JP2008147776A - Portable communication terminal and antenna switching control program of portable communication terminal - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a portable communication terminal provided with a plurality of antennas for the same band and capable of reducing power consumption while securing the quality of communication, an antenna switching controller and an antenna switching control program. <P>SOLUTION: A portable telephone set 100 is provided with first and second antennas 109 and 110 capable of receiving the radio waves of the same frequency band, and when the antenna selected in an antenna switching circuit 106 starts reception, a reception level is measured in an RSSI part of small power consumption of a power measurement part 107. As a result, when it exceeds a relatively high first threshold, the antenna is held for the reception. When it is equal to or lower than a second threshold, the antenna is selected using an RSCP part 112 of large power consumption. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a portable communication terminal such as a cellular phone and an antenna switching control program for the portable communication terminal, and more particularly to a portable communication terminal and an antenna of the portable communication terminal that can reduce power consumption during reception. The present invention relates to a switching control program.

  A portable communication terminal such as a mobile phone, a personal handy-phone system (PHS) or a PDA (Personal Digital Assistant) equipped with a communication function is placed in a posture (chassis) when placed on a desk or standing on a charging stand. The direction in which the body faces is greatly different. In addition, when moving with a hand, the posture often changes with time. Furthermore, when a user carries a portable communication terminal, the radio wave condition changes at each location. In order to stabilize communication in such various situations, it has been proposed as a first proposal to incorporate a plurality of antennas in a portable communication terminal and switch them appropriately (for example, see Patent Document 1). ).

  In the first proposal, two antennas (both not shown) of a first antenna having a high gain and a second antenna having a low gain are arranged in the mobile phone. These are also connected to an antenna switch (not shown) so that the antenna switching to the second antenna is less likely to occur than the antenna switching to the first antenna, and an antenna with a low gain is selected. The data reception performance is improved by reducing the possibility.

  Further, in the first proposal, when the first antenna having a high gain is selected and the electric field strength value becomes less than the threshold value, the electric field strength value is measured by switching to the second antenna. ing. Then, when the electric field strength value of the second antenna is equal to the electric field strength value of the first antenna or when the electric field strength value of the second antenna is also less than the threshold, switch to the first antenna, A timer (not shown) is started, and then the antenna is not switched for a certain time. As a result, when the field strength values of the first and second antennas are both less than the threshold value, the situation where the antennas are frequently switched between them is prevented, and the power consumption associated with the useless switching operation is reduced. Yes.

  As described above, in the first proposal, when the radio wave condition of a mobile phone (not shown) having two antennas is bad, after confirming that the electric field strength values of these two antennas are both less than the threshold value. The first antenna with higher gain is selected. Then, when the first antenna is selected, a timer is started, and the antenna switching operation is stopped for a certain period of time, thereby reducing power consumption.

On the other hand, as a second proposal, there is also proposed a technique for switching between two types of antennas (not shown) by measuring both the electric field level and the communication quality. This second proposed portable terminal has one type of received power measuring means (not shown), and does not switch the antenna when the reception level is equal to or higher than a specified value, and does not switch the antenna at other reception levels. I am trying to switch.
JP 2006-174355 A (paragraphs 0041 to 0051, FIG. 4) Japanese Patent Laying-Open No. 2006-254110 (paragraphs 0043 to 0045, FIG. 2)

  In this second proposal, the reception level of radio waves is measured over a wide range with one type of received power measuring means, and an antenna with good reception quality is selected even in a relatively weak radio wave state. For this reason, the received power measuring means must have a processing procedure for receiving only radio waves of a predetermined frequency from the radio base station.

  Therefore, for example, the received power measuring means that is always used in the second proposal tends to consume more power than the received power measuring means that omits such a special processing procedure in a relatively strong radio wave state. In other words, when the second proposal is adopted, it is necessary to use a reception power measuring means with relatively large power consumption for the overall measurement of the reception level, and there is a problem that the effect of reducing the overall power consumption is reduced. It was.

  Therefore, an object of the present invention is to provide a portable communication terminal having a plurality of antennas for the same band and capable of reducing power consumption while ensuring communication quality, and an antenna switching control program for the portable communication terminal There is to do.

