JP2003037640A - Transmitting circuit for radio communication equipment - Google Patents

Abstract

PROBLEM TO BE SOLVED: To save power by adaptively controlling the operational characteristics of a power amplifier corresponding to a modulation system concerning each of time division multiplexed time slots. SOLUTION: An adaptive modulation part 12 changes the modulation system concerning each of the time slots. According to the modulation system determined by the adaptive modulation part 12, a CPU 21 makes a gain control part 25 control the gain of a power amplifier 17 and the output power of the transmission circuit is controlled. Thus, power can be saved. Besides, according to the modulation system determined by the adaptive modulation part 12, the CPU 21 makes a power control part 23 control the maximum amplitude of a voltage controlled attenuator 16 and the level of the power to be inputted to the power amplifier 17 is controlled. Thus, a transmission quality is secured.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a transmission circuit of an adaptive modulation type time division multiplexing wireless communication device.

[0002]

2. Description of the Related Art In the field of wireless communication, an adaptive modulation method is used in which a modulation method is changed according to a propagation path condition in order to maintain transmission quality at a high level. Conventionally, the power amplifier used in the adaptive modulation type transmission circuit is selected so as to satisfy the condition of the modulation method that requires the most linearity, and the operating characteristics (for example, gain and operation) of the power amplifier are selected. Point) is fixed. Although there is a technique of feedback controlling the gain of the power control unit, the purpose thereof is to stabilize the transmission power and is independent of the change of the modulation method.

[0003]

Since the transmission circuit of the conventional adaptive modulation type time division multiplexing wireless communication apparatus is configured as described above, a power amplifier which has an unnecessarily high power for a certain modulation method is used. There was a problem such as being consumed in.

The present invention has been made to solve the above problems, and adaptively controls the operating characteristics of a power amplifier according to the modulation system for each time slot of the time division multiplexing system to save power. An object of the present invention is to obtain a transmission circuit of an adaptive modulation type time division multiplex wireless communication device which can be realized.

[0005]

A transmission circuit of a radio communication apparatus according to the present invention includes a time division multiplexing control unit for generating a code block suitable for a time slot of a time division multiplexing system from a transmitted user signal, and a situation. Adaptive modulation section capable of changing the modulation method of each code block according to the above, a modulator for modulating each code block into a modulated wave according to the modulation method defined by the adaptive modulation section, and the modulated wave An attenuator for attenuating the attenuator, an amplifier for amplifying the modulated wave attenuated by the attenuator, and a damping method of the attenuator for each time slot according to the modulation method defined by the adaptive modulator. A possible attenuation control section and a gain control section capable of controlling the gain of the amplifier for each time slot in accordance with the modulation method defined by the adaptive modulation section. It is intended.

The transmission circuit of the radio communication apparatus according to the present invention comprises a frequency conversion unit capable of changing the transmission frequency for each time slot according to the situation, and the attenuation control unit is determined by the adaptive modulation unit. It is possible to control the attenuation performance of the attenuator for each time slot according to the modulation method and the frequency determined by the frequency converter.

The transmitter circuit of the wireless communication device according to the present invention comprises a temperature measuring unit for measuring the temperature of the wireless transmitter circuit or the vicinity thereof, and the attenuation control unit has the modulation system defined by the adaptive modulator and the temperature measuring unit. It is possible to control the attenuation performance of the attenuator for each time slot according to the temperature measured by.

In the transmission circuit of the wireless communication apparatus according to the present invention, the signal line connecting the attenuation control section and the attenuator is provided with a temperature dependent characteristic changer whose characteristic changes with temperature, and the attenuation control section will control. The damping performance of the attenuator is influenced by the characteristics of the temperature dependent characteristic changer.

