JP2011071834A - Radio communication equipment - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide radio communication equipment capable of maintaining successful ACP (adjacent channel leakage power) characteristics without depending on a transmission frequency and suppressing the deterioration of signal quality. <P>SOLUTION: The radio communication equipment transmits a transmission signal in a predetermined frequency band, and is provided with: a power amplifier which amplifies the transmission signal; a storage part which preliminarily stores bias setting data showing a correspondence relation between a transmission output setting value and a bias voltage setting value set based on adjacent channel leakage power characteristics and frequency correction data showing a correspondence relation between a transmission frequency setting value and a frequency correction value of the transmission output setting value; and a control part which acquires the frequency correction value corresponding to the present transmission frequency setting value from the frequency correction data, corrects the present transmission output setting value using the acquired frequency correction value, and determines a bias voltage setting value corresponding to the transmission output setting value after correction based on the bias setting data. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

 The present invention relates to a wireless communication apparatus.

  For example, Patent Document 1 listed below discloses a power amplifier (power amplifier) that amplifies a transmission signal in accordance with a bias voltage in order to optimize adjacent channel leakage power (ACP) of a transmission circuit in a wireless communication device. The bias setting table indicating the correspondence between the target transmission output of the transmission signal and the bias voltage, which is set based on the ACP characteristic of (), is prepared, and the bias voltage corresponding to the current target transmission output is determined using this bias setting table. A technique for setting is disclosed.

JP 2009-1000044 A

  By the way, in the wireless communication apparatus, by providing a band limiting filter for limiting the transmission frequency of the transmission signal to a predetermined frequency band (system band) at the final stage of the transmission circuit, unnecessary radiation outside the band (that is, adjacent) It is common to suppress the influence on a wireless system using another frequency band. FIG. 15 is a diagram illustrating a transmission output-frequency characteristic of a transmission signal finally transmitted through the band limiting filter. As shown in FIG. 15, it can be seen from the characteristics of the band limiting filter that the transmission output of the transmission signal decreases as it approaches the end (band end) of the system band and becomes substantially constant near the center frequency.

  Since it is desirable that the transmission output of the transmission signal be constant within the system band, as shown in FIG. 15, the upstream end of the band limiting filter is set so that the transmission output at the band edge is larger than the transmission output near the center frequency. It is necessary to control the output of the power amplifier arranged in the. However, paying attention to the output of the power amplifier, since the transmission output near the center frequency becomes larger than that at the band edge, as shown in FIG. There is a problem that decreases.

  The present invention has been made in view of the above-described circumstances, and provides a wireless communication apparatus capable of maintaining good ACP characteristics and suppressing deterioration in signal quality without depending on a transmission frequency. With the goal.

  To achieve the above object, a wireless communication apparatus according to a first aspect of the present invention is a wireless communication apparatus that transmits a transmission signal of a predetermined frequency band, and includes a power amplifier that amplifies the transmission signal, The bias setting data indicating the correspondence between the transmission output setting value of the transmission signal set based on the adjacent channel leakage power characteristic and the bias voltage setting value of the power amplifier, the transmission frequency setting value of the transmission signal, and the A storage unit for storing frequency correction data indicating a correspondence relationship between the transmission output setting value and the frequency correction value; and a frequency correction value corresponding to the current transmission frequency setting value is acquired from the frequency correction data, and the acquired frequency Control that corrects the current transmission output setting value using the correction value and determines a bias voltage setting value corresponding to the corrected transmission output setting value based on the bias setting data Characterized in that it comprises a and.

  In the wireless communication apparatus according to the first aspect, the frequency correction data is set to a value other than “0” as a frequency correction value corresponding to a transmission frequency setting value included in an end of the frequency band, “0” is set as a frequency correction value corresponding to a transmission frequency setting value included in a predetermined range excluding an end of the frequency band.

 The wireless communication apparatus according to the second aspect of the present invention is a wireless communication apparatus that transmits a transmission signal of a predetermined frequency band, and includes a power amplifier that amplifies the transmission signal, and an adjacent channel leakage power characteristic in advance. A storage unit for storing bias setting data indicating a correspondence relationship between a transmission output setting value of the transmission signal set based on the bias voltage setting value of the power amplifier, and a current transmission frequency setting value of the frequency band A bias voltage setting value corresponding to a current transmission output setting value is determined based on the bias setting data when included in a predetermined range excluding an end portion, while the current transmission frequency setting value is an end portion of the frequency band A control unit that corrects the current transmission output setting value and determines a bias voltage setting value corresponding to the corrected transmission output setting value based on the bias setting data. , Characterized in that it comprises a.

