JP2001339318A - Mobile communication equipment and its output power control method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a mobile communication equipment that can properly control its output power with a simple circuit configuration. SOLUTION: A base band signal processing section 4 gives an amplification control signal for instruction of reducing the output signal power to an APC (Automatic Power Controller) 6 when transmission of a radio signal in a slot block is finished. The APC 6 reduces the amplification factor of an HPA(High Power Amplifier) 7 according to the amplification control signal received from the base band signal processing section 4. In this case, the base band signal processing section 4 gives a switch control signal to a VCO 10 and turns off a power supply of the VCO 10 timing when the output signal power is attenuated from a transmission power at transmission of the radio frequency signal by predetermined power.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a mobile communication device for transmitting and receiving a radio signal to perform communication, and in particular, to a TDMA (TiDMA) device.
BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a mobile communication device that performs wireless communication using a me Division Multiple Access (Me Division Multiple Access) method, and to a mobile communication device that can easily and appropriately control output signal power.

[0002]

2. Description of the Related Art TDMA (Time Division Multiple Acc)
ess) Mobile phones and PHS that perform wireless communication using the method
(Personal Handy-phone System), a mobile communication device assigns a slot synchronized with a base station,
Communication is performed by alternately transmitting and receiving wireless signals in a time-division manner. FIG.
FIG. 1 is a diagram illustrating a configuration of a conventional mobile communication device applied to a mobile communication system using such a TDMA system. In this configuration, HPA (High Power Ampli
The fier) 57 starts or stops the output of the transmission signal according to the control of the APC (Automatic Power Controller) 56 when the output of the transmission signal starts and stops, and adjusts the output signal power. The transmission-side RF signal processing unit 5
5 is the VCO 60 at the timing shown in FIG.
By generating a local oscillation signal by switching on / off of the power supply, a transmission signal can be generated. FIG. 6 shows an ideal output signal power waveform.

In such a mobile communication device, it is necessary to control the transmission power when transmitting a radio signal with a time characteristic within a range defined as a transmission wave power / time template in the standard of the mobile communication system. At this time, if the mobile communication device emits an unnecessary radio wave in a time zone other than the assigned slot or emits a transmission signal having a time characteristic outside the range specified by the transmission wave power / time template, the mobile communication device moves. Not only does the communication state of the mobile communication device deteriorate, but also the communication quality of the entire mobile communication system deteriorates significantly.

[0004]

In the above prior art, H
The PA 57 adjusts the output signal power to control the transmission power at the time of transmitting the wireless signal so as to conform to the transmission wave power / time template. Therefore, the transmission power waveform is restricted by the dynamic range of the HPA 57.

For example, when reducing the output signal power, GS
In order to conform to the M (Global System for Mobile communication) standard, the output signal power must be reduced to -59 dBc or less with respect to the transmission power (peak power) when transmitting a radio signal in a slot section. No. However, at the time of transmission, generally, the HPA 57 has 0 to 10 dB.
Since about m transmission signals are input, if the output signal power is controlled only by the HPA 57, there is a problem that the margin with the transmission wave power / time template is reduced as in the section from timing t51 to timing t52 shown in FIG. is there.

Here, a high-performance HPA 57 having a dynamic range of 60 dB or more may be used, but there is a problem that the product cost increases. As shown in FIG. 8, the transmission-side RF signal processing unit 55 and the HPA 5
It is conceivable to widen the dynamic range by interposing a buffer circuit 58 between the circuit and the circuit 7, but there is a problem that the circuit configuration becomes complicated, and the manufacturing cost and power consumption increase.

The present invention has been made in view of the above situation, and has as its object to provide a mobile communication device capable of appropriately controlling output signal power with a simple circuit configuration.

[0008]

In order to achieve the above object, a mobile communication device according to a first aspect of the present invention is applied to a mobile communication system for performing wireless communication using a time division multiple access system. Transmitting a radio signal in a slot section, and stopping oscillation of an oscillator for generating a transmission signal in synchronization with a timing of reducing output signal power.

According to the present invention, after transmitting the radio signal in the slot section, the oscillation of the oscillator for generating the transmission signal is stopped in synchronization with the timing of reducing the output signal power. This makes it possible to easily and appropriately reduce the output signal power after transmitting the wireless signal. That is, the output signal power can be appropriately controlled with a simple circuit configuration.

[0010] A mobile communication device according to a second aspect of the present invention has an oscillator, a transmission signal generating means for generating a radio frequency signal for transmission, and a radio frequency signal generated by the transmission signal generating means. Amplifying means for amplifying, means for supplying the radio frequency signal amplified by the amplifying means to the antenna for transmission, and power control means for controlling output signal power when transmitting the radio frequency signal, After transmitting the radio frequency signal, the control means stops the oscillation of the oscillator of the transmission signal generation means in synchronization with the timing of reducing the output signal power.