[0009]

BEST MODE FOR CARRYING OUT THE INVENTION An embodiment of the present invention will be described below. Embodiment 1. 1 is a block diagram showing a transmission circuit of an adaptive modulation type time division multiplexing wireless communication apparatus according to Embodiment 1 of the present invention. In the figure, 11 is a time division multiplexing control unit, 12 is an adaptive modulation unit, 13 is a modulator, 14 is a mixer, 15 is a band pass filter, 16 is a voltage control type attenuator, 17 is a power amplifier, 18 is a low pass filter, 19
Is an antenna, 20 is a frequency synthesizer (frequency converter), 21 is a CPU (central processing unit, attenuation controller,
Frequency converter), 22 is an internal memory, 23 is a power controller (attenuation controller), 24 is a D / A converter (attenuation controller), and 25 is a gain controller.

Next, the operation will be described. These components constitute a transmission circuit of the wireless communication device. However, this wireless communication device is also provided with a reception circuit (not shown). In order to realize the adaptive modulation scheme, the communication service system allocates channels (frequency bands) to users according to traffic, propagation environment, service requirements, and other conditions.

The signal notifying the channel is transmitted from a base station of the communication service system to this wireless communication device and received by the receiving circuit of this wireless communication device. In addition, signals related to the channel are sent from the receiving circuit
Supplied to U21. This transmission circuit is adapted for time division multiplexing, and different channels (frequencies) can be used depending on various conditions, so that the transmission circuit must be able to transmit a new significant user signal before it starts transmission. After negotiating with the communication service system, the communication service system issues a signal announcing the channel.

The CPU 21 saves information about the notified channel in the internal memory 22. Then, each time the channel frequency needs to be changed (when another kind of user signal should be transmitted), the CPU 21 adjusts the frequency synthesizer 20 in order to optimize the frequency of each time slot based on the information about the channel. To do. As a result, the frequency synthesizer 20 outputs an oscillation signal that oscillates at the used frequency.

The significant transmitted user signal is supplied to the time division multiplex control unit 11, and the time division multiplex control unit 11 uses the CPU.
Under the control of 21, the user signal is converted into a format required by the protocol of the wireless communication section. Also, the time division multiplexing control unit 11 time-divisions the signal, allocates the divided code blocks to time slots, and supplies them to the adaptive modulation unit 12.

The adaptive modulator 12 is provided to execute the high speed adaptive modulation method. In the high speed adaptive modulation system,
In order to reduce the effect of instantaneous fading fluctuations, the optimal modulation multi-level number and symbol rate are selected within the allocated band while monitoring the delay spread. This selection is made while the wireless communication device negotiates with the base station before transmitting the user signal because the wireless communication device needs to cooperate with the base station.

Then, the adaptive modulation section 12 selects a modulation method according to the conditions such as the destination of the signal received from the time division multiplexing control section 11 and the communication protocol, converts the modulator 13 to the selected modulation method, and codes the code. Transfer the block to the modulator 13. The modulator 13 modulates the code block according to the selected modulation method, and generates a voltage fluctuation, that is, a modulated wave. Since each code block can use a different modulation scheme, the adaptive modulation unit 12 notifies the modulator 13 of the modulation scheme each time the modulation scheme needs to be changed.

The modulated wave output from the modulator 13 is integrated by the mixer 14 with the oscillation signal output from the frequency synthesizer 20. That is, it is converted into a radio frequency for wireless communication. The modulated wave whose frequency has been converted is filtered by the bandpass filter 15 so as to have only a component in a constant band, and is supplied to the voltage control type attenuator 16. The voltage control type attenuator 16 adjusts the amount of attenuation of the electric power of the modulated wave as needed, and adjusts this to the power amplifier 1
Supply to 7. The power amplifier 17 amplifies the modulated wave and supplies it to the low-pass filter 18. The amplified modulated wave is filtered by the low-pass filter 18, and then the antenna 19 is excited.

The CPU 21 has a function of reading out power information for various conditions stored in the internal memory 22 and giving this to the power control unit 23. When the electric power information is given, the electric power control unit 23 outputs this after a delay of a certain time. The power information output from the power control unit 23 is D /
It is supplied to the A converter 24, converted into an analog signal here, and further supplied to the voltage control type attenuator 16 as its control information.

The voltage control type attenuator 16 attenuates the maximum amplitude of the voltage of the modulated wave to the same level as the maximum amplitude of the voltage signal derived from the power information, and the power of the modulated wave is output from the D / A converter 24. Prepare according to the signal.

