JP2012060375A - Portable terminal, and phase deviation amount adjusting method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a portable terminal capable of resolving a problem in which a device scale is expanded for satisfying regulations to a phase deviation amount.SOLUTION: An amplifier amplifies a power of a modulation signal. A power supply controller 2 drives the amplifier by inputting a driving voltage VCC to the amplifier. A digital signal processor 5 uses the amplifier to switch over the power of the modulation signal. The digital signal processor 5 uses the power supply controller 2 to adjust the driving voltage VCC according to the power of the modulation signal, and thereby adjusts a phase deviation amount which is an amount of phase shift of the modulation signal that is generated at a switching timing of the power.

Description

  The present invention relates to a portable terminal and a phase deviation amount adjusting method, and more particularly, to a portable terminal and a phase deviation amount adjusting method that perform communication using a WCDMA (Wideband Code Division Multiple Access) method.

  A mobile terminal that performs communication using the WCDMA system modulates a transmission signal by a modulation system corresponding to the WCDMA system and outputs the modulated signal as a modulated signal, and amplifies the modulation signal from the RFIC And an RF device having a PA (Power Amplifier) for transmitting to the radio base station. Further, such a portable terminal switches the power of the transmission signal in units of time slots by switching the bias voltage of PA in units of time slots. Note that the time slot is a minimum division unit when time-dividing and transmitting a signal, and in the case of the WCDMA system, it is 666.666 μs (a value obtained by dividing one frame period “1 ms” by 15).

  When the power of the transmission signal is switched in units of time slots as described above, a shift occurs in the phase of the modulation signal at the switching timing. The magnitude of this phase shift is called Phase discontinuity (hereinafter referred to as phase deviation amount), and is defined in 6.8.4 and 6.8.5 of 3GPP TS25.101. Particularly in 6.8.5 of 3GPP TS25.101, it is stipulated that the amount of phase deviation is suppressed to ± Δ30 degrees or less with respect to a fluctuation of 7 dB in transmission power. It has become.

  On the other hand, Patent Document 1 describes a mobile communication terminal capable of reducing the amount of phase deviation. This mobile communication terminal includes a phase shifter that changes the phase of a transmission signal in front of the PA. When the power of the modulation signal is switched, the phase shifter changes the phase of the transmission signal according to the power of the transmission signal. As a result, the amount of phase deviation caused by the change in power of the transmission signal can be reduced by the amount of change in phase by the phase shifter.

JP 2005-318266 A

  In the mobile communication terminal described in Patent Document 1, it is necessary to newly provide a phase shifter.

  An object of the present invention is to provide a portable terminal and a phase deviation amount adjusting method capable of solving the problem that the apparatus scale increases in order to satisfy the above-described provision for the phase deviation amount. .

  A portable terminal according to the present invention is a portable terminal that transmits a modulation signal, an amplification unit that amplifies the power of the modulation signal, and a power supply control unit that drives the amplification unit by inputting a drive voltage to the amplification unit The power of the modulation signal is switched using the amplifier, and the drive voltage is adjusted according to the power using the power controller, and the phase of the modulation signal generated at the power switching timing And an adjustment unit that adjusts a phase deviation amount that is the magnitude of the deviation.

  A phase deviation adjustment method according to the present invention is based on a portable terminal having an amplifying unit that amplifies and transmits the power of a modulation signal, and a power supply control unit that inputs a driving voltage to the amplifying unit to drive the amplifying unit. A method for adjusting a phase deviation amount, wherein the power of the modulation signal is switched using the amplification unit, the drive voltage is adjusted according to the power of the modulation signal using the power supply control unit, and the power of the modulation signal is adjusted. A phase deviation amount that is a magnitude of a phase deviation of the modulation signal generated at the switching timing is adjusted.

  According to the present invention, it is possible to suppress an increase in the device scale for satisfying the definition for the phase deviation amount.

