JPH04373218A - Transmitter with distortion compensation circuit - Google Patents

Abstract

PURPOSE:To attain the operation with very excellent distortion compensation at all times by applying a distortion compensation data for transmission power control at operation and a distortion compensation data for transmission power control at nonoperation from a distortion compensation data setting means to a distortion compensation circuit respectively. CONSTITUTION:The transmitter is provided with a distortion compensation circuit 1, a high output amplifier 2, an automatic level control means 3, and a transmission power control means 4. Moreover, each distortion compensation data for transmission power control at operation and for transmission power control at non operation is set to a distortion compensation data setting means 6. When the transmission power control means 4 is in operation, the distortion compensation data for transmission power control operation is fed to the distortion compensation circuit 1. On the other hand, when the transmission power control means 4 is not in operation, the distortion compensation data for transmission power control operation is fed to the distortion compensation circuit 1 through the changeover of a switch means 7.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a transmitter having a high output amplifier with a distortion compensation circuit. In recent years, the direction of technological development regarding high-power amplifier boards attached to transmitting devices has centered on control of transmission power for the purpose of reducing power consumption. Furthermore, transmission power is likely to be distorted by external factors.

However, at the same time, the inherent distortion characteristics of the amplifier in a high-power amplifier board cannot be ignored. Therefore, it is necessary to develop mutually interlocking control means for both.

0003

2. Description of the Related Art FIG. 6 is a circuit diagram of a conventional transmitting device mounted on a high-power amplifier board. In FIG. 6, A is a transmitting device, and B is a receiving device corresponding to transmitting device A. . Here, the transmitter A includes a frequency converter, that is, a transmitter 10 equipped with an up-converter, and a high-output amplification board 11 that amplifies the signal from the transmitter 10, and also receives a reception level signal from the receiver B. It is equipped with a receiver panel 12 and a demodulator 13 for Note that the transmitting device A also has a transmitting antenna 14 and a receiving antenna 15.

[0004] The high output amplifier board 11 includes a first variable attenuator 11
1, ALC (automatic level control) circuit detection section 112, distortion compensation and amplification section 113, first ALC circuit 114-a,
Second ALC circuit 114-b, adder 115-a, 115
-b, distortion compensation data setting circuit 116, transmission power control (
ATPC) circuit 117.

First, the first variable attenuator 111 is an ATPC
The input stage level attenuation amount of the high output amplifier board 11 is changed in conjunction with the circuit 117. ALC circuit detection section 11
2 is composed of a second variable attenuator 1121, an amplifier 1122 and a diode circuit 1123, and an adder 115-a.
through the first ALC circuit 114-a and the ATPC circuit 1
17 is received by the second variable attenuator 1121, while the output is input to the first ALC circuit 114-a through the diode circuit 1123, and the distortion compensation/amplification section 11
3.

The distortion compensation circuit/amplification section 113 is composed of a distortion compensation circuit section 1131 and a high output amplification section 1132. First, the distortion compensation circuit section 1131 includes two hybrid circuits 11311-a and 11311-b, a third variable attenuator 11312, and a linearizer (distortion generation circuit) 1.
1313 and a phase shifter 11314.

[0007] The first hybrid circuit 11311-a is
Receives input from the ALC circuit detection section 112, sends one side to the third variable attenuator 11312 and the other side to the phase shifter 1131.
4.

The third variable attenuator 11312 responds to the level setting input (PD level setting input) from the level setting section 1161 of the distortion compensation data setting circuit 116.
The attenuation amount is changed, and the phase shifter 11314 is adapted to shift the phase according to the phase setting input (PD phase setting input) from the phase setting section 1162 of the distortion compensation data setting circuit 116. The third variable attenuator 1131 of
2. The signal from the phase shifter 11314 is mixed in the second hybrid circuit 11311-b and then sent to the high output amplifier 1.
132.