According to the present invention, after transmitting the radio frequency signal, the power control means stops the oscillation of the oscillator of the transmission signal generation means in synchronization with the timing of reducing the output signal power. This makes it possible to easily and appropriately reduce the output signal power after transmitting the radio frequency signal. That is, the output signal power can be appropriately controlled with a simple circuit configuration.

More specifically, the power control means stops the oscillation of the oscillator of the transmission signal generation means at a timing when the output signal power is reduced from the power at the time of transmitting the radio frequency signal to a predetermined power. It is desirable.

For example, the power control means constantly measures the output signal power to specify the amount of attenuation with respect to the transmission of the radio frequency signal, and when it is detected that the output signal power matches a predetermined reference value, the power control means transmits the output signal power. The oscillation of the oscillator included in the signal generation means may be stopped.

Alternatively, the power control means includes amplification control means for controlling an amplification factor when the amplification means amplifies a radio frequency signal received from the transmission signal generation means,
Further, the power control unit transmits a radio frequency signal based on a time at which the amplification control unit reduces the amplification factor of the amplification unit and the output signal power attenuates to a predetermined power, and then transmits a predetermined radio frequency signal. The oscillation of the oscillator included in the transmission signal generation means may be stopped at the timing of (1).

An output power control method for a mobile communication device according to a third aspect of the present invention is applied to a mobile communication system for performing wireless communication using a time division multiple access method. In the control method, after transmitting a radio signal in a slot section, the oscillation of an oscillator for generating a transmission signal is stopped in synchronization with a timing of reducing an output signal power.

[0016]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, a mobile communication device according to an embodiment of the present invention will be described in detail with reference to the drawings.

FIG. 1 is a diagram showing a configuration of a mobile communication device 100 according to an embodiment of the present invention. The mobile communication device 100 is, for example, a GSM (Global System for Mo
It is a mobile phone or the like applied to a mobile communication system of a bile communication) type. As shown in the figure, the mobile communication device 100 includes an antenna 1, an antenna switch 2, a reception-side RF (Radio Frequency) signal processing unit 3.
A baseband signal processing unit 4, a transmission-side RF signal processing unit 5, an APC (Automatic Power Controller) 6,
An HPA (High Power Amplifier) 7 is provided.

The antenna switch 2 supplies the RF signal received from the HPA 7 to the antenna 1 and supplies the RF signal received by the antenna 1 to the receiving-side RF signal processing unit 3. Note that a circulator or a duplexer may be used instead of the antenna switch 2.

The receiving-side RF signal processing unit 3 includes a downconverter, a PLL (Phase Lock Loop) synthesizer, a quadrature detector, and the like.
The baseband signal is demodulated from the signal and sent to the baseband signal processing unit 4.

The baseband signal processing unit 4 includes a DSP (Di-
gital Signal Processor), CPU (Central Processi)
ng Unit) for reproducing an audio signal or a data signal from the baseband signal received from the reception-side RF signal processing unit 3 and executing a process according to the reproduced signal. Further, the baseband signal processing unit 4 executes a predetermined process to generate a baseband signal for transmitting a voice signal or a data signal to the base station, and sends the generated baseband signal to the transmission-side RF signal processing unit 5.

Here, the baseband signal processing unit 4
By transmitting an amplification control signal to the PC 6, the signal amplification factor of the HPA 7 is controlled, and the transmission power when transmitting the RF signal is controlled. Further, the baseband signal processing unit 4 sends a switching control signal to the VCO 10 included in the transmission-side RF signal processing unit 5 to switch on / off the power of the VCO 10.

The transmitting-side RF signal processing unit 5 is composed of a quadrature modulator and the like, generates an RF signal corresponding to the baseband signal received from the baseband signal processing unit 4, and sends it to the HPA 7. Further, the transmission-side RF signal processing unit 5 transmits the RF signal for transmission.
A VCO 10 for generating a signal is provided.

The VCO 10 is a voltage-controlled oscillator for generating a local oscillation signal used when the transmission-side RF signal processing section 5 generates an RF signal for transmission.

The APC 6 controls the output signal power of the mobile communication device 100 by controlling the signal amplification factor of the HPA 7 according to the amplification control signal received from the baseband signal processing unit 4.

The HPA 7 is an amplifier for amplifying the RF signal received from the transmission-side RF signal processing unit 5 at a signal amplification rate according to the control of the APC 6. The HPA 7 supplies the amplified RF signal to the antenna 1 via the antenna switch 2, and transmits the signal as a wireless signal.

