JP2010232907A - Wireless communication apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a wireless communication apparatus, capable of performing efficient mode switching for suppressing reduction in the throughput. <P>SOLUTION: A cellular phone 1, which performs wireless communications with a plurality of communication systems, includes a transceiver 42 that performs wireless communications via a main antenna 50; a receiver 43, that performs wireless communications via a sub antenna 60 of which the sensitivity is lower than that of the main antenna 50; and a CPU 30 in which, when awaiting CDMA 2000_1x, while communicating with EVDO via the main antenna 50, if the receiving sensitivity of the sub antenna 60 is lower than or equal to a lower limit threshold; switching is performed to wait by the transceiver 42; and if the receiving sensitivity of the main antenna 50 is equal to or higher than an upper limit threshold, switching is performed to wait by the receiver 43. On the basis a receiving sensitivity difference of CDMA 2000_1x in the main antenna 50 and the sub antenna 60 measured, before and after switching, the CPU 30 updates the upper limit threshold with a value obtained, by adding at least the receiving sensitivity difference to the lower limit threshold. <P>COPYRIGHT: (C)2011,JPO&amp;INPIT

Description

  The present invention relates to a wireless communication apparatus that communicates with a plurality of communication systems.

  2. Description of the Related Art Conventionally, in a wireless communication device such as a mobile phone, a plurality of communication systems such as a CDMA2000_1x system capable of voice communication and a CDMA2000_1x_EVDO (Evolution Data Only or Evolution Data Optimized, hereinafter referred to as EVDO) system dedicated to data communication. Is used.

  In addition, a plurality of antennas are provided to improve reception quality and to communicate with a plurality of communication systems. For example, there is a method of intermittently receiving a CDMA2000_1x paging channel with a main antenna having higher reception sensitivity than the sub antenna while performing EVDO diversity communication with both the main antenna and the sub antenna (hereinafter referred to as a Hybrid mode). .

  FIG. 7 is a sequence diagram illustrating the Hybrid mode in the wireless communication apparatus. The wireless communication apparatus performs EVDO diversity communication using both the main antenna and the sub-antenna, and prioritizes the signal of the antenna having the better reception sensitivity, or combines both signals to remove noise. Then, the paging channel of CDMA2000_1x is intermittently received by the main antenna at a predetermined cycle.

  However, in the Hybrid mode, EVDO communication is temporarily interrupted due to the intermittent reception of CDMA2000_1x, so there is a concern about data quality deterioration and throughput reduction. For example, a broadcast transmission service called BCMCS (Broad-Cast Multi-Cast Service) may fail in data reception because it cannot perform retransmission processing.

  Therefore, in order to improve the data quality of EVDO, it is equipped with SHDR (Simultaneous Hybrid Dual Receive) function that performs communication with communication systems with different protocols simultaneously with multiple antennas. A method of performing intermittent reception of CDMA2000 — 1x (hereinafter referred to as “Simulantaneous mode”) has been proposed.

  FIG. 8 is a sequence diagram showing the Simulaneous mode in the wireless communication apparatus. The wireless communication device performs EVDO diversity communication as in the Hybrid mode, but continues EVDO communication with the main antenna even at the intermittent reception timing of CDMA2000_1x. The wireless communication apparatus receives the CDMA2000_1x paging channel by the sub-antenna. Thereby, since EVDO communication is not interrupted, an improvement in throughput can be expected.

  By the way, in the case of the Simulaneous mode, paging channel reception in CDMA2000_1x is performed by a sub-antenna having lower sensitivity than the main antenna. Therefore, when the radio wave condition deteriorates, it is preferable to switch to the Hybrid mode and receive the paging channel in CDMA2000_1x using the main antenna. Therefore, a method of switching between the Hybrid mode and the Simultaneous mode based on a predetermined threshold has been proposed (see, for example, Patent Document 1).

  FIG. 9 is a diagram illustrating a method of switching between the Hybrid mode and the Multi-mode in the wireless communication apparatus based on the reception sensitivity of each antenna.

