JP2006067303A - Mobile communication terminal - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a mobile communication terminal for keeping the RMS value as a constant value and also reducing PAR. <P>SOLUTION: The mobile communication terminal comprises a modulating unit 101 for outputting an in-phase signal and an orthogonal signal by IQ multiplexing the transmitting data of data channel and the control data of a first control channel, and by IQ multiplexing the control data of a second control channel in addition to the transmitting data of data channel and the control data of the first control channel; a control unit 103 for outputting, to the modulating unit, a first gain factor corresponding to the data channel, a second gain factor corresponding to the first control channel, and a third gain factor corresponding to the second control channel; and a peak reduction constituting unit 102 including a compensating unit for compensating for the in-phase signal and orthogonal signal using the gain corresponding to the first to third gain factors outputted to the modulating unit from the control unit. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a mobile communication terminal device.

  Among the communication systems called third generation, W-CDMA (Wideband Code Division Multiple Access) system has been commercialized in Japan since 2001. In a system that provides a communication service using the W-CDMA scheme, a mobile station and a base station use a downlink in which the base station transmits data to the mobile station and an uplink in which the mobile station transmits data to the base station. Communication is performed at a communication speed of about 2 Mbps (bit per second). In recent years, HSDPA (High Speed DownLink Packet Access), which adds a new downlink (channel for packet transmission) in addition to the conventional downlink, has been achieved in order to further increase the speed of data transmission using the downlink. ) Method has been proposed and studied. When a new downlink is added, a dedicated control channel (signaling channel) for transmitting response data for downlink high-speed packet data transmitted via the new downlink to the base station is added. It is necessary to

By the way, in a system for realizing HSDPA, a dedicated control channel is added to the uplink from the mobile station to the base station. Therefore, when the base station permits the mobile station to perform communication using HSDPA, the mobile station needs to additionally multiplex a signaling ring channel for controlling communication using HSDPA on a normal uplink. For this reason, at the time of communication using HSDPA, there arises a problem that the multiplex wave number of the modulation signal modulated by the mobile station increases and the PAR (Peak to Average Ratio) of the modulation signal changes. Further, there arises a problem that the PAR changes depending on the multiple wave ratio (a combination of the amplitude coefficients β _d and β _c and β _HS ) of the additional signaling ring channel.

  Conventionally, in general, when transmitting a transmission signal in a multiplexed manner, the RMS (Root Mean Square) value (average amplitude value) varies according to the multiplexed signal, and the peak factor (PAR: Peak to Average Ratio) increases. There are problems such as. When the RMS value of the signal output to the D / A converter differs depending on the input signal, the input / output characteristics of the device in the subsequent stage change, and power adjustment is required. Further, since power adjustment is required, correction of frequency characteristics and temperature characteristics becomes very complicated in line adjustment. In addition, the increase in PAR greatly affects the dynamic range of the D / A converter as well as the efficiency of the amplifier.

  In order to solve these problems, a technique disclosed in Patent Document 1 has been proposed. As shown in FIG. 1 of the same document, this document is based on the time when limiters 1a and 1b act on a code multiplexed signal to be transmitted and a signal of a given limiter threshold level is output. The limiter rate calculation unit 4 measures the ratio (limiter rate), and the limiter threshold setting unit 5 varies the limiter threshold so that the measured limiter rate approaches a predetermined limiter rate, and the limiters 1a and 1b. Is a transmission peak factor suppression circuit.

JP-A-11-136210

  However, the conventional technique has the following problems. In other words, it is possible to reduce the peak factor (PAR) by suppressing the peak of the baseband signal, but the average amplitude (RMS) value after peak reduction differs for input signals with different amplitude levels. There was a problem.

  The present invention has been made in view of the problems as described above. When the number of multiplexed transmission signals increases, for example, an HS-DPCCH is added in order for a terminal to perform communication using HSDPA with permission from a base station. In some cases, an object of the present invention is to provide a mobile communication terminal apparatus including a peak reduction circuit that can keep the RMS value constant regardless of the amplitude level of the signal or the number of multiplexing and can also reduce the PAR.

