JPH0983380A - Radio communication equipment - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a radio communication equipment with which a transmission signal output level can be regulated lower than a specified output level at all times. SOLUTION: This equipment has a transmission signal generator 2 for generating a transmission signal, transmission preamplifiers 3 and 4 for amplifying the generated transmission signal, brancher 7 for branching the transmission signal of the transmission pre-amplifiers 3 and 4 into a main transmission signal (p) and a subordinate transmission signal (q) and delayer 11 for outputting a delayed transmission signal delaying the signal (p) and is provided with a variable attenuator 5 for outputting an attenuated transmission signal attenuating the delayed transmission signal just for prescribed quantity, transmission final step amplifier 6 for amplifying the attenuated transmission signal, and transmission signal output level detector 9 for outputting a level detect signal (c) by detecting the transmission signal output level from the signal (q). Then, a control part 10 is provided for calculating the attenuation quantity of the variable attenuator 5 based on the signal (c) and outputting an attenuation quantity control signal (d) showing the calculated value to the variable attenuator 5 within prescribed time.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a wireless communication device such as a mobile phone and a cordless phone.

[0002]

2. Description of the Related Art In recent years, wireless communication devices such as mobile phones and cordless phones have rapidly spread. Further, in the case of a simple type mobile phone, it can be used as a mobile phone outdoors and as a cordless phone indoors, so that future market expansion is expected.

A conventional wireless communication device will be described below with reference to the drawings. FIG. 5 is a block diagram showing a conventional wireless communication device. In FIG. 5, 1 is a transmitter for transmitting a transmission signal from the transmission antenna 8, 2 is a transmission signal generator for generating a transmission signal based on an operation control signal a and a transmission data signal b from a control unit 10 described later, 3 Is a transmission first-stage amplifier that amplifies the input transmission signal, 4 is a transmission intermediate-stage amplifier that amplifies the transmission signal output from the transmission first-stage amplifier 3, and 5 attenuates and outputs the transmission signal output from the transmission intermediate-stage amplifier 4. A variable attenuator, 6 is a transmission final stage amplifier that amplifies the transmission signal output from the variable attenuator 5, and 7 is a distribution that divides the transmission signal output from the transmission final stage amplifier 6 into a main transmission signal and a sub transmission signal. And 8 is a transmission antenna that radiates the main transmission signal output from the distributor 7 as a radio signal, and 9 is a level detection signal that receives the sub-transmission signal output from the distributor 7 and indicates the output level of the transmission signal. Transmission signal output level detector that outputs c, 10 is activated, and outputs the transmission data signal b indicating the contents of the operation control signal a and the transmission signal for stopping the transmission signal generator 2, also the input level detection signal c
The control unit outputs the attenuation amount control signal d to the variable attenuator 5 based on

FIG. 6 is a transmission signal waveform diagram showing the transmission signal output level in the time division multiplexing system (TDMA system) at the time when the transmission time after the start of transmission has sufficiently passed, with the horizontal axis representing time and the vertical axis. Indicates the transmission signal output level. In FIG. 6, S21 is the transmission signal waveform of the first transmission slot, S22 is the transmission signal waveform of the second transmission slot,
S23 is the transmission signal waveform of the third transmission slot, LV
L is a specified output level of the transmission signal.

FIG. 7 is a transmission signal waveform diagram showing the transmission signal output level in the TDMA system at the time of starting transmission, where the horizontal axis represents time and the vertical axis represents the transmission signal output level.
In FIG. 7, S11 is the transmission signal waveform of the first transmission slot, S12 is the transmission signal waveform of the second transmission slot, S13 is the transmission signal waveform of the third transmission slot, and LVL is the specified output of the transmission signal. It is a level.

The operation of the radio communication apparatus configured as described above will be described below. Here, a TDMA type device will be described. First, the operation control signal a and the transmission data signal b are sent from the control unit 10 to the transmission signal generator 2. The transmission signal generator 2 which receives the signals a and b generates a transmission signal of radio frequency. The output level of the transmission signal at this point is, except for the level shown by the waveform S11,
As shown in FIG. 7, it is sufficiently lower than the specified output level LVL. The transmission signal in the TDMA system is a signal that is intermittent in time as shown in FIG. 6, and has a waveform S21 and a waveform S2.
2. The waveform S23 is repeatedly output at equal time intervals. The transmission signal output from the transmission signal generator 2 is amplified by the transmission initial stage amplifier 3 and further amplified by the transmission intermediate stage amplifier 4. After that, the transmission signal output from the transmission intermediate stage amplifier 4 is attenuated by the variable attenuator 5 to become an attenuation transmission signal, and this attenuation transmission signal is amplified to a specified output level by the transmission final stage amplifier 6 and is mainly transmitted through the distributor 7. The transmission signal is sent to the transmission antenna 8 and output as a radio signal. The demultiplexer 7 divides the input transmission signal into the main transmission signal and the sub transmission signal, and the sub transmission signal is sent to the transmission signal output level detector 9.