  According to the first aspect of the present invention, (a) a plurality of antennas capable of receiving radio waves in the same frequency band, and (b) antenna selecting means for selecting one of the plurality of antennas for receiving radio waves. (C) first received power measurement means capable of measuring reception of radio waves by the antenna selected by the antenna selection means in a range of a predetermined level or higher; and (d) radio waves by the antenna selected by the antenna selection means. A second received power measuring means that can measure the received signal even below the predetermined level, and the power consumption required for the measurement is larger than that of the first received power measuring means; (e) a first received power measuring means; A received power measuring means selecting means for selecting one of the second received power measuring means for measuring the received power; and (f) using the received power measuring means selecting means at the start of reception. Received power measuring means initial selecting means for selecting the received power measuring means, and (g) the antenna selecting means selects the first received power measuring means with the received power measuring means initial selecting means selected. Whether the reception level of the current radio wave of the antenna is measured, and whether the reception level is higher than the first reference as the lowest reference that is in a good reception state regardless of which of the plurality of antennas is selected by the antenna selection means (H) when the reception level initial determination means determines that the reception level is higher than the first reference, the antenna selection operation by the antenna selection means is performed to select the current antenna. The portable communication terminal is provided with an antenna selection holding means for holding the state.

  That is, in the present invention, the received power measuring means consumes less power, but the first received power measuring means that can measure the reception of radio waves in a range of a predetermined level or higher, and can measure to a level lower than this. Two second received power measuring means for increasing the power are prepared. Initially, the reception state of the antenna is measured by the first reception power measuring means with low power consumption, and any of the plurality of antennas provided in the mobile phone capable of receiving radio waves in the same frequency band is the antenna. When the reception level is higher than the first reference as the lowest reference that provides a good reception state even when selected by the selection means, the reception is continued by the antenna. As a result, the power consumption required for switching the antennas becomes unnecessary, and the power consumption can be reduced while ensuring the communication quality.

  This mobile phone can further reduce power consumption if the receiving operation is performed intermittently. When communication such as reception is continuously performed, power consumption can be similarly reduced by fixing transmission and reception with the same antenna until the attitude of the mobile phone changes. As a reference for determining the reception level, a second reference set in the vicinity of the predetermined level may be provided. In this case, the control in the direction in which the first reception power measuring means is actively used. Therefore, it is possible to reduce power consumption while ensuring communication quality.

  According to a sixth aspect of the present invention, a portable type comprising a plurality of antennas capable of receiving radio waves in the same frequency band, and an antenna selecting means for selecting one of the plurality of antennas for receiving radio waves. (B) a first received power measurement process for measuring reception of radio waves by the antenna selected by the antenna selection means in a range equal to or higher than a predetermined level as an antenna switching control program for the portable communication terminal; (B) A second received power measurement process in which the reception of radio waves by the antenna selected by the antenna selection means is measured even below the predetermined level, and the power consumption required for the measurement is larger than the first received power measurement process. And (c) the current radio wave reception level using the antenna selected by the antenna selection means in the first received power measurement process at the start of intermittent reception. The reception level initial stage for determining whether or not the reception level is higher than the first reference as the lowest reference that is in a good reception state regardless of which of the plurality of antennas is selected by the antenna selection means. And (d) when the reception level initial determination process determines that the reception level is higher than the first reference, the antenna selection operation by the antenna selection means is performed until the next intermittent reception starts. When it is determined that the reception level is not higher than the first reference in the antenna selection holding process to hold in the selected state and (e) the reception level initial determination process, the reception level is set in the vicinity of the predetermined level. Reception level limit determination processing for determining whether or not the received second reference is below the second reference, and (f) the reception level exceeds the second reference in this reception level limit determination processing When it is determined, the first received power measurement process is performed, and the antenna having the highest reception level is selected from the plurality of antennas. When it is determined that the reception level is equal to or lower than the second reference, the second received power measurement process is performed. And performing the antenna selection process for selecting the antenna having the highest reception level from the plurality of antennas.

  In other words, according to the present invention, in the portable communication terminal that performs intermittent reception, the first reference and the second reference are provided, and the quality is ensured while saving power in the three cases classified by each reference. An antenna switching control program for a portable communication terminal is realized.

  As described above, according to the present invention, by preparing a plurality of reception power measuring means or reception power measurement processing, the reception power of the antenna is initially measured by a method with low power consumption. In addition to reducing power consumption, even if a failure occurs in a part of the received power measurement means, measurement may be possible by using other received power measurement means or other received power measurement processing instead. The reliability of antenna selection can be improved.

  Hereinafter, the present invention will be described in detail with reference to examples.