In the wireless communication apparatus according to the first and second aspects, the storage unit stores the bias setting data for each modulation class, and the control unit determines the bias voltage setting value. The bias setting data corresponding to the current modulation class is used.
The wireless communication device according to the first and second aspects further includes a temperature detection unit that detects a temperature of a transmission unit that transmits the transmission signal, and the control unit is detected by the temperature detection unit. The present transmission output set value is further corrected in accordance with the temperature.

  According to the wireless communication apparatus according to the present invention, it is possible to maintain a good ACP characteristic without depending on the transmission frequency, and as a result, it is possible to suppress a decrease in signal quality.

1 is a block configuration diagram of a wireless communication device 10 according to a first embodiment of the present invention. 2 is a block configuration diagram of a transmission unit 13 in the wireless communication device 10. FIG. 3 is a circuit configuration example of a bias voltage generation unit 13i in a transmission unit 13. 4 is a flowchart illustrating an operation at the time of transmission of a control unit 15 in the wireless communication device 10. It is a figure which shows an example of the transmission output calibration table 14c. It is a figure which shows an example of the frequency correction table 14b. It is a figure which shows the ACP characteristic of the power amplifier 13j at the time of normal temperature. It is a figure which shows an example of the bias setting table 14a. It is a block block diagram of the radio | wireless communication apparatus 20 which concerns on 2nd Embodiment of this invention. 4 is a flowchart illustrating an operation at the time of transmission of a control unit 15 ′ in the wireless communication device 20. It is a figure which shows an example of the transmission output temperature correction table 14d. It is a figure which shows the ACP characteristic of the power amplifier 13j at the time of high temperature. It is a figure which shows an example of the bias temperature correction table 14e. It is a figure which shows frequency correction table 14b 'which is a modification of frequency correction table 14b. It is a figure which shows the transmission output-frequency characteristic of the transmission signal which passes through a band-limiting filter and is finally transmitted conventionally.

Hereinafter, an embodiment of the present invention will be described with reference to the drawings.
[First Embodiment]
FIG. 1 is a block configuration diagram of a wireless communication device 10 according to the first embodiment of the present invention. As shown in FIG. 1, a wireless communication device 10 according to the first embodiment performs wireless communication with another wireless communication device using an adaptive modulation method, and includes an antenna 11, a receiving unit 12, a transmitting unit 13, A storage unit 14 and a control unit 15 are provided.
Note that the wireless communication device 10 transmits a signal compliant with OFDM, for example, and is used in a wireless communication system such as LTE, WiMAX, or XGP.

 The antenna 11 converts the received radio wave into a received signal that can be processed by the receiving unit 12, and outputs the received signal to the receiving unit 12. The antenna 11 converts a transmission signal input from the transmission unit 13 into a transmission radio wave and transmits the transmission signal. The receiving unit 12 generates a reception baseband signal that can be processed by the control unit 15 by down-converting the reception signal input from the antenna 11 to a baseband frequency, and sends the reception baseband signal to the control unit 15. Output.

 The transmission unit 13 generates a transmission signal by up-converting the transmission baseband signal input from the control unit 15 to a transmission frequency (radio frequency: RF), and outputs the transmission signal to the antenna 11. FIG. 2 is a block configuration diagram of the transmission unit 13. As shown in FIG. 2, the transmitter 13 includes an IF local oscillator 13a, an IF mixer 13b, an AGC voltage generator 13c, an IF stage AGC amplifier 13d, an IF amplifier 13e, an RF local oscillator 13f, an RF mixer 13g, and an RF stage AGC. It comprises an amplifier 13h, a bias voltage generation unit 13i, a power amplifier 13j (power amplifier), and a band limiting filter 13k.

 The IF local oscillator 13a generates an IF local signal IFLO having an intermediate frequency (IF) and outputs the IF local signal IFLO to the IF mixer 13b. The IF mixer 13b multiplies the transmission baseband signal input from the control unit 15 by the IF local signal IFLO input from the IF local oscillator 13a, thereby up-converting the transmission baseband signal to an intermediate frequency. The transmission IF signal generated as a result is output to the IF stage AGC amplifier 13d.

 The AGC voltage generation unit 13c generates an AGC voltage corresponding to the AGC voltage setting value input from the control unit 15, and outputs the generated AGC voltage to the IF stage AGC amplifier 13d and the RF stage AGC amplifier 13h. The IF stage AGC amplifier 13d amplifies the transmission IF signal input from the IF mixer 13b with an amplification degree (gain) corresponding to the AGC voltage input from the AGC voltage generation unit 13c, and outputs the amplified IF signal to the IF amplifier 13e. The IF amplifier 13e amplifies the transmission IF signal input from the IF stage AGC amplifier 13d with a predetermined amplification and outputs the amplified signal to the RF mixer 13g.