Next, a method of controlling the output level of the transmission signal will be described. The transmission signal output level is stipulated by law and an upper limit is set. In particular, the base station of the mobile phone is a public system, so that it does not interfere with the communication of other base stations and terminals,
It is necessary to strictly comply with the regulations for the transmission signal output level. That is, the output level of the transmission signal needs to be lower than the specified output level LVL as shown in FIG. For the transmission signal output level, a part of the transmission signal output from the transmission final stage amplifier 6 (a minute level signal that does not affect the transmission signal output level at the transmission antenna 8) is taken out by the distributor 7 as a sub-transmission signal, The transmission signal is sent to the transmission signal output level detector 9, and the transmission signal output level detector 9 detects a voltage value corresponding to the transmission signal output level of the radio frequency one to one. The voltage value corresponding to one-to-one is a voltage value having a positive characteristic such that the voltage value also increases when the transmission signal output level increases. The level detection signal c indicating this voltage value is sent from the transmission signal output level detector 9 to the control unit 10. The control unit 10 stores a voltage value (hereinafter, referred to as “specified voltage value”) corresponding to the specified output level LVL and one-to-one, and the control unit 10 stores the voltage value and the specified voltage value indicated by the level detection signal c. And the attenuation control signal d from the difference voltage value.
Is calculated to control the attenuation amount of the variable attenuator 5.

[0008]

However, in the conventional wireless communication device, the transmission signal output level is the specified output level LVL as shown by the transmission signal waveform S11 (FIG. 7) of the first slot at the start of transmission. If it exceeds, it cannot be adjusted to lower the output level of the transmission signal below the specified output level LVL, so that the transmission antenna 8 directly transmits radio waves of the specified output level LVL or higher.
Will be sent from. Further, when the transmission signal output level suddenly changes due to the increase of the amplification degree of the amplifier due to the vibration and exceeds the specified output level LVL, the conventional device can adjust the transmission signal output level as described above. Since it is not possible, similarly, the radio wave having the specified output level LVL or more is transmitted from the transmitting antenna 8 as it is. In order to solve this problem, the transmission signal output level of the transmission signal generator 2, the amplification degree of the amplifiers 3, 4, and 6 and the attenuation amount of the variable attenuator 5 have strict accuracy including environmental characteristics. Need to be made. However, it is technically difficult to give strict accuracy to all of them, and the use of high-priced parts to increase the accuracy causes an increase in cost. That is, in the conventional device, in consideration of technical difficulty and cost increase, the transmission signal output level is always set to the specified output level LV, including at the start of transmission and when the transmission signal output level suddenly rises.
Since it cannot be adjusted to be equal to or lower than L, there is a problem that it is impossible to prevent interference with other wireless communication devices such as a base station and a terminal.

The present invention solves the above-mentioned conventional problems, and it is possible to constantly adjust the transmission signal output level to a prescribed output level or less, including at the start of transmission and when the transmission signal output level suddenly rises. An object of the present invention is to provide a wireless communication device capable of preventing interference with other wireless communication devices.

[0010]

In order to achieve this object, a wireless communication device according to claim 1 of the present invention, a transmission signal generator for generating a transmission signal, and an amplified transmission signal for output. A pre-transmission amplifier, a distributor for distributing the transmission signal output from the pre-transmission amplifier into a main transmission signal and a sub-transmission signal, a delay device for delaying the main transmission signal by a predetermined time, and a delay transmission A variable attenuator that outputs an attenuated transmission signal that is attenuated by a predetermined amount, a transmission final-stage amplifier that amplifies the attenuation transmission signal and outputs it to the transmission antenna, and an output level that detects the output level of the transmission signal from the sub-transmission signal. When a level detection signal is input, a transmission signal output level detector that outputs a level detection signal that indicates that the attenuation amount of the variable attenuator is calculated based on the level detection signal, and an attenuation amount control signal that indicates the calculated attenuation amount is input. It has a configuration in which a control unit for outputting to the variable attenuator in Luo predetermined time.