The high output amplifier section 1132 includes a fourth variable attenuator 11321, high output amplifiers 11322-a and 1132
2-b and a diode circuit 11323, and the inputs of the second ALC circuit 114-b and the ATPC circuit 117 are connected to the fourth variable attenuator 11321 through the adder 115-b.
On the other hand, the output is input to the second ALC circuit 114-b and the transmitting antenna 14 through the diode circuit 11323.

The first ALC circuit 114-a controls the output level by feeding back the output level from the ALC circuit detection section 112 as described above, and the second ALC circuit 114-b controls the output level as described above. The output level is controlled by feeding back the output level from the distortion compensation and amplification section 113.

[0011] The adder 115-a is connected to the ALC circuit 114-
The adder 115-b adds the output from the ALC circuit 114-b and the output from the ATPC circuit 117.
The output from the ATPC circuit 117 is added to the output from the ATPC circuit 117.

The distortion compensation data setting circuit 116 sets distortion compensation data, and for this purpose, the distortion compensation data setting circuit 116 includes a level setting section 1161 and a phase setting section 1162.

[0013] The ATPC circuit 117 controls transmission power based on information received from receiving device B. The receiving board 12 has a built-in receiving section 120, a diode circuit 121, and a level detector 122, and the output from the receiving board 12 is inputted to an ATPC circuit 117 via a demodulator 13, and is input to a variable attenuator. 111, 1121, and 11321.

The receiving device B includes a receiving board 20 and a demodulator 21, as well as a modulator 22, a transmitter 23, and a high-power amplifier board 24 for sending received information to the transmitting device A side. Note that the receiving device B has a receiving antenna 25.
, and a transmitting antenna 26.

The receiving board 20 includes a receiving section 200, a diode circuit 201, and a level detector 202. The output from the receiving section 200 of this receiving board 20 is input to the demodulator 21, and the diode circuit 201 After the level detector 202 detects the received level, the received level is modulated by the modulator 22, and then sent to the transmitter 23 and high output amplifier board 24.
After that, the signal is input again to the receiving board 12 of the transmitting device A from the transmitting antenna 26. Therefore, a feedback circuit is configured between these transmitting device A and receiving device B.

With such a configuration, the ATPC circuit 11
7, that is, when the transmission level is raised by 8 dB, for example, when the ALC circuit detection section (DET section) 112
The voltage is controlled and artificially adjusted so that the output level of this ALC circuit detection section 112 increases by 8 dB. Then, the level input to the distortion generation circuit (LRZ) 11313 increases by 8 dB, and the amount of distortion generated increases accordingly. As a result, the amplification section (AMP section) 1132
Even if the distortion that occurs in At that time, the attenuation amount (PD level) of the variable attenuator 11312 and the shift amount (PD level) of the phase shifter 11314 are determined.
phase) is adjusted so as to be optimal when the ATPC circuit 117 is turned off.

[0017]

[Problems to be Solved by the Invention] As described above, the technical development in recent years of transmitting devices equipped with conventional high-output amplification boards has generally focused primarily on reducing power consumption. Control is performed such that when the level of incoming calls to the board drops, the transmission level is increased, and at other times, the transmission power is decreased. At the same time, for example, high-output amplification boards that support multi-carriers are usually equipped with distortion compensation circuits, and in this field, distortion compensation is performed in conjunction with transmission power control.
The issue is whether distortion compensation can be achieved in an optimal state.

However, in such conventional high-output amplifier boards, since the distortion characteristics of the amplifiers (AMPs) themselves are different, it is difficult to maintain input/output level control and distortion adjustment/compensation between the AMPs in an optimal state. It is difficult.

For example, FIG. 7 is a graph schematically showing the mutual distortion characteristics of FETs in an AMP in the prior art using a coordinate system in which the horizontal axis represents the input level and the vertical axis represents the output level. The ideal adjustment between input/output characteristics and AMP is shown in Figure 7 (a).
As can be seen in Figure 7, the distortion characteristics of input and output and the mutual distortion characteristics of AMP should be maintained in a certain harmony and balance, but in reality, the examples in (b) and (c) of Figure 7 As seen in the above, situations often arise in which harmony and balance are lost.