It is a block diagram which shows the structure of the portable terminal of 1st embodiment of this invention. It is a block diagram which shows the structural example of RF part. It is a block diagram which shows the structural example of a power amplifier (PA). It is a figure which shows an example of the relationship between the phase deviation amount in PA, and the power of a modulation signal. It is a figure which shows an example of the relationship between the amount of phase deviation in RFIC, and the power of a modulation signal. It is a figure which shows the relationship between the power of the modulation signal when ACLR becomes a regulation value, and the drive voltage VCC. It is a figure which shows the other example of the relationship between the phase deviation amount in PA, and the power of a modulation signal. It is a figure which shows an example of a VCC linear interpolation table. It is a flowchart for demonstrating an example of operation | movement of the portable terminal of 1st embodiment of this invention. It is a figure which shows the other example of a VCC linear interpolation table. It is a figure which shows an example of the measurement result of a phase deviation amount. It is a figure which shows the other example of the measurement result of a phase deviation amount. It is a figure which shows an example of a lower limit table. It is a flowchart for demonstrating an example of operation | movement of the portable terminal of 2nd embodiment of this invention. It is a flowchart for demonstrating an example of operation | movement of the portable terminal of 3rd embodiment of this invention.

  Embodiments of the present invention will be described below with reference to the drawings. In the following description, components having the same function may be denoted by the same reference numerals and description thereof may be omitted.

  FIG. 1 is a block diagram showing the configuration of the mobile terminal according to the first embodiment of the present invention. In FIG. 1, a portable terminal includes a battery 1, a power control unit 2, a memory 3, a CPU 4, a digital signal processing unit 5, an analog signal processing unit 6, an RF unit 7, an antenna 8, and a measuring unit. 9. In this embodiment, it is assumed that the WCDMA method is used as the wireless access method of the mobile terminal. In FIG. 1, a solid line with a white arrow indicates a data line for transmitting a data signal, a broken line with a black arrow indicates a power supply line, and a solid line with a Λ-shaped arrow indicates a control line. The control line which a signal transmits is shown.

  The battery 1 is a power source for the portable terminal. The power control unit 2 supplies power from the battery 1 to the memory 3, CPU 4, digital signal processing unit 5, analog signal processing unit 6 and RF unit 7, and the memory 3, CPU 4, digital signal processing unit 5. Each of the analog signal processing unit 6 and the RF unit 7 is driven.

  The memory 3 is a recording medium that can be read by the CPU 4, records a program that defines the operation of the CPU 4, and is used as a working area for the program. The memory 3 functions as a recording unit that records various control information for controlling the mobile terminal.

  The CPU 4 reads a program from the memory 3 and executes the read program to realize the following functions. That is, the CPU 4 generates a digital signal to be transmitted to a radio base station (not shown) and outputs the digital signal to the digital signal processing unit 5. Further, the CPU 4 receives a digital signal from the digital signal processing unit 5 and performs various processes according to the digital signal.

  The digital signal processing unit 5 receives a digital signal from the CPU 4, encodes the digital signal, and outputs the encoded digital signal to the analog signal processing unit 6. The digital signal processing unit 5 receives a digital signal from the analog signal processing unit 6, decodes the digital signal, and outputs it to the CPU 4. The digital signal processing unit 5 functions as an adjustment unit that adjusts the power of the modulation signal transmitted from the mobile terminal.

  The analog signal processing unit 6 receives a digital signal from the digital signal processing unit 5, performs AD conversion on the digital signal, generates an analog signal, and outputs the analog signal to the RF unit 7. The analog signal processing unit 6 receives an analog signal from the RF unit 7, performs DA conversion on the analog signal, generates a digital signal, and outputs the digital signal to the digital signal processing unit 5.

  The RF unit 7 performs modulation / demodulation of a radio signal. More specifically, the RF unit 7 receives an analog signal from the analog signal processing unit 6, modulates the analog signal, and transmits the modulated analog signal from the antenna 8. The RF unit 7 demodulates the modulated signal received by the antenna 8 and outputs the demodulated signal to the analog signal processing unit 6 as an analog signal. It is assumed that the modulation / demodulation of the radio signal is performed by a modulation / demodulation method (for example, QPSK (Quadrature Phase Shift Keying) method) compatible with WCDMA.