 The RF local oscillator 13f generates an RF local signal RFLO having a transmission frequency (radio frequency: RF) set by the control unit 15 (specifically, a transmission frequency setting unit 15b) and outputs the RF local signal RFLO to the RF mixer 13g. The RF mixer 13g multiplies the transmission IF signal input from the IF amplifier 13e by the RF local signal RFLO input from the RF local oscillator 13f, thereby up-converting the transmission IF signal to a transmission frequency (radio frequency). The transmission signal generated as a result is output to the RF stage AGC amplifier 13h. The RF stage AGC amplifier 13h amplifies the transmission signal input from the RF mixer 13g with an amplification degree corresponding to the AGC voltage input from the AGC voltage generation unit 13c, and outputs the amplified signal to the power amplifier 13j.

 The bias voltage generation unit 13i generates a bias voltage corresponding to the bias voltage setting value input from the control unit 15, and outputs the generated bias voltage to the power amplifier 13j. The power amplifier 13j amplifies the transmission signal input from the RF mixer 13g with an amplification degree corresponding to the bias voltage input from the bias voltage generation unit 13i, and outputs the amplified signal to the band limiting filter 13k. The band limiting filter 13k is a band pass filter that limits the transmission signal input from the power amplifier 13j to a predetermined frequency band (system band), and outputs the transmission signal after band limitation to the antenna 11.

 FIG. 3 is a circuit configuration example when the bias voltage generation unit 13i is configured using a DC-DC converter. The bias voltage can be determined by setting the resistance values of the variable resistors R1 and R2 in the drawing. That is, the variable resistors R1 and R2 are applied to the power amplifier 13j by using a resistance variable device such as a digital variable resistor capable of adjusting a resistance value according to a bias voltage setting value input from the control unit 15. The power bias voltage can be controlled.

 Returning to FIG. 1, the storage unit 14 is a bias indicating a correspondence relationship between the transmission output setting value of the transmission signal set in advance based on the adjacent channel leakage power characteristic (ACP characteristic) and the bias voltage setting value of the power amplifier 13j. A setting table 14a (bias setting data), a frequency correction table 14b (frequency correction data) indicating a correspondence relationship between the transmission frequency setting value and the frequency correction value of the transmission output setting value, a transmission output setting value, and an AGC voltage setting value. Is stored in the transmission output calibration table 14c.

The control unit 15 performs overall control of the overall operation of the wireless communication device 10 and, as a function thereof, when transmitting a transmission signal (when outputting a transmission baseband signal to the transmission unit 13), A transmission output setting unit 15a for setting the transmission output and a transmission frequency setting unit 15b for setting the transmission frequency of the transmission signal are provided.
When transmitting the transmission signal, the control unit 15 refers to the transmission output calibration table 14c and sets the AGC voltage corresponding to the transmission output (transmission output setting value) set by the transmission output setting unit 15a. A value is acquired, and the acquired AGC voltage setting value is output to the AGC voltage generation unit 13 c of the transmission unit 13.
Further, when transmitting the transmission signal, the control unit 15 refers to the frequency correction table 14b and transmits a transmission output corresponding to the transmission frequency (transmission frequency setting value) set by the transmission frequency setting unit 15b. A frequency correction value of the set value is acquired, the transmission output setting value set by the transmission output setting unit 15a is corrected using the acquired frequency correction value, and further, referring to the bias setting table 14a described above The bias voltage setting value corresponding to the corrected transmission output setting value is acquired, and the acquired bias voltage setting value is output to the bias voltage generation unit 13 i of the transmission unit 13.

Next, an operation at the time of transmission of the wireless communication apparatus 10 configured as described above will be described in detail with reference to FIGS.
FIG. 4 is a flowchart showing a transmission output control process executed by the control unit 15 when transmitting a transmission signal. As shown in FIG. 4, when transmitting a transmission signal (when transmitting a transmission baseband signal to the transmission unit 13), first, the transmission output setting unit 15a of the control unit 15 is changed in, for example, a modulation class. The transmission output of the transmission signal is set (step S1), and the transmission frequency setting unit 15b sets the transmission frequency of the transmission signal (step S2).