  The wireless communication apparatus is determined by a lower limit threshold of the reception sensitivity where the paging channel reception rate of CDMA2000_1x at the sub-antenna is 100%, a difference in reception sensitivity due to an assumed gain difference between the two antennas and a difference in antenna position in the apparatus. The upper limit threshold is held.

  In the Hybrid mode, when the reception sensitivity at the main antenna rises and exceeds the upper threshold value, the mode is switched to the Simultaneous mode, and CDMA2000_1x paging channel reception moves to the sub-antenna. At this time, the reception sensitivity at the sub-antenna becomes the lower limit threshold value.

  After that, when the reception mode at the sub-antenna decreases and falls below the lower limit threshold value in the Simplaneous mode, the mode is switched to the Hybrid mode, and the CDMA2000_1x paging channel reception shifts to the main antenna. At this time, the reception sensitivity at the main antenna becomes the upper threshold.

JP 2008-85793 A

  However, the gain difference in the actual environment varies depending on the band class, the channel, the deformation state of the wireless communication device, the radio wave environment, and the like. If the assumed gain difference is different from the gain difference in the actual environment, the reception sensitivity of the paging channel changes from the upper threshold to the lower threshold, or from the lower threshold to the upper threshold when the receiving antenna is switched when the mode is switched. Instead of changing, it shifts to a shifted position.

  FIG. 10 is a diagram illustrating a case where the gain difference in the real environment is smaller than the assumed gain difference in the wireless communication device.

  In this case, when the reception sensitivity at the main antenna increases in the Hybrid mode and exceeds the upper limit threshold value, the mode is switched to the Simultaneous mode, and CDMA2000_1x paging channel reception moves to the sub-antenna. At this time, the reception sensitivity at the sub-antenna becomes higher than the lower limit threshold. In other words, in practice, it was possible to switch to the Simpleneous mode earlier, but since the Hybrid mode is maintained, the throughput decreases.

  FIG. 11 is a diagram illustrating a case where the gain difference in the real environment is larger than the assumed gain difference in the wireless communication device.

  In this case, when the reception sensitivity at the main antenna increases in the Hybrid mode and exceeds the upper limit threshold value, the mode is switched to the Simultaneous mode, and CDMA2000_1x paging channel reception moves to the sub-antenna. At this time, the reception sensitivity at the sub-antenna is lower than the lower limit threshold. Then, it will switch to Hybrid mode again. As described above, repeated switching of modes (fluttering) increases the CPU load of the wireless communication device and increases power consumption.

  Also, when the reception sensitivity at the sub-antenna decreases in the Simplaneous mode and falls below the lower limit threshold, the mode is switched to the Hybrid mode, and CDMA2000_1x paging channel reception moves to the main antenna. At this time, the reception sensitivity at the main antenna is higher than the upper limit threshold. Then, the mode is switched again to the simultaneous mode. As described above, repeated switching of modes (fluttering) increases the CPU load of the wireless communication device and increases power consumption.

  As described above, efficient mode switching cannot be performed unless the upper and lower thresholds are set appropriately. Even in Patent Document 1, each threshold value may not have sufficient accuracy because it is not based on the difference in reception sensitivity of CDMA2000_1x in an actual environment.

  An object of the present invention is to provide a wireless communication apparatus capable of efficient mode switching for suppressing a decrease in throughput.

  A wireless communication device according to the present invention is a wireless communication device that performs wireless communication with a plurality of communication systems, and a first communication unit that wirelessly communicates with one of the plurality of communication systems via a first antenna; A second communication unit that wirelessly communicates with one of the plurality of communication systems via a second antenna having a lower sensitivity than the one antenna, and a first communication system that communicates with the first communication system via the first antenna, When waiting for two communication systems, if the reception sensitivity of the second antenna is less than or equal to a lower threshold, the first communication unit waits, and if the reception sensitivity of the first antenna is greater than or equal to an upper threshold, the second communication unit A control unit configured to switch so as to wait for the second communication system in the first antenna and the second antenna measured before and after the switching. Based on the reception sensitivity difference beam, and updates the upper limit threshold value obtained by adding at least the reception sensitivity difference to the lower threshold.