  The antenna 8 transmits and receives modulated signals. As long as the antenna 8 includes an antenna element that transmits and receives a modulation signal corresponding to the WCDMA system, the antenna 8 may include an antenna element that transmits and receives a modulation signal corresponding to another radio access system.

  The measurement unit 9 measures the phase deviation amount of the modulation signal transmitted from the antenna 8 in units of time slots. A detailed description of the phase deviation amount will be described later.

  FIG. 2 is a block diagram illustrating a configuration example of the RF unit 7. In FIG. 2, the RF unit 7 includes an ANTSW (antenna switch) 71, a duplexer 72, a BPF (Band-pass filter) 73, an LNA (Low Noise Amplifier) 74, and an RFIC 75. , BPF 76, PA 77, and isolator 78.

  The antenna switch 71 is connected to the antenna 8 via the ANT end 80, and switches the antenna element used by the mobile terminal. In the following description, it is assumed that the antenna switch 71 uses an antenna element that transmits and receives a modulation signal corresponding to the WCDMA system as an antenna element used by the mobile terminal.

  The duplexer 72 is a filter that separates a transmission signal that is a modulation signal transmitted from the antenna 8 and a reception signal that is a modulation signal received by the antenna 8. The BPF 73 attenuates the frequency band other than the necessary frequency band and outputs the reception signal separated by the duplexer 72. The LNA 74 amplifies and outputs the power of the received signal from the duplexer 72 while suppressing noise as much as possible.

  The RFIC 75 demodulates the received signal from the LNA 74 and outputs it to the analog signal processing unit 6 as an analog signal. Further, the RFIC 75 modulates the analog signal from the analog signal processing unit 6 and outputs it to the BPF 76 as a modulated signal. The RFIC 75 includes a modulation / demodulation circuit, a transmission gain variable amplifier, a reception gain variable amplifier, a baseband filter, an amplifier, and a PLL synthesizer.

  The BPF 76 attenuates and outputs a frequency band other than the necessary frequency band from the modulation signal from the RFIC 75. The PA 77 is an amplifying unit that amplifies the power of the modulated signal from the BPF 76 and transmits the modulated signal obtained by amplifying the power from the antenna 8 through the isolator 78, the duplexer 72, and the antenna switch 71 in this order. The isolator 78 prevents the backflow of the transmission signal.

  FIG. 3 is a diagram illustrating a configuration example of the PA 77. In FIG. 3, PA 77 includes amplifier elements 771 and 772 and a bias circuit 773.

  Amplifier elements 771 and 772 are connected in series with each other. The amplifier elements 771 and 772 amplify the power of the modulation signal received by the input terminal IN, and output the modulation signal obtained by amplifying the power from the output terminal OUT. Note that the drive voltage of the amplifier elements 771 and 772 is the drive voltage VCC.

  The bias circuit 773 supplies a bias voltage to the amplifier elements 771 and 772. Note that the drive voltage of the bias circuit 773 is a drive voltage Vcb. The bias circuit 773 outputs a bias control voltage Vref for adjusting the value of the bias voltage. The drive voltages VCC and Vcb are supplied from the power supply control unit 2.

  Next, the phase deviation amount will be described in more detail.

  As described above, the phase deviation amount is the magnitude of the phase shift of the modulation signal generated at the switching timing for switching the power of the modulation signal. In this embodiment, since the power of the modulation signal is switched in units of one time slot, the phase deviation amount is the magnitude of the phase shift of the modulation signal generated at the boundary between adjacent time slots.

