JP3196892B2 - Transmission output control device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a transmission power control apparatus, and more particularly to TDMA (time division multiple access) communication / TDD.
The present invention relates to a transmission output control device that controls transmission output to be constant when intermittent transmission is performed in (time-division two-way) communication.

[0002]

2. Description of the Related Art Generally, transmission power control detects the level of an output signal, compares it with a reference signal by a level comparator, and increases the transmission gain if the output level is lower than the reference signal. If the output level is higher than the reference signal, the transmission power is controlled so as to reduce the transmission gain. In recent years, it has been required to perform transmission power control even when a transmission signal is burst-like as in a TDMA / TDD device.

In order to meet this demand, for example, as disclosed in Japanese Patent Application Laid-Open No. 6-232665, it has been proposed to use a reference signal as envelope information in accordance with a burst signal. In the technique disclosed in this prior art document, a reference signal is generated by a digital envelope generator as shown in FIG. 4 and compared with an output level to perform transmission power control.

[0004]

However, in this technique, since the level comparison is performed on the digital envelope, the detector for detecting the level and the error detection amplifier must follow the digital envelope signal. There is a problem.

Further, when the transmission speed of the transmission signal is high and the amount of information to be transmitted at one time is small, the digital envelope signal also becomes high speed, so that a detector capable of high-speed operation and an error detection amplifier are required. There is also.

Therefore, the present invention is to control the transmission power of a burst signal to be constant using a low-speed level detector and a level comparator irrespective of the transmission speed of a transmission signal and the amount of information transmitted at one time. Is an issue.

[0007]

According to the present invention, there is provided a specific pattern signal generator for generating a specific pattern signal, an input switch for inputting the specific pattern signal and a transmission data signal, and A variable attenuator for attenuating the output of the input switch, a main amplifier for amplifying the output of the variable attenuator, a level detector for detecting an output level of the main amplifier and feeding back to the variable attenuator; An output switch for inputting the output of the amplifier, a transmission output control device having a timing controller for controlling the opening and closing of the input switch and the output switch, wherein the timing controller, when there is the transmission data signal,
While the transmission data signal is input to the variable attenuator and the output switch is closed to output the transmission data, the specific pattern signal is input to the variable attenuator when there is no transmission data signal, and the output switch is Is opened so that the specific pattern signal is not output and the transmission output level is controlled to be constant .

That is, in the transmission output control device according to the present invention, the switch (4) is provided at the transmission data input portion of the amplifier in the TDMA / TDD device, and the timing signal (3) is provided.
, The transmission data (1) and the output of the pattern generator (2) are switched.

The switch (4) switches the output of the intermittently transmitted transmission data (1) and the output of the continuously transmitted pattern generator (2) and inputs the same to the feedforward amplifier. When there is transmission data, the transmission data side is controlled to select the pattern generator side when there is no transmission data, and the output side of the switch (4) operates so as to be continuous data.

Therefore, the level detector (1) at the subsequent stage
1) has an effect that the level of continuous data can be detected. The final output is output only from the transmission data section by the transmission output switch ( 18 ).

In the case where a feedforward amplifier is used, when there is no transmission data (3), a variable phase shift is performed.
The output level of the power combiner (17) is kept low by shifting the phase of the combiner (15) relatively by 180 degrees.

[0012]

Embodiments of the present invention will be described below with reference to the drawings.

Referring to FIG. 1, there is shown a transmission output control device according to an embodiment of the present invention. This transmission output control device has a switch 4 in an input stage of a main amplifier in a TDMA / TDD device. The switch 4 switches the output of the intermittently transmitted transmission data 1 and the output of the continuously transmitted pattern generator 2 and inputs them to the main amplifier. At this time, if there is transmission data, the transmission data side is switched. When there is no transmission data, control is performed so as to select the pattern generator side, and the output side of the switch 4 operates so as to be continuous data. The level of the signal from the switch 4 is adjusted by the variable attenuator 6 and then amplified by the main amplifier 7.
The level of the output of the main amplifier 7 is detected by a level detector 11, and the variable attenuator 6 is controlled to control the transmission output level to be constant.