Then, the voltage control type attenuator 16 adjusts the attenuation amount of the modulated wave by the control signal derived from the power information so that the input power of the power amplifier 17 becomes optimum.

The gain of the power amplifier 17 is controlled by the CPU 21 and the gain controller 25. CPU21
Has a function of reading the gain information stored in the internal memory 22 and giving the gain information to the gain controller 25. When the gain information is provided, the gain control unit 25 supplies the gain information to the power amplifier 17 after delaying for a fixed time.

As described above, in the first embodiment, the adaptive modulation is executed and the power amplifier 1 for the modulated wave is used.
The input power of 7 and the gain of the power amplifier 17 are adjusted. The operation will be described with reference to the timing chart of FIG.

Clock pulses are supplied to the CPU 21 from a clock device (not shown). CPU21
The slot timing reference signal is output each time a clock pulse is input.

At the stage of transmitting the user signal, the slot timing reference signal is periodically output from the CPU 21. After a certain delay time Td from a certain slot timing reference signal, a transmitted signal corresponding to this slot timing reference signal is assigned to a time slot and transmitted. A certain guard time is provided between the front and back time slots. By this guard time, the frequency, modulation scheme and other conditions are set and applied to the next time slot.

More specifically, the time division multiplexing control unit 11 notifies the CPU 21 of the conditions such as the destination and the protocol to be used when the user signal is time-divided and the divided code blocks are assigned to the time slots. is doing. C
The PU 21 determines the frequency to be used based on these conditions and the information on the channel read from the internal memory 22, and adapts the frequency synthesizer 20 to the next time slot by the guard time. For example, within the guard time immediately before slot S2 in FIG. 2, the switching to the frequency adapted to slot S2 has been completed.

Further, as described above, the adaptive modulation section 12 selects the modulation method for each code block according to the conditions such as the destination of the signal received from the time division multiplexing control section 11 and the communication protocol, and modulates by the guard time. Bowl 1
Adapt 3 to the next time slot. For example, in FIG.
Within the guard time immediately before slot S2, the switching to the modulation system adapted to slot S2 has been completed.

The adaptive modulation unit 12, when converting the modulator 13 to the selected modulation system, uses the selected modulation system as the CPU.
Notify 21. Thereby, the CPU 21 recognizes the modulation method for each time slot, and adjusts the input power of the power amplifier 17 and the gain of the power amplifier 17 related to the modulated wave according to the modulation method.

For example, as shown in FIG. 2, the slot S2
Output a slot timing reference signal for
The PU 21 reads the gain information (X2) from the internal memory 22, gives it to the gain controller 25, reads the power information (Y2) from the internal memory 22, and gives it to the power controller 23. The gain information (X2) is the slot S
The power information (Y2) is information about the gain suitable for the modulation method of No. 2, and the power information (Y2) is information about the input power of the power amplifier 17 suitable for the modulation method of the slot S2.

When the gain information is given, the gain control section 25 supplies the gain information to the power amplifier 17 after a fixed time delay (during the guard time). Therefore, by the next time slot, the power amplifier 17 is adjusted to have a gain adapted to the next time slot. That is, by adjusting during the guard time, the influence of the transmission output due to the burst transient response characteristic is eliminated.

When the power information is given, the power control section 23 delays a fixed time (during the guard time).
This is supplied to the D / A converter 24. The D / A converter 24 immediately converts the electric power information into an analog signal and supplies it to the voltage controlled attenuator 16 as control information for the signal. Therefore, by the next time slot, the voltage-controlled attenuator 16 is adjusted so as to attenuate the power of the modulated wave so that the input power of the power amplifier 17 adapted to the next time slot is obtained.

Next, the effect of the transmission circuit according to the first embodiment will be described with reference to FIGS. 3 to 6 are graphs showing the gain characteristics of the power amplifier 17, where the horizontal axis represents the input power P _in and the vertical axis represents the output voltage P in.
represents _out . P _{S on the} vertical axis represents the saturated output.