When the control unit 15 obtains the transmission output set value as described above, the control unit 15 refers to the transmission output calibration table 14c stored in the storage unit 14 and acquires the AGC voltage set value corresponding to the transmission output set value. (Step S3).
When a large dynamic range is required for output according to the specifications of the wireless communication apparatus 10, an AGC amplifier is often used for each of the IF stage and the RF stage as shown in FIG. When the transmission output unit 13 calibrates the transmission output, the AGC voltage is adjusted so that the transmission output falls within the value of the transmission output calibration table 14c determined by the specification. FIG. 5 is a diagram illustrating an example of the transmission output calibration table 14c. In FIG. 5, the left side represents the transmission output set value, and the right side represents the AGC voltage set value. In FIG. 5, the AGC voltage setting value is expressed in stages, and when the AGC voltage setting value is “1024”, the AGC voltage has a relationship corresponding to 3 (V).
That is, for example, when the transmission output setting value is “26 (dBm)”, “877” is obtained as the AGC voltage setting value from the transmission output calibration table 14 c shown in FIG. 5 (this “877” is the AGC voltage 2). .57 (V)).

On the other hand, the control unit 15 refers to the frequency correction table 14b stored in the storage unit 14 and acquires the frequency correction value of the transmission output setting value corresponding to the transmission frequency setting value (step S4). The transmission output set value is corrected using the frequency correction value (step S5). Here, when the control unit 15 obtains the corrected transmission output setting value as described above, the control unit 15 refers to the transmission output calibration table 14c stored in the storage unit 14 and corresponds to the corrected transmission output setting value. The AGC voltage setting value to be acquired is reacquired, and the reacquired AGC voltage setting value is output to the AGC voltage generation unit 13c of the transmission unit 13 (step S6).
As a result, the AGC voltage generation unit 13c of the transmission unit 13 generates an AGC voltage corresponding to the corrected AGC voltage setting value and outputs the AGC voltage to the IF stage AGC amplifier 13d and the RF stage AGC amplifier 13h.

Further, the control unit 15 refers to the bias setting table 14a stored in the storage unit 14, acquires a bias voltage setting value corresponding to the corrected transmission output setting value (step S7), and acquires the acquired bias. The voltage setting value is output to the bias voltage generation unit 13i of the transmission unit 13 (step S8).
As a result, the bias voltage generation unit 13i of the transmission unit 13 generates a bias voltage according to the corrected bias voltage setting value and outputs the bias voltage to the power amplifier 13j.

Hereinafter, the processing of steps S4 to S8 will be described in detail.
As already described, when attention is paid to the output of the power amplifier 13j arranged in the previous stage of the band limiting filter 13k in the transmission unit 13, the transmission output near the center frequency is larger than that at the band end (end of the frequency band). Therefore, as shown in FIG. 15, there is a problem that the ACP at the band edge is deteriorated and the signal quality is lowered as compared with the vicinity of the center frequency.
On the other hand, in the present embodiment, a frequency correction table indicating a correspondence relationship between the transmission frequency setting value and the frequency correction value of the transmission output setting value so that the ACP is maintained at an appropriate value without depending on the transmission frequency. 14b was prepared. FIG. 6 is a diagram illustrating an example of the frequency correction table 14b. As shown in FIG. 6, when 2310.3125 (MHz) of Index “8” is set as the center frequency, the frequency correction at this center frequency is the smallest, and the frequency correction is set so as to increase toward the band edge. ing.

    FIG. 7 is a diagram showing the ACP characteristic of the power amplifier 13j at normal temperature (35 ° C.). FIG. 7 shows the ACP characteristics for each modulation class when the bias voltage is 3.6 (V) and 4.2 (V). The vertical axis indicates the ACP value (dB), and the horizontal axis indicates the output value (dBm) of the power amplifier 13j. As the output increases, the ACP characteristic deteriorates. However, it can be seen that the ACP characteristic differs depending on the bias voltage when signals of the same modulation class are output. It can also be seen that the ACP characteristics are different when the modulation class is different even at the same bias voltage.

    For example, when the modulation class is BPSK and the output is 28 (dBm), the bias setting of 4.2 (V) is superior to the bias setting of 3.6 (V). However, when the output is 26 (dBm) or less, the bias setting of 3.6 (V) is superior to the bias setting of 4.2 (V). When the modulation class is 16QAM and the output is 27 (dBm), the bias setting of 4.2 (V) is superior to the bias setting of 3.6 (V). However, when the output is 26 (dBm) or less, the bias setting of 3.6 (V) is superior to the bias setting of 4.2 (V). When the modulation class is QPSK, when the output is 28 (dBm), the bias setting of 4.2 (V) is superior to the bias setting of 3.6 (V). However, when the output is 27 (dBm) or less, the bias setting of 3.6 (V) is superior to the bias setting of 4.2 (V).

    That is, normally, the bias voltage of the power amplifier 13j is set in consideration of the ACP characteristic at the maximum output, but the bias voltage is set to 4.2 (V) in order to improve the ACP characteristic at the maximum output. In this case, the ACP when the output is lowered is not the optimum ACP for this output.

