KR19980076476A - Analog / Code Division Multiple Access Booster and Control Method - Google Patents

Abstract

The booster, which is provided with a transmission power amplifier and connected to a cell phone for an analog / code division multiple access method, includes a variable attenuator connected to a front end of the transmission power amplifier to control a transmission gain, and is input from the mobile phone. And a gain control unit for comparing a predetermined control signal with a transmission power level detected by the detector and adjusting the variable attenuator according to the result.

Description

Analog / code division multiple access booster and its control method

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a booster in a wireless communication system, and more particularly, to a booster for use in connection with a dual mode cellular phone of an analog method and a Code Division Multi Access (CDMA) method. It relates to a control method.

In general, a CDMA modulation scheme is called a digital system, and a frequency modulation scheme is called an analog or new mobile phone service (AMPS) system. CDMA cellular systems are used in dual mode with analog systems in practical use. In other words, it is designed and used as dual mode phone that can be used in AMPS mode as well as CDMA mode.

Currently, CDMA mobile phone services are becoming practical, and the number of subscribers is gradually increasing. If the number of subscribers increases, the base station should be installed accordingly, but it is insufficient at present. In addition, a problem has been raised that it is impossible to make a telephone call in an electric field area at a low transmission power terminal. Therefore, in order to alleviate this problem in the analog mobile phone, many subscribers use in-vehicle boosters. In general, a booster for a wireless receiver is a high frequency preamplifier inserted into an antenna input terminal and has excellent selectivity, and a booster for a wireless transmitter is a high frequency power amplifier that increases the high frequency output by 5 to 10 times. Most boosters combine these two functions.

1 is a block diagram showing a conventional wireless transceiver configuration, wherein a part belonging to the reference numeral '3' indicated by a dotted line is a booster.

Terminal 1 is a handset and hands free 2 handles a control operation to allow a subscriber to make a call without lifting the handset 1. The booster 3 is connected between the antenna 11 for transmitting and receiving radio waves and the hands free 2, and the duplexer 4, the transmit power amplifier 5, the detector 6, the isolator 7, the transmit gain control unit 8, and the low noise amplifier (hereinafter referred to as LNA). 9 and duplexer 10.

The duplexer 4 alternates the connection between the hands-free 2 and the transmitting / receiving part. The duplexer 10 alternates the connection between the antenna 11 and the transmitting and receiving parts. Transmit power amplifier 5 amplifies the signal to be transmitted to some extent. The detector 6 detects the level, i.e., the magnitude of the signal output from the transmission power amplifier 5. The isolator 7 is to transmit the radio wave of the radio frequency output from the transmission power amplifier 5 to the duplexer 10 without the reflected wave. The transmission gain control unit 8 compares the transmission power related control signal inputted from the terminal 1 through the hands-free 2 with the magnitude information detected by the detector 6, and controls the transmission power amplifier 5 according to the result to determine the amplification degree of the signal. Adjust The low noise amplifier 9 is referred to as LNA 9 to low noise amplify the received signal provided from the duplexer 10 and transmit the same to the duplexer 4.

However, the analog booster cannot be used as it is because the specifications of the transmitting side are different, and a class C transmission power amplifier is used. This is because, in the analog method, the saturation of the amplitude of the transmission wave does not become a problem and increases the efficiency. On the other hand, the transmission power amplifier required for the CDMA method operates in class A or class AB because of its high linearity and dynamic range. In addition, since the transmission gain control method used in both the analog method and the CDMA method is different, it cannot be shared with the analog method and the CDMA method as it is.

Accordingly, an object of the present invention is to provide a booster and a control method thereof that are compatible with analog and CDMA terminals.

The present invention for achieving the above object is a booster having a transmission power amplifier, connected to an analog system / code division multiple access system combined mobile phone, connected to the front end of the transmission power amplifier to control the transmission gain And a gain control unit for comparing the variable attenuator with a predetermined control signal input from the mobile phone and the transmission power level detected by the detector, and adjusting the variable attenuator according to the result.

1 is a block diagram showing a conventional wireless transceiver configuration

2 is a block diagram showing the configuration of a wireless transceiver according to an embodiment of the present invention.

3 is a block diagram showing a configuration of a gain control unit in FIG.

4A and 4B are flowcharts illustrating a variable attenuator gain control process according to an exemplary embodiment of the present invention.

Explanation of symbols for main parts of the drawings

1: terminal 2: hands free

3: booster 4: duplexer

5: transmit power amplifier 6: detector

7: Isolator 8: Transmission gain control circuit

9: low noise amplifier 10: duplexer

11: antenna 12: variable attenuator

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings. First of all, in adding reference numerals to the components of each drawing, it should be noted that the same reference numerals have the same reference numerals as much as possible even if displayed on different drawings. Also, in the following description, many specific details such as components of specific circuits are shown, which are provided to help a more general understanding of the present invention, and the present invention may be practiced without these specific details. It is self-evident to those of ordinary knowledge in Esau. In the following description of the present invention, if it is determined that a detailed description of a related known function or configuration may unnecessarily obscure the subject matter of the present invention, the detailed description thereof will be omitted.

FIG. 2 is a block diagram illustrating a wireless transceiver according to an exemplary embodiment of the present invention, except for the variable attenuator 12 installed at the front end of the A or AB transmission power amplifier 5 having good linearity. Same as FIG. 1 described above. The transmitting side receives the control signal from the terminal and controls the gain by switching for each method as shown in Table 1 below.