  FIG. 1 shows a main part of the configuration of a mobile phone according to an embodiment of the present invention. The cellular phone 100 includes a control unit 103 that stores a work memory 102 such as a CPU (Central Processing Unit) 101 and a RAM (Random Access Memory). The control unit 103 is connected to each unit in the apparatus. The wireless unit 105 includes an antenna switching circuit 106 and a power measuring unit 107 inside. Among these, the antenna switching circuit 106 is connected to the antenna unit 108. The antenna unit 108 includes two antennas, a first antenna 109 and a second antenna 110, for a frequency band for transmitting and receiving, and both are connected to the antenna switching circuit 106. The power measurement unit 107 includes two types of measurement units, an RSSI (Received Signal Strength Indicator) unit 111 and an RSCP (Received Signal Code Power: signal power in a common pilot channel) unit 112. These will be described in detail later.

  The control unit 103 uses a key switch or a touch panel (not shown) to input various operations such as outgoing and incoming calls from the user, and visually displays the operation results and various data of the operation unit 114 to the user. A display unit 115 such as a liquid crystal display for displaying automatically and an opening / closing detection unit 116 for detecting opening / closing of the mobile phone 100 are also connected. Here, the cellular phone 100 according to the present embodiment is a foldable type in which two housings (not shown) can be opened and closed by a hinge mechanism, and the open / close detection unit 116 uses a switch or an optical sensor (not shown). Open / close is detected.

  In such a cellular phone 100, the control unit 103 implements various functions by executing a control program stored in the control program storage area 117 of the storage unit 104. In particular, in the case of the cellular phone 100 of the present embodiment, the antenna switching circuit 106 of the wireless unit 105 can be controlled from the viewpoint of power saving. Two types of threshold values for power saving are stored in the threshold value storage area 118 in the storage unit 104.

  FIG. 2 compares the power measurement characteristics of the RSSI unit and the RSCP unit provided in the power measurement unit of the present embodiment. In this figure, the vertical axis indicates the reception level of radio waves transmitted from a base station (not shown) in the radio unit 105 shown in FIG. 1, and the horizontal axis indicates the reception level input to the antenna. Among these, the reception level 121 of the RSSI part represents the total received power. That is, the RSSI unit 111 illustrated in FIG. 1 measures an amount including noise in addition to the received power from the base station. Typically, it is noise generated from a circuit such as each LSI (Large Scale Integration) in the apparatus, such as thermal noise existing in the reception frequency band. Therefore, the reception level 121 of the RSSI section does not decrease below a certain value due to the presence of noise components even when the amount of power input to the first or second antenna 109, 110 (FIG. 1) is low. .

  On the other hand, the reception level 122 of the RSCP unit is power indicating the power of the specific code itself as a measurement result of the signal power in the common pilot channel by the RSCP unit 112 shown in FIG. For this reason, basically, the correlation with other interference components is low, and the characteristic is proportional to the received power of the desired channel.

  Therefore, as can be seen from FIG. 2, when the reception level of the antenna unit 108 (FIG. 1) is relatively high, the characteristics of the reception level 121 of the RSSI unit indicated by a broken line and the reception level 122 of the RSCP unit indicated by a solid line. Are substantially the same, and both can accurately measure the amount of power input to the antenna unit 108 shown in FIG. On the other hand, when the reception level is relatively low, a relatively large error accompanies the reception level 121 of the RSSI part. For this reason, the input power measurement by the RSSI unit 111 cannot be performed below a predetermined reception level that is greatly affected by thermal noise. On the other hand, since the measurement of the reception level by the RSCP unit 112 is not easily affected by thermal noise or the like, the reception level 122 of the RSCP unit is necessary for measurement below the reception level that is greatly affected by the thermal noise. .

  FIG. 3 shows an outline of reception processing of the mobile phone of this embodiment using such an RSSI part and an RSCP part. This will be described with reference to FIG. The cellular phone 100 according to the present embodiment is not in a state where the power of predetermined portions such as the CPU 101 and the wireless unit 105 is always energized in order to suppress power consumption. (Step S201).

  When predetermined portions such as the CPU 101 and the wireless unit 105 are started up, an antenna selection process for the antenna unit 108 is executed (step S202). Then, the incoming call is confirmed (step S203), and if there is an incoming call (step S204: Y), a predetermined incoming call process is executed (step S205). When there is no incoming call (step S204: N), an intermittent falling process is performed (step S206). That is, the power of predetermined portions such as the CPU 101 and the wireless unit 105 is turned off. Then, the process returns to step S201 after a predetermined time (return).