In the figure, a point PA is an operating point of a certain modulation system A, a point PB is an operating point of another modulation system B,
Point PC is an operating point of another modulation method C. Modulation scheme A requires the highest linearity between input power P _in and output voltage P _out , modulation scheme B requires the second highest linearity, and modulation scheme C requires the lowest linearity. However, as shown in FIG. 3, the maximum modulation schemes lower maximum input power P _in the A, maximum input power P _in the modulation scheme B is lower in the second modulation scheme C in the input power P _in The highest limit.

In this case, the power amplifier 17 is selected so that the characteristics match the modulation method A which requires the highest linearity. For the modulation methods B and C _{in which} the maximum input power P _in is high, the output power P _out is inevitably high, but it is assumed that such high output power is not necessary.

In the first embodiment, in order to reduce power consumption, as shown in FIGS. 4 and 5, the modulation methods B and C are used.
For, the gain of the power amplifier 17 is reduced. Figure 4
5 and FIG. 5, due to the decrease in gain, the saturation output P
_It can be seen that _SB and P _SC are lower than the original saturation power P _S.

However, in a measure that only lowers the gain,
This will deteriorate the linearity. As shown in FIG. 4, the operating point PB corresponds to the maximum P _INB1 the original input power for the modulation scheme B is very close to the new saturation output P _SB. Further, as shown in FIG. 5, the operating point PC corresponding to the maximum input power P _inc1 of the modulation method C substantially matches the new saturation output P _SC . This may hinder the transmission quality.

Therefore, in the first embodiment, the power control unit 23 and the voltage control type attenuator 16 suppress the amplitude of the power input to the power amplifier 17. It should be noted that the curves shown by the solid lines in FIGS. 4 and 5 are reduced not only in the vertical direction but also in the horizontal direction as compared to the original characteristic curves shown by the broken lines. In these figures, P _inb2 and P _inc2 are maximum new input powers. As shown in FIG. 4, for the modulation method B, the maximum new input power P
operating point PB2 corresponding to _inb2 is spaced margin MB from the new saturation power P _SB. In addition, as shown in FIG.
The operating point PC2 corresponding to the maximum new input power P _inc2 is away from the new saturation output P _SC by a margin MC. Therefore, almost constant linearity is ensured until the operating points PB2 and PC2 are reached, and higher transmission quality can be achieved.

As shown in FIG. 6, for the modulation method A which requires the highest linearity and has the lowest maximum input power P _in , the gain of the power amplifier 17 and the amplitude of the power input to the power amplifier 17 are as follows. Is adjusted to be the same as the condition of FIG. Maximum P of input power for modulation method A
_The operating point PA corresponding to _ina is separated from the saturated output P _SA (P _S ) by a margin MA, and almost constant linearity is ensured until the operating point PA is reached, so that there is no problem in transmission quality.

As described above, according to the first embodiment, the gain of the power amplifier 17 and the maximum amplitude of the power are dynamically adaptively controlled according to the modulation method for each time slot of the time division multiplexing method. Further, it is possible to obtain an effect that power saving can be achieved and transmission quality can be improved or maintained. Since the gain and the saturated output power are controlled before each time slot, a stable transmission output can be obtained during signal transmission.

Embodiment 2. Regarding the above-described first embodiment, the influence of the used frequency on the output power of the transmission circuit is ignored. However, actually, the output power of the transmission circuit is affected by the used frequency. Such fluctuations
Mixer 14, bandpass filter 15, power amplifier 1
7. The frequency affects the low-pass filter 18 and is generated. Therefore, in the second embodiment of the present invention, fluctuations in the output power of the transmission circuit based on the used frequency are eliminated and the transmission output is set to a desired level.

The structure of the transmission circuit according to the second embodiment may be the same as that shown in FIG. Also in this embodiment, the power information is stored in the internal memory 22, but the power information, especially the maximum allowable power thereof, is corrected by an amount corresponding to the fluctuation of the output power of the transmission circuit based on the used frequency.