TABLE 1

Analog method CDMA method Transmission power (dBm) PL: +36 + 2 / -4PL: +32 + 2 / -4PL: +28 + 2 / -4PL: +24 + 2 / -4PL: +20 + 2 / -4PL: +16 + 2 / -4PL: +12 + 2 / -4PL: +8 + 2 / -4 -50-+36

3 is a block diagram illustrating a configuration of the gain control unit 8 in FIG. 2. The gain control section 8 is composed of an analog control section 81, a CDMA control section 82, and a mode switching switch 83. As shown in the figure, there are three signals input to the gain control unit 8. FIG. One is the signal Vdet input from the detector 6, the other is the gain control signal Vgc, and the other is the mode switching signal. Among them, the signal input from the detector 6 is input only to the analog control part 81, the mode switching signal is input only to the mode switching switch 83, and the gain control signal is input to both the analog control part 81 and the CDMA control part 82. A power density modulated signal, that is, a signal controlled by a pulse width. The mode switching signal is a signal having a high or low state, and is used to select a CDMA or analog mode. However, the switching of the CDMA or analog mode is performed by the terminal 1 receiving the command in software when the switching command is sent from the system to the terminal 1. The output signal Vcon of the gain control unit 8 is a DC voltage signal for controlling the variable attenuator 12. Specifically, in the analog mode, the gain control unit 8 compares the input signal, that is, the gain control signal Vgc and the detection output signal Vdet, and outputs a control voltage Vcon corresponding to the difference. In the CDMA mode, the gain control unit 8 outputs a control voltage Vcon corresponding to the input signal, that is, the gain control signal Vgc.

4A and 4B are flowcharts illustrating a variable attenuator gain control process according to an exemplary embodiment of the present invention. In step a, it is checked whether it is in CDMA mode. If the check result is not in the CDMA mode, the analog power level is set in step b. In this embodiment, it is assumed that there are levels of PL0 to PL7, for example. When the power level is set, make a call in step c and proceed to step d to check whether the output voltage of detector 6 (hereinafter referred to as Vdet) is equal to the output voltage of gain control unit 8 (hereinafter referred to as Vcon). If the result of the check is not the same, in step e, Vcon corresponding to the difference between the gain control signal Vgc and Vdet is generated to control the gain of the variable attenuator 6, and then the process returns to step d. On the other hand, if Vdet and Vcon are the same, the process proceeds to step f while maintaining Vcon as it is and checks whether the PL is changed. If there is a change in the PL as a result of the check, the process returns to step d. If the change is not made, it is determined whether the hook is on in step g. If the hook-on is detected, the operation is terminated. If is not detected, the flow returns to step d.

If it is determined in the above-described step a that the CDMA mode is set, the process proceeds to step h to set the CDMA mode PL. Then set the transmit power (hereinafter referred to as Pout) to -50 to +36 [dBm]. After the setting is completed, the call is made in step i, and then the flow proceeds to step j to check whether the Pout is changed. If Pout is changed as a result of the check, in step k, Vcon corresponding to the gain control signal Vgc is generated to control the gain of the variable attenuator, and then the operation returns to step j to check whether Pout is changed. On the other hand, if the Pout is changed to go to step l determines whether the hook-on. If the hook-on is detected as a result of the determination, the call is ended, and if the hook-on is not detected, the operation returns to step j and checks whether the Pout is changed.

Meanwhile, in the detailed description of the present invention, specific embodiments have been described, but various modifications may be made without departing from the scope of the present invention. Therefore, the scope of the present invention should not be limited to the described embodiments, but should be defined not only by the scope of the following claims, but also by the equivalents of the claims.

The present invention as described above has the advantage that the booster can be used in both analog and CDMA system, the expansion of the CDMA service area and the call in the analog service area where the CDMA base station is not provided.

Claims (4)

A booster equipped with a transmission power amplifier connected to an analog / code division multiple access mobile phone, A variable attenuator connected to a front end of the transmission power amplifier to control a transmission gain; And a gain control unit which compares a predetermined control signal input from the cellular phone with a transmission power level detected by the detector and adjusts the variable attenuator according to the result. A booster equipped with a transmission power amplifier connected to an analog / code division multiple access mobile phone, A variable attenuator connected to a front end of the transmission power amplifier to control a transmission gain; In the analog mode, the input signal and the detection output signal are compared and the control voltage corresponding to the difference is output. In the code division multiple access mode, the control voltage corresponding to the input signal is output to control the variable attenuator. Booster. The method of claim 2, wherein the gain control unit, An analog control section for inputting a detector output signal and a gain control signal, A code division multiple access control section for inputting a gain control signal; And a mode switching switch for selecting only one of the output of the analog control part and the output of the code division multiple access control part according to an analog or code division multiple access mode switching signal and transferring the gain control voltage to a variable attenuator. Featured Booster. A variable attenuator, a detector and a gain control unit connected to a transmission power amplifier and a front end of the transmission power amplifier to control the transmission gain, and the gain of the variable attenuator in a booster connected to an analog mode / code division multiple access mode mobile phone. In the control method, The first step of checking the mode, A second process of setting a predetermined analog power level in an analog mode, and setting a predetermined code division multiple access mode power level in a code division multiple access mode and making a call; During the call at the analog mode power level, the detector output voltage and the gain control unit output voltage are compared at regular intervals and whenever the power level is changed, and the gain of the variable attenuator is controlled by the difference, and the code division multiple access mode power level is compared. And a third process of controlling the gain of the variable attenuator at regular intervals during the call and whenever the transmit power is changed.