JP2009267653A - Radio communication device, and method for controlling transmission power - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To allow transmission power control in which cost increase and power consumption are suppressed without separately requiring an exclusive mounting space, and a back off amount is reduced as much as possible while approximately exactly satisfying ACPR (Adjacent Channel leakage Power Ratio) characteristics. <P>SOLUTION: A transmission IC circuit part 40 converts a transmission signal of a base band into a transmission signal with a transmission frequency, adjusts transmission power of the transmission signal to output it from an antenna 10. A reception IC circuit part 20 converts the signal with a reception frequency, received by the antenna 10 into a reception signal in the base band. The reception IC circuit part 20 is controlled so that the reception frequency approximately equals to the transmission frequency by a reception IC control signal from the control part. A modem part provided at a rear stage of the reception IC circuit part 20, obtains an RSSI (Received Signal Strength Indicator) value from the reception base band signal, and transmits the RSSI value to the control part. The control part presumes the ACPR characteristics from the RSSI value, and generates transmission AG control voltage for controlling an AGC amplifier 42 of the transmission IC circuit part 40 according to the ACPR characteristics. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a wireless communication apparatus such as a mobile phone terminal, and more particularly to a wireless communication apparatus having a function of controlling maximum transmission power and a transmission power control method thereof.

  In recent years, 1xEV-DO Rev., which is an extension of the so-called third generation data communication standard in mobile communication. As in the A standard, a communication method in which the transmission data rate of mobile communication is increased has become widespread.

  In these communication systems, in order to realize a high-speed data communication rate, as a modulation system of a signal transmitted from a mobile communication terminal, more advanced such as so-called QPSK (Quadrature Phase Shift Keying) and 8PSK (8 Phase Shift Keying) are used. Various modulation schemes are used.

  However, these modulation schemes have a problem that the peak factor increases, and therefore the ACPR (Adjacent Channel leakage Power Ratio) characteristics deteriorate.

  On the other hand, in the standard of a mobile communication transmitter, it is required to ensure an ACPR characteristic equivalent to that of a conventional modulation method. Therefore, for example, the required characteristic of ACPR is satisfied without reducing the maximum transmission power. Therefore, a power amplifier (PA) with better linearity is required.

  However, when a power amplifier with good linearity is used, efficiency (efficiency such as transmission power versus power consumption) is reduced compared to conventional power amplifiers, and heat generation is increased. There are disadvantages such as shortage and shortened battery usage time.

  For this reason, a power amplifier equivalent to the conventional one is used, and when a high-speed communication rate is used, the maximum transmission power is lowered (that is, backed off) in order to satisfy the ACPR characteristic. Control is generally performed.

  However, the higher the data rate, the greater the C / I (carrier power to interference noise power ratio) required when demodulating at the base station is required, so in order to achieve better throughput and the like, A smaller backoff amount is desirable.

  On the other hand, in the conventional technology, the back-off amount is uniformly determined for each data rate, and the back-off amount for each data rate takes into account all worst cases such as individual differences of mobile communication terminals and temperature conditions, for example. Therefore, there is a problem that the back-off amount cannot be reduced so much.

  Japanese Patent Laid-Open No. 2003-163607 (Patent Document 1) discloses a wireless device that uses a plurality of radio frequency transmission channels and transmits a plurality of transmission signals. In the wireless device described in this publication, the power value of the transmission signal of the transmission channel and the power value leaking to the adjacent channel are measured by the measuring means, and the measurement result is compared with the desired value. In the wireless device described in this publication, the control means controls the supply voltage and the input signal of the amplification means according to the comparison result, thereby obtaining good power efficiency and enabling effective use of the frequency.

Japanese Patent Laying-Open No. 2003-163607 (FIG. 1)

  Here, in the mobile communication terminal, as described in Patent Document 1, a transmission signal power value and a leakage power value to an adjacent channel are measured, and transmission is performed based on a comparison result between the measured value and a desired value. Good power efficiency can be obtained by controlling the supply voltage to the amplifier of the circuit.

  On the other hand, mobile phone terminals, which are typical examples of mobile communication terminals in recent years, are required to be thin and miniaturized in housings, and to reduce costs. Therefore, it is very difficult to secure a space for mounting the dedicated hardware for measuring the transmission signal power value and the leakage power value to the adjacent channel in the mobile phone terminal. If dedicated hardware is installed, an increase in cost is inevitable.