  It is known that the amount of phase deviation changes according to the drive voltage VCC of PA77. When the drive voltage VCC is fixed at the upper limit “3.5V”, the phase deviation amount generated in the PA 77 is high in the modulation signal power (Power @ ANT end) at the ANT end 80 as shown in FIG. By the way, it is assumed that −Δ15 degree / Δ7 dB or more. At this time, it is assumed that the phase deviation amount generated in the RFIC 75 becomes −Δ20 degree / Δ7 dB at a power at which the phase deviation amount generated in the PA 77 is −Δ15 degrees / Δ7 dB or more as shown in FIG. In this case, since the phase deviation amount measured at the ANT end 80 is the sum of the phase deviation amounts generated by the PA 77 and the RFIC 75, it becomes −Δ35 degree / Δ7 dB, that is, the phase deviation amount becomes ± Δ30 degrees or more and 3GPP It will not be possible to satisfy the provisions.

  In addition, in the case of a general PA used in a portable terminal that performs communication using the WCDMA system, the higher the drive voltage VCC, the better the linearity of the PA. From the viewpoint of the linearity of the PA, the drive voltage VCC is high. The lower the drive voltage VCC, the better from the viewpoint of power efficiency.

  In order to perform communication by the WCDMA system, it is not necessary to keep the drive voltage VCC fixed at the upper limit value “3.5 V” to keep the PA linearity high. As the PA linearity, 3GPP / TS25.101 6 It is sufficient to ensure that the regulation for ACLR (Adjacent Channel Leakage Ratio) defined in .6.2.2 is satisfied. For this reason, in a mobile terminal that performs communication by the WCDMA system, it is common to reduce the power consumption by reducing the drive voltage VCC as much as possible while satisfying the regulations for ACLR.

  FIG. 6 is a diagram illustrating the relationship between the power of the modulation signal at the ANT end 80 and the drive voltage VCC when the ACLR reaches the specified value (−40 dBc). As shown in FIG. 6, in order to set ACLR to the specified value, it is necessary to adjust the drive voltage VCC according to the power of the modulation signal. For this reason, a function of adjusting the drive voltage VCC is usually provided in the mobile terminal.

  The mobile terminal of the present embodiment adjusts the phase deviation amount by using the function of adjusting the drive voltage VCC and the fact that the phase deviation amount changes according to the drive voltage VCC of the PA 77. More specifically, the digital signal processing unit 5 switches the power of the modulation signal using the PA 77 and adjusts the drive voltage VCC according to the power using the power supply control unit 2 to obtain the phase deviation amount. adjust.

  As a result, the relationship between the phase deviation amount in PA 77 and the power of the modulation signal changes to, for example, the relationship shown in FIG. 7, and becomes + Δ15 degrees / Δ7 dB or more when the power is high. For this reason, the sum of the phase deviation amounts generated in the PA 77 and the RFIC 75 becomes −Δ5 degree / Δ7 dB, and the phase deviation amounts of the PA 77 and the RFIC 75 are large, but the phase deviation amounts cancel each other, and the ANT end 80 Therefore, the phase deviation amount at the time sufficiently satisfies the requirements of the 3GPP specifications.

  Next, the operation of the mobile terminal of this embodiment will be described.

  First, operations relating to control of the drive voltage VCC will be described.

  In order to appropriately adjust the phase deviation amount at the ANT end 80, a VCC linear interpolation table showing a correspondence relationship between the drive voltage VCC and the power of the modulation signal at the ANT end 80 (hereinafter referred to as transmission power) is stored in the memory 3 in advance. Keep a record.

  The transmission power in the WCDMA system is specified in 6.2.1 and 6.4.3 of 3GPP TS25.101. More specifically, the maximum transmission power that is the maximum value of the transmission power is specified in 6.2.1 of 3GPP · TS25.101, and the minimum transmission power that is the minimum value of the transmission power is 6 of 3GPP · TS25.101. 4.3. For example, when the power class is 3, the transmission power needs to be +24 dBm or more and −50 dBm or less. In this case, for example, a table as shown in FIG. 8 is recorded in the memory 3 as the VCC linear interpolation table.

  The digital signal processing unit 5 periodically switches the transmission power using the PA 77. At this time, the digital signal processing unit 5 controls the drive voltage VCC supplied to the PA 77 according to the VCC linear interpolation table in the memory 3.

