KR20060069666A - Apparatus and method for automatic gain control by using received signal strength detect of bast transceiver station receiver in mobile communication system - Google Patents

Abstract

The present invention provides an automatic gain control apparatus and method using a reception strength detection of a base station receiver in a mobile communication system, comprising: a variable attenuator for performing variable attenuation on a received RF signal; An RSSI circuit unit configured to receive the received RF signal and detect RSSI; And a control unit for determining the strength of the received signal by using the RSSI detected by the RSSI circuit unit and performing AGC control on the variable attenuator, thereby using a reception strength detection circuit used for the reception path check. You can control the gain automatically.

Description

Apparatus and method for automatic gain control by using received signal strength detect of bast transceiver station receiver in mobile communication system}

1 is a block diagram of a general mobile communication system,

2 is a block diagram of a base station receiver in a conventional mobile communication system,

3 is a detailed block diagram of the RSSI circuit unit in FIG.

4 is a detailed block diagram of an AGC circuit in FIG. 2;

5 is a flowchart illustrating an operation of a base station receiver in a conventional mobile communication system.

6 is a block diagram of a neighboring block including an automatic gain control apparatus using a reception strength detection of a base station receiver in a mobile communication system according to the present invention;

7 is a flowchart illustrating an automatic gain control method using detection strength of a base station receiver in a mobile communication system according to the present invention.

Explanation of symbols on the main parts of the drawings

101: RF signal receiver 102: frequency converter

103, 106: Band filter 104: Directional coupler

105, 108: variable attenuator 107: amplifier                 

109: receiving baseband signal processing unit 110: RF local signal generator

120: RSSI circuit portion 121: log amplification unit

122: operational amplifier 130: control unit

131: A / D conversion unit 132: Processor

133: lookup table 134: D / A conversion unit

The present invention relates to automatic gain control of a base station receiver in a mobile communication system. In particular, the present invention relates to an automatic gain control of a base station receiver in a mobile communication system suitable for automatically controlling the gain of the receiver by using a reception strength detection circuit used to check a reception path. An automatic gain control apparatus using reception strength detection and a method thereof are provided.

In general, a mobile communication system is a communication system that targets mobile devices such as people, cars, ships, trains, and airplanes, which includes key phone systems, mobile phones (mobile phones, vehicle phones), port phones, aircraft phones, and mobile phones. Trains, cruise ships, express buses), radio calling, radiotelephony, satellite mobile communication, amateur radio, and fishing service ships.

The mobile communication system includes an AMPS (Advanced Mobile Phone Service) system using an analog method, a Code Division Multiple Access (CDMA) system using a digital method, a Wideband Code Division Multiple Access (WCDMA), and a TDMA (Time). Division Multiple Access, Time Division Multiple Access (FDMA) system, Frequency Division Multiple Access (FDMA) system, Wireless Local Loop (WLL), CDMA2000-1x, IMT-2000 (International Mobile Telecommunication in the year) 2000, global mobile communication (GSM) systems, and GSM (Global System for Mobile communication) systems.

Thus, a base station is used in such a mobile communication system, and is a network termination device that is directly connected to a subscriber terminal by performing baseband signal processing, wired / wireless conversion, and transmission and reception of a wireless signal.

1 is a block diagram of a general mobile communication system.

Where reference number 1 is a mobile switching center / visitor location register (MSC / VLR), 2 is a home location register (HLR), 3 is a public switched telephone network (PSTN) , 4 is a base station (Basic Station Controller / Base station Transceiver System, BSC / BTS), 5 is a mobile terminal (Mobile Station, MS).

The MSC 1 thus performs an exchange function, serving as roads and intersections of all communication lines.

The HLR 2 is a database in which subscriber information is stored, and the VLR is a device that temporarily stores important subscriber information in order to prevent frequent HLR 2 inquiry.

PSTN (3) refers to the entire telephone network used in homes.

Therefore, when making a phone call from the home telephone to the mobile communication terminal 5 of the mobile subscriber, the home telephone signal is first connected to the PSTN 3 and then inputted to the switch 1 of the mobile communication operator using the telephone number. do.

The exchange 1 of the mobile communication provider inquires whether the subscriber is a valid subscriber and the location of the subscriber to the HLR 2 and transmits the information to the corresponding base station 4 to call the mobile communication terminal 5.

The location of the BSC and VLR in terms of systems may vary depending on the equipment manufacturer. For example, the BSC may be in the same spatial location as the MSC or may be in the BTS, which is the base station 4. The base station 4 means that the BSC and the BTS are combined.

2 is a block diagram of a base station receiver in a conventional mobile communication system.

Here, reference numeral 10 is an RF signal receiver for receiving a radio frequency (RF) signal input from the outside, 11 is a frequency converter for outputting an IF (Intermediate Frequency) signal by converting the output of the RF receiver 10, 12 is a band pass filter for band-filtering the output of the frequency converter 11, and 13 is a directional coupler for receiving and outputting the output of the band pass filter 12.

In addition, reference numeral 14 denotes a variable attenuator which receives the output of the directional coupler 13 and performs a variable attenuation according to the AGC (Automatic Gain Control) control voltage of the AGC circuit part, and 15 denotes the variable attenuator 14. A band filter for performing band filtering on the output of the amplifier, 16 is an amplifier amplifying the output of the band filter 15, and 17 is variable according to the AGC control voltage of the AGC circuit part with respect to the output of the amplifier 16 A variable attenuator for performing attenuation, and 18 is a directional coupler for receiving and branching the output of the variable attenuator 17.