  In the case of the technique described in Patent Document 1, since a signal obtained by branching a part of the transmission signal by the coupler is sent to the measurement circuit, the transmission power is reduced accordingly. In addition, although it is possible to supplement the transmission power for the branch by the coupler, in that case, the supplemented power becomes unnecessary and power consumption increases.

  The present invention has been proposed in view of such circumstances, and it is not necessary to secure a separate dedicated mounting space in the terminal housing, and it is possible to suppress a rise in cost and power consumption. It is another object of the present invention to provide a transmission power control method.

  The present invention also provides a radio communication apparatus and a transmission power control method that enable transmission power control that minimizes the back-off amount while satisfying the ACPR characteristics with respect to the adjacent channel leakage power actually radiated from the antenna. The purpose is to do.

  The wireless communication device of the present invention converts a transmission signal of a baseband band into a transmission signal of a transmission frequency, adjusts the transmission power of the transmission signal and outputs from the antenna, and a reception frequency received by the antenna And a receiving circuit unit for converting the received signal into a received signal in the baseband band. In addition, the wireless communication apparatus of the present invention includes a reception frequency control unit that controls the reception frequency of the reception circuit unit to be substantially equal to the transmission frequency of the transmission circuit unit. Furthermore, the wireless communication apparatus of the present invention has an adjacent channel leakage power ratio acquisition unit that obtains an adjacent channel leakage power ratio of the transmission signal of the own apparatus from the signal strength of the reception signal having a reception frequency substantially equal to the transmission frequency. And the radio | wireless communication apparatus of this invention has a transmission power control part which adjusts and controls the transmission power of a transmission circuit part according to the adjacent channel leakage power ratio of the transmission signal of the said own apparatus. Thereby, this invention solves the subject mentioned above.

  The transmission power control method of the present invention converts a baseband transmission signal into a transmission frequency signal, adjusts the transmission power of the signal and outputs the signal from the antenna, while receiving the reception frequency signal received by the antenna. It is a transmission power control method of a radio communication device for converting into a baseband signal. Here, in the transmission power control method of the present invention, the step of controlling the reception frequency to be substantially equal to the transmission frequency, and the signal strength of the reception signal of the reception frequency substantially equal to the transmission frequency, Determining an adjacent channel leakage power ratio. In addition, the transmission power control method of the present invention includes a step of adjusting and controlling the transmission power of the transmission circuit unit according to the adjacent channel leakage power ratio of the transmission signal of the device itself. Thereby, this invention solves the subject mentioned above.

  That is, according to the present invention, by making the reception frequency of the reception circuit unit approximately equal to the transmission frequency of the transmission circuit unit, the transmission signal of the own device is received by the reception circuit unit of the own device, and the received signal The adjacent channel leakage power ratio is obtained from the signal strength.

  In the present invention, the reception frequency is made substantially equal to the transmission frequency, the transmission signal of the own apparatus is received by the reception circuit unit, and the adjacent channel leakage power ratio is obtained from the signal strength of the reception signal. Therefore, in the present invention, it is not necessary to separately provide a dedicated circuit for measuring the adjacent channel leakage power ratio and its mounting space. Further, in the present invention, it is possible to suppress an increase in cost and power consumption. In the present invention, transmission power control is performed to reduce the backoff amount as much as possible while satisfying the ACPR characteristic for the adjacent channel leakage power actually radiated from the antenna by performing transmission power control based on the adjacent channel leakage power ratio. It is possible.

  Hereinafter, an embodiment of the present invention will be described with reference to the drawings.

  In the present embodiment, a mobile phone terminal is cited as an application example of the wireless communication apparatus and the transmission power control method of the present invention. Of course, the content described here is merely an example, and the present invention is not limited to this example. Needless to say, it is not limited to.

[Configuration of main parts of mobile phone terminal]
FIG. 1 shows a schematic configuration of a transmission / reception circuit unit (RF unit) of a so-called CDMA (Code Division Multiple Access) mobile phone terminal. FIG. 2 shows a schematic overall configuration of the mobile phone terminal, and the transmission / reception circuit section of FIG. 1 is provided in the communication circuit 2 of FIG.

  The baseband signal input terminal 50 in FIG. 1 is supplied with in-phase and quadrature component transmission baseband signals from the modem unit 6 of the communication circuit 2 in FIG. The transmission baseband signal is input to the transmission IC (TxIC) circuit unit 40 of the transmission / reception circuit unit 5.