  FIG. 4 is a diagram for explaining processing timings in the intermittent startup and intermittent shutdown processing of the mobile phone according to the present embodiment. In this figure, the vertical axis indicates the current consumption of the mobile phone 100 (FIG. 1), and the horizontal axis indicates the passage of time.

The cellular phone 100 used in this embodiment performs communication by a CDMA (Code Division Multiple Access) method. In such a communication system apparatus, the RSSI unit 111 and the RSCP unit 112 in the power measuring unit 107 shown in FIG. 1 have different times T ₁ and T ₂ required for current measurement and antenna switching processing. The time T ₁ is obtained by adding the time CS of the three-stage cell search to the time T ₂ .

In such a portable telephone 100, after the current measurement processing by the RSSI unit 111 or the RSCP 112 is completed, it is provided processing time T ₃ required for reception processing in the intermittent reception. After the processing time T ₃ has elapsed, the power of predetermined portions such as the CPU 101 and the wireless unit 105 is cut off for a predetermined time. After this, the aforementioned times T ₁ and T ₂ for measuring the current start. The same applies hereinafter.

Therefore, when the RSCP unit 112 is used, a time T _{4 obtained} by adding the time T ₃ to the time T ₁ is an energization time necessary for intermittent reception, and when the RSSI unit 111 is used, the time T ₂ is set to the time T _{2. 3} time T ₅ plus is the energization time required for the intermittent reception. As described above, when the RSCP unit 112 is used, power consumption can be reduced by an amount corresponding to omitting the section of the time CS of the three-stage cell search as compared with the case where the RSSI unit 111 is used.

  Further, in the mobile phone 100 of the present embodiment, as shown in FIG. 4, since energization is intermittently performed while monitoring incoming calls, the overall power consumption is compared with the case where energization is continuously performed. Savings.

  In the intermittent reception process described above, the reception of the incoming signal is less likely to be received by the antenna having the better reception state out of the first antenna 109 and the second antenna 110, and the reception rate is improved. Can be achieved.

  5 and 6 show the state of the antenna selection process shown in step S202. Among these, FIG. 5 shows processing when the RSCP unit 112 shown in FIG. 1 is used. This will be described with reference to FIG.

  The RSCP unit 112 of this embodiment performs despreading processing on the radio wave received by the antenna unit 108, and performs RSSI measurement after detecting the base station side timing and specifying the code. First, a reception frequency to be measured is set (step S221). Next, a three-stage cell search is performed which is performed by a CDMA (Code Division Multiple Access) apparatus such as the mobile phone 100 used in the present embodiment. This is a process performed at the time indicated as the time CS of the three-stage cell search in FIG.

  In the first step of the three-step cell search, slot synchronization is performed by receiving the first SCH (Primary-Synchronization Channel) in a state where the currently selected antenna (this is assumed to be the first antenna 109) can be received. Symbol synchronization is established (step S222). In the next second step, frame synchronization is established and a scrambling group is specified by receiving a second SCH (Secondly-Synchronization Channel) (step S223). Further, in the third step, a scrambling code is specified to specify a cell (step S224).

  When the three-step cell search normally performed in such a CDMA method is completed, RSCP measurement is performed on the currently selected first antenna 109 (step S225). At this stage, the control unit 103 determines whether or not the antenna unit 108 has performed two measurements (step S226). This is a determination as to whether or not the measurement by each of the first and second antennas 109 and 110 existing in the antenna unit 108 has been completed.

  When the measurement has been performed only once (N), the antenna switching circuit 106 is operated to switch the antenna in the antenna unit 108 (step S227). In this example, only measurement using the first antenna 109 is performed. Therefore, this time, a three-step cell search is performed using the second antenna 110 (steps S222 to S224). Then, RSCP measurement using the second antenna 110 is performed (step S225).

  When the measurement of both the first and second antennas 109 and 110 connected to the antenna switching circuit 106 is completed as described above (step S226: Y), an antenna having a better reception level can be obtained by measurement using these RSCPs. Select (step S228). For example, if the reception level of the first antenna 109 is higher, the control unit 103 controls the antenna switching circuit 106 to switch to the first antenna 109. When the reception level of the second antenna 110 is higher, the switching operation of the antenna switching circuit 106 is not performed. This is because the second antenna 110 is already selected at this point.