Usually, in a TDMA / TDD device, the main amplifier 7 is used.
Is transmitted intermittently, but the switch 4 is provided according to the present invention, so that the main amplifier 7 is always supplied with data. As a result, the normal level detector 11 has to instantaneously detect the intermittent transmission output level, but the present device only needs to detect the continuous transmission output level. The final transmission output is controlled by the transmission output switch 18 so that only the transmission data portion is output.

Referring to FIG. 2, there is shown a transmission power control apparatus when a feedforward amplifier is used in the present invention. This transmission output control device is a TDMA / T
A switch 4 is provided at the input stage of the feedforward amplifier in the DD device. The switch 4 includes a transmission data 1 intermittently transmitted and a pattern generator 2 continuously transmitted.
Is switched and input to the feedforward amplifier. At this time, when there is transmission data, the transmission data side is controlled, and when there is no transmission data, the pattern generator side is controlled to be selected. The output side operates so as to be continuous data. The signal from the switch 4 is supplied to the power divider 5. One output signal of the power divider 5 is adjusted by a variable attenuator 6 and then amplified by a main amplifier 7. The output of the main amplifier 7 is further input to the power divider 8, and the output is branched. Power distributor 8
The output signal is adjusted through the variable attenuator 12. The other output signal of the power divider 5 is a delay line 10
Thus, the output signal of the variable attenuator 12 is synchronized with the output signal, the signal is combined by the power combiner 13, and a distortion component is extracted.
The distortion component is adjusted in level and phase through a variable attenuator 14 and a variable phase shifter 15 and then amplified by an auxiliary amplifier 16. The other output signal of the power divider 8 is synchronized with the output signal of the auxiliary amplifier by the delay line 9, combined by the power combiner 17, and removes the distortion component generated by the main amplifier 7. The output of the delay line 9 is used as a level detector 1
In step 1, the level is detected, and the variable attenuators 6, 12, and 14 are controlled to control the transmission output level to be constant.

Usually, in a TDMA / TDD device, the main amplifier 7 is used.
Is transmitted intermittently, but since the switch 4 is provided according to the present invention, the main amplifier 7 is always supplied with data. As a result, the normal level detector 11 has to instantaneously detect the intermittent transmission output level, but the present device only needs to detect the continuous transmission output level. The final transmission output is controlled by the transmission output switch 18 so that only the transmission data portion is output. Also, more transmission ON / OFF
In order to obtain a ratio, when the transmission data 3 does not exist, control is performed such that the phase of the variable phase shifter 15 is relatively shifted by 180 degrees, so that the transmission output level can be kept low except during transmission.

Next, the operation of the apparatus of the present invention will be described with reference to FIG.

Since the apparatus of the present invention performs a TDMA / TDD operation, an example of a frame configuration will be described. In this example, one frame is divided into six slots, and the first three slots are downlinked (transmitted in the case of a base station). , The latter three slots are allocated to the uplink (reception in the case of a base station). In this example, slot 1 is used for downlink to the terminal station 1, slot 3 is used for downlink to the terminal station 2, and slot 2 is empty.

On the other hand, the operation of the switch 4 is connected to the TX DATA side at the timing of the transmission data (transmission 1) section of slot 1 and the transmission data (transmission 2) section of slot 3. At timing when transmission data does not exist such as a guard time in slots 1 and 3, P.P. Connected to G side. In slot 2 which is vacant and slots 4 to 6 which are receivers, P.I. Connected to G side.

By this operation, the output of the switch 4 is transmitted 1
And at the timing of transmission 2, the data of transmission 1 and transmission 2 are transmitted. G data is output. That is, at all timings, the switch 4
Is operating to output data.

The level detector 11 detects the level of a signal obtained by subjecting the output of the switch 4 to phase adjustment, amplification, delay adjustment, etc., and thus can detect the level of a continuous waveform instead of a burst waveform.