  More specifically, first, the digital signal processing unit 5 reads from the memory 3 the drive voltage VCC corresponding to each of the transmission power that is periodically switched in the VCC linear interpolation table. When the transmission power that is periodically switched does not exist in the VCC linear interpolation table, the digital signal processing unit 5 uses the drive voltage VCC supplied to the power supply control unit 2 from the drive voltage corresponding to the transmission power in the vicinity of the transmission power. Ask for. For example, in the case where the VCC linear interpolation table is the table shown in FIG. 8, if the transmission power is +22 dBm, the digital signal processing unit 5 has a drive voltage “3.5 V” corresponding to the transmission powers “+24 dBm” and “+20 dBm”. ”And“ 3.0 V ”are read out, and the drive voltage VCC supplied to the power supply control unit 2 is obtained as (3.5 V + 3.0 V) /2=3.25 V.

  Then, the digital signal processing unit 5 outputs to the power supply control unit 2 a first control signal for switching the transmission power in units of one time slot and a second control signal for switching the drive voltage VCC in units of one time slot. The first control signal indicates transmission power, and the second control signal indicates the drive voltage VCC read from the memory 3.

  When the power supply control unit 2 receives the first control signal and the second control signal, the power supply control unit 2 supplies the drive voltage Vcb corresponding to the first control signal to the bias circuit 773 of the PA 77 to transmit the transmission power in units of one time slot. And the driving voltage VCC corresponding to the second control signal is supplied to the amplifier elements 771 and 772 of the PA to switch the driving voltage VCC in units of one time slot.

  Next, the operation of the mobile terminal for setting the phase deviation amount to an appropriate value by optimizing the VCC linear interpolation table will be described.

  In order to optimize the VCC linear interpolation table, when the phase deviation amount is larger than the threshold value even if the drive voltage VCC is adjusted, the digital signal processing unit 5 gradually increases the drive voltage VCC until the phase deviation amount becomes equal to or less than the threshold value. Change to. Then, the drive voltage corresponding to the transmission power in the VCC linear interpolation table is updated to the drive voltage VCC when the phase deviation amount is equal to or less than the threshold value.

  FIG. 9 is a flowchart for explaining a more detailed operation example of the mobile terminal that updates the drive voltage VCC.

  In the following operation, in the VCC linear interpolation table, as shown in FIG. 10, the initial value of the drive voltage corresponding to each transmission power is set to the upper limit value “3.5 V”. Further, the CPU 4 holds a power variable X for defining transmission power. Furthermore, it is assumed that the following operations are performed in advance before the operation of the mobile terminal.

  First, the CPU 4 sets the power variable X to an initial value “0” (step A1).

  Subsequently, the CPU 4 commands the digital signal processing unit 5 so that the transmission power can be repeatedly switched between (+ 24−X) dBm and (+ 16−X) dBm in units of time slots. When the digital signal processing unit 5 receives the command, the digital signal processing unit 5 reads the drive voltage VCC corresponding to each of the transmission power (+ 24−X) dBm and (+ 16−X) dBm from the memory 3 in the VCC linear interpolation table. The digital signal processing unit 5 controls the PA 77 through the power supply control unit 2 so that the transmission power repeats (+ 24−X) dBm and (+ 16−X) dBm in units of time slots, and also drives the drive voltage VCC. The power supply control unit 2 is controlled so as to repeat each of the drive voltages read from the memory 3 in units of time slots (step A2).

  Thereby, for example, when the power variable X is the initial value “0”, the transmission power is repeatedly switched in units of time slots as +24 dBm → + 16 dBm → + 24 dBm. Note that the control method of the PA 77 and the power supply control unit 2 is the same as that described in the operation relating to the control of the drive voltage VCC, and therefore detailed description thereof is omitted.

  Thereafter, the measuring unit 9 measures the phase deviation amount of the modulation signal in units of one time slot, and outputs the measurement result to the CPU 4 (step A3). Note that the measurement unit 9 may further measure the transmission power in units of one time slot.