  Moreover, when the said reception sensitivity difference is measured 1st time, it is preferable that the said control part updates the said upper limit threshold value with the value which added the average and the margin of the said measured value.

  The control unit may increase the margin and increase the upper limit threshold when the switching occurs a plurality of times within a predetermined period and the measured difference in received sensitivity is larger than the difference between the upper limit threshold and the lower limit threshold. Is preferably updated.

  Further, it is preferable that the control unit updates the upper limit threshold value by reducing the margin when the situation of increasing the margin does not occur during the predetermined number of times of switching.

  In addition, when the reception sensitivity of the second antenna is near the lower limit threshold, the control unit succeeds in receiving from the second communication system through the second antenna a second number of times. It is preferable to lower the lower threshold and raise the lower threshold in the case of failure.

  Moreover, when the said control part raises the said minimum threshold value, it is preferable to increase the said 2nd frequency | count for making it fall again.

  The radio communication device according to the present invention associates the lower threshold and the upper threshold with at least one of a frequency band, a band class, a channel, or a deformation state of the own device of the second communication system. It is preferable to provide a storage unit for storing.

  The second communication system is a time division multiple access method, and the control unit communicates with the first communication system via the first antenna while waiting for the second communication system. It is preferable to switch between communication by the first communication system and standby of the second communication system in a time division manner.

  Further, it is preferable that the first communication system is an EVDO system in 3GPP2 standard and the second communication system is a CDMA2000_1x system.

  According to the present invention, efficient mode switching for suppressing a decrease in throughput can be performed.

1 is an external perspective view of a mobile phone according to an embodiment of the present invention. It is a block diagram which shows the function of the mobile telephone which concerns on embodiment of this invention. It is a flowchart which shows the setting process of the upper limit threshold value which concerns on embodiment of this invention. It is a flowchart which shows the setting process of the minimum threshold value which concerns on embodiment of this invention. It is a sequence diagram which illustrates a mode that the upper limit threshold value and lower limit threshold value which concern on embodiment of this invention are reset. It is a sequence diagram which illustrates a mode that the margin which concerns on embodiment of this invention is adjusted. It is a sequence diagram which shows Hybrid mode in a radio | wireless communication apparatus. It is a sequence diagram which shows the Simultaneous mode in a radio | wireless communication apparatus. It is a figure which shows the method in which a wireless communication apparatus switches between a Hybrid mode and a Simpleneous mode. In a wireless communication apparatus, it is a figure which shows the case where the gain difference of a real environment is smaller than an assumed gain difference. In a wireless communication apparatus, it is a figure which shows the case where the gain difference of a real environment is larger than an assumed gain difference.

  Hereinafter, an example of a preferred embodiment of the present invention will be described. In the present embodiment, a mobile phone 1 will be described as an example of a wireless communication device. Note that the wireless communication device of the present invention is not limited to this. For example, in addition to PHS and PDA (Personal Digital Assistant), a navigation device having a communication function, a personal computer, and a communication module connected thereto. It can be applied to various wireless communication devices.

  FIG. 1 is an external perspective view of a mobile phone 1 (wireless communication apparatus) according to the present embodiment. FIG. 1 shows a so-called foldable mobile phone, but the mobile phone according to the present invention is not limited to this. For example, a sliding type in which one casing is slid in one direction from a state in which both casings are overlapped, or a rotary type in which one casing is rotated around an axis along the overlapping direction ( Turn type), or a type (straight type) in which the operation unit and the display unit are arranged in one housing and does not have a connecting unit.

  The mobile phone 1 includes an operation unit side body 2 and a display unit side body 3. The operation unit side body 2 includes an operation unit 11 and a microphone 12 into which a voice uttered by a user of the mobile phone 1 is input on the surface unit 10. The operation unit 11 includes a function setting operation button 13 for activating various functions such as various setting functions, a telephone book function, and a mail function, and an input operation button 14 for inputting numbers of telephone numbers, mail characters, and the like. , And a determination operation button 15 for performing determination and scrolling in various operations.