[0020] Furthermore, in the prior art, the ATPC circuit ON/
Since it is necessary to change the ALC output level of the two stages according to the OFF control, the circuit size and corresponding overhead costs are large, and the problem remains that the control becomes rough.

The present invention was devised in view of the above-mentioned problems, and provides a distortion compensation circuit that enables distortion compensation interlock control between the input/output level and the amplifier, regardless of the mutual distortion characteristics of the amplifier itself. The purpose is to provide a transmitting device.

[0022]

[Means for Solving the Problems] FIG. 1 is a block diagram of the principle of the present invention. In this FIG. This is a high-power amplifier that amplifies and transmits a compensated transmission signal.

Further, 3 is an automatic level control means for controlling the output level of the high-output amplifier 2, and 4 is a transmission power control means for controlling the transmission power based on information received from the receiving device 5.

Reference numeral 6 denotes distortion compensation data setting means, and this distortion compensation data setting means 6 sets distortion compensation data for when the transmission power control is activated and distortion compensation data for when the transmission power control is not activated.

7 is a switch means, and this switch means 7
When the transmission power control means 4 is in operation, the distortion compensation data for the transmission power control operation is supplied from the distortion compensation data setting means 6 to the distortion compensation circuit 1;
When the distortion compensation circuit 1 is not in operation, the distortion compensation data setting means 6 is switched to supply the distortion compensation data for the time when the transmission power control is not in operation to the distortion compensation circuit 1.

[0026]

[Operation] In the above-described transmitting device with a distortion compensation circuit according to the present invention, the distortion compensation circuit 1 first compensates for distortion in a transmission signal. The distortion-compensated transmission signal is sent to the high-power amplifier 2, where it is amplified and transmitted to the receiving device 5.

At this time, the automatic level control means 3 controls the output level of the high-power amplifier 2, and the transmission power control means 4 controls the transmission power based on the information received from the receiving device 5. .

By the way, when the transmission power control means 4 operates, the distortion compensation data for the transmission power control operation is supplied from the distortion compensation data setting means 6 to the distortion compensation circuit 1.
When the transmission power control means 4 is not in operation, the switch means 7 is switched so that the distortion compensation data for when the transmission power control is not in operation is supplied from the distortion compensation data setting means 6 to the distortion compensation circuit 1.

As a result, the level of the signal input to the distortion compensation circuit 1 remains constant regardless of whether the transmission power control is activated or not. In this case, the distortion compensation data is set in advance so that mutual distortion is optimized. If this is done, it becomes possible to perform a transmission operation in which distortion compensation is always optimal regardless of the mutual distortion characteristics of the amplifier itself.

[0030]

Embodiments Hereinafter, embodiments of the present invention will be described with reference to the drawings. (a) Description of the first embodiment FIG. 2 is a block diagram showing the first embodiment of the present invention.
In FIG. 2, the same reference numerals as in FIG. 6 indicate substantially the same parts.

Now, in this first embodiment, as in the conventional case, the transmitter A includes a frequency converter, that is, a transmitter 10 equipped with an up-converter, and a high-output amplification board for amplifying the signal from the transmitter 10. 11, a receiving panel 12 and a demodulator 13 are provided for receiving the received level signal from the receiving device B, and furthermore, a transmitting antenna 14,
It has a receiving antenna 15.

Here, the high output amplifier board 11 includes an ALC (automatic level control) circuit detection section 112, a distortion compensation and amplification section 113, a first ALC circuit 114-a, a second ALC circuit 114-b, and an adder 115-. b, a distortion compensation data setting circuit (distortion compensation data setting means) 118A, a switch circuit 118B, and a transmission power control (ATPC) circuit 117.

First, the ALC circuit detection section 112 includes a variable attenuator 1121, an amplifier 1122, and a diode circuit 1.
123, the input of the first ALC circuit 114-a is received by a variable attenuator 1121, and the output is inputted to the first ALC circuit 114-a through a diode circuit 1123 and also inputted to the distortion compensation/amplification section 113. It has become.