    Therefore, in the present embodiment, a bias setting table 14a is prepared that indicates the correspondence between the transmission output setting value of the transmission signal and the bias voltage setting value of the power amplifier 13j, which is set based on the ACP characteristic of the power amplifier 13j to be used. Then, the transmission output is calibrated using this, and the bias of the power amplifier 13j corresponding to a predetermined output is set at the time of actual output transmission. The bias setting table 14a is associated with a bias voltage setting value for obtaining an optimum ACP according to the transmission output setting value, and a table is prepared for each modulation class to be used. Since the power amplifier 13j changes the gain when the bias voltage is changed, the output adjustment is performed using the voltage setting of the bias setting table 14a when the transmission output is calibrated.

FIG. 8 shows an example of the bias setting table 14a that optimizes the ACP characteristics of the power amplifier 13j. As shown in FIG. 8, the bias setting table 14a is configured for each modulation class. In FIG. 8, DAC1, DAC2, DAC3, and DAC4 are voltage values corresponding to resistance values set in the variable resistors R1 and R2 of the bias voltage generating unit 13i shown in FIG. When the set values of the variable resistors R1 and R2 are DAC1 and DAC2, the bias voltage is 3.6V, and when the set values of the variable resistors R1 and R2 are DAC3 and DAC4, the bias voltage is 4.2V.
In FIG. 8, the bias voltage setting value between 10 (dBm) and −20 (dBm) is the same as the previous and subsequent values, and is omitted.

  If the bias voltage is set according to the transmission output setting value using the bias setting table 14a, the ACP characteristic of the power amplifier 13j shown in FIG. 7 is 3 when the modulation class is BPSK and the modulation class is 26 (dBm) or less. A bias voltage of .6 (V) is set to maintain a good ACP characteristic. When the modulation class is QPSK, a bias voltage of 3.6 (V) is set when the modulation class is 27 (dBm) or less. Therefore, when the modulation class is 16QAM, a bias voltage of 3.6 (V) is set to 26 (dBm) or less and the good ACP characteristic is maintained. . As a result, the power amplifier 13j has a good ACP characteristic at any output setting, and can obtain a transmission characteristic in which signal quality is deteriorated and transmission spurious is minimized.

Specifically, for example, when the transmission frequency setting value is “2300.3125 (MHz)”, “1.0 (dBm)” is obtained as a frequency correction value from the frequency correction table 14b illustrated in FIG. Is obtained. If the transmission output setting value is “26 (dBm)”, the transmission output setting value is corrected to “27 (dBm)” in step S5. In step S6, an AGC voltage setting value “881” corresponding to the corrected transmission output setting value “27 (dBm)” is obtained from the transmission output calibration table 14c.
The AGC voltage generation unit 13c generates 2.58 (V) as the AGC voltage corresponding to the AGC voltage set value “881” obtained in this way.
In FIG. 5, the AGC voltage setting value “881” corresponding to the transmission output setting value “27 (dBm)” is omitted, but the AGC voltage corresponding to the transmission output setting value “27 (dBm)” is omitted. The set value is “881” because it is an intermediate value between the transmit output set values “26 (dBm)” and “28 (dBm)”.

  If the modulation class is BPSK in step S7, the bias voltage setting value corresponding to the corrected transmission output setting value “27 (dBm)” from the bias setting table 14a shown in FIG. DAC3 and DAC4 are selected as the set value of R2. As a bias voltage corresponding to the bias voltage setting value thus obtained, 4.2 (V) is generated by the bias voltage generation unit 13i, and good ACP characteristics are maintained.

  As described above, according to the wireless communication device 10 according to the present embodiment, it is possible to maintain a good ACP characteristic without depending on the transmission frequency and the transmission output, and as a result, it is possible to suppress a decrease in signal quality. It becomes possible to do.

[Second Embodiment]
Next, a second embodiment of the present invention will be described.
The ACP characteristic of the power amplifier 13j changes with temperature. The power amplifier 13j generally has a lower saturation point at the output stage of the power amplifier 13j at a high temperature than at a normal temperature, and the ACP deteriorates at the same output transmission time. Conversely, ACP tends to be better at low temperatures than at normal temperatures. Therefore, when only correcting the output based on the AGC voltage when correcting the temperature of the transmission output, the bias voltage may not always provide an optimal ACP. In the second embodiment, the bias voltage of the power amplifier 13j can be set so that the optimum ACP is always maintained even when the temperature of the transmission output is corrected.