  The in-phase and quadrature component transmission baseband signals input to the transmission IC circuit unit 40 are amplified by the in-phase and quadrature component amplifiers 27 and 28, respectively, and then sent to the quadrature up-converter 43.

  The quadrature up-converter 43 performs quadrature modulation on the in-phase and quadrature component transmission baseband signals and upconverts the signals to signals in the transmission frequency band. At this time, the transmission frequency when the orthogonal up-converter 43 performs up-conversion is supplied from the transmission frequency generation circuit.

  The transmission frequency generation circuit includes an oscillator (VCO) 49, a transmission PLL (TXPLL) circuit 47 and a loop filter 48, and a local generator / distributor 46. The oscillator 49 generates a local oscillation reference frequency. The transmission PLL circuit 47 and the loop filter 48 generate a transmission frequency from the local oscillation reference frequency. The local generator / distributor 46 supplies the transmission frequency of the transmission PLL circuit 47 to the orthogonal up converter 43 as a local transmission frequency signal.

  The transmission signal orthogonally modulated and upconverted by the orthogonal upconverter 43 is subjected to gain adjustment by an AGC amplifier (variable gain amplifier) 42 and then sent to the bandpass filter 17 via the amplifier 41. The bandpass filter 17 passes only the transmission frequency band and removes other unnecessary components.

  The transmission signal after filtering by the bandpass filter 17 is amplified by the power amplifier 16 and then sent from the antenna duplexer (duplexer) 11 to the antenna 10. Thereby, the transmission signal is transmitted from the antenna 10 to a base station (not shown). Since the transmission frequency and the reception frequency are separated from each other by several tens to several hundreds of MHz, the antenna duplexer 11 can share one antenna 10 by using the frequency difference between them.

  In addition, the output of the power amplifier 16 is detected by the detection circuit 15, and the detected voltage value is sent from the terminal 18 to the control unit 1 in FIG.

  2 is also supplied with a transmission IC control signal (TxIC control signal) through a terminal 51 and a transmission AGC control signal (TxAGC control voltage value) through a terminal 52 from the control unit 1 in FIG. . The transmission IC control signal is an operation control signal of each part of the transmission IC circuit unit 40, and the transmission AGC control signal is a control voltage value for determining a gain adjustment value of the AGC amplifier 42. Although details will be described later, in particular, the cellular phone terminal of the present embodiment adjusts the gain of the AGC amplifier 42 with the transmission AGC control signal so as to minimize the back-off amount while satisfying the ACPR characteristics. Transmission power control can be realized.

  On the other hand, a signal transmitted from the base station is received by the antenna 10, and the received signal is input from the antenna duplexer 11 to the reception IC circuit unit 20 of the transmission / reception circuit unit 5.

  The received signal received by the antenna 10 and input to the receiving IC circuit unit 20 is amplified by the low noise amplifier 21 and then sent to the band pass filter 22. The bandpass filter 22 passes only the reception frequency band and removes other unnecessary components.

  The received signal after filtering by the bandpass filter 22 is further amplified by the low noise amplifier 23 and then sent to the orthogonal down converter 24.

  The quadrature down-converter 24 down-converts the reception signal in the reception frequency band into a reception base band signal and converts the received signal into a reception base band signal having in-phase and quadrature components by quadrature detection. At this time, the reception frequency when the orthogonal down converter 24 performs down-conversion is supplied from the reception frequency generation circuit.

  The reception frequency generation circuit includes an oscillator (VCO) 30, a reception PLL (RXPLL) circuit 31, a loop filter 32, and a local generator / distributor 29. The oscillator 30 generates a local oscillation reference frequency. The reception PLL circuit 31 and the loop filter 32 generate a reception frequency from the local oscillation reference frequency. The local generator / distributor 29 supplies the reception frequency of the reception PLL circuit 31 to the orthogonal down converter 24 as a local reception frequency signal.

  The reception signals subjected to quadrature detection and down-conversion by the quadrature dow converter 24 are respectively filtered by in-phase and quadrature component low-pass filters 25 and 26 (hereinafter referred to as baseband filters 25 and 26 in particular). The filtered received signal is amplified by the in-phase and quadrature component amplifiers 44 and 45, respectively, and then output from the baseband signal output terminal 33 to the modem unit 6 of the communication circuit 2 in FIG.