  FIG. 11 is an example of a measurement result table in which measurement results are arranged in time series. The measurement result table 10 shown in FIG. 11 shows the time slot number (Slot No.) 11, the transmission power (Power [dBm]) 12 in the time slot of number 11, and the phase deviation amount in the time slot of number 11 ( ΔPhase [degree]) 13. The phase deviation amount 13 indicates the magnitude of the phase shift at the boundary between the own time slot and the previous time slot.

  The CPU 4 compares the phase deviation amount as the measurement result with a predetermined threshold value to determine whether or not the phase deviation amount is equal to or smaller than the threshold value (step A4).

  For example, when the threshold is set to a value of ± 5 degrees with respect to the value ± 30 degrees specified in 6.8.5 of 3GPP / TS25.101, that is, when the threshold is set to ± 25 degrees, it is shown in FIG. In the elapsed result table, the phase deviation amount is larger than the threshold value. Each time the phase deviation amount is measured, the CPU 4 may compare the phase deviation amount with a threshold value, or may compare the average value of the phase deviation amounts with the threshold value within a predetermined period.

  When it is determined in step A4 that the phase deviation amount is larger than the threshold value, the CPU 4 instructs the digital signal processing unit 5 to lower the drive voltage VCC by a predetermined value ΔVCC. Here, the CPU 4 only selects one of the drive voltages VCC that are periodically switched (for example, the drive voltage VCC having the lower transmission power, that is, the drive voltage VCC having the transmission power of (+ 16−X) dBm). Is lowered by a predetermined value ΔVCC. This is because the phase deviation amount changes when one of the drive voltages VCC is switched.

  When the digital signal processing unit 5 accepts the command, the digital signal processing unit 5 uses the power supply control unit 2 to lower the drive voltage VCC having a transmission power of (+ 16−X) dBm by a predetermined value ΔVCC (step A5). For example, when the predetermined ΔVCC = 0.1V, the drive voltage VCC when the transmission power is (+ 16−X) dBm is VCC = 3.5V−0.1V = 3.4V. When step A5 ends, the process returns to step A3.

  Thereafter, steps A3 to A5 are repeated until the phase deviation amount becomes equal to or smaller than the threshold value. At this time, for example, when the drive voltage VCC with the transmission power of (+ 16−X) dBm becomes 2.5V, the measurement result table has a result as shown in FIG. 12, and the phase deviation amount is equal to or less than the threshold value. Suppose that In this case, the drive voltage VCC is lowered to 2.5V while steps A3 to A5 are repeated. That is, since the initial value of the power supply voltage is 3.5V and the predetermined value ΔVCC is 0.1V, the processing from steps A3 to A5 is repeated 10 times.

  On the other hand, when it is determined in step A4 that the phase deviation amount is equal to or smaller than the threshold, the CPU 4 determines whether or not the processing from steps A1 to A5 has been performed for all transmission powers in the VCC linear interpolation table. That is, the CPU 4 determines whether or not the power variable X is 68, and determines whether or not the transmission power repeats −44 dBm → −52 dBm in units of time slots (step A6).

  When the power variable X is not 68, the CPU 4 increases the power variable X by 4 (step A7) and returns to step A2.

  On the other hand, when the power variable X is 68, the CPU 4 updates the drive voltage VCC of each transmission power in the linear interpolation table to the drive voltage VCC when the phase deviation amount is equal to or less than the threshold (step A8), and processing Exit.

  As described above, according to the present embodiment, the PA 77 amplifies the power of the modulation signal. The power supply control unit 2 inputs the drive voltage VCC to the PA 77 and drives the PA 77. The digital signal processing unit 5 switches the power of the modulation signal using the PA 77. Then, the digital signal processing unit 5 uses the power supply control unit 2 to adjust the drive voltage VCC in accordance with the power of the modulation signal, and the magnitude of the phase shift of the modulation signal generated at the power switching timing. Adjust a certain amount of phase deviation.

  Therefore, since the phase deviation amount is adjusted by adjusting the driving voltage of PA 77, it is not necessary to newly provide a phase shifter in order to satisfy the definition for the phase deviation amount. For this reason, it becomes possible to suppress an increase in the scale of the apparatus for satisfying the definition for the phase deviation amount.