In the wireless communication device according to the second aspect, the delay device is a bandpass filter.

[0012]

With this configuration, the transmission signal output level detector detects the transmission signal output level by the sub-transmission signal from the distributor placed before the delay device and the variable attenuator. The control unit can control the amount of attenuation of the variable attenuator so that the transmission signal output level is always below the specified output level during the delay time of the predetermined time. It is possible to constantly adjust the transmission signal output level to be equal to or lower than the specified output level, including when the signal rises, and to prevent interference with other wireless communication devices.

[0013]

【Example】

(Embodiment 1) A wireless communication apparatus according to an embodiment of the present invention will be described below with reference to the drawings. FIG. 1 is a block diagram showing a wireless communication device according to an embodiment of the present invention. In FIG. 1, 2 is a transmission signal generator, 3 is a transmission initial stage amplifier, 4
5 is a transmission intermediate stage amplifier, 5 is a variable attenuator, 6 is a transmission final stage amplifier, 7 is a distributor, 8 is a transmission antenna, 9 is a transmission signal output level detector, and 10 is a control unit.
Since it is the same as the above, the same reference numerals are given and the description is omitted. Reference numeral 1A is a transmission unit that transmits a transmission signal from the transmission antenna 8, and 11 is a delay device that outputs a delayed transmission signal obtained by delaying the main transmission signal p output from the distributor by a predetermined time (for example, 6 μsec). The amplifiers 3 and 4 form a pre-transmission amplifier.

FIG. 2 is a transmission signal waveform diagram showing the transmission signal output level of the transmission final stage amplifier 6 in the TDMA system at the transmission start time, the horizontal axis shows the time, and the vertical axis shows the transmission signal output level. In FIG. 2, S1 is the transmission signal waveform of the first transmission slot, S2 is the transmission signal waveform of the second transmission slot, S3 is the transmission signal waveform of the third transmission slot, and LVL is the specified output of the transmission signal. It is a level.

FIG. 3 is a transmission signal waveform diagram showing the transmission signal output level of the transmission intermediate stage amplifier 4 in the TDMA system at the transmission start time, the horizontal axis shows time, and the vertical axis shows the transmission signal output level. In FIG. 3, SA1 is the transmission signal waveform of the first transmission slot, SA2 is the transmission signal waveform of the second transmission slot, SA3 is the transmission signal waveform of the third transmission slot, and LVL is the specified output of the transmission signal. It is a level.

The operation of the radio communication apparatus configured as above will be described below. First, the operation control signal a and the transmission data signal b are sent from the control unit 10 to the transmission signal generator 2. The transmission signal generator 2 which receives the signals a and b generates a transmission signal of radio frequency. The output level of the transmission signal in the transmission intermediate stage amplifier 4 at this time is sufficiently lower than the specified output level LVL as shown in FIG.
However, the level indicated by the waveform SA1 is higher than the other levels, and the output level at the time when the transmission signal of the waveform SA1 is output from the transmission final stage amplifier 6 is the specified output level LV.
L may be exceeded. The transmission signal in the TDMA system is a signal that is intermittent in time as shown in FIG. 2, and is repeatedly output at equal time intervals as in waveforms S1, S2, and S3. The transmission signal output from the transmission signal generator 2 is amplified by a transmission first stage amplifier (amplifier with amplification degree G1) 3 and further amplified by a transmission intermediate stage amplifier (amplifier with amplification degree G2) 4. The amplified transmission signal from the transmission intermediate stage amplifier 4 is divided by the distributor 7 into the main transmission signal p and the sub transmission signal q. The main transmission signal p is input to the delay device 11 through the distributor 7 and becomes a delayed transmission signal delayed by a predetermined time. This delayed transmission signal is input to the variable attenuator (attenuator having the attenuation amount L) 5 and attenuated by a predetermined amount. Becomes the attenuated transmission signal. The attenuated transmission signal output from the variable attenuator 5 is amplified to a specified output level by a transmission final stage amplifier (amplifier with amplification degree G3) 6, sent to a transmission antenna 8, and output as a radio wave signal. The sub transmission signal q is sent to the transmission signal output level detector 9, and the transmission signal output level detector 9 detects the transmission signal output level in the transmission intermediate stage amplifier 4 based on the sub transmission signal q, and the level detection signal c Output as.