  In addition, a reception IC control signal (RxIC control signal) is supplied to the reception IC circuit unit 20 from the control unit 1 of FIG. The reception IC control signal is an operation control signal for each part of the reception IC circuit unit 20. Although details will be described later, in particular, the cellular phone terminal according to the present embodiment is handled by the orthogonal down converter 24 by controlling the oscillator 30 and the reception PLL circuit 31 of the reception frequency generation circuit with the reception IC control signal. The reception frequency can be changed. The cellular phone terminal according to the present embodiment can change the frequency characteristics (cut-off frequency) of the baseband filters 25 and 26 by controlling the baseband filters 25 and 26 with the reception IC control signal. ing.

  FIG. 3 shows a schematic frequency-amplitude characteristic diagram of the baseband filters 25 and 26. As shown in FIG. 3, the baseband filters 25 and 26 are basically low-pass filters having a cut-off frequency characteristic that passes only the desired reception signal band while removing the interference wave from the adjacent channel. . However, in the case of the present embodiment, the baseband filters 25 and 26 are variable filters that can change the frequency characteristics by a reception IC control signal.

  In addition, the transmission IC circuit unit 40 and the reception IC circuit unit 20 are also supplied with a reference clock from a temperature compensated crystal oscillator (TCXO) 12.

  The other block 4 in FIG. 2 is a block that collectively represents each component provided in a general mobile phone terminal. Examples of these components include operation units such as a speaker, a microphone, a sound processing circuit, an image processing circuit, a numeric keypad, a speech key, an end / power key, a cross key, and a jog dial. Examples of each component include a display unit such as a liquid crystal display and an organic EL (ElectroLuminescent) display, a digital camera unit, and an LED (light emitting diode) unit for key illumination and incoming light. In addition, each component includes a battery that supplies power to each unit, a power management IC unit that controls the power, a GPS (Global Positioning System) communication unit, an external memory slot, a digital broadcast reception tuner unit, and an AV codec unit And so on. In addition, each component includes a short-range wireless communication unit for performing short-range wireless communication using a so-called Bluetooth method (Bluetooth: registered trademark), UWB (Ultra Wide Band) method, wireless LAN (Local Area Network), or the like. Also mentioned.

  2 includes a control program and application program for the control unit 1 to control the communication circuit 2, control of audio processing, control of image processing, other various signal processing and control of each unit, and the like. Various data to be stored is stored. In particular, although details will be described later, the memory unit 3 of the present embodiment stores a communication control program for the control unit 1 to realize transmission power control that minimizes the backoff amount while satisfying the ACPR characteristics. Has been. Similarly, although details will be described later, the memory unit 3 stores the difference in baseband signal strength received before and after the change of the reception frequency in the reception IC circuit unit 20 and the change of the frequency characteristics of the baseband filters 25 and 26, and the ACPR characteristic. Also stored is look-up table data in association with ACPR characteristics for realizing transmission power control that minimizes the back-off amount while satisfying.

  In addition, the temperature sensor 60 measures the temperature of the mobile phone terminal, and the measured temperature signal is sent from the terminal 61 to the control unit 1. Thereby, the control part 1 can know the present temperature of a mobile telephone terminal.

[Estimation of ACPR characteristics]
In the mobile phone terminal of the present embodiment, the control unit 1 controls the reception IC circuit unit 20 and the transmission IC circuit unit 40 as follows, and performs the calculation / reference processing described later, thereby actually radiating from the antenna 10. It is possible to estimate the ACPR characteristic for the adjacent channel leakage power. The calculation / reference processing is calculation / reference processing using the intensity of the received baseband signal obtained from the receiving IC circuit unit 20 and the lookup table of the memory unit 3.

  FIG. 4 shows a flowchart of control and calculation / reference processing in the control unit 1 when estimating the ACPR characteristic.

  In FIG. 4, the control unit 1 first performs control for operating the transmission IC circuit unit 40 in the same manner as during normal signal transmission by the transmission IC control signal as the control process of step S <b> 1. At the same time, the control unit 1 controls the oscillator 30 and the reception PLL circuit 31 of the reception IC circuit unit 20 according to the reception IC control signal so that the reception frequency of the reception IC circuit unit 20 is the transmission frequency of the transmission IC circuit unit 40. To be equal to That is, the oscillator 30 and the reception PLL circuit 31 of the reception IC circuit unit 20 at this time are controlled to operate at the same frequency as the oscillator 49 and the transmission PLL circuit 47 of the transmission IC circuit unit 20. As a result, the same local frequency signal output from the local generator / distributor 46 of the transmission IC circuit unit 40 is output from the local generator / distributor 29 of the reception IC circuit unit 20 and is sent to the orthogonal down converter 24. It will be.