  The mobile communication terminal apparatus according to the present invention IQ multiplexes at least transmission data of the data channel and control data of the first control channel, and in response to an instruction from a base station, the transmission data of the data channel and the data In addition to the control data of the first control channel, the control data of the second control channel is further IQ-multiplexed to generate a complex signal, and outputs a in-phase signal and a quadrature signal, and the data A control unit that outputs a first gain factor corresponding to the channel, a second gain factor corresponding to the first control channel, and a third gain factor corresponding to the second control channel to the modulation unit; The control unit uses the gains corresponding to the first gain factor, the second gain factor, and the third gain factor that are output to the modulation unit. And a peak reduction component having a correction unit that corrects the signal and the orthogonal signal.

  According to the present invention, in the baseband signal, the RMS value can be made constant by correcting the I and Q signals using the gain corresponding to the gain factor. Further, PAR can be reduced by performing limiter processing on amplitude values above a certain level. Therefore, the mobile communication terminal apparatus can perform transmission power control intended by the base station. In addition, when the mobile station performs transmission power control intended by the base station, interference between terminals can be reduced and the subscriber capacity of the system can be increased.

Embodiment 1 FIG.
The mobile communication terminal apparatus according to Embodiment 1 of the present invention multiplies a baseband signal by a gain that makes the RMS value constant, suppresses a peak value above a certain value using a limiter, and the RMS value is It has a peak reduction circuit that is constant and can reduce PAR. FIG. 1 shows a block diagram of a mobile communication terminal device equipped with a peak reduction circuit, and FIG. 2 shows a block diagram of the peak reduction circuit.

A mobile communication terminal apparatus shown in FIG. 1 includes a modulation unit 101 that modulates a signal, a peak reduction configuration unit 102 that limits a band to the modulation output and suppresses a peak value, and a control unit 103 that manages the amplitude level of the signal. The D / A converter 4 converts a digital signal into analog, a quadrature modulation unit (QMOD) 105 that performs quadrature modulation, and an amplifier (AMP) 106 that amplifies power. More specifically, the control unit 103 stores the gain factors (β _d , β _c , β _HS ) notified from the base station via the downlink control channel, and these gain factors (β _d , In accordance with (β _c , β _HS ), the IQ multiplexing processing of the modulation unit 101 and the processing of the peak reduction configuration unit 102 described later are controlled.

  The peak reduction configuration unit 102 illustrated in FIG. 2 is output from the band limiting unit 201 (referred to as a first band limiting unit in distinction from the peak reduction band limiting unit 807 described later), the gain unit 202, and the gain unit 202. The multiplier 203 is configured to multiply the in-phase signal and the quadrature signal by a gain, and a limiter 204. The multiplier 203 functions as a correction unit that corrects the in-phase signal and the quadrature signal according to the gain factor.

  Next, the operation of the peak reduction configuration unit 102 that is a feature of the present invention will be described. The baseband signals of the in-phase input unit and the quadrature input unit are subjected to waveform shaping by the band limiting unit 201. The signal that has passed through the band limiting unit 201 is multiplied by the gain output from the gain unit 202 that has received the signal from the control unit 103 by the multiplier 203, and is changed to a certain RMS regardless of the number of multiplexed input signals. The For a signal with a constant RMS, for example, a peak value equal to or greater than a predetermined limiter value is suppressed by the limiter 204, and an output can be obtained from the in-phase output unit and the quadrature output unit.

Here, as an example will be described with reference to Uplink of the W-CDMA system has been standardized in ^{3GPP (3 rd Generation Partnership Project)} . Uplink assumes DPDCH (data channel), DPCCH (first control channel), and HS-DPCCH (second control channel) channels defined in TS25.213V5.5.0. Yes. Here, when there is one DPDCH, DPDCH becomes an in-phase component (I), DPCCH, and HS-DPCCH become a quadrature component (Q), and after a complex operation is performed, a scrambling code is multiplied. In this case, DPDCH gain factor β _d (first gain factor), DPCCH gain factor β _c (second gain factor), and HS-DPCCH gain factor β _HS (third The PAR and RMS values change depending on the combination of the gain factor.

  The amplitude level of the multiple wave in this case is, for example,

Can be written. That is, the RMS value of the multiwave signal can be predicted from the gain factors (β _d , β _c , β _HS ). Therefore, the control unit 103 outputs a control signal corresponding to the gain factors (β _d , β _c , β _HS ) to the gain unit 202.

The gain unit 202 has values corresponding to the gain factors (β _d , β _c , β _HS ), for example, in the table shown in FIG. 4 and corresponds to the gain factors (β _d , β _c , β _HS ). Receives a control signal and outputs a corresponding value. At this time, the corresponding value stored in the gain unit 202 is determined by the following equation, for example.