The distortion compensation circuit/amplification section 113 is composed of a distortion compensation circuit section 1131 and a high output amplification section 1132, which has the same structure as the conventional one. In addition, the first ALC circuits 114-a, 114-a, the adder 1
15-b is also similar to the conventional one.

The distortion compensation data setting circuit 118A sets distortion compensation data for when the transmission power control is activated and distortion compensation data for when the transmission power control is not activated. Level setting section 1161-a for control operation, level setting section 1161-b for transmission power control non-operation, phase setting section 1162-a for transmission power control operation, and phase setting section 1162- for transmission power control non-operation. It has b. Note that the transmission power control operation level (PD level) set by the transmission power control operation level setting section 1161-a and the transmission power control operation phase setting section 1162-a are set by the transmission power control operation phase setting section 1162-a. The time phase (PD phase) is ATP
It is set to a value that optimizes the mutual distortion when the C circuit 117 is in operation, and is set to a value that optimizes the mutual distortion when the C circuit 117 is in operation, and is set at a value that is equal to the transmission power control non-operation level (PD level) set by the transmission power control non-operation level setting unit 1161-b. ) and the transmission power control non-operation phase (PD phase) set by the transmission power control non-operation phase setting unit 1162-b are values such that the mutual distortion when the ATPC circuit 117 is not activated is optimal. is set to .

The switch circuit 118B has two switches 1181 and 1182, and the ATPC circuit 117
When the ATPC circuit 117 is in operation, distortion compensation data for transmission power control operation is supplied from the distortion compensation data setting circuit 118A to the distortion compensation circuit section 1131, while when the ATPC circuit 117 is not in operation. ,
The switches 1181 and 1182 are configured to switch so that the distortion compensation data for when the transmission power control is not activated is supplied from the distortion compensation data setting circuit 118A to the distortion compensation circuit section 1131.

The ATPC circuit 117 controls the transmission power based on the information received from the receiver B, and the control signal from the ATPC circuit 117 is transmitted to the high output amplification section 1132 together with the first ALC circuit 114-b. is supplied to the variable attenuator 11321 of the switch circuit 1.
18B as a switch switching signal.

Note that the receiving board 12 and demodulator 13 are the same as those of the conventional ones. In addition, the receiving device B includes a receiving board 20 and a demodulator 21, as well as a modulator 22, a transmitter 23, and a high-power amplifier board 24 in order to send received information to the transmitting device A side, and further includes a receiving antenna. 25 and a transmitting antenna 26, this configuration is also the same as the conventional one.

Therefore, this first embodiment differs from the conventional example shown in FIG. 6 in the following points. That is, the first variable attenuator 11
1 is removed, and the level detection section 112 and the first ALC are removed.
The circuit 114-a is independent from the control of the ATPC circuit 117, and a switch circuit 118B is added, which is controlled by the ATPC circuit 117, and the distortion compensation data setting circuit 118A is also switched depending on when the ATPC is activated or not. The point is that two stages are provided to make it possible.

With the above configuration, in this first embodiment,
In the distortion compensation circuit section 1131, the distortion of the transmission signal is compensated, and the transmission signal with this distortion compensation is sent to the high-output amplification section 1132, where it is amplified and transmitted to the receiving device B. At this time, in the ALC circuit,
The output level of the amplifier section 1132 is controlled, and the
TPC circuit 117 controls transmission power based on information received from receiving device B.

By the way, when the ATPC circuit 117 is in operation, the distortion compensation data for transmission power control operation is supplied from the distortion compensation data setting circuit 118A to the distortion compensation circuit section 1131, while when the ATPC circuit 117 is not in operation, the distortion compensation data for the transmission power control operation is supplied to the distortion compensation circuit section 1131. The switch circuit 118B is connected to the ATPC circuit 11 so that the distortion compensation data for when the transmission power control is not activated is supplied from the data setting circuit 118A to the distortion compensation circuit section 1131.
Switching is performed based on a control signal issued from 7.