  On the other hand, FIG. 6 shows processing when the RSSI unit 111 shown in FIG. 1 is used. This will be described with reference to FIG. In this case, first, the frequency to be measured is set (step S241). After this, unlike the processing by the RSCP unit 112 shown in FIG. Therefore, RSSI is immediately measured using the currently selected antenna (assuming this is the first antenna 109) (step S242). This is because RSSI measurement is basically possible if the frequencies are matched.

  When the measurement by the first antenna 109 is completed, the control unit 103 determines whether or not the antenna unit 108 has performed the measurement twice (step S243). This is a determination as to whether or not the measurement of each of the first and second antennas 109 and 110 existing in the antenna unit 108 has been completed.

  When the measurement has been performed only once (N), the antenna switching circuit 106 is operated to switch the antenna in the antenna unit 108 (step S244). In this example, only the measurement using the first antenna 109 is performed at this stage. Therefore, RSSI is measured using the second antenna 110 (step S242).

  When the measurement of both the first and second antennas 109 and 110 connected to the antenna switching circuit 106 is completed as described above (step S243: Y), an antenna with a better reception level can be obtained by measurement using these RSSIs. Select (step S245). For example, if the reception level of the first antenna 109 is higher, the control unit 103 controls the antenna switching circuit 106 to switch to the first antenna 109. When the reception level of the second antenna 110 is higher, the switching operation of the antenna switching circuit 106 is not performed. This is because the second antenna 110 is already selected at this point.

  By the way, the control by the power measurement unit 107 shown in FIGS. 5 and 6 has been described as performing measurement using both the first and second antennas 109 and 110 for the sake of explanation. However, depending on the situation of radio waves, always performing such antenna switching processing wastes power consumption for the switching operation time. In the present embodiment, consumption of power (or current) is effectively suppressed and a good reception situation is ensured by using two types of thresholds corresponding to the situation of radio waves.

As a premise of this, the cellular phone 100 of this embodiment uses the following properties for antenna switching.
(1) When the RSCP unit 112 is used, more power consumption is required for switching between the first antenna 109 and the second antenna 110 than when the RSSI unit 111 is used.
(2) When the RSCP unit 112 is used, the antenna can be favorably selected particularly in a low electric field state as compared with the case where the RSSI unit 111 is used.

  Therefore, in this embodiment, three-stage state transition is performed based on the received electric field situation determined using the first and second threshold values stored in the threshold value storage area 118 shown in FIG. Yes. Thereby, an antenna in a good state is selected while reducing power consumption (current consumption). Here, the three-stage state of transition refers to a state of “no antenna switching”, a state of “antenna switching based on RSSI unit”, and a state of “antenna switching based on RSCP unit”.

  The first threshold value of the two threshold values is a value that serves as a determination criterion for fixing the first and second antennas 109 and 110 in the antenna unit 108 and determining RSSI by the RSSI unit 111. The second threshold value is a value serving as a determination criterion for switching between the first and second antennas 109 and 110 by the RSSI unit 111 and switching between the antennas 109 and 110 by the RSCP unit 112.

  In this embodiment, it is necessary to switch the antenna in a state where the first “no antenna switching” state is a high electric field state and any of the first and second antennas 109 and 110 can receive an incoming call. Not in a state. In the “no antenna switching” state, the selection process of the first and second antennas 109 and 110 for achieving a better reception state is not performed. This is because the first threshold value is set to a value that is a minimum reference value in which both of the first and second antennas 109 and 110 in the antenna unit 108 are selected by the antenna switching circuit 106 to obtain a good reception state. Because it is. Therefore, for example, if the received power as a result measured by the RSSI unit 111 is equal to or higher than the first threshold value, the antenna switching circuit 106 does not need to operate. Thus, in the first “no antenna switching” state, the power consumption (current consumption) is reduced by eliminating the selection operation of the first and second antennas 109 and 110 by the antenna unit 108.

  In addition, the third “antenna switching based on RSCP unit” state is a state in which the first and second antennas 109 and 110 are switched below a predetermined reception level greatly influenced by the thermal noise shown in FIG. It is said. In such a low electric field environment, it is difficult to determine the good reception state of the first and second antennas 109 and 110 by the determination based on the RSSI unit 111. For this reason, the switching process of the first and second antennas 109 and 110 is performed using the RSCP unit 112. As described above, in the state of “antenna switching based on the RSCP unit”, the power consumption of the mobile phone 100 increases, but the maximum incoming rate can be obtained by surely selecting a good antenna.