  The display unit side body 3 includes a display unit 21 for displaying various types of information on the surface unit 20 and a receiver 22 for outputting the voice of the other party of the call.

  Further, the upper end portion of the operation unit side body 2 and the lower end portion of the display unit side body 3 are connected via a hinge mechanism 4. In addition, the mobile phone 1 relatively rotates the operation unit side body 2 and the display unit side body 3 which are connected via the hinge mechanism 4, so that the operation unit side body 2 and the display unit side body 3 are rotated. The body 3 can be in an open state (open state), or the operation unit side body 2 and the display unit side body 3 can be folded (folded state).

  FIG. 2 is a block diagram showing functions of the mobile phone 1 according to the present embodiment. The mobile phone 1 includes an operation unit 11, a display unit 21, a CPU 30 (control unit), a communication unit 40 (first communication unit and second communication unit), a main antenna 50 (first antenna), and a sub antenna. 60 (second antenna), an audio unit 70, and a memory 80 (storage unit).

  The CPU 30 controls the entire mobile phone 1, and performs predetermined control on the display unit 21, the communication unit 40, the voice unit 70, and the like, for example. Further, the CPU 30 receives input from the operation unit 11 or the like and executes various processes. Then, the CPU 30 controls the memory 80 to execute reading of various programs and data and writing of data when executing processing. In the present embodiment, the CPU 30 particularly performs switching control between the Hybrid mode and the Simultaneous mode, and processing for setting an upper limit threshold and a lower limit threshold of reception sensitivity, which are determination conditions for this switching (details will be described later).

  The communication unit 40 includes a baseband unit 41, a transmission / reception unit 42 (first communication unit), and a reception unit 43 (second communication unit), and a predetermined use frequency band (for example, a 2 GHz band, an 800 MHz band, or the like). ) To communicate with an external device (base station). The communication unit 40 demodulates the signal received by the transmission / reception unit 42 from the main antenna 50 by the baseband unit 41 or demodulates the signal received by the reception unit 43 from the sub-antenna 60 by the baseband unit 41. Is supplied to the CPU 30. The signal supplied from the CPU 30 is modulated by the baseband unit 41 and transmitted to the external device via the main antenna 50 by the transmission / reception unit 42.

  Here, the communication unit 40 uses both EVDO (first communication system), which is a communication protocol dedicated to data communication in the 3GPP2 standard, and CDMA2000_1x (second communication system), which is a voice communication protocol that provides voice communication. It corresponds. In the Hybrid mode described above, when EVDO communication is performed by the transmission / reception unit 42 via the main antenna 50 and CDMA2000_1x standby is performed, EVDO communication and CDMA2000_1x standby are switched in a time-sharing manner. Further, in the case of the aforementioned Simulaneous mode, EVDO communication by the transmission / reception unit 42 via the main antenna 50 continues. When waiting for CDMA2000_1x, the reception unit 43 via the sub-antenna 60 performs time-division sharing of EVDO communication. Switches between standby for CDMA2000_1x.

  In the CDMA2000_1x system and the EVDO system, there are a plurality of frequency channels that can be used even in each communication system, that is, in one frequency band (band class). In Japan, the CDMA2000_1x scheme has been covered only by the so-called old 800 MHz band of band class 3 in the past, but usable band classes are now added by reviewing the frequency band. That is, it is possible to use a so-called new 800 MHz band in which the frequency band of the uplink and downlink is switched and the frequency channel is reconsidered to comply with the band class 0 and a higher frequency band class 6 2 GHz band.

  The audio unit 70 performs predetermined audio processing on the signal supplied from the communication unit 40 under the control of the CPU 30, and outputs the processed signal to the receiver 22. The receiver 22 outputs the signal supplied from the audio unit 70 to the outside. This signal may be output from a speaker (not shown) instead of or together with the receiver 22.