  Further, in the present embodiment, the CPU 4 adjusts the drive voltage VCC so as to be a drive voltage corresponding to the power of the modulation signal in the VCC linear interpolation table. If the phase deviation amount is larger than the threshold value even if the drive voltage is adjusted, the CPU 4 changes the drive voltage stepwise until the phase deviation amount becomes equal to or less than the threshold value, and the power of the modulation signal in the VCC linear interpolation table. The driving voltage corresponding to is updated to the driving voltage when the phase deviation amount is equal to or less than the threshold value. Therefore, the VCC linear interpolation table can be automatically optimized.

  Next, a second embodiment of the present invention will be described.

  The mobile terminal according to the present embodiment satisfies the requirement for ACLR (Adjacent Channel Leakage Power Ratio) when the VCC linear interpolation table is optimized. And different.

  In addition to the VCC linear interpolation table, the memory 3 further records a VCC lower limit table showing the correspondence between the transmission power and the lower limit value of the drive voltage VCC as shown in FIG. Here, the lower limit value of the drive voltage VCC is set to a value slightly larger than that in consideration of the minimum value or margin of the drive voltage VCC that can satisfy the regulation for ACLR.

  When the phase deviation amount is larger than the threshold value, the CPU 4 makes the phase deviation amount less than the threshold value, or the drive voltage VCC becomes the lower limit value of the drive voltage VCC corresponding to the current transmission power in the lower limit table in the memory 3. Up to this point, the drive voltage VCC is prevented from becoming lower than the lower limit value by causing the digital signal processing unit 5 to lower the drive voltage stepwise.

  Next, the operation of the mobile terminal of this embodiment will be described. FIG. 14 is a flowchart for explaining an example of this operation by the mobile terminal.

  When it is determined in step A4 that the phase deviation amount is larger than the threshold value, the CPU 4 reads the lower limit value of the drive voltage VCC corresponding to the current transmission power from the VCC lower limit table in the memory 3, and the current drive voltage VCC is It is determined whether or not the lower limit is exceeded (step B1).

  When the drive voltage VCC is equal to or higher than the lower limit value, the CPU 4 proceeds to step A5 and lowers the drive voltage VCC when the transmission power is (+ 16−X) dBm by the predetermined value ΔVCC. On the other hand, when the drive voltage VCC is less than the lower limit value, the CPU 4 ends the process.

  As described above, according to the present embodiment, it is possible to prevent the requirement for the ACLR from becoming unsatisfactory in order to satisfy the requirement for the phase deviation amount.

  Next, a third embodiment of the present invention will be described.

  The mobile terminal of this embodiment sets the initial value of the drive voltage VCC in the VCC linear interpolation table to the lower limit value of the drive voltage VCC described in the second embodiment, and when the phase deviation amount is larger than the threshold value, The signal processing unit 5 is different from the portable terminal of the first embodiment in that the drive voltage VCC is increased stepwise.

  More specifically, the memory 3 records the VCC lower limit table described in the second embodiment as shown in FIG. 13 as the VCC linear interpolation table. In addition to the VCC linear interpolation table, the memory 3 further records a VCC upper limit table showing the correspondence between the transmission power and the upper limit value of the drive voltage VCC as shown in FIG.

  When the phase deviation amount is larger than the threshold value, the CPU 4 makes the phase deviation amount less than the threshold value, or the drive voltage VCC becomes the upper limit value of the drive voltage VCC corresponding to the current transmission power in the upper limit table in the memory 3. Up to this point, the drive voltage VCC is prevented from becoming larger than the upper limit value by causing the digital signal processing unit 5 to increase the drive voltage stepwise.

  Next, the operation of the mobile terminal of this embodiment will be described. FIG. 15 is a flowchart for explaining an example of this operation by the mobile terminal. In FIG. 15, the same processes as those in FIG.

  When it is determined in step A4 that the phase deviation amount is larger than the threshold value, the CPU 4 reads the upper limit value of the drive voltage VCC corresponding to the current transmission power from the VCC upper limit table in the memory 3, and the current drive voltage VCC is It is determined whether or not the upper limit value is not reached (step C1).