In the limiter 204, for example, the limit is performed with a fixed limit value that satisfies the adjacent channel leakage power (ACLR: Adjacent Channel Leakage Ratio) defined by 3GPP in all gain factors (β _d , β _c , β _HS ). .

In FIG. 2, the table in FIG. 4 is assumed as the gain unit 202. However, the gain unit 202 receives a control signal corresponding to the gain factors (β _d , β _c , β _HS ) and calculates the gain in the gain unit 202. I do not care. Further, as shown in FIG. 3, the gain unit 202 may be omitted, and a gain value corresponding to the gain factors (β _d , β _c , β _HS ) may be directly input to the multiplier 203 as a control signal.

Incidentally, it was beta _HS in above, but may be used [Delta] Hs-DPCCH.

  As described above, according to the first embodiment, the baseband signal is multiplied by the gain output from the gain unit, and the peak value of a certain value or more is reduced by the limiter from the signal in which the RMS is constant. The RMS value can be made constant regardless of the wave, and the PAR can be reduced.

  Further, in the baseband signal, the RMS value can be made constant by correcting the I and Q signals using a gain corresponding to the gain factor. Furthermore, PAR can be reduced by performing limiter processing on amplitude values above a certain level. Therefore, the mobile communication terminal apparatus can perform transmission power control intended by the base station. Furthermore, when the mobile station performs transmission power control intended by the base station, interference between terminals can be reduced and the subscriber capacity of the system can be increased.

Embodiment 2. FIG.
In addition to the fact that the peak reduction component in the present second embodiment can reduce the PAR by keeping the RMS value constant by multiplying the gain in the final stage based on the first embodiment, In this configuration, the dynamic range of the D / A converter 104 at the subsequent stage can be used effectively.

  FIG. 5 shows the configuration. The same elements as those in FIG. 2 are denoted by the same reference numerals, and the description thereof is omitted. Here, the description will focus on parts different from the first embodiment. As shown in FIG. 5, the multiplier 501 can adjust the amplitude level to a desired bit width by multiplying the signal after the limiter processing by the signal (gain) from the control unit 103. Thus, the dynamic range of the D / A converter 104 at the subsequent stage can be used effectively. The amplitude adjustment gain multiplier 501 functions as a second correction unit in the same manner as the multiplier 203 functions as a correction unit.

  A signal (gain) from the control unit 103 will be described. For example, when the limiter value is L, the number of output bits of the in-phase output unit and the quadrature output unit is n bits, and the gain G when the dynamic range of the D / A converter 104 is fully used is

Can be expressed as Therefore, the control unit 103 can effectively use the dynamic range of the D / A converter 104 by outputting the gain G and multiplying the signal after the limiter processing.

  In the second embodiment, the signal (gain) from the control unit 103 is multiplied. For example, the gain value is stored in a memory, and the gain value is read with the signal from the control unit 103 and multiplied by the multiplier 501. It is also possible to do so.

  As described above, according to the peak reduction configuration unit of the second embodiment, the baseband signal is multiplied by the gain output from the gain unit 202, and a peak value of a certain level or more is limited from a signal with a constant RMS. 204, and by multiplying the signal (gain) output from the control unit 103, the RMS value is constant and PAR can be reduced, and the dynamic range of the D / A converter 104 can be used effectively. Is possible.

Embodiment 3 FIG.
A peak reduction configuration according to Embodiment 3 of the present invention will be described. FIG. 6 shows the configuration, and the same elements as those in the first embodiment are denoted by the same reference numerals and the description thereof is omitted. Here, the description will focus on the parts different from the first embodiment.

  In the configuration of the third embodiment, the baseband signals of the in-phase input unit and the quadrature input unit are waveform-shaped by the band limiting unit 201 and output from the variable limit value output unit 601 that has received the signal of the control unit 103. By limiting the peak value in the limiter 602 that can make the limit value variable, the multiplier 203 multiplies the gain that adjusts the RMS value from the gain unit 202 that receives the signal from the control unit 103, In this configuration, each orthogonal output signal is obtained.