  In general, the antenna duplexer 11 sends a signal in the reception frequency band to the reception IC circuit unit 20 side. Further, the band-pass filter 22 provided in the subsequent stage of the low noise amplifier 21 on the reception IC circuit unit 20 side uses a filter that passes only the reception frequency band (in other words, a filter having a large attenuation in the transmission frequency band). However, normally, in the vicinity of the maximum transmission power in which the ACPR characteristic is a problem, a transmission signal of a certain level may be received even if it is divided by the antenna duplexer 11 or attenuated by the bandpass filter 22. Are known.

  Therefore, as described above, the transmission IC circuit unit 40 is operated as usual, and at the same time, the oscillator 30 and the reception PLL circuit 31 of the reception IC circuit unit 20 are controlled to receive the reception frequency in the reception IC circuit unit 20. Is set to be equal to the transmission frequency of the transmission IC circuit unit 40, the above-mentioned transmission signal of a certain level or more is input to the orthogonal down converter 24 as a reception signal.

  Therefore, the orthogonal down converter 24 in this case outputs a signal obtained by down-converting the transmission signal to the baseband.

  Next, as a control process in step S2, the control unit 1 controls the baseband filters 25 and 26 of the reception IC circuit unit 20 by the reception IC control signal, and sets the frequency characteristics of the baseband filters 25 and 26 to ACPR characteristics. Is controlled to be narrower than the detuning frequency defined as. As an example, when the use frequency band is the 800 MHz band, the detuning frequency is 885 kHz, so the control unit 1 controls the cutoff frequency of the baseband filters 25 and 26 to be narrower than at least 885 kHz.

  Then, the control unit 1 calculates the intensity of the baseband signal output from the baseband signal output terminal 33 in the state in which the cutoff frequency of the baseband filters 25 and 26 is narrowly controlled as described above as the calculation process in step S3. Measure. More specifically, the modem unit 6 provided at the subsequent stage of the baseband signal output terminal 33 performs a so-called RSSI (Received Signal Strength Indicator) when the received baseband signal is A / D converted. ) To measure. Therefore, the control unit 1 at this time acquires the RSSI value measured by the modem unit 6 as the intensity of the baseband signal.

  Next, as a control process in step S4, the control unit 1 controls the baseband filters 25 and 26 of the reception IC circuit unit 20 by the reception IC control signal, and the frequency characteristics of the baseband filters 25 and 26 are changed to the ACPR characteristics. The frequency is controlled to be wider than the detuning frequency specified as. As an example, the control unit 1 performs control so that the cutoff frequency of the baseband filters 25 and 26 is widened to about 1.98 MHz.

  Then, the control unit 1 calculates the intensity of the baseband signal output from the baseband signal output terminal 33 in a state where the cutoff frequency of the baseband filters 25 and 26 is widely controlled as described above as the calculation process in step S5. Is measured in the same manner as in step S3 described above.

  Next, the control unit 1 calculates the difference between the baseband signal strength obtained by the above-described step S2 and step S3 and the baseband signal strength obtained by the above-described step S4 and step S5 as the calculation process of step S6. Calculate

  Thereafter, the control unit 1 associates a plurality of baseband signal strength differences with a plurality of ACPR characteristics in advance based on the baseband signal strength difference values obtained by the calculation processing in step S6 as the reference processing in step S7. The ACPR characteristic corresponding to the baseband signal strength difference in step S6 is obtained by referring to the lookup table prepared in the memory unit 3.

  That is, by performing the control and calculation / reference processing as described above, the control unit 1 uses the reception IC circuit unit 20 of its own terminal to detect the adjacent channel leakage power actually radiated from the antenna 10 of its own terminal. The ACPR characteristic can be known.