As a result, the level of the signal input to the distortion compensation circuit section 1131 remains constant regardless of whether the ATPC is activated or not. By doing so, it becomes possible to perform a transmission operation in which distortion compensation is always optimal regardless of the mutual distortion characteristics of the amplifier itself.

(b) Explanation of the second embodiment FIG. 3 is a block diagram showing the second embodiment of the present invention.
The second embodiment shown in FIG. 2 has substantially the same configuration as the first embodiment described above.

However, the points different from the first embodiment described above are as follows.
In place of the two-stage distortion compensation data setting circuit 118A and switch circuit 118B used in the first embodiment, an A/D converter 118C-1 and a ROM table 11 are used.
8C-2, D/A converter 118C-3 connected in this order
The point is that a chip microcomputer type distortion compensation data setting circuit 118C is used. Note that, as the name suggests, the above circuit is composed of a one-chip microcomputer.

[0045] Here, the A/D converter 118C-1
The control signal from the TPC circuit 117 is digitally converted and used as an address signal for the ROM table 118C-2.

The ROM table 118C-2 also sets distortion compensation data for when the transmission power control is activated and distortion compensation data for when the transmission power control is not activated.
Upon receiving the control signal from the C circuit 117, the ATPC circuit 1
17, distortion compensation data for transmission power control operation is supplied to the distortion compensation circuit section 1131, while the ATP
When the C circuit 117 is not in operation, the distortion compensation data for when the transmission power control is not in operation is supplied to the distortion compensation circuit section 1131. Therefore, this ROM table 118
In C-2, the level for when the transmission power control is activated, the level for when the transmission power control is not activated, the phase for when the transmission power control is activated, and the phase for when the transmission power control is not activated are stored at the required addresses. , A/D converter 118C-1
Using the digitally converted signal as an address signal, R
When OM table 118C-2 is accessed, this RO
Desired distortion compensation data (level data and phase data) is read from the M table 118C-2.

The D/A converter 118C-3 converts digital data from the ROM table 118C-2 into analog data for use in the distortion compensation circuit section 1131. That is, in this second embodiment, the ATPC circuit 1
The control signal from the ROM table 118C-2 is converted into a digital signal by the A/D converter 118C-1, and the desired distortion compensation data (level data and phase data) is read out from the ROM table 118C-2 using this digital signal as an address signal. The D/A converter 118C-3 converts the signal into an analog signal and then sends it to the distortion compensation circuit section 1131.

In this way, in the second embodiment, the distortion of the transmission signal is compensated in the distortion compensation circuit section 1131, and the transmission signal on which this distortion compensation has been performed is sent to the high output amplification section 1132. Here, it is amplified and transmitted to receiving device B, but at this time, the ALC circuit
132 is controlled, and the ATPC circuit 117 controls the transmission power based on the information received from the receiving device B, which is the same as in the first embodiment described above, but the A/D conversion When the ATPC circuit 117 operates, distortion compensation data for transmission power control operation is supplied from the ROM table 118C-2 to the distortion compensation circuit section 1131 using the signal digitally converted by the ROM table 118C-1 as an address signal. When circuit 117 is inactive, R
Distortion compensation data for when transmission power control is not activated is supplied from the OM table 118C-2 to the distortion compensation circuit section 1131.

[0049] As a result, also in this second embodiment,
The same effects and advantages as in the first embodiment described above can be obtained.

(c) Description of the third embodiment FIG. 4 is a block diagram showing the third embodiment of the present invention.
This is a configuration in which a two-stage distortion compensation data means 118A and a switch circuit 118B are attached to parts 1161 and 1162 of the distortion compensation data setting circuit in the conventional configuration, and the other configuration is the same as the configuration shown in FIG. be. Even in this case, substantially the same effects and advantages as those of the first embodiment described above can be obtained.

(d) Explanation of the fourth embodiment FIG. 5 is a block diagram showing the fourth embodiment of the present invention.
This is because the A/D converter 118C-1 is installed in the parts 1161 and 1162 of the distortion compensation data setting circuit in the conventional configuration.
, ROM table 118C-2, D/A converter 118C
This is equipped with a one-chip microcomputer-type distortion compensation data setting circuit 118C connected in the order of -3 to one. Even in this case, substantially the same effects and advantages as those of the second embodiment described above can be obtained.