  Finally, the second “antenna switching based on RSSI unit” state is an intermediate state between the first “no antenna switching” state and the third “antenna switching based on RSCP unit” state. In this state, if the antenna unit 108 is fixed to one of the first and second antennas 109 and 110, there is a possibility that the selection of the antenna is wrong due to the reception level. Therefore, in this state before reaching the predetermined reception level that is greatly influenced by the thermal noise, the RSCP unit 112 is switched by switching the first and second antennas 109 and 110 while using the RSSI unit 111. The switching operation is performed in a state where the power consumption is lower than that of the antenna, and an antenna in a good reception state is positively selected.

  FIG. 7 shows the reception control of the mobile phone of this embodiment as described above. When the mobile phone 100 shown in FIG. 1 is turned on for the first time and the reception operation is started, or by the intermittent reception described with reference to FIG. 4, the power of predetermined parts such as the CPU 101 and the wireless unit 105 is turned off for a predetermined time. When the wireless unit 105 is turned on after the power is turned on, the wireless unit 105 initially selects the RSSI unit 111 with low power consumption and starts operation (step S261). At this time, the antenna switching circuit 106 is maintained in the current selected state, and the previously selected first or second antenna 109, 110 receives radio waves from a base station (not shown), and the RSSI unit 111 The reception level is measured (step S262).

When the measurement of the reception level is completed, the control unit 103 determines whether or not the value exceeds the first threshold value stored in the threshold value storage area 118 (step S263). When the reception level exceeds the first threshold (Y), good reception is possible with either the first or second antenna 109, 110. Therefore, the control unit 103 fixes the antenna selection processing until the next measurement of the reception level by the RSSI unit 111 (step S262) (step S264). Thereby, the antenna switching circuit 106 maintains the current connection state of the antenna. Then, the reception processing in the processing time T ₃ in FIG. 4 in a fixed state of the antenna is executed (step S265). In such a good reception environment, the first or second antenna 109, 110 is not switched, so that reception processing is performed and power consumption is reduced.

  On the other hand, when the reception level as a measurement result by the RSSI unit 111 is equal to or less than the first threshold (step S263: N), the control unit 103 instructs the antenna switching circuit 106 to switch the antenna (step S266). Then, the reception level of the other antenna is measured by the RSSI unit 111 (step S267). The control unit 103 compares the reception level measured at this time with the first threshold value, and if it exceeds this (step S268: Y), the control unit 103 proceeds to step S264 and fixes it to the currently selected antenna. To do. This is because a state with a good reception level can be secured, so that the antenna 109 (or 110) after switching is used for reception until the next reception is resumed.

  On the other hand, when the reception level of measurement by the RSSI unit 111 is equal to or lower than the first threshold value regardless of which of the first and second antennas 109 and 110 is used (step S268: N), the control unit 103 It is determined whether or not the measured value is equal to or lower than a second threshold value that is lower than the first threshold value (step S269). When the reception level is equal to or lower than the second threshold (Y), a normal measurement value may not be obtained by the measurement by the RSSI unit 111. Therefore, the control unit 103 stops the operation of the RSSI unit 111 and operates the RSCP unit 112 instead (step S270).

  Then, it is determined whether or not the reception level obtained by the current antenna by the measurement by the RSCP unit 112 exceeds the first threshold (step S271). If the first threshold value is exceeded (Y), there is no problem in receiving with the antenna, so the process proceeds to step S264 to fix the antenna to the current state.

  On the other hand, when the measurement value of the reception level by the RSCP unit 112 is equal to or less than the first threshold (step S271: N), the control unit 103 switches the antenna to the other (step S272), and the reception level obtained as a result Is compared with the reception level of the antenna before switching (step S273). Then, the antenna with the higher reception level is selected (step S274), and the reception process is executed in this state (step S265). Thereafter, the power is turned off, and the processing is restarted again from step S261 after a predetermined time has elapsed (return).

  If it is determined in step S269 that the second threshold is exceeded by the measurement by the RSSI unit 111 (N), the process proceeds to step S272 and the subsequent processing is performed. That is, in this case, since measurement by the RSSI unit 111 is possible, the antenna is switched (step S272), and the reception level obtained thereby is compared with the reception level of the previous antenna (step S273). The higher antenna is selected (step S274).