  Here, in FIGS. 5 and 6, the cut-off frequencies of the baseband filters 25 and 26 are changed in the above-described steps S2 and S4, and the cut-off frequencies are changed in steps S3 and S5. The figure for demonstrating that an ACPR characteristic can be estimated from the measured baseband signal intensity | strength is shown. FIG. 5 shows the relationship between the baseband signal when the ACPR characteristic is relatively good (the signal obtained by down-converting the transmission signal into the baseband band) and the frequency-amplitude characteristic of the baseband filter whose cutoff frequency is changed. Represents a relationship. FIG. 6 shows the relationship between the baseband signal when the ACPR characteristic is relatively poor and the frequency-amplitude characteristic of the baseband filter whose cutoff frequency is changed.

  When the ACPR characteristic is relatively good as in the example of FIG. 5, it can be seen that the signal intensity of the portion outside the detuning frequency defined by the ACPR characteristic is small. On the other hand, as shown in the example of FIG. 6, when the ACPR characteristic is relatively poor, it can be seen that the signal intensity of the portion outside the detuning frequency defined by the ACPR characteristic is large.

  That is, when FIG. 5 and FIG. 6 are compared, the signal intensity measured using the baseband filter whose cutoff frequency is narrower than the detuning frequency and the baseband filter whose cutoff frequency is wider than the detuning frequency. 6 is larger than that of FIG. 5 in terms of the difference from the signal intensity measured in a state where the symbol is used, in other words, the area of the hatched portion in the figure. Therefore, it is possible to estimate the ACPR characteristic with respect to the adjacent channel leakage power actually radiated from the antenna 10 of the terminal by examining how much the difference between the signal strengths is. In the present embodiment, a lookup table in which a plurality of baseband signal strength differences and a plurality of ACPR characteristics are associated in advance is prepared in the memory unit 3, and the cutoff frequency of the baseband filter is actually changed. The ACPR characteristic is acquired by referring to the lookup table based on the difference in baseband signal intensity measured in step (1).

  4 is performed when the user uses the mobile phone terminal for the first time, or when the temperature measured by the temperature sensor 60 in FIG. This is executed when a substantial communication such as a telephone call or data communication is not performed at the telephone terminal and every time a predetermined period of time elapses. This is because if the processing of this flowchart is performed during communication with the base station, the mobile phone terminal cannot receive a transmission signal from the base station. However, for example, when the mobile phone terminal has a function capable of separately receiving a signal from the base station even when measuring the ACPR characteristic (for example, reception using the diversity communication function), It is also possible to perform the processing of the flowchart of FIG. 4 regardless of whether or not communication such as data communication is performed.

[Transmission power control based on ACPR characteristics]
The mobile phone terminal according to the present embodiment determines a margin with respect to the standard of the ACPR characteristic based on the ACPR characteristic estimated as described above, and controls the maximum transmission power according to the margin. It is possible to realize transmission power control that minimizes the backoff amount while satisfying the characteristics.

  FIG. 7 shows a flowchart of the margin determination based on the estimated ACPR characteristic in the control unit 1 and the transmission power control according to the margin.

  In FIG. 7, the control unit 1 determines whether or not the signal transmission from the mobile phone terminal has a transmission power equal to or higher than a predetermined threshold as a determination process in step S <b> 10. Advances to the process of step S11, and when it is less than the predetermined threshold value, returns to the beginning of the flow of FIG. In general, when the transmission power is low to some extent, the ACPR characteristic does not become a problem. In this embodiment, a low transmission power value that does not cause a problem with the ACPR characteristic is obtained in advance. The transmission power value is set as the predetermined threshold value. Therefore, when it is determined in step S10 that the transmission power is less than the predetermined threshold, the control unit 1 of the present embodiment returns to the beginning of the flow of FIG. 7 so as not to proceed to the processing after step S11. Yes.

  When the process proceeds to step S11, the control unit 1 acquires the ACPR characteristic according to the flow described with reference to FIG.

  Next, when the process proceeds to step S12, the control unit 1 determines whether the ACPR characteristic acquired in step S11 satisfies the standard value of the ACPR characteristic.

  If it is determined in step S12 that the standard value is not satisfied, the control unit 1 advances the processing to step S15, and sets the transmission IC circuit unit 40 to reduce the maximum transmission power in order to satisfy the ACPR standard. Control. That is, the control unit 1 at this time controls the transmission control voltage value so as to lower the gain of the AGC amplifier 42, for example.