[0052]

As described in detail above, according to the transmitting device with a distortion compensation circuit of the present invention, when the transmission power control means is activated, the distortion compensation data for the transmission power control operation is transmitted from the distortion compensation data setting means to the distortion compensation data for when the transmission power control is activated. While being supplied to the compensation circuit, when the transmission power control means is not in operation, the distortion compensation data for when the transmission power control is not in operation is supplied from the distortion compensation data setting means to the distortion compensation circuit. Regardless of differences in distortion characteristics of the amplifiers themselves, there is an advantage that optimal device operation with complete distortion compensation can always be achieved during transmission power control.

[Brief explanation of drawings]

FIG. 1 is a block diagram of the principle of the present invention.

FIG. 2 is a block diagram showing a first embodiment of the present invention.

FIG. 3 is a block diagram showing a second embodiment of the present invention.

FIG. 4 is a block diagram showing a third embodiment of the present invention.

FIG. 5 is a block diagram showing a fourth embodiment of the present invention.

FIG. 6 is a block diagram showing a conventional example.

FIG. 7 is a supplementary explanatory diagram of mutual distortion characteristic adjustment.

[Explanation of symbols]

1 Distortion compensation circuit 2 High output amplifier 3 Automatic level control means 4 Transmission power control means 5 Receiving device 6 Distortion compensation data setting means 7 Switch means 10 Transmitter 11 High output amplifier board 12 Receiving board 13 Demodulator 14 Transmitting antenna 15 Receiving antenna 20 Receiving board 21 Demodulator 22 Modulator 23 Transmitter 24 High power amplifier board 25 Receiving antenna 26 Transmitting antenna 111 First variable attenuator 112 ALC circuit detection section 113 Distortion compensation circuit/amplification section 114-a First automatic level control circuit (1st ALC circuit) 114-b 2nd automatic level control circuit (2nd ALC circuit) 115-a, 115-b Adder 116 Distortion compensation data setting circuit 117 Transmission power control circuit (APTC circuit) 118A
Two-stage distortion compensation data setting circuit 118B Switch circuit 118C 1-chip microcomputer distortion compensation data setting circuit 118C-1 A/D converter 118C-2 ROM table 118C-3 D/A converter 121 Diode circuit 122 Level detector 201 Diode circuit 202 Level detector 1121 Second variable attenuator 1122 Amplifier 1123 Diode circuit 1131 Distortion compensation circuit section 1132 High output amplifier section 1161-a, 1161-b Level setting circuit 116
2-a, 1162-b Phase setting circuit 1181, 11
82 Switches 11311-a, 11311-b Hybrid circuit 11312 Third variable attenuator 11313 Distortion generation circuit (linearizer) 1131
4 Phase shifter 11321 Fourth variable attenuator 11322-a, 11322-b High output amplifier 11
323 Diode circuit A Transmitter B Receiver

Claims (1)

[Claims] Claim 1: A distortion compensation circuit (1) for compensating for distortion in a transmission signal, and a high-output amplifier (2) for amplifying and transmitting the transmission signal whose distortion has been compensated for by the distortion compensation circuit (1). , automatic level control means (3) for controlling the output level of the high-power amplifier (2), and a receiving device (5).
), the distortion compensation data setting includes a transmission power control means (4) that controls transmission power based on information received from the transmitter, and sets distortion compensation data for when transmission power control is activated and distortion compensation data for when transmission power control is not activated. When the means (6) and the transmission power control means (4) are activated, distortion compensation data for when the transmission power control is activated is supplied from the distortion compensation data setting means (6) to the distortion compensation circuit (1). , a switch that is switched so that when the transmission power control means (4) is not in operation, distortion compensation data for when the transmission power control is not in operation is supplied from the distortion compensation data setting means (6) to the distortion compensation circuit (1); means (7);
Transmitter device with distortion compensation circuit.