Next, a method of controlling the output level of the transmission signal will be described. As described above, the transmission signal output level is regulated by law and the upper limit value is set. In particular, since the base station of a mobile phone is a public system, it is necessary to strictly comply with the regulation of the transmission signal output level so as not to interfere with the communication of other base stations and terminals. That is, the output level of the transmission signal needs to be lower than the specified output level LVL as shown in FIG. As the transmission signal output level, a part of the transmission signal output from the transmission intermediate stage amplifier 4 (a minute level signal that does not affect the transmission signal output level at the transmission antenna 8) is distributed to the distributor 7.
At the transmission signal output level detector 9, and the transmission signal output level detector 9 detects a voltage value corresponding to the transmission signal output level of the radio frequency on a one-to-one basis. To do. As described in the section of the related art, the voltage value corresponding to one-to-one is a voltage value having a positive characteristic such that the voltage value also increases when the transmission signal output level increases. The level detection signal c indicating this voltage value is sent from the transmission signal output level detector 9 to the control unit 10.
The control unit 10 compares the voltage value indicated by the level detection signal c with the above-mentioned specified voltage value, calculates the attenuation amount indicated by the attenuation amount control signal d from the difference voltage value, and determines the attenuation amount L of the variable attenuator 5. Control. That is, when the difference voltage value is positive (when the voltage value indicated by the level detection signal c is larger than the specified voltage value),
The attenuation amount L is increased so that the differential voltage value becomes zero.
On the contrary, when the difference voltage value is negative (when the voltage value indicated by the level detection signal c is smaller than the specified voltage value), the attenuation amount L is decreased so that the difference voltage value becomes zero.

When such processing is performed, the control unit 10 requires a processing time of about 5 μs from the reception of the level detection signal c to the control of the variable attenuator 5.
Therefore, before the transmission signal is sent from the distributor 7 to the variable attenuator 5, it is necessary to delay the transmission time by about 6 μsec (predetermined time), which is longer than the processing time. Here, a delay device 11 is inserted between the distributor 7 and the variable attenuator 5 in order to create a transmission time of about 6 μsec. The delay time (predetermined time) of the delay device 11 is about 6 μsec. Therefore, the transmission signal output level at the start of transmission indicated by the waveform SA1 in FIG. 3 corresponds to the specified output level of the transmission intermediate stage amplifier 4, that is, the specified output level LVL of the transmission final stage amplifier 6, and the specified value of the transmission intermediate stage amplifier 4. Even when the output level (lower than the level LVL) is exceeded, the delay unit 1
1, the transmission signal is delayed, and within the delay time, the control unit 10
Can control the variable attenuator 5 to adjust the transmission signal output level of the transmission final stage amplifier 6 so as not to exceed the specified output level LVL. It is possible to obtain a transmission signal that does not exceed. This means that even if the transmission signal output level suddenly rises, a transmission signal that does not exceed the specified output level LVL can be obtained at the output of the transmission final stage amplifier 6. That is, the transmission signal output level can always be adjusted to be equal to or lower than the specified output level.

As described above, according to this embodiment, the distributor 7
Is placed in front of the delay device 11 and the variable attenuator 5, and the transmission signal output level detector 9 detects the transmission signal output level by the sub transmission signal q from the distributor 7. Within the delay time of the delay device 11 after receiving the detection signal c, the attenuation amount of the variable attenuator 5 can be controlled so that the transmission signal output level always becomes equal to or lower than the specified output level. The transmission signal output level can always be adjusted to be equal to or lower than the specified output level, including when the transmission signal output level suddenly rises.
It is possible to prevent interference with other wireless communication devices.

(Embodiment 2) A radio communication apparatus according to a second embodiment of the present invention will be described below with reference to the drawings.

FIG. 4 is a block diagram showing a wireless communication apparatus according to this embodiment. In FIG. 1, 1A is a transmission unit, 2 is a transmission signal generator, 3 is a transmission first stage amplifier, 4 is a transmission intermediate stage amplifier, 5 is a variable attenuator, 6 is a transmission final stage amplifier, 7 is a distributor, and 8 is transmission. An antenna, 9 is a transmission signal output level detector, and 10 is a control unit. Since these are the same as those in FIG. 1, the same reference numerals are given and description thereof is omitted. Reference numeral 12 is a bandpass filter as a delay device that outputs a delayed transmission signal obtained by delaying the main transmission signal p output from the distributor by a predetermined time (for example, 6 μsec). In this embodiment, the delay device 11 of FIG. 1 is used as a bandpass filter 12, and the operation is not different from that of the first embodiment, and therefore its explanation is omitted. However, the effect is different. That is, the bandpass filter 12 can obtain not only the delay time but also a desired frequency band, so that a transmission signal with an improved S / N ratio can be obtained.