  On the other hand, if it is determined in step S12 that the standard value is satisfied, the control unit 1 proceeds to step S13 and determines whether or not signal transmission from the mobile phone terminal is performed with the maximum transmission power.

  If it is determined in step S13 that the transmission power is maximum, it can be determined that there is a margin in the ACPR characteristics and there is room for further increase in transmission power. Therefore, the control unit 1 proceeds to step S14, and the maximum transmission power is reached. The transmission IC circuit unit 40 is controlled to increase That is, the control unit 1 at this time controls the transmission control voltage value so as to increase the gain of the AGC amplifier 42, for example.

  On the other hand, when it is determined in step S13 that the transmission power is not the maximum, the control unit 1 returns to the beginning of the flow of FIG.

  The control unit 1 repeatedly performs the processing of the flow of FIG. 7 during transmission. Thereby, according to the mobile phone terminal of the present embodiment, it is possible to control the maximum transmission power according to the margin of the ACPR characteristic.

[Summary]
As described above, according to the embodiment of the present invention, the back-off amount can be reduced within the range allowed by the ACPR characteristic, as compared with the case where the back-off is performed with a certain fixed amount as in the prior art. . As a result, according to the embodiment of the present invention, C / I on the base station side is improved, and an improvement in throughput during uplink communication to the base station side is expected. Further, according to the present embodiment, even when the ACPR characteristic is deteriorated due to, for example, a malfunction of the transmission IC circuit unit 40, it is possible to detect this and take a file-safe measure such as stopping transmission, for example. become able to.

  Further, in the embodiment of the present invention, the ACPR characteristic is obtained by diverting the receiving IC circuit unit 20 provided for receiving the signal from the base station. There is no need to secure a mounting space unlike when a circuit is separately provided. Further, in the embodiment of the present invention, it is possible to suppress an increase in cost due to an increase in hardware, and it is possible to suppress power consumption. Of course, in the present embodiment, since no dedicated circuit is provided, it is not necessary to add a new control process for controlling the dedicated circuit. In the embodiment of the present invention, it is possible to obtain an accurate ACPR characteristic with respect to the adjacent channel leakage power actually radiated from the antenna.

  The above description of the embodiment is an example of the present invention. For this reason, the present invention is not limited to the above-described embodiment, and it is needless to say that various modifications can be made according to the design or the like as long as the technical idea according to the present invention is not deviated.

  The present invention is not limited to the mobile phone terminals described in the above-described embodiments, but can be applied to various terminals such as PDAs and navigation devices having a communication function, portable game machines, and AV devices.

It is a circuit diagram which shows schematic structure of the transmission / reception circuit part (RF part) of the mobile telephone terminal of this invention embodiment. 1 is a block diagram showing a schematic overall configuration of a mobile phone terminal according to an embodiment of the present invention. FIG. 4 is a schematic frequency-amplitude characteristic diagram of a baseband filter in a reception IC circuit unit. It is a flowchart of the control in a control part at the time of estimating an ACPR characteristic, and a calculation and reference process. It is a frequency-amplitude characteristic diagram used for explaining the relationship between the baseband signal when the ACPR characteristic is relatively good and the frequency-amplitude characteristic of the baseband filter whose cutoff frequency is changed. It is a frequency-amplitude characteristic diagram used for explaining the relationship between the baseband signal when the ACPR characteristic is relatively poor and the frequency-amplitude characteristic of the baseband filter whose cutoff frequency is changed. It is a flowchart of the judgment of the margin based on the estimated ACPR characteristic in a control part, and the transmission power control according to the said margin.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 Control part, 2 Communication circuit, 3 Memory part, 4 Other blocks, 5 Transmission / reception IC circuit part, 6 Modem part, 10 Antenna, 11 Antenna duplexer, 12 Temperature compensation type crystal oscillator, 15 Detection circuit, 16 Power amplifier, 17 , 22 Bandpass filter, 20 Receiver IC circuit unit, 21, 23 Low noise amplifier, 24 Quadrature down converter, 25, 26 Low pass filter (baseband filter), 27, 28, 41, 44, 45 Amplifier, 29, 46 Local generation・ Distributor, 30, 49 oscillator (VCO), 31 reception PLL circuit, 32, 48 loop filter, 47 transmission PLL circuit, 33 baseband signal output terminal, 34 reception IC control signal input terminal, 40 transmission IC circuit section, 50 Baseband signal input terminal, 51 Input of transmission IC control signal Terminal, 60 a temperature sensor, an output terminal 61 the temperature detection signal