Here, as an example will be described with reference to Uplink of the W-CDMA system has been standardized in ^{3GPP (3 rd Generation Partnership Project)} . As described above, the PAR and RMS values change depending on the combination of DPDCH, DPCCH, and HS-DPCCH gain factors (β _d , β _c , β _HS ) that determine the multiwave ratio. That is, the peak also varies depending on the gain factor. However, in other words, if the gain factor is known, a possible peak value is also determined. Therefore, the amplitude level of the multiple wave in the case of the gain factor (β _d , β _c , β _HS ) is, for example,

Can be written. Therefore, the control unit 103 outputs a control signal corresponding to the gain factors (β _d , β _c , β _HS ) to the variable limit value output unit 601 and the gain unit 202.

The variable limit value output unit 601 has values corresponding to the gain factors (β _d , β _c , β _HS ), for example, in the table shown in FIG. 7, and the gain factors (β _d , β _c , β _HS ) The control signal corresponding to is received and the corresponding value is output. At this time, the corresponding value stored in the variable limit value output unit 601 is the limit value variable limiter 602, for example, an adjacent channel defined by 3GPP for each combination of gain factors (β _d , β _c , β _HS ). The value satisfies the leakage power (ACLR: Adjacent Channel Leakage Ratio).

The variable limit value output unit 601 directly writes, in the limit value variable limiter 602, the limiter value obtained by the control unit 103 using a formula determined from the gain factors (β _d , β _c , β _HS ). Then, it can be configured without having a table.

The gain unit 202 is assumed to be a table, but a configuration in which a gain value corresponding to the gain factors (β _d , β _c , β _HS ) is directly input from the control unit 103 to the multiplier 203 is also possible.

  As described above, according to the peak reduction configuration unit in the third embodiment, the limiter process according to the amplitude level can be performed by passing the baseband signal through the limiter 602 that can change the limit value. 2, by multiplying the peak-reduced signal by the gain of the gain unit 202, PAR can be reduced and the RMS value can be made constant.

Embodiment 4 FIG.
The peak reduction configuration according to the fourth embodiment reduces the PAR and keeps the RMS value constant by switching between two types of band limiting units having different coefficients without using a limiter. FIG. 8 shows a block diagram of the fourth embodiment.

  The peak reduction configuration illustrated in FIG. 8 includes a peak prediction unit 801, a determination unit 804, a delay unit 805, a switching unit 806, a normal band limiting unit 201 (first band limiting unit), and a peak reduction band limiting. Unit 807 (second band limiting unit), an adder 808 that adds two types of filter outputs, a control unit 103, a gain unit 202, and a multiplier 203 (correction unit) that multiplies the gain. The

  Also, the peak prediction unit 801 adds the normal band limiting unit 201 and the multiplier 802 for squaring the band limiting unit output, and the output signals of the multipliers 802 on the in-phase input unit side and the quadrature input unit side. And an adder 803. In addition, the same code | symbol as FIG. 2 shows the same element, and abbreviate | omits description.

  Next, the operation will be described. The baseband signals of the in-phase input unit and the quadrature output unit are input to the peak prediction unit 801 and the delay unit 805, respectively. The peak predicting unit 801 takes the signal into the band limiting unit 201, squares each in the multiplier 802, and adds in the adder 803 to measure the instantaneous power. Based on the instantaneous power value, the determination unit 804 loads the peak reduction band limiting unit 807 with a reduced coefficient if this value is a certain value or more, and loads the normal band limiting unit 201 otherwise. Thus, an instruction signal is output to the switching unit 806. At this time, “0” is input to the band limiting unit turned OFF by the switching unit 806.

  On the other hand, the delay unit 805 performs a delay so that each signal of the in-phase input unit and the quadrature input unit passes through the peak prediction unit 801 and has the same timing as the data output from the determination unit 804. The switching unit 806 captures these two signals, receives the signal from the determination unit 804, switches the signal from the delay unit 805 to either the peak reduction band limiting unit 807 or the band limiting unit 201, and outputs the signal. . The adder 808 adds the output results of the two band limiting units, and the multiplier 203 multiplies the gain of the gain unit 202 whose gain is determined from the control unit 103 at the final stage.

Next, the operation of the determination unit 804 will be described. The determination unit 804 compares the input signal with a threshold value and outputs the result. Here, the threshold value of the determination unit 804 is set according to an input signal from the control unit 103. The method for determining the threshold value from the input signal is obtained in accordance with, for example, the aforementioned 3GPP gain factors (β _d , β _c , β _HS ). For example, when the signal from the peak prediction unit 801 exceeds the threshold set by the control unit 103, the determination unit 804 outputs the 2-bit timing in the middle of the number of taps of the band limiting unit. In addition, an output “1” is output, and an output “0” is output otherwise. Here, as an example, a flag is set in the middle 2 bits and only 2 bits are subjected to peak suppression. However, the number of bits is not limited, and may be 4 bits or the number of taps of the band limiting unit.