Specifically, the power information (Y) for each type of modulation method relating to a certain reference frequency and the correction information (Y _f ) due to the frequency change are stored in the internal memory 22.
The correction information (Y _f ) to be stored in the internal memory 22 can be prepared by measuring the variation of the transmission output power depending on the used frequency in advance.

The operation of the transmission circuit of this embodiment when in use is basically the same as that of the first embodiment. However,
The CPU 21 reads the power information (Y) from the internal memory 22 based on the modulation method used, reads the correction information (Y _f ) from the internal memory 22 based on the frequency used, and corrects the power information (Y). It is corrected by the information (Y _f ) and the corrected power information is supplied to the D / A converter 24.

As described above, according to the second embodiment, it is possible to obtain the effect that the fluctuation of the output power of the transmission circuit based on the used frequency can be eliminated.

Further, various kinds of power information corresponding to the frequency used and the modulation method used may be stored in the internal memory 22. In this case, the CPU 21 has only to read the power information from the internal memory 22 based on the frequency used and the modulation method used, and directly reads the power information into the D / A converter 24 without correcting the power information. Can be supplied.

Embodiment 3. Regarding Embodiments 1 and 2 above, the influence of environmental temperature on the output power of the transmission circuit is ignored. However, in reality, the output power of the transmission circuit is affected by the environmental temperature and may become unstable. Therefore, in the third embodiment of the present invention, fluctuations in the output power of the transmission circuit based on the environmental temperature are eliminated, and the transmission output is set to a desired level.

FIG. 7 is a block diagram showing a transmitting circuit of an adaptive modulation type time division multiplexing radio communication apparatus according to Embodiment 3 of the present invention. In the figure, reference numeral 26 indicates a temperature detecting circuit (temperature measuring unit). The temperature detection circuit 26 measures the temperature of the transmission circuit or its vicinity and notifies the CPU 21 of this. The third embodiment differs from the first embodiment shown in FIG. 1 only in that a temperature detection circuit 26 is provided.

In this embodiment as well, the power information is stored in the internal memory 22, but the power information, especially the maximum allowable power, is corrected by the amount corresponding to the fluctuation of the output power of the transmission circuit based on the environmental temperature. To be done.

Specifically, the electric power information (Y) for each type of modulation method relating to a certain reference temperature and the correction information (Y _t ) due to the temperature change are stored in the internal memory 22. The correction information (Y _t ) to be stored in the internal memory 22 can be prepared by measuring the change in the transmission output power due to the temperature change in advance.

The operation of the transmission circuit of this embodiment when used is basically the same as that of the first embodiment. However,
The CPU 21 reads the power information (Y) from the internal memory 22 based on the modulation method used, and the temperature detection circuit 2
Correction information (Y _t ) based on the environmental temperature notified from 6
Is read from the internal memory 22, the power information (Y) is corrected by the correction information (Y _t ), and the corrected power information is D
Supply to the / A converter 24.

As described above, according to the third embodiment, it is possible to obtain the effect that the fluctuation of the output power of the transmission circuit due to the environmental temperature can be eliminated.

Further, various kinds of power information corresponding to the frequency used and the environmental temperature may be stored in the internal memory 22. In this case, the CPU 21 sends the power information to the internal memory 2 based on the environmental temperature and the modulation method used.
It suffices to read the data from No. 2, and the power information can be directly supplied to the D / A converter 24 without being corrected.

Fourth Embodiment Features and implementation of the second embodiment
Embodiment 3 of the present invention by combining the features of Embodiment 3
4 may be realized. In this Embodiment 4, a certain criterion
Power information for each modulation type related to frequency and reference temperature
(Y) and correction information (Y _f) And warm
Correction information (Y_t) Is stored in the internal memory 22
Has been done.

The operation of the transmission circuit of this embodiment at the time of use is basically the same as that of the first embodiment. However,
The CPU 21 reads the power information (Y) from the internal memory 22 based on the modulation method used, reads the correction information (Y _f ) from the internal memory 22 based on the frequency used, and is notified from the temperature detection circuit 26. The correction information (Y _t ) is read from the internal memory 22 based on the ambient temperature and the power information (Y) is read as the correction information (Y _f ) and (Y _t ).
And the corrected power information is supplied to the D / A converter 24.