As described above, according to this embodiment, the same effect as that of the first embodiment can be obtained, and a desired frequency band can be extracted to improve the S / N ratio.

[0023]

As described above, the present invention mainly includes a transmission signal generator for generating a transmission signal, a transmission pre-stage amplifier for amplifying and outputting the generated transmission signal, and a transmission signal output from the transmission pre-stage amplifier. A distributor for distributing the transmission signal and the sub-transmission signal, a delay device for outputting a delayed transmission signal obtained by delaying the main transmission signal for a predetermined time, and a variable attenuator for outputting an attenuated transmission signal obtained by attenuating the delayed transmission signal by a predetermined amount. A transmission final-stage amplifier that amplifies the attenuated transmission signal and outputs it to the transmission antenna; a transmission signal output level detector that detects the output level of the transmission signal from the sub-transmission signal and outputs a level detection signal indicating the output level; A control unit that calculates the attenuation amount of the variable attenuator based on the level detection signal and outputs an attenuation amount control signal indicating the calculated attenuation amount to the variable attenuator within a predetermined time after the input of the level detection signal is provided. As a result, the transmission signal output level is detected by the sub-transmission signal from the distributor placed in front of the delay device and variable attenuator, so that the attenuation of the variable attenuator during the delay time of a predetermined time in the delay device. It is possible to control the amount and adjust so that the transmission signal output level in the transmission final stage amplifier is always below the specified output level,
Wireless communication capable of constantly adjusting the output level of the transmission signal to be equal to or lower than the specified output level, including at the time of starting transmission and when the output level of the transmission signal suddenly rises, thereby preventing interference with other wireless communication devices. The device can be realized.

Further, by using a bandpass filter as the delay device, it is possible to prevent interference with other wireless communication devices and to realize a wireless communication device with an improved S / N ratio.

[Brief description of drawings]

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

FIG. 2 is a transmission signal waveform diagram showing the transmission signal output level of the transmission final stage amplifier in the TDMA system at the start of transmission.

FIG. 3 is a transmission signal waveform diagram showing the transmission signal output level of the transmission intermediate stage amplifier in the TDMA system at the start of transmission.

FIG. 4 is a block diagram showing a wireless communication device according to the present embodiment.

FIG. 5 is a block diagram showing a conventional wireless communication device.

FIG. 6 is a transmission signal waveform diagram showing the transmission signal output level in the time division multiplexing system (TDMA system) at the time when the transmission time after the start of transmission has sufficiently passed.

FIG. 7 is a transmission signal waveform diagram showing a transmission signal output level in the TDMA system at the time of starting transmission.

[Explanation of symbols]

 1A transmitter 2 transmitter signal generator 3 transmitter first stage amplifier (transmitter pre-stage amplifier) 4 transmitter intermediate stage amplifier (transmitter pre-stage amplifier) 5 variable attenuator 6 transmitter final stage amplifier 7 distributor 8 transmitter antenna 9 transmitter signal output level detector 10 Control unit 11 Delay device 12 Bandpass filter

Claims (2)

[Claims] 1. A transmission signal generator that generates a transmission signal, a pre-transmission amplifier that amplifies and outputs the generated transmission signal, and a transmission signal output from the pre-transmission amplifier as a main transmission signal and a sub-transmission signal. A distributor for distributing the main transmission signal to a delayed transmission signal delayed by a predetermined time, a variable attenuator for outputting an attenuated transmission signal obtained by attenuating the delayed transmission signal by a predetermined amount, and the attenuation transmission A transmission final-stage amplifier that amplifies a signal and outputs it to a transmission antenna; a transmission signal output level detector that detects an output level of the transmission signal from the sub-transmission signal and outputs a level detection signal indicating the output level; The attenuation amount of the variable attenuator is calculated based on the level detection signal, and the attenuation amount control signal indicating the calculated attenuation amount is input to the variable attenuator within the predetermined time after the input of the level detection signal. Radio communication apparatus characterized by comprising a control unit for outputting. 2. The wireless communication device according to claim 1, wherein the delay device is a bandpass filter.