  Next, the band limiting unit 201 and the peak reduction band limiting unit 807 (second band limiting unit) will be described. The peak reduction band limiting unit 807 is a filter that holds in advance a coefficient obtained by multiplying the coefficient of the band limiting unit 201 by a value smaller than 1.0. If the signal generates a peak value, the signal is taken into the peak reduction band limiting unit 807 and the band limiting unit 201 otherwise, and the respective outputs are added to obtain the band limiting unit 201 as shown in FIG. The output response 201R and the output response 807R of the peak reduction band limiting unit 807 are overlapped to realize peak reduction.

  Here, as shown in FIG. 11, the peak reduction band limiting unit 807 multiplies the signal by a reduction coefficient value 1101 {R (<1.0)} smaller than 1.0 by a coefficient multiplier 1102 and then sets the band. The same effect can be obtained by incorporating the limiting unit 201.

  For the peak prediction unit 801, as shown in FIG. 10, a bit string P2 of a peak generation pattern is prepared in advance, matched with the bit string P1 of an actual input signal, and input to the determination unit 804. It is also possible to perform peak prediction. For example, when the input signal is binary (0, 1) and the peak prediction is performed on the 6-bit data string, the 6-bit data string for generating the peak is multiplied by the actual 6-bit data string, The multiplication results are added and output to the determination unit 804. If the values match, the value is 6. If the values do not match, the value is other than that, so the determination unit 804 determines whether the value is 6, and outputs a signal to the switching unit 806. Moreover, if it can perform peak prediction, it will not be restricted to this.

  The RMS value of the output obtained by adding the outputs of the two types of band limiting units 201 and 807 is made constant by the gain unit 202 whose gain is determined by the control unit 103. As in the third embodiment, the gain of the gain unit 202 is output according to the input signal.

  As described above, according to the peak reduction configuration unit of the fourth embodiment, when the peak is detected by measuring the instantaneous power in the peak prediction unit 801 from the baseband signal, and it is determined that the peak value is more than a specific value. In this case, the peak reduction band limiting unit 807 in which the tap coefficient of the band limiting unit is reduced, the other band is taken into the normal band limiting unit 201, and the outputs of these two band limiting units are added. Peaks can be reduced and PAR is reduced. Further, by multiplying the gain of the gain unit 202 in the final stage, the RMS value can be made constant.

Embodiment 5. FIG.
The peak reduction configuration in the fifth embodiment realizes the part using the two types of band limiting units in the fourth embodiment with one band limiting unit, reduces the PAR, and makes the RMS value constant. is there. Here, only coefficient variable band limiting section 1201 having a configuration different from that in Embodiment 4 will be described. In other configurations, the same elements as those in FIG.

  FIG. 12 shows a block diagram of the fifth embodiment, and FIG. 13 shows a configuration diagram of the coefficient variable band limiting unit 1201.

  As shown in FIG. 13, the coefficient variable band limiting unit 1201 includes a determination unit output storage register 1301, an input signal storage register 1302, a normal tap coefficient 1303, a reduced tap coefficient 1304, a tap coefficient multiplier 1305, And a filter output adder 1306.

  The coefficient variable band limiting unit 1201 internally has two types of tap coefficients, a normal tap coefficient and a reduced tap coefficient, and receives an output signal of the determination unit 804, for example, a binary signal such as “0” or “1”, and a switch It is possible to switch with. That is, when the output of the determination unit 804 is determined to be a peak value and is a signal for which peak suppression is to be performed, for example, the above-described signal “1” takes in the bit that affects the peak occurrence in the smaller coefficient. When the switch is turned on and the peak value is not reached, for example, the signal “0” is switched to a normal coefficient.

  As described above, according to the peak reduction configuration unit of the fifth embodiment, when the peak is measured in the peak prediction unit from the baseband signal and it is determined that the peak value is greater than a specific value, the tap coefficient of the coefficient variable filter is determined. By switching the normal tap coefficient to the smaller one, the output equivalent to that of the fourth embodiment can be obtained, the peak can be smoothly reduced, and the PAR is reduced. Further, the RMS value can be made constant by multiplying the gain part in the final stage.