  In addition, the voice unit 70 processes the signal input from the microphone 12 according to the control of the CPU 30, and outputs the processed signal to the communication unit 40. The communication unit 40 performs predetermined processing on the signal supplied from the audio unit 70 in the baseband unit 41, and outputs the processed signal from the main antenna 50 through the transmission / reception unit 42.

  The memory 80 includes, for example, a working memory and is used for arithmetic processing by the CPU 30. The memory 80 stores various programs according to the present embodiment, various upper counters, lower thresholds, various counters, measured reception sensitivity, and the like. Note that the memory 80 may also serve as a removable external memory.

Hereinafter, processing contents of the CPU 30 will be described.
FIG. 3 is a flowchart showing an upper limit threshold setting process according to the present embodiment.

  In step S1, the CPU 30 performs initialization processing of various parameters. For example, an upper limit threshold = −85 dB, a lower limit threshold = −95 dB, and the like are set as initial values at the time of shipment of the mobile phone 1. Also, a reception sensitivity measurement counter described later is cleared.

  In step S2, the CPU 30 performs a CDMA2000_1x paging channel acquisition process. This acquisition process is intermittently performed via the main antenna 50 in the hybrid mode and via the sub-antenna 60 in the simultaneous mode.

  In step S <b> 3, the CPU 30 acquires band class or frequency band, channel, and information on the open / close state of the mobile phone 1.

  In step S4, the CPU 30 measures the reception sensitivity of the paging channel captured in step S2.

  In step S5, the CPU 30 stores the reception sensitivity measured in step S4 in association with the antenna, the band class or frequency band, the channel, and the open / close state of the mobile phone 1. At this time, the CPU 30 stores at least the measurement values for the current and previous two times.

  In step S6, the CPU 30 determines whether or not the mode has been switched from the hybrid mode to the simultaneous mode, or from the simultaneous mode to the hybrid mode, based on the measurement result of step S4. If this determination is YES, the process proceeds to step S7, and if the determination is NO, the process returns to step S2.

In step S7, the CPU 30 calculates a reception sensitivity difference before and after mode switching based on the measurement value stored in step S5. In particular,
Reception sensitivity difference = | Current reception sensitivity-Previous reception sensitivity |
Calculate as

  In step S <b> 8, the CPU 30 stores the reception sensitivity difference calculated in step S <b> 7 in the database of the memory 80 for each band class or frequency band, channel, and open / close state.

  In step S9, the CPU 30 counts up a reception sensitivity difference measurement counter prepared for each band class or frequency band, channel, and open / close state.

  In step S10, the CPU 30 determines whether or not the reception sensitivity difference measurement counter counted up in step S9 exceeds a predetermined counter threshold (first number: for example, 50 times). If this determination is YES, the process proceeds to step S11, and if the determination is NO, the process returns to step S2.

In step S11, the CPU 30 determines that the data of the reception sensitivity difference has been sufficiently collected, calculates a new upper limit threshold value, and resets it. Specifically, the upper limit threshold for each band class or frequency band, channel, and open / close state,
New upper limit threshold = lower limit threshold + average of reception sensitivity difference + standard deviation + margin The standard deviation and the margin are values for absorbing measurement value variations. For the margin, for example, a predetermined value such as 2 dB is used.

  In step S12, the CPU 30 initializes a reception sensitivity difference measurement counter and returns to step S2. That is, the CPU 30 resets the upper limit threshold every predetermined counter threshold (for example, 50 times).

  FIG. 4 is a flowchart showing a lower limit threshold setting process according to the present embodiment.

  In step S21, the CPU 30 performs various parameter initialization processing. For example, a lower threshold = −95 dB or the like is set as an initial value at the time of shipment of the mobile phone 1. Also, a reception success counter described later is cleared.

  In step S22, the CPU 30 performs a CDMA2000_1x paging channel acquisition process. This acquisition process is intermittently performed via the main antenna 50 in the hybrid mode and via the sub-antenna 60 in the simultaneous mode.