As described above, according to the fourth embodiment, it is possible to eliminate the fluctuation of the output power of the transmission circuit due to the used frequency and the environmental temperature.

The frequency used, the ambient temperature,
Various kinds of power information according to the modulation method used may be stored in the internal memory 22. In this case, the CPU
21 is based on the frequency used, the environmental temperature notified from the temperature detection circuit 26, and the modulation method used,
The power information may be read from the internal memory 22, and the power information can be directly supplied to the D / A converter 24 without being corrected.

Embodiment 5. FIG. 8 is a block diagram showing a transmission circuit of an adaptive modulation type time division multiplexing wireless communication apparatus according to Embodiment 5 of the present invention. In the figure, 27
Is a resistor, and 28 is a thermistor (temperature-dependent characteristic changer). The resistor 27 and the thermistor 28 are provided on the signal line between the D / A converter 24 and the voltage controlled attenuator 16. The fifth embodiment differs from the first embodiment shown in FIG. 1 only in that a resistor 27 and a thermistor 28 are provided.

In the fifth embodiment, the temperature correction is performed by the thermistor 28, instead of the temperature correction operation based on the temperature detection in the third and fourth embodiments. The operation of the transmission circuit of this embodiment at the time of use is the same as that of the first embodiment, but the resistance of the thermistor 28 fluctuates depending on the environmental temperature, so that the power information is substantially corrected and the voltage control type. Reach attenuator 16. Therefore, the attenuation characteristic of the voltage control type attenuator 16 is affected by the fluctuation of the resistance of the thermistor 28.

Therefore, the internal memory 22 need only store power information according to the modulation method used. However, similarly to the second embodiment, it is possible to combine the correction of the power information according to the used frequency with the fifth embodiment.

As described above, according to the fifth embodiment, it is possible to obtain the effect that the fluctuation of the output power of the transmission circuit due to the environmental temperature can be eliminated.

[0059]

As described above, according to the present invention, a time division multiplexing control unit for generating a code block suitable for a time slot of the time division multiplexing system from a transmitted user signal, and each code according to the situation. Adaptive modulation unit capable of changing the modulation system of blocks, modulator for modulating each code block into a modulated wave according to the modulation system defined by the adaptive modulation unit, and attenuator for attenuating the modulated wave An amplifier for amplifying the modulated wave attenuated by the attenuator, and an attenuation controller capable of controlling the attenuation performance of the attenuator for each time slot according to the modulation method defined by the adaptive modulator. According to the modulation method defined by the adaptive modulation unit, the gain control unit capable of controlling the gain of the amplifier for each time slot is provided. It is possible to dynamically adaptively control the gain and saturation output power of the amplifier according to the modulation method for each time slot of the division multiplexing method to save power and improve or maintain transmission quality. Has the effect of.

According to the present invention, the frequency conversion section capable of changing the transmission frequency for each time slot according to the situation is provided, and the attenuation control section has the modulation system defined by the adaptive modulation section and the above frequency conversion. Since it is possible to control the attenuation performance of the attenuator for each time slot according to the frequency specified by the department, it is possible to eliminate the fluctuation of the output power of the transmission circuit based on the used frequency. effective.

According to the present invention, the temperature measuring section for measuring the temperature of the wireless transmission circuit or its vicinity is provided, and the attenuation control section follows the modulation method defined by the adaptive modulating section and the temperature measured by the temperature measuring section. Since the attenuation performance of the attenuator for each time slot is configured to be controllable, it is possible to eliminate variations in output power of the transmission circuit due to temperature.

According to the present invention, the signal line connecting the attenuation control section and the attenuator is provided with the temperature dependent characteristic changer whose characteristic changes with temperature, and the attenuation control section controls the attenuator. Since the attenuation performance is configured to be influenced by the characteristics of the temperature-dependent characteristic changer, there is an effect that fluctuations in output power of the transmission circuit due to temperature can be eliminated.