  As described above, according to the present embodiment, when only reception is performed, the mobile phone 100 repeats intermittent reception. Therefore, power consumption can be suppressed while reception is not performed. In addition, since the RSSI unit 111 is initially operated in the reception state and the RSCP unit 112 is operated only when the reception level of the radio wave is low, the portion of the three-stage cell search performed by the operation of the RSCP unit 112 is determined. An increase in power consumption can be minimized.

  <Deformability of invention>

  FIG. 8 shows a state of reception control of the mobile phone in the modification of the present invention. FIG. 8 corresponds to FIG. 7. For the same processing as in FIG. 7, the main part of the reception operation of this modification will be described using the step numbers shown in FIG. In this modification, when the reception level measured by the RSSI unit 111 in step S263 is equal to or lower than the first threshold value (N), the reception level is then compared with the second threshold value (step S301). ). If it is equal to or smaller than the second threshold (Y), the RSCP unit 112 is operated (step S270), and thereafter, the two antennas are measured as shown in FIG. We will select the antenna of the other.

  On the other hand, when it is determined in step S301 that the reception level exceeds the second threshold (N), the antenna is switched to the other while being held in the RSSI unit 111 (step S272). Thereafter, as shown in FIG. 7, the antenna having the higher reception level of the two antennas is selected.

  According to this modification, when the mobile phone 100 is placed in a poor radio wave state, the antenna selection process by the RSCP unit 112 can be performed without the antenna switching process in the RSSI unit 111.

  In the embodiment and the modification described above, assuming that intermittent reception is performed, the RSSI unit 111 is first operated when reception is resumed. For example, such power on / off control cannot be performed in a state where a telephone call or transmission is being performed. In such a case, after fixing the antenna to one side in step S264, the time is measured by a timer, and the RSSI unit 111 is operated every time a predetermined time elapses (step S261) to check the reception level ( Step S262) may be performed.

  Alternatively, instead of the processing by the timer, when the opening / closing processing of the mobile phone 100 by the open / close detection unit 116 shown in FIG. 1 is detected, or when the movement of the mobile phone 100 is detected by a three-dimensional position sensor (not shown), the RSSI unit 111 may be operated (step S261), and the reception level may be checked (step S262).

  In the embodiment, the two antennas of the first antenna 109 and the second antenna 110 are prepared for reception of the same frequency. However, an antenna may be provided for each frequency band. In this case, for example, the reception level is measured for each of the frequency band A and another frequency band B, and an antenna suitable for each frequency band is selected.

  Further, in the embodiment and the modified example, it has been described that the two antennas of the first antenna 109 and the second antenna 110 are used in the same frequency band. However, three or more antennas are prepared and switched between them. Of course, it may be possible to do so.

  In the embodiment and the modification, antenna switching is performed using RSCP, but Ec / No (Received energy per chip divided by the power density in the band) or radio wave propagation loss (Passl Loss). You may make it switch an antenna using another reference | standard. Furthermore, it is also possible to determine antenna switching by combining a plurality of criteria such as RSCP and Ec / No.

  Further, in the embodiment and the modification, two threshold values for comparing the reception levels are prepared, but three or more threshold values may be prepared. Further, depending on the antenna characteristics, thermal noise characteristics, or current consumption performance of the mobile phone to be mounted, for example, the process can be simplified by omitting the antenna switching process based on RSSI.

  In the embodiments and the modifications, the cellular phone has been described as an example, but it is natural that the present invention can be applied to all portable communication terminals. Furthermore, the communication method is not limited to the CDMA method, and various methods can be applied.

It is a block diagram showing the principal part of the structure of the mobile telephone in one Example of this invention. It is the characteristic view which compared the characteristic of the power measurement of the RSSI part and RSCP part with which the electric power measurement part of a present Example is equipped. It is a flowchart showing the outline | summary of the reception process of the mobile telephone of a present Example. It is the timing figure which showed the processing timing in the intermittent rise and the intermittent fall processing of the portable telephone of this example. It is a flowchart which shows the antenna selection process using an RSCP part in a present Example. It is a flowchart which shows the antenna selection process using an RSSI part in a present Example. It is a flowchart showing the mode of reception control of the mobile phone of the present embodiment. It is the flowchart showing the mode of reception control of the mobile telephone in the modification of this invention.