  In step S <b> 23, the CPU 30 acquires band class or frequency band, channel, and information on the open / close state of the mobile phone 1.

  In step S24, the CPU 30 measures the reception sensitivity of the paging channel captured in step S22.

  In step S25, the CPU 30 determines whether or not the current mode is the simultaneous mode. If this determination is YES, the process moves to step S26, and if the determination is NO, the process returns to step S22.

  In step S26, the CPU 30 determines whether or not the paging channel has been successfully received. If this determination is YES, the process proceeds to step S27, and if the determination is NO, the process proceeds to step S32.

  In step S27, the CPU 30 determines whether or not the reception sensitivity measured in step S24 is near the lower limit threshold value. Specifically, for example, the CPU 30 determines whether or not the reception sensitivity is equal to or lower than the lower limit threshold value +1 dB. Alternatively, when the measurement is in units of 1 dB, it may be determined whether or not it is equal to the lower limit threshold value +1 dB (the lowest value that can maintain the Simple mode). If this determination is YES, the process proceeds to step S28, and if the determination is NO, the process returns to step S22.

  In step S28, the CPU 30 counts up a reception success counter prepared for each band class or frequency band, channel, and open / close state.

  In step S29, the CPU 30 determines whether or not the reception success counter counted up in step S28 exceeds a predetermined reception success count threshold (second number: for example, 100 times). If this determination is YES, the process proceeds to step S30, and if the determination is NO, the process returns to step S22.

In step S30, the CPU 30 determines that the reception of the paging channel has succeeded sufficiently continuously in the vicinity of the lower threshold, and calculates and resets a new lower threshold. Specifically, the lower limit threshold for each band class or frequency band, channel, and open / close state,
New lower limit threshold = old lower limit threshold−lowering range. Note that a predetermined value such as 1 dB is used for the lowering amount.

  In step S31, the CPU 30 initializes a reception success counter and returns to step S22. In other words, the CPU 30 may be able to maintain the single-mode mode even with a lower reception sensitivity when the reception of the paging channel succeeds more than a predetermined reception success count threshold (for example, 100 times) near the lower threshold. And lower the lower threshold and reset it.

In step S32, the CPU 30 fails to receive the paging channel in the vicinity of the lower limit threshold value. Therefore, the CPU 30 determines that the paging channel reception rate is not sufficient with the lower limit threshold value, and calculates and resets a new lower limit threshold value. Specifically, the lower limit threshold for each band class or frequency band, channel, and open / close state,
Calculated as New Lower Threshold = Old Lower Threshold + Raising Range. For the raising width, a predetermined value such as 1 dB is used.

  In step S33, the CPU 30 initializes a reception success counter and returns to step S22. That is, when the paging channel reception has failed even once near the lower threshold value, the CPU 30 raises the lower threshold value and resets it in order to improve the paging channel reception rate in the simultaneous mode.

  FIG. 5 is a sequence diagram illustrating how the upper and lower thresholds are reset according to the present embodiment. It is assumed that the mobile phone 1 is downloading BCMCS (Broad-Cast Multi-Cast Service) data as an example of EVDO communication.

  When the download of BCMCS was started, it was a strong electric field, so that the reception sensitivity of the main antenna 50 exceeded the upper limit threshold value, and the mobile phone 1 was in the Simultaneous mode. Thereafter, the CPU 30 measures the reception sensitivity while intermittently receiving the CDMA2000_1x paging channel by the sub-antenna 60.

  As a result of calculating the reception sensitivity difference of the paging channel of CDMA2000_1x before and after switching to the Simplified mode, the CPU 30 updates the upper limit threshold when data collection over a predetermined counter threshold (for example, 50 times) is completed. The new upper threshold is stored in the memory 80.