  The mobile communication terminal apparatus according to the present invention can be applied to code division multiplexing.

It is a block diagram which shows the mobile communication terminal device which concerns on this invention. It is a block diagram which shows the structure of the peak reduction structure part in Embodiment 1 of this invention. It is a block diagram which shows another structure of the peak reduction structure part in Embodiment 1 of this invention. 6 is a table example of a gain unit in the first embodiment. It is a block diagram which shows the structure of the peak reduction structure part in Embodiment 2 of this invention. It is a block diagram which shows the structure of the peak reduction structure part in Embodiment 3 of this invention. It is an example of a table in the variable limit value output part in Embodiment 3. It is a block diagram which shows the structure of the peak reduction structure part in Embodiment 4 of this invention. It is an addition image figure of the output of the band limitation part and peak reduction band limitation part in this invention. It is a figure which shows the processing image of the peak estimation part in Embodiment 4. FIG. FIG. 10 is a block diagram of a peak reduction band limiting unit in a fourth embodiment. It is a block diagram which shows the structure of the peak reduction structure part in Embodiment 5 of this invention. FIG. 10 is a block diagram of a coefficient variable band limiting unit in a fifth embodiment.

Explanation of symbols

101 modulator, 102 peak reduction component,
103 control unit, 104 D / A converter,
105 quadrature modulator, 106 amplifier,
201 band limiting unit, 202 gain unit,
203 multiplier for RMS adjustment gain, 204 limiter,
501 multiplier for amplitude adjustment gain, 601 variable limit value output unit,
602 variable limiter, 801 peak predictor,
802 square multiplier, 803 square signal adder,
804 determiner, 805 delay unit,
806 switching unit, 807 peak reduction band limiting unit,
808 filter output adder, 1101 reduction factor,
1102 coefficient multiplier, 1201 coefficient variable band limiting unit,
1301 judgment unit output storage register, 1302 input signal storage register,
1303 Normal tap coefficient, 1304 Reduction tap coefficient,
1305 Multiplier for tap coefficient, 1306 Adder for filter output.

Claims (6)

At least the transmission data of the data channel and the control data of the first control channel are IQ-multiplexed, and according to the instruction from the base station, the transmission data of the data channel and the control data of the first control channel are In addition, a modulation unit that IQ multiplexes control data of the second control channel to generate a complex signal, and outputs an in-phase signal and a quadrature signal;
Control for outputting to the modulator a first gain factor corresponding to the data channel, a second gain factor corresponding to the first control channel, and a third gain factor corresponding to the second control channel. And
Correction for correcting the in-phase signal and the quadrature signal by using gains according to the first gain factor, the second gain factor, and the third gain factor output from the control unit to the modulation unit. A mobile communication terminal apparatus comprising: a peak reduction configuration unit having a unit.   The mobile communication terminal according to claim 1, wherein the peak reduction configuration unit includes a limiter unit that suppresses peaks of the in-phase signal and the quadrature signal output from the modulation unit using a predetermined limiter value. apparatus.   The peak reduction configuration unit is configured to set a limit value according to a first gain factor, a second gain factor, and a third gain factor output from the control unit to the modulation unit. The mobile communication terminal device according to claim 2.   The peak reduction configuration unit corrects the in-phase signal and the quadrature signal output from the limiter unit by a gain obtained based on the limit value used by the limiter unit, the number of bits of the in-phase signal and the quadrature signal. The mobile communication terminal apparatus according to claim 2, further comprising a second correction unit.   The peak reduction configuration unit is configured to set the instantaneous power measured from the in-phase signal and the quadrature signal output from the modulation unit according to the first gain factor, the second gain factor, and the third gain factor. A determination unit that determines the occurrence of a peak in comparison with a threshold value includes a filter having a different tap coefficient, and selects the filter having a different tap coefficient in accordance with a determination result of the determination unit, so that the in-phase signal and the quadrature signal The mobile communication terminal apparatus according to claim 1, further comprising a band limiting unit that performs band limiting.   The peak reduction configuration unit includes a first band limiting unit and a second band limiting unit having different tap coefficients, an adder for adding output signals of the first band limiting unit and the second band limiting unit, And a switching unit that selectively inputs the in-phase signal and the quadrature signal from the modulation unit to either the first band limiting unit or the second band limiting unit according to the determination result of the determination unit. The mobile communication terminal apparatus according to claim 5.

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