The operation of mobile communication device 100 according to the embodiment of the present invention will be described below. After the transmission of the radio signal in the slot section is completed, the mobile communication device 100 operates at the timing at which the output signal power drops to a predetermined power level at the V-side of the transmission-side RF signal processing unit 5.
By turning off the power of CO10 and stopping oscillation,
This is an apparatus that can easily and appropriately reduce the output signal power even when the dynamic range of the HPA 7 is narrow.

The mobile communication device 100 performs communication by transmitting and receiving radio signals to and from base stations constituting a mobile communication system. That is, the RF signal received by the antenna 1 is sent to the receiving-side RF signal processing unit 3 via the antenna switch 2. The receiving-side RF signal processing unit 3 demodulates a baseband signal from the received RF signal and sends the demodulated baseband signal to the baseband signal processing unit 4. The baseband signal processing unit 4 reproduces an audio signal, a data signal, and the like from the baseband signal received from the reception-side RF signal processing unit 3,
Execute various processes.

The baseband signal processing unit 4 generates a baseband signal for transmitting a voice signal or a data signal to the base station and sends the baseband signal to the transmission-side RF signal processing unit 5 to generate an RF signal for transmission. Let it. The RF signal generated by the transmission-side RF signal processing unit 5 is amplified by the HPA 7, sent to the antenna 1 via the antenna switch 2, and transmitted as a radio signal to the base station.

At this time, since communication is performed using a TDMA system such as GSM, the transmission power waveform must be controlled so as to fall within a range defined as a transmission wave power / time template in a mobile communication system standard. No.

Here, when increasing the output signal power,
In general, a sufficient margin for the transmitted wave power / time template can often be ensured, and there are few problems.

On the other hand, when reducing the output signal power after transmitting the radio signal in the slot section, the transmission power waveform is restricted by the dynamic range of the HPA 7, and the margin for the transmission power / time template is insufficient. Often.

Therefore, when reducing the output signal power, the mobile communication device 100 synchronizes the timing at which the power of the VCO 10 is turned off with the timing at which the output signal power is reduced, so that the transmission signal power / time template is reduced. Secure margins. More specifically, the power of the VCO 10 is turned off at a timing when the output signal power is attenuated by a predetermined power from the transmission power (output power when transmitting a wireless signal in a slot section).

Specifically, the baseband signal processing unit 4
When transmission of a wireless signal in a slot section ends, A
An amplification control signal for instructing the PC 6 to reduce the output signal power is sent. Here, the slot section corresponds to the mobile communication device 1.
00 is a time section corresponding to a slot allocated when wireless communication is performed using a TDMA method with a base station included in a mobile communication system. The APC 6 reduces the amplification factor of the HPA 7 according to the amplification control signal received from the baseband signal processing unit 4. Thereby, the output signal power of mobile communication device 100 is reduced.

At this time, the baseband signal processing unit 4
A switching control signal is sent to the CO 10, and at the timing when the output signal power attenuates from the transmission power by a predetermined power, VC
Turn off the power of O10. As a result, the VCO 10 stops oscillating.

For example, the baseband signal processing unit 4 determines that the output signal power is -30 with respect to the transmission power (peak power).
At a predetermined timing when the VCO
Turn off the power supply of 10.

More specifically, as shown in FIG. 2, for example, the APC 6 is configured such that a coupler 21 provided on a line 20 connecting the HPA 7 and the antenna switch 2 branches a part of a transmission output signal, and a diode circuit. 22 receives the detected signal. The voltage value of the signal detected by the diode circuit 22 increases or decreases according to the transmission output level. APC
6 specifies the transmission output level from the voltage value of the signal received from the diode circuit 22 and notifies the baseband signal processing unit 4 of the transmission output level. The baseband signal processing unit 4 sets the transmission output level notified from the APC 6 to transmission power (peak power).
When the switching control signal is detected to have decreased to -30 to -50 dBc, the switching control signal is sent to the VCO 10 to stop the oscillation.

Alternatively, the baseband signal processing unit 4
Based on synchronization control in a TDMA mobile communication system, the VCO 10
Stop oscillation. That is, in the mobile communication system of the TDMA system, all timings such as a timing of transmitting and receiving a radio signal are synchronously controlled. Therefore,
Output signal power is -30 to -50 dBc with respect to transmission power
Can be obtained in advance by calculation. Therefore, the baseband signal processing unit 4 sends a switching control signal to the VCO 10 based on the previously obtained timing, and stops the oscillation of the VCO 10 at a predetermined timing.