On the other hand, with respect to the transmission output, the transmission output switch 18 is controlled by the transmission timing control signal so that the transmission is not performed at the timing when transmission is not performed, such as during reception.

The output of the transmission output switch 18 becomes the transmission output of FIG. 2 and is sent to the air.

As a means for improving the transmission ON / OFF ratio, at the timing when a data signal is not transmitted, control is performed so that the output phase of the variable phase shifter 15 shown in FIG. 3 is shifted by 180 degrees. Therefore, when the transmission is turned off, the inputs of the power combiner 17 cancel each other, so that the input of the transmission output switch 18 can be kept low.

Further, when transmission is OFF, the transmission output switch is turned off, so that the transmission ON / OFF ratio is improved.

It is apparent that the present invention is not limited to the above-described embodiment, but can be appropriately changed within the scope of the technical idea of the present invention.

[0027]

According to the present invention described above, the TDM
In a device such as an A / TDD device that performs intermittent transmission output, a switch 4 is provided in a stage preceding the main amplifier,
When there is no transmission data, the switch 4 selects the data of the pattern generator, and the transmission level detection unit performs continuous transmission instead of intermittent transmission based on the basic configuration that data is not always interrupted except at the transmission timing. Since the output is realized, it can be used even if the response speed performance of the level detector is low.

[Brief description of the drawings]

FIG. 1 is a block diagram of a transmission output control device according to the present invention.

FIG. 2 is a block diagram of a transmission output control device of the present invention including a feedforward amplifier.

FIG. 3 is a time chart for explaining the operation of the transmission output control device of the present invention.

FIG. 4 shows a conventional transmission output control device.

[Explanation of symbols]

REFERENCE SIGNS LIST 1 transmission data 2 pattern generator 3 timing signal 4 switch 5, 8 power divider 6, 12, 14 variable attenuator 15 variable phase shifter 7 main amplifier 9, 10 delay line 11 level detector 13, 17 power combiner 16 Auxiliary amplifier 18 Transmission output switch

Continuation of the front page (56) References JP-A-10-126282 (JP, A) JP-A-8-204605 (JP, A) JP-A-7-212255 (JP, A) JP-A-6-232665 (JP) JP-A-5-315978 (JP, A) JP-A-4-14320 (JP, A) JP-A-1-198809 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB H04B 1/04 H03G 3/30 H03G 5/16 H04J 3/00-3/26 H04L 5/22-5/26

Claims (2)

(57) [Claims] And 1. A specific pattern signal generator for generating a specific pattern signal, an input switch for inputting the specific pattern signal and the transmission data signal, and a variable attenuator for attenuating the output of said input switch, said variable attenuation A main amplifier for amplifying the output of the main amplifier, a level detector for detecting the output level of the main amplifier and feeding it back to the variable attenuator, an output switch for inputting the output of the main amplifier, the input switch and the output A timing controller for controlling opening and closing of a switch, wherein the timing controller, when there is the transmission data signal, inputs the transmission data signal to the variable attenuator, and While the switch is closed to output the transmission data, when there is no transmission data signal, the specific pattern signal is output. A transmission output control device , wherein the transmission output level is controlled so as to be input to the variable attenuator and not to output the specific pattern signal by opening the output switch and to keep the transmission output level constant . 2. A first power divider is connected to an output terminal of the input switch and an input terminal of the variable attenuator, and one output of the first power divider is connected to an input terminal of the variable attenuator. An input terminal of a second power divider is connected to an output terminal of the main amplifier, one output terminal of the second power divider is connected to an input terminal of a first delay line, and an output terminal of the first delay line; Was connected to the level detector, the output terminal of the first delay line was connected to one input terminal of the first power combiner, and the output of the first power combiner was connected to the input terminal of the output switch. A transmission power control device, wherein a signal obtained by delaying an output of the other terminal of the first power divider by a second delay line and an output of the other terminal of the second power divider are subjected to a second power combining. The other input terminal of the first power combiner outputs the output combined by the combiner. Transmission output control apparatus according to claim 1, wherein the inputting.