  In addition, after the switching to the Simulaneous mode, when the reception sensitivity of the paging channel of CDMA2000_1x in the sub-antenna 60 is near the lower threshold (for example, −95 dB) (for example, −95 dB + 1 dB), the CPU 30 continues the paging channel. Count the number of successful receptions. When the continuous reception success count becomes equal to or greater than a predetermined reception success count threshold (for example, 100 times), the CPU 30 updates the lower limit threshold by a predetermined decrease (for example, 1 dB), and stores the new lower limit threshold in the memory. Store in 80.

  Thereafter, when the electric field is weak and the reception sensitivity at the sub-antenna 60 is equal to or lower than the new lower limit threshold, the mobile phone 1 switches from the simultaneous mode to the hybrid mode. Also at this time, the CPU 30 calculates the paging channel reception sensitivity difference of CDMA2000_1x before and after the mode switching. As a result, the reception sensitivity difference measurement counter is counted up, but since it was reset at the previous mode switching, the upper limit threshold is not updated this time.

  During the weak electric field, since the paging channel reception of CDMA2000_1x is performed by the main antenna 50, the CPU 30 does not count the number of successful receptions. When a strong electric field is generated and the reception sensitivity of the paging channel of the CDMA2000_1x in the main antenna 50 becomes equal to or higher than the new upper limit threshold, the mobile phone 1 switches from the Hybrid mode to the Simultaneous mode. Also at this time, the CPU 30 calculates the paging channel reception sensitivity difference of CDMA2000_1x before and after the mode switching, but does not update the upper limit threshold because the calculation count has not yet reached the counter threshold.

  Then, after the mobile phone 1 is switched to the simultaneous mode, if the sub-antenna 60 fails to intermittently receive the CDMA2000_1x paging channel, the CPU 30 determines that the current lower limit threshold is too low, and increases the lower limit threshold by a predetermined range (for example, 1dB) and update and store the new lower threshold in the memory 80.

  As described above, according to the present embodiment, the upper limit threshold and the lower limit threshold can be set for each band class or frequency band, channel, and open / closed state. A threshold value suitable for the environment can be set. Thereby, the mobile phone 1 can perform efficient mode switching.

  In the above processing, the margin related to the setting of the upper limit threshold has been described as a constant value, but the present invention is not limited to this. The smaller the margin is, the smaller the upper threshold value is, so that it becomes easier to switch to the Simultaneous mode where throughput can be expected to improve. However, if the upper limit threshold is made too small, the above-mentioned fluttering occurs, so it is desirable to adjust the margin appropriately and maintain an appropriate value. Next, this margin adjustment processing will be described.

FIG. 6 is a sequence diagram illustrating a state in which the margin according to this embodiment is adjusted.
When the download of BCMCS is started and the mobile phone 1 is in the simultaneous mode, the sub-antenna 60 receives the CDMA2000_1x paging channel. When the reception sensitivity of the paging channel is equal to or lower than the lower limit threshold, the mobile phone 1 switches to the Hybrid mode. That is, mode switching is continuously executed.

  Then, the CPU 30 calculates a reception sensitivity difference between the reception sensitivity of the paging channel by the main antenna 50 and the reception sensitivity of the paging channel by the sub antenna 60 before switching after switching to the Hybrid mode. Then, the CPU 30 determines that a flutter has occurred when the difference in reception sensitivity is greater than the difference between the current upper limit threshold and the lower limit threshold.

  Furthermore, if the reception sensitivity of the paging channel by the main antenna 50 after switching to the Hybrid mode is equal to or higher than the upper limit threshold value, the mobile phone 1 switches to the Simultaneous mode.

  When such a continuous mode switching occurs a predetermined number of times (a plurality of times) in a certain period, the CPU 30 increases the margin (for example, +1 dB) to suppress the fluttering, and the upper limit accordingly. Update by increasing the threshold.

  Further, if no fluttering occurs during the predetermined number of mode switchings, the margin is reduced (for example, -1 dB), and the upper limit threshold is reduced accordingly and updated.

  As described above, according to the present embodiment, when calculating the automatically adjusted upper limit threshold value, the margin for absorbing variations can be finely adjusted, so that the upper limit threshold value can be set with higher accuracy.