As a result, as shown in FIG. 3, the VCO 10 operates at a predetermined timing t when the output signal power is attenuating.
1 Turn off the power. When the power supply of the VCO 10 is turned off and the oscillation is stopped, the transmission-side RF signal processing unit 5 does not generate an RF signal, so that the signal level input to the HPA 7 rapidly decreases. Therefore, the mobile communication device 100
The output signal power has a waveform as shown in FIG. 4, and a sufficient margin with the transmission wave power / time template in the GSM standard, for example, can be secured. For example, H
Even if the dynamic range of the PA 7 is 60 dB or less, the output signal power can be immediately reduced to a noise level of about -90 dBm.

As described above, according to the present invention,
By turning off the power supply of the VCO 10 provided for generating the transmission signal at the timing when the output signal power is attenuated by a predetermined power from the transmission power, even if the dynamic range of the HPA 7 is narrow, it is easy and appropriate. The output signal power can be reduced. That is, transmission power can be appropriately controlled with a simple circuit configuration.

The present invention is not limited to a mobile communication apparatus applied to a GSM mobile communication system, but includes a TDM
The present invention can be applied to any communication device that performs communication using the A method. Further, in the above-described embodiment, the reception side RF signal processing unit 3 is described as being provided. However, this may be omitted to configure a transmission-only communication device.

[0041]

As described above, according to the present invention, the output signal power is easily and appropriately controlled by synchronizing the timing of stopping the oscillation of the oscillator and the timing of reducing the output signal power. can do.

[Brief description of the drawings]

FIG. 1 is a diagram showing a configuration of a mobile communication device according to an embodiment of the present invention.

FIG. 2 is a diagram for explaining an operation when a VCO turns off a power supply.

FIG. 3 is a diagram for explaining a timing at which a VCO turns off a power supply.

FIG. 4 is a diagram illustrating output signal power of a mobile communication device.

FIG. 5 is a diagram illustrating a configuration of a conventional mobile communication device.

FIG. 6 is a diagram for explaining the timing at which the conventional mobile communication device turns off the power of the VCO.

FIG. 7 is a diagram showing output signal power of a conventional mobile communication device.

FIG. 8 is a diagram illustrating a configuration of a mobile communication device in which a buffer circuit is interposed.

[Explanation of symbols]

 1, 51 Antenna 2, 52 Antenna Switch 3, 53 Receiving RF Signal Processing Unit 4, 54 Baseband Signal Processing Unit 5, 55 Transmission RF Signal Processing Unit 6, 56 APC 7, 57 HPA 10, 60 VCO 20 Line 21 Coupler 22 Diode circuit 58 Buffer circuit 100 Mobile communication device

 ──────────────────────────────────────────────────続 き Continued on the front page F term (reference) 5K028 AA00 BB04 KK12 LL12 MM12 RR02 SS29 5K060 BB07 CC04 DD04 FF09 HH09 HH26 HH32 LL01 MM00

Claims (6)

[Claims] 1. A mobile communication device applied to a mobile communication system for performing wireless communication using a time division multiple access system, wherein a wireless signal is transmitted in a slot section, and then an output signal power is reduced. A mobile communication device comprising: stopping oscillation of an oscillator for generating a transmission signal in synchronization with timing. A transmission signal generating means for generating a radio frequency signal for transmission, an amplifying means for amplifying the radio frequency signal generated by the transmission signal generating means, and an amplifier amplified by the amplifying means. Means for supplying and transmitting a radio frequency signal to an antenna, and power control means for controlling output signal power when transmitting the radio frequency signal, wherein the power control means outputs the radio frequency signal after transmitting the radio frequency signal. A mobile communication device, wherein the oscillation of an oscillator included in the transmission signal generation means is stopped in synchronization with a timing at which the signal power is reduced. 3. The power control means stops the oscillation of the oscillator of the transmission signal generation means at a timing when the output signal power is reduced from a power at the time of transmitting a radio frequency signal to a predetermined power. The mobile communication device according to claim 2, wherein: 4. The power control means constantly measures the output signal power to determine the amount of attenuation with respect to the transmission of the radio frequency signal, and when it is detected that the output signal power matches a predetermined reference value, the power control means transmits the output signal power. The mobile communication device according to claim 3, wherein the oscillation of an oscillator included in the signal generation means is stopped. 5. The power control means includes amplification control means for controlling an amplification factor when the amplification means amplifies a radio frequency signal received from the transmission signal generation means. After transmitting the radio frequency signal based on the time of the timing when the amplification control means reduces the amplification factor of the amplification means and the output signal power attenuates to a predetermined power, the transmission signal generation means at a predetermined timing The mobile communication device according to claim 3, wherein oscillation of an oscillator included in the mobile communication device is stopped. 6. A method for controlling output power of a mobile communication device applied to a mobile communication system for performing wireless communication using a time division multiple access method, comprising: transmitting a radio signal in a slot section; A method for controlling output power of a mobile communication device, comprising: halting the oscillation of an oscillator for generating a transmission signal in synchronization with a timing of reducing signal power.