and 142 is provided in the receiving circuit unit 106 that demodulates the combined output of the ANC circuit unit 105 and measures the level of the noise component included in the combined output. At least of the measurement results of the stored memory unit 110 and the detection unit 134 A failure determination unit 107 that determines whether one of the application circuit units 141 and 142 has failed by comparing two measurement results with predetermined memory information stored in the memory unit 110, Although it has a detection unit 134 for measuring the level, a failure determination unit 107 for determining a failure of the application circuit units 141 and 142, and a memory unit 110, a dedicated sensor and a circuit therefor are not required. The increase can be kept low. In addition, since the noise level is measured on the signal whose frequency after frequency conversion is low, an inexpensive detector 134 for measuring the noise level can be used. Further, the noise level can be increased by using the ANC circuit unit 105 in reverse of the original use at the time of failure diagnosis, and high-precision failure diagnosis is possible. In particular, the noise level can be maximized by controlling the phase of the noise received by the noise receiving antenna 102 to be in phase with the phase of the desired wave signal received by the main antenna 101, and the failure is highly accurate. Diagnosis is possible.

(Embodiment 2)
The radio terminal according to the second embodiment of the present invention has the same circuit configuration as that of the radio terminal 100 according to the first embodiment described above, and a part of control at the time of failure diagnosis is added. Since the circuit configuration is the same as that of wireless terminal 100 according to Embodiment 1, reference is made to FIG. 1 and reference numeral 100A is given.

  FIG. 12 is a flowchart showing an operation of radio terminal 100A according to Embodiment 2 in the failure diagnosis mode. The flowchart of FIG. 11 shows the gain of the low noise amplification unit (LNA unit) 104 as the next step of the gain control of the gain variable unit 122 and the phase control of the phase variable unit 121 of the ANC circuit unit 105 of the flowchart of FIG. Control is performed (step 4A). When noise from the outside (for example, broadcast wave) is large at the time of failure diagnosis, it is possible to accurately measure the self-poisoning noise level by suppressing the level from the main antenna 101. When the noise level input to the noise receiving antenna 102 is extremely low, the gain of the ANC circuit unit 105 is reduced to reduce the thermal noise level added to the combining unit 120 in the ANC circuit unit 105, Improve fault diagnosis accuracy.

  The present invention has an effect that a failure diagnosis can be performed with low cost and high accuracy, and can be applied to a small wireless terminal such as a mobile phone.

100, 100A Wireless terminal 101 Main antenna 102 Noise receiving antenna 104 Low noise amplification unit 105 ANC circuit unit 106 Reception circuit unit 107 Failure judgment unit 108 ANC control unit 109 Mode setting unit 110 Memory unit 120 Combining unit 121 Variable phase unit 122 Variable gain Unit 130 frequency conversion unit 131 filter 132 variable gain unit 133 demodulation unit 134 detection unit 135 local frequency generation unit 140 application control units 141 and 142 application circuit unit

Claims (3)

A main antenna for receiving the desired signal,
A plurality of application circuit units that execute different applications;
A noise receiving antenna for receiving noise caused by one of the plurality of application circuit units;
An active noise canceller circuit for combining the previous SL desired wave signal to control said noise receiving antenna the noise of the phase received on such a phase and phase of the desired signal received by the main antenna,
A noise level measuring unit that is provided in a receiving circuit unit that demodulates a combined output of the active noise canceller circuit unit, and that measures a level of a noise component included in the combined output;
A memory unit storing predetermined memory information corresponding to the plurality of application circuit units;
A failure that determines whether one of the plurality of application circuit units has failed by comparing at least two measurement results of the measurement results of the noise level measurement unit with predetermined memory information stored in the memory unit A determination unit;
Wireless terminal equipped with. The wireless terminal according to claim 1 ,
A radio terminal further comprising an amplifying unit for amplifying the desired wave signal received by the main antenna, and adjusting a ratio between a gain of the active noise canceller circuit unit and a gain of the amplifying unit. The wireless terminal according to claim 1 or 2 , wherein
The receiving circuit unit is a wireless terminal which is a receiving circuit unit for receiving digital television broadcasts.

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