  When the drive voltage VCC is equal to or lower than the upper limit value, the CPU 4 increases the drive voltage VCC when the transmission power is (+ 16−X) dBm by the predetermined value ΔVCC instead of step A5 (step C2), and returns to step A3. On the other hand, when the drive voltage VCC is larger than the upper limit value, the CPU 4 ends the process.

  As described above, according to the present embodiment, in order to satisfy the definition for the phase deviation amount, it is possible to prevent the ACLR specification from being unsatisfactory and to make the phase deviation amount equal to or less than the threshold value. It is considered that there is a high possibility that this procedure can be reduced.

  In each embodiment described above, the illustrated configuration is merely an example, and the present invention is not limited to the configuration.

1 Battery 2 Power Control Unit 3 Memory 4 CPU
5 Digital Signal Processing Unit 6 Analog Signal Processing Unit 7 RF Unit 8 Antenna 9 Measuring Unit 71 ANTSW (Antenna Switch)
72 Duplexer 73, 76 BPF (band pass filter)
74 LNA (Low Noise Amplifier)
75 RFIC (Radio Frequency Integrated Circuit)
77 PA (Power Amplifier)
78 Isolator 771, 772 Amplifier element 773 Bias circuit

Claims (8)

A mobile terminal that transmits a modulated signal,
An amplifier for amplifying the power of the modulated signal;
A power supply controller for driving the amplifier by inputting a drive voltage to the amplifier;
The power of the modulation signal is switched using the amplification unit, and the drive voltage is adjusted according to the power using the power control unit, and the phase of the modulation signal generated at the power switching timing is adjusted. And an adjustment unit that adjusts a phase deviation amount that is a magnitude of the deviation. A recording unit that records a table indicating a correspondence relationship between the driving voltage and the power of the modulation signal;
The mobile terminal according to claim 1, wherein the adjustment unit adjusts the drive voltage so as to be a drive voltage corresponding to a power of the modulation signal in the table. A measurement unit for measuring the phase deviation amount;
If the phase deviation amount is greater than a threshold value even after adjusting the drive voltage, the adjustment unit changes the drive voltage step by step until the phase deviation amount is equal to or less than the threshold value. The portable terminal according to claim 2, wherein the driving voltage corresponding to the power of the modulation signal is updated to the driving voltage when the phase deviation amount is equal to or less than the threshold value. In the table, the driving voltage corresponding to each of the power of the modulation signal is set to an upper limit value,
The mobile terminal according to claim 3, wherein, when the phase deviation amount is larger than the threshold value, the adjustment unit gradually decreases the drive voltage until the phase deviation amount becomes equal to or less than the threshold value.   When the phase deviation amount is larger than the threshold value, the adjustment unit gradually decreases the drive voltage until the phase deviation amount becomes equal to or smaller than the threshold value or the phase deviation amount becomes a lower limit value. The mobile terminal according to claim 4. In the table, the driving voltage corresponding to each of the power of the modulation signal is set to a lower limit value,
The portable terminal according to claim 3, wherein, when the phase deviation amount is larger than the threshold value, the adjustment unit increases the drive voltage stepwise until the phase deviation amount becomes equal to or less than the threshold value.   The adjustment unit, when the phase deviation amount is larger than the threshold value, gradually increases the drive voltage until the phase deviation amount becomes equal to or smaller than the threshold value or the phase deviation amount reaches an upper limit. 6. The mobile terminal according to 6. A method of adjusting a phase deviation amount by a portable terminal having an amplification unit that amplifies and transmits the power of a modulation signal, and a power supply control unit that drives the amplification unit by inputting a drive voltage to the amplification unit,
Switching the power of the modulation signal using the amplification unit,
Using the power supply control unit, the drive voltage is adjusted according to the power of the modulation signal, and the phase deviation amount that is the magnitude of the phase shift of the modulation signal generated at the power switching timing is adjusted. , Phase deviation adjustment method.

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