  FIG. 9 is a block configuration diagram of the wireless communication device 20 according to the second embodiment of the present invention. In FIG. 9, the same components as those in FIG. As illustrated in FIG. 9, the wireless communication device 20 according to the second embodiment newly includes a temperature detection unit 16 that detects the temperature of the transmission unit 13. Accordingly, the storage unit 14 ′ in the second embodiment is set to correct the AGC voltage in addition to the bias setting table 14a, the frequency correction table 14b, and the transmission output calibration table 14c described in the first embodiment. The transmission output temperature correction table 14d showing the correspondence between the temperature detection value and the temperature correction value of the transmission output set value, and the temperature detection value and the transmission output set value set for correcting the temperature of the bias voltage. A bias temperature correction table 14e indicating a correspondence relationship with the temperature correction value is stored.

  In addition to the function of the control unit 15 described in the first embodiment, the control unit 15 ′ in the second embodiment performs the temperature detection value (that is, the temperature detection value acquired from the temperature detection unit 16 when performing the AGC voltage setting process). The temperature of the AGC voltage is corrected using the transmission output temperature correction table 14d based on the temperature of the transmission unit 13) and the bias temperature correction table 14e is also based on the temperature detection value when performing the bias voltage setting process. And a function of correcting the temperature of the bias voltage by using.

Next, the operation during transmission of the wireless communication device 20 configured as described above will be described in detail with reference to FIGS.
FIG. 10 is a flowchart showing a transmission output control process executed by the control unit 15 ′ when transmitting a transmission signal. As shown in FIG. 10, when transmitting a transmission signal (when transmitting a transmission baseband signal to the transmission unit 13), first, the transmission output setting unit 15a of the control unit 15 ' Is set (step S11), and the transmission frequency setting unit 15b sets the transmission frequency of the transmission signal (step S12). Furthermore, the control unit 15 ′ acquires a temperature detection value from the temperature detection unit 16 (step S13).

 And control part 15 'refers to the transmission output temperature correction table 14d memorize | stored in memory | storage part 14', acquires the temperature correction value of the transmission output setting value corresponding to a temperature detection value (step S14), The transmission output set value is corrected using the acquired temperature correction value (step S15). Further, the control unit 15 ′ refers to the frequency correction table 14b stored in the storage unit 14 ′, acquires the frequency correction value of the transmission output setting value corresponding to the transmission frequency setting value (step S16), and Using the acquired frequency correction value, the transmission output set value is further corrected (step S17).

 Then, the control unit 15 ′ refers to the transmission output calibration table 14c stored in the storage unit 14, and acquires the AGC voltage setting value corresponding to the corrected transmission output setting value (step S18). The AGC voltage set value is output to the AGC voltage generation unit 13c of the transmission unit 13 (step S19).

Hereinafter, the processing of steps S14 to S19 will be described in detail. FIG. 11 is a diagram illustrating an example of the transmission output temperature correction table 14d. The transmission output temperature correction table 14d shows the amount of deviation of the transmission output based on the normal temperature (35 ° C.) when the temperature changes under the same AGC voltage. As shown in FIG. 11, the transmission output decreases at a high temperature and increases at a low temperature under the same AGC voltage setting. For example, when the output setting is 26 (dBm), the transmission output is reduced by 2.06 (dB) at 70 ° C. compared to 35 ° C., and at 10 ° C., the transmission output is 1. It has risen 81 (dB).

   Therefore, the AGC voltage is adjusted based on the transmission output temperature correction table 14d so that the output is suppressed by increasing the AGC voltage at high temperatures and decreasing the AGC voltage at low temperatures to suppress output. Make corrections so as not to shift. Specifically, for example, when the transmission output set value is “26 (dBm)” and the temperature detection value is “70 ° C.”, the temperature correction value is set as “2. 06 (dB) "is obtained, and in step S15, the transmission output set value is corrected to" 28 (dBm) "using the temperature correction value" 2.06 (dB) ".

For example, when the transmission frequency setting value is “2300.3125 (MHz)”, “1.0 (dBm)” is obtained as the frequency correction value from the frequency correction table 14 b shown in FIG. 6 in step S 16. In step S17, the transmission output set value is corrected to “29 (dBm)”. In step S18, the AGC voltage setting value “889” corresponding to the corrected transmission output setting value “29 (dBm)” is obtained from the transmission output calibration table 14c.
2.6 (V) is generated by the AGC voltage generation unit 13c as the AGC voltage corresponding to the AGC voltage set value “889” obtained in this way.
In FIG. 5, the AGC voltage setting value “889” corresponding to the transmission output setting value “29 (dBm)” is omitted, but the AGC voltage corresponding to the transmission output setting value “29 (dBm)” is omitted. The setting value is “889” because it is an intermediate value between the transmission output setting values “28 (dBm)” and “30 (dBm)”.