Claims (7)

A transmission circuit unit that converts a transmission signal of a baseband band into a transmission signal of a transmission frequency, adjusts the transmission power of the transmission signal, and outputs it from an antenna;
A receiving circuit unit for converting a signal of a reception frequency received by an antenna into a reception signal of a baseband;
A reception frequency control unit for controlling the reception frequency of the reception circuit unit to be substantially equal to the transmission frequency of the transmission circuit unit;
An adjacent channel leakage power ratio acquisition unit for obtaining an adjacent channel leakage power ratio of the transmission signal of the own device from a signal strength of a reception signal having a reception frequency substantially equal to the transmission frequency;
A transmission power control unit that adjusts and controls the transmission power of the transmission circuit unit according to the adjacent channel leakage power ratio of the transmission signal of the device itself;
A wireless communication device. The reception circuit unit includes a reception frequency generation unit that generates a reception frequency, a reception signal frequency conversion unit that converts a reception signal of the reception frequency into a reception signal of a baseband, and a base that passes the reception signal of the baseband A band filter,
The reception frequency control unit controls the reception frequency generation unit so that the reception frequency is substantially equal to the transmission frequency, and sets the frequency characteristics of the baseband filter as characteristics of the adjacent channel leakage power ratio in advance. Change control to a frequency characteristic separated by a predetermined frequency with respect to the specified detuning frequency,
The transmission power control unit determines an adjacent channel leakage power ratio from a plurality of adjacent channel leakage power ratios prepared in advance based on a difference in signal strength of a received signal that has passed through the baseband filter before and after the frequency characteristic change. To obtain the adjacent channel leakage power ratio of the transmission signal of the own device,
The transmission power control unit adjusts and controls the transmission power of the transmission circuit unit according to a margin that the adjacent channel leakage power ratio of the transmission signal of the own device has with respect to a predetermined adjacent channel leakage power ratio. The wireless communication apparatus according to claim 1. The reception frequency control unit controls the frequency characteristic of the baseband filter so as to be narrower by a predetermined frequency than the detuning frequency defined in advance as the characteristic of the adjacent channel leakage power ratio, and the predetermined frequency from the detuning frequency. Perform control to change the frequency characteristics of the baseband filter so that only the frequency is widened,
The transmission power control unit performs control to change the signal strength of the received signal that has passed through the baseband filter whose frequency characteristics have been controlled to be narrowed by the predetermined frequency, and the frequency characteristics to be widened by the predetermined frequency. The wireless communication device according to claim 2, wherein the difference from the signal strength of the received signal that has passed through the baseband filter is obtained.   The transmission power control unit has a correspondence table of a plurality of difference values and a plurality of adjacent channel leakage power ratios, and the adjacent channel leakage power ratio obtained by referring to the correspondence table with the obtained difference The wireless communication device according to claim 2, wherein the adjacent channel leakage power ratio of the transmission signal of the own device is used.   The transmission power control unit, when the adjacent channel leakage power ratio of the transmission signal of the own device satisfies a predetermined adjacent channel leakage power ratio, and the transmission power of the transmission circuit unit is the maximum transmission power The wireless communication apparatus according to claim 2, wherein adjustment control is performed to further increase the transmission power.   The transmission power control unit performs adjustment control so as to reduce the transmission power of the transmission circuit unit when the adjacent channel leakage power ratio of the transmission signal of the own apparatus does not satisfy a predetermined adjacent channel leakage power ratio. The wireless communication apparatus according to claim 5. The transmission circuit unit converts the transmission signal of the baseband band into a transmission signal of the transmission frequency, adjusts the transmission power of the transmission signal, and outputs from the antenna;
The reception circuit unit converts the reception frequency signal received by the antenna into a reception signal of the baseband, and
Controlling the reception frequency of the reception circuit unit so that the reception frequency control unit is substantially equal to the transmission frequency of the transmission circuit unit;
From the signal strength of the received signal having a reception frequency substantially equal to the transmission frequency, the adjacent channel leakage power ratio acquisition unit obtains the adjacent channel leakage power ratio of the transmission signal of the own device;
The transmission power control unit adjusts and controls the transmission power of the transmission circuit unit according to the adjacent channel leakage power ratio of the transmission signal of the own device,
A transmission power control method characterized by the above.

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