  In the above processing, the lower threshold is updated by raising / lowering the CDMA2000_1x paging channel reception success / failure. However, there is a possibility that the lower threshold with a track record of failure in the past may be failed again. Therefore, the CPU 30 may perform control so as not to set the lower threshold with a track record of failure. In addition, depending on changes in the radio wave environment, even the lower threshold with a track record of failure may succeed in reception with high probability, so the CPU 30 increases the above-described threshold for successful reception (see FIG. 4). Thus, it may be difficult to set, and a state where it is not set at all may be prevented.

  As described above, the CPU 30 can maintain the reception probability of the paging channel of CDMA2000_1x high by dynamically changing the threshold value of successful reception times, and can maintain a long single-mode that can be expected to improve the throughput.

  As mentioned above, although embodiment of this invention was described, this invention is not restricted to embodiment mentioned above. The effects described in the embodiments of the present invention are only the most preferable effects resulting from the present invention, and the effects of the present invention are limited to those described in the embodiments of the present invention. is not.

1 Mobile phone (wireless communication device)
11 Operation Unit 21 Display Unit 30 CPU (Control Unit)
40 communication unit (first communication unit, second communication unit)
41 Baseband unit (first communication unit, second communication unit)
42 Transmission / reception unit (first communication unit)
43 Receiving part (second communication part)
50 Main antenna (first antenna)
60 Sub antenna (second antenna)
70 voice part 80 memory (memory part)

Claims (9)

A wireless communication device that performs wireless communication with a plurality of communication systems,
A first communication unit that wirelessly communicates with one of the plurality of communication systems via a first antenna;
A second communication unit that wirelessly communicates with one of the plurality of communication systems via a second antenna that is less sensitive than the one antenna;
When waiting for the second communication system while communicating with the first communication system via the first antenna, the first communication unit waits if the reception sensitivity of the second antenna is lower than a lower threshold, A control unit that switches to awaiting by the second communication unit if the reception sensitivity of one antenna is equal to or greater than an upper threshold, and
The control unit is a value obtained by adding at least the reception sensitivity difference to the lower limit threshold based on the reception sensitivity difference of the second communication system between the first antenna and the second antenna measured before and after the switching. The wireless communication apparatus, wherein the upper limit threshold is updated.   2. The wireless communication according to claim 1, wherein, when the reception sensitivity difference is measured a first number of times, the control unit updates the upper limit threshold with a value obtained by adding an average and a margin of the measurement values. apparatus.   The control unit updates the upper limit threshold by increasing the margin when the switching occurs a plurality of times within a predetermined period and the measured difference in received sensitivity is larger than the difference between the upper limit threshold and the lower limit threshold. The wireless communication apparatus according to claim 2, wherein:   The said control part updates the said upper limit threshold value by making the said margin small, when the condition which enlarges the said margin does not generate | occur | produce during the said predetermined number of times of the said switching. Wireless communication device.   The control unit, when the reception sensitivity of the second antenna is near the lower limit threshold, when the reception from the second communication system via the second antenna succeeds a second number of times, 5. The wireless communication apparatus according to claim 1, wherein the lower limit threshold value is lowered and the lower limit threshold value is raised if the lower limit threshold value is unsuccessful. 6.   The wireless communication apparatus according to claim 5, wherein when the lower limit threshold is increased, the control unit increases the second number of times to decrease the lower limit threshold again.   The storage unit for storing the lower limit threshold and the upper limit threshold in association with at least one of a frequency band, a band class, a channel, and a deformation state of the own apparatus of the second communication system. Item 7. The wireless communication device according to any one of Item 6. The second communication system is a time division multiple access system,
When the control unit performs standby with the second communication system while performing communication with the first communication system via the first antenna, communication by the first communication system and the second communication system are performed in a time division manner. The wireless communication device according to claim 1, wherein the wireless communication device is switched to standby.   The radio communication apparatus according to claim 8, wherein the first communication system is an EVDO system in a 3GPP2 standard, and the second communication system is a CDMA2000_1x system.

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