[Brief description of drawings]

FIG. 1 is a block diagram showing a transmission circuit of an adaptive modulation type time division multiplexing wireless communication apparatus according to Embodiment 1 of the present invention.

FIG. 2 is a timing chart showing a signal generated by the transmission circuit shown in FIG. 1 and a result thereof.

3 is a graph showing a gain characteristic of a power amplifier of the transmission circuit shown in FIG.

FIG. 4 is a graph showing one of gain characteristics of the power amplifier that can be realized by changing the characteristics according to the first embodiment of the present invention.

FIG. 5 is a graph showing another one of gain characteristics of the power amplifier that can be realized by changing the characteristics according to the first embodiment of the present invention.

FIG. 6 is a graph showing yet another gain characteristic of the power amplifier that can be realized by changing the characteristic according to the first embodiment of the present invention.

FIG. 7 is a block diagram showing a transmission circuit of an adaptive modulation type time division multiplexing wireless communication apparatus according to Embodiment 3 of the present invention.

FIG. 8 is a block diagram showing a transmission circuit of an adaptive modulation type time division multiplexing wireless communication apparatus according to Embodiment 5 of the present invention.

[Explanation of symbols]

11 time division multiplexing control unit, 12 adaptive modulation unit, 13 modulator, 14 mixer, 15 band pass filter, 16
Voltage control type attenuator, 17 power amplifier, 18 low pass filter, 19 antenna, 20 frequency synthesizer (frequency converter), 21 CPU (attenuation controller, frequency converter), 22 internal memory, 23 power controller (attenuation controller) ), 24 D / A converter (attenuation control unit), 2
5 gain control section, 26 temperature detection circuit (temperature measurement section), 27 resistor, 28 thermistor (temperature dependent characteristic changer).

─────────────────────────────────────────────────── ─── Continuation of front page (51) Int.Cl. ⁷ Identification code FI theme code (reference) H04Q 7/38 H04B 7/26 109E 109F F term (reference) 5J100 JA01 KA05 LA11 QA01 QA02 SA01 5K004 AA01 AA05 AA08 BC00 EE00 EF02 FE00 FF05 5K028 AA00 BB04 KK01 SS02 5K060 BB07 CC04 CC11 DD04 FF09 HH01 HH06 HH16 HH31 HH32 KK01 KK06 LL01 LL16 LL22 5K067 AA33 AA43 CC04 DD27 GG08 KK00

Claims (4)

[Claims] 1. A time division multiplexing control unit for generating a code block suitable for a time slot of the time division multiplexing system from a transmitted user signal, and a modulation system of each code block can be changed according to circumstances. An adaptive modulator, a modulator that modulates each code block into a modulated wave according to the modulation method defined by the adaptive modulator, an attenuator that attenuates the modulated wave, and a modulated attenuator that is attenuated by the attenuator. An amplifier for amplifying a wave, an attenuation control unit capable of controlling the attenuation performance of the attenuator for each time slot according to the modulation system defined by the adaptive modulation unit, and a modulation system defined by the adaptive modulation unit. And a gain control unit capable of controlling the gain of the amplifier for each time slot. 2. A frequency conversion section capable of changing the transmission frequency for each time slot according to the situation is provided, and the attenuation control section is defined by the modulation system defined by the adaptive modulation section and the frequency conversion section. Circuit according to claim 1, characterized in that it is possible to control the attenuation performance of the attenuator for each time slot according to the frequency. 3. A temperature measuring unit for measuring the temperature of the wireless transmission circuit or the vicinity thereof, wherein the attenuation control unit determines, for each time slot, according to the modulation method defined by the adaptive modulating unit and the temperature measured by the temperature measuring unit. 3. A circuit according to claim 1 or 2, characterized in that it is possible to control the damping performance of said attenuator. 4. A temperature-dependent characteristic changer whose characteristic changes with temperature is provided on a signal line connecting the attenuation control section and the attenuator, and the attenuation performance of the attenuator which the attenuation control section attempts to control is the above-mentioned. 3. The temperature-dependent characteristic changer is influenced by the characteristic of the temperature-dependent characteristic changer.
The circuit described.