  On the other hand, the control unit 15 ′ refers to the bias temperature correction table 14 e stored in the storage unit 14 ′, and acquires the temperature correction value of the transmission output set value corresponding to the temperature detection value (step S 20). The control unit 15 ′ further corrects the transmission output setting value corrected in steps S15 and S17 using the temperature correction value acquired in step S20, and then stores the bias setting table stored in the storage unit 14 ′. 14a, the bias voltage setting value corresponding to the corrected transmission output setting value is acquired (step S21), and the acquired bias voltage setting value is output to the bias voltage generation unit 13i of the transmission unit 13 (step S21). S22).

Hereinafter, the process of said step S20-S22 is demonstrated in detail.
FIG. 12 is a diagram showing the ACP characteristic of the power amplifier 13j at a high temperature (65 ° C.). The ACP characteristic of the power amplifier 13j at high temperature (65 ° C) is shifted by 1 (dBm) toward the low output side compared to the characteristic at normal temperature (35 ° C) shown in FIG. Compared to the time characteristics, the ACP deteriorates at the same transmission output. This is because the saturation point of the output stage of the power amplifier 13j is lower at high temperatures than at normal temperatures. For example, when a 16QAM modulated wave is transmitted with an output of 26 (dBm), an optimal ACP can be obtained with a bias voltage of 3.6 (V) at room temperature, as shown in FIG. Similarly, at 26 (dBm) output, as shown in FIG. 12, an optimum ACP can be obtained with a bias voltage of 4.2 (V). That is, the optimum bias setting at 26 (dBm) output at the high temperature is the same as the bias setting at 27 (dBm) output setting at normal temperature.

    FIG. 13 is a diagram illustrating an example of the bias temperature correction table 14e. The bias temperature correction table 14e shows the amount of deviation of the transmission output based on the normal temperature (35 ° C.) when the temperature changes under the same ACP characteristic. As shown in FIG. 13, under the same ACP characteristic, the transmission output increases at a high temperature and decreases at a low temperature. For example, compared to the ACP obtained when the output setting is 26 (dBm) at 335 ° C., the transmission output is increased by 1.00 (dB) in the case of 65 ° C. compared to the case of 35 ° C. It becomes the same value as ACP. Further, in the case of 10 ° C., it becomes the same value as the ACP when the transmission output decreases by 0.71 (dB).

Therefore, the bias voltage is increased at a high temperature, the bias voltage is increased at a low temperature, and the bias voltage is adjusted based on the bias temperature correction table 14e to perform correction so that an optimum ACP characteristic is obtained at each temperature. Specifically, for example, as described above, when the transmission output setting value is “26 (dBm)”, the transmission frequency setting value is “2300.3125 (MHz)”, and the temperature detection value is “70 ° C.” The transmission output set value is corrected to “29 (dBm)” through steps S15 and S17.
In step S20, 1.17 (dB) is obtained as the temperature correction value from the bias temperature correction table 14e, and the bias setting corresponding to the transmission output setting of 30 (dBm) is finally referred to as the bias voltage. It becomes the voltage value of the table 14a.

In step S21, when the modulation class is BPSK, DAC3 is set as the bias voltage setting value corresponding to the corrected transmission output setting value “30 (dBm)” from the bias setting table 14a, that is, the setting values of the variable resistors R1 and R2. , DAC4 is selected.
As a result, the bias voltage generation unit 13i of the transmission unit 13 generates a temperature-corrected bias voltage and outputs it to the power amplifier 13j.
As shown in FIG. 13, the ACP characteristic at high temperature (65 ° C.) is shifted by 1 (dBm) to the low output side as compared with the characteristic at normal temperature (35 ° C.). If the values of DAC3 and DAC4 are set in the variable resistors R1 and R2 of the bias voltage generator 13i shown in FIG. 4, the bias voltage is set to 4.2V, and it is possible to maintain good ACP characteristics regardless of temperature. Become.

    As described above, according to the wireless communication device 20 according to the second embodiment, it is possible to maintain good ACP characteristics without depending on the transmission frequency, the transmission output, and the temperature, and as a result, the signal quality. Can be suppressed.

In addition, this invention is not limited to the said embodiment, The following modifications are mentioned.
(1) In the above embodiment, the bias voltage of 3.6 (V) or 4.2 (V) is set to the power amplifier 13j, but the present invention is not limited to these bias voltage values. The bias voltage values are not limited to two. Since the bias voltage varies depending on the characteristics of the power amplifier 13j, the bias setting table 14a is set according to the characteristics of the power amplifier 13j. In the above embodiment, the bias setting table 14a in which the correspondence relationship between the transmission output setting value and the bias voltage setting value is set for each modulation class is prepared. However, depending on the modulation class, the transmission output setting value and the bias voltage setting value are set. If the correspondence relationship between the transmission output setting value and the bias voltage setting value does not need to be set for each modulation class, it is not necessary to set the correspondence relationship between the transmission output setting value and the bias voltage setting value.