Explanation of symbols

100 mobile phone 101 CPU
DESCRIPTION OF SYMBOLS 103 Control part 105 Radio | wireless part 106 Antenna switching circuit 107 Power measuring part 108 Antenna part 109 1st antenna 110 2nd antenna 111 RSSI part 112 RSCP part 117 Control program storage area 118 Threshold storage area

Claims (6)

A plurality of antennas capable of receiving radio waves in the same frequency band;
An antenna selecting means for selecting one of the plurality of antennas for reception of radio waves;
First received power measuring means capable of measuring reception of radio waves by the antenna selected by the antenna selecting means in a range of a predetermined level or more;
A second received power measuring means capable of measuring reception of radio waves by the antenna selected by the antenna selecting means even below the predetermined level, and having a power consumption required for measurement larger than that of the first received power measuring means;
A received power measuring means selecting means for selecting one of the first received power measuring means and the second received power measuring means for measuring received power;
A reception power measurement means initial selection means for selecting the first reception power measurement means using the reception power measurement means selection means at the start of reception; and
With the received power measuring means initial selecting means, the current received signal level of the antenna selected by the antenna selecting means is measured while the first received power measuring means is selected, and any of the plurality of antennas is A reception level initial determination means for determining whether or not the reception level is higher than the first reference as the lowest reference that is in a good reception state even if selected by the antenna selection means;
Antenna selection holding means for holding the antenna selection operation by the antenna selection means in the current antenna selection state when the reception level initial determination means determines that the reception level is higher than the first reference. A portable communication terminal characterized by the above.   2. The portable communication terminal according to claim 1, further comprising intermittent reception control means for intermittently starting a reception operation, wherein the reception level initial determination means determines the reception level every time the reception operation is started. . A posture change detection means that is housed in the device body and detects a change in the posture of the device body;
An antenna selection holding release means for releasing the holding of the antenna selection holding means and starting the antenna selection control every time the attitude change detecting means detects a change in the attitude of the apparatus main body. The portable communication terminal according to claim 1. When the reception level initial determination means determines that the reception level is not higher than the first reference, it is determined whether the reception level is equal to or lower than the second reference set near the predetermined level. Level limit discrimination means;
When the reception level limit determination means determines that the reception level is less than or equal to the second reference, the selection of the reception power measurement means selection means is changed from the first reception power measurement means to the second reception power measurement means. Received power measuring means switching instruction means for switching,
Using the second received power measuring means switched by the received power measuring means switching instruction means, an antenna having a high reception level is detected from the plurality of antennas, and the selection of the antenna selecting means is switched to this antenna. The portable communication terminal according to claim 1, further comprising antenna switching instruction means when using the second received power measuring means. When the reception level initial determination means determines that the reception level is not higher than the first reference, it is determined whether the reception level is equal to or lower than the second reference set near the predetermined level. Level limit discrimination means;
When the reception level limit determination unit determines that the reception level is not less than or equal to the second reference, the first reception power measurement unit is used to detect an antenna having a high reception level from the plurality of antennas, and 2. The portable communication terminal according to claim 1, further comprising an antenna switching instruction means when using the first received power measuring means for switching the selection of the antenna selecting means to the antenna. A computer of a portable communication terminal comprising a plurality of antennas capable of receiving radio waves in the same frequency band and an antenna selection means for selecting one of the plurality of antennas for receiving radio waves,
A first received power measurement process for measuring reception of radio waves by the antenna selected by the antenna selection means in a range equal to or higher than a predetermined level;
A second received power measurement process in which the reception of radio waves by the antenna selected by the antenna selection means is measured even below the predetermined level, and the power consumption required for the measurement is greater than the first received power measurement process;
At the start of intermittent reception, the reception level of the current radio wave is measured using the antenna selected by the antenna selection means in the first received power measurement process, and any of the plurality of antennas is selected by the antenna selection means Reception level initial determination processing for determining whether or not the reception level is higher than the first reference as the lowest reference that is in a good reception state even if
When the reception level initial determination process determines that the reception level is higher than the first reference, the antenna selection operation by the antenna selection unit is held in the current antenna selection state until the next intermittent reception is started. Antenna selection holding process,
When it is determined in the reception level initial determination process that the reception level is not higher than the first reference, it is determined whether the reception level is equal to or lower than the second reference set in the vicinity of the predetermined level. Receiving level limit determination processing,
When it is determined that the reception level exceeds the second reference in the reception level limit determination process, the antenna having the highest reception level is selected from the plurality of antennas measured by the first reception power measurement process, Performing an antenna selection process of selecting the antenna having the highest reception level from the plurality of antennas when the second reception power measurement process is determined to be less than or equal to a second reference. Antenna switching control program for portable communication terminals.

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