(2) In the above embodiment, as shown in FIG. 6, when the frequency correction table 14b in which the correspondence relationship between the transmission frequency setting value and the frequency correction value is set for a wide range from the center frequency to the band edge is used. Was illustrated. On the other hand, the portion where the influence of unnecessary radiation on other radio systems is the largest (that is, the degradation of the ACP characteristic is the largest) is the band edge, so that as shown in FIG. A value other than “0” is set as the frequency correction value corresponding to the transmission frequency setting value included in the part), and “0” is set as the frequency correction value corresponding to the transmission frequency setting value included in the predetermined range excluding the band edge. The set frequency correction table 14b ′ may be used.
By using such a frequency correction table 14b ′, the correction processing for the transmission frequency setting values other than the band edge is omitted, so that the processing load during the transmission operation can be reduced. Note that in FIG. 14, only the frequency correction value “0” corresponding to the center frequency is illustrated in order to mean that the correction process is omitted at the portion where “0” is set as the frequency correction value.

(3) In the above embodiment, a favorable ACP characteristic can be maintained without depending on the transmission frequency and the transmission output by using the bias setting table 14a and the frequency correction table 14b previously stored in the storage unit 14 (14 ′). A case of determining a proper bias voltage setting value has been illustrated. On the other hand, for example, when only the bias setting table 14a is stored in the storage unit 14 (14 ′) and the transmission frequency setting value is included in a predetermined range excluding the band edge, the transmission output setting is made from the bias setting data 14a. The bias voltage setting value corresponding to the value is determined, and when the transmission frequency setting value is included in the band edge, the transmission output setting value is corrected, and the bias voltage corresponding to the corrected transmission output setting value is corrected from the bias setting data 14a. You may provide the control part which has the function to determine a setting value.
Thereby, the same effect (reduction of processing load) as that described in the modification of (2) can be obtained.

  DESCRIPTION OF SYMBOLS 10, 20 ... Wireless communication apparatus, 11 ... Antenna, 12 ... Reception part, 13 ... Transmission part, 14, 14 '... Memory | storage part, 15, 15' ... Control part, 16 ... Temperature detection part, 13j ... Power amplifier (electric power) Amplifier), 14a... Bias setting table (bias setting data), 14b... Frequency correction table (frequency correction data)

Claims (5)

A wireless communication device that transmits a transmission signal of a predetermined frequency band,
A power amplifier for amplifying the transmission signal;
Bias setting data indicating a correspondence relationship between a transmission output setting value of the transmission signal and a bias voltage setting value of the power amplifier set in advance based on adjacent channel leakage power characteristics, and a transmission frequency setting value of the transmission signal, A storage unit for storing frequency correction data indicating a correspondence relationship with a frequency correction value of the transmission output setting value;
A frequency correction value corresponding to the current transmission frequency setting value is acquired from the frequency correction data, the current transmission output setting value is corrected using the acquired frequency correction value, and transmission is corrected based on the bias setting data. A control unit for determining a bias voltage setting value corresponding to the output setting value;
A wireless communication apparatus comprising:   In the frequency correction data, a value other than “0” is set as a frequency correction value corresponding to the transmission frequency setting value included in the end of the frequency band, and transmission included in a predetermined range excluding the end of the frequency band The wireless communication apparatus according to claim 1, wherein “0” is set as a frequency correction value corresponding to the frequency setting value. A wireless communication device that transmits a transmission signal of a predetermined frequency band,
A power amplifier for amplifying the transmission signal;
A storage unit for storing bias setting data indicating a correspondence relationship between a transmission output setting value of the transmission signal set in advance based on adjacent channel leakage power characteristics and a bias voltage setting value of the power amplifier;
When the current transmission frequency setting value is included in a predetermined range excluding the end of the frequency band, the bias voltage setting value corresponding to the current transmission output setting value is determined based on the bias setting data, while the current When the transmission frequency setting value is included at the end of the frequency band, the current transmission output setting value is corrected, and a bias voltage setting value corresponding to the corrected transmission output setting value is determined based on the bias setting data. A control unit;
A wireless communication apparatus comprising: The storage unit stores the bias setting data for each modulation class,
The wireless communication apparatus according to claim 1, wherein the control unit uses bias setting data corresponding to a current modulation class when determining the bias voltage setting value. A temperature detection unit for detecting the temperature of the transmission unit for transmitting the transmission signal;
The wireless communication according to any one of claims 1 to 4, wherein the control unit further corrects the current transmission output setting value according to the temperature detected by the temperature detection unit. apparatus.

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