In addition, reference numeral 19 is a receiving baseband signal processing unit for receiving the signal branched from the directional coupler 18 to perform the receiving baseband signal processing, 20 is to generate an RF local signal to supply to the frequency converter 11 21 is an RF local signal generator, 21 is an RSSI circuit unit for receiving RSSI (Received Signal Strength Indicator) received from the output branched from the directional coupler 13, and 22 is a branch from the directional coupler 18. The AGC circuit unit receives the output and outputs the AGC control voltage to the variable attenuators 14 and 17.

In addition, reference numeral 23 is a control unit that receives the RSSI value from the RSSI circuit unit 21 and determines the strength of the received signal.

In the control unit 23, reference numeral 24 denotes an analog to digital (A / D) converter which receives an analog RSSI value from the RSSI circuit unit 21 and converts it into a digital signal, and 25 denotes the A / D. The processor 24 receives the RSSI value converted into the digital signal by the converter 24 and determines the strength of the received signal with reference to a look-up table, and 26 denotes a look-up table by the processor 25. Provides a lookup table.

FIG. 3 is a detailed block diagram of the RSSI circuit unit in FIG. 2.

In the RSSI circuit 21, reference numeral 31 denotes a log amplification unit that receives the output branched from the directional coupler 13 and logs amplifies the signal, and 32 denotes an operation amplified by receiving the output of the log amplifier 31. An operational amplifier for transmitting the analog RSSI value to the control unit 23.

4 is a detailed block diagram of an AGC circuit in FIG. 2.

Here, the reference numeral 41 in the AGC circuit unit 22 is a log amplification unit for receiving the log output a branched from the directional coupler 18, log amplification unit, 42 is received by the output of the log amplification unit 41 and integrated to the It is an integral part which outputs AGC control voltage to the variable attenuators 14,18.

5 is a flowchart illustrating the operation of a base station receiver in a conventional mobile communication system.

As shown therein, a first step ST1 of receiving a signal from the base station 4; A second step ST2 of detecting a voltage of a signal received after the first step; A third step (ST3) of performing AGC control after the second step; A fourth step ST4 of detecting the RSSI of the received signal after the first step; And a fifth step ST5 of determining the strength of the received signal after the fourth step.

The operation of the prior art configured as described above will be described in detail with reference to the accompanying drawings.

First, in the receiver of the conventional base station 4, the AGC circuit section 22 operates separately from the RSSI circuit section 21.

Thus, when the input RF external input signal is received by the RF signal receiving unit 10, it is converted into an IF signal through the frequency converter 11 and the RF local signal generator 20.

Then, the signal passing through the band filter 12, 15, variable attenuator 14, 17, and amplifier 16 is coupled through the directional coupler 18, and the signal is input to the AGC circuit section 22.                         

The signal input to the AGC circuit section 22 is converted into a signal magnitude through a log amplifier 41, and the changed voltage is controlled through the integrating section 42 to control the variable attenuators 14 and 17. It will change to AGC control voltage.

Therefore, when the input signal received by the RF signal receiver 10 is large, the AGC control voltage is lowered to increase the attenuation amount of the variable attenuators 14 and 17, and conversely, when the input signal received by the RF signal receiver 10 is low. The AGC control voltage is increased to reduce the attenuation amount of the variable attenuators 14 and 17, thereby keeping the output signal magnitude of the directional coupler 18 constant.

Meanwhile, in the receiver of the conventional base station 4, the RSSI circuit portion 21 is not connected to the AGC circuit portion 22 and operates separately.

The signal coupled at the directional coupler 13 in the middle of the receiver of the base station 4 is thus input to the RSSI circuitry 21.

The RSSI circuit section 21 then changes the signal strength to voltage through the log amplifier 31 and the operational amplifier 32.

The controller 23 converts the signal into a digital signal through the A / D converter 24 and compares the signal with the lookup table 26 in the controller 23 to determine an input signal strength. Will be.

However, this conventional technology has the following problems.

First, there is a problem in that the AGC circuit is configured separately from the RSSI circuit, resulting in a complicated circuit and a separate cost.                         

Second, precise automatic gain control is difficult because of the AGC circuit, which is an analog device.

Accordingly, the present invention has been proposed to solve the above-mentioned general problems, and an object of the present invention is to provide a mobile communication system that can automatically control the gain of a receiver by using a reception strength detection circuit used to check a reception path. To provide an automatic gain control apparatus and method using the detection strength of the base station receiver.

In order to achieve the above object, the automatic gain control apparatus using the reception strength detection of the base station receiver in the mobile communication system according to an embodiment of the present invention,

A variable attenuator for performing variable attenuation on the received RF signal; An RSSI circuit unit configured to receive the received RF signal and detect RSSI; The technical configuration is characterized by including a control unit for determining the strength of the received signal using the RSSI detected by the RSSI circuit unit, and performs AGC control for the variable attenuator.

In order to achieve the above object in the mobile communication system according to an embodiment of the automatic gain control method using the detection strength of the base station receiver,

A tenth step of detecting a RSSI of the received signal and determining the strength of the received signal when the receiver of the base station receives the signal; And a 20th step of performing AGC control by calculating the AGC control voltage after the tenth step.

Hereinafter, an embodiment according to the present invention, an automatic gain control apparatus using a reception strength detection of a base station receiver and a method thereof in a mobile communication system will be described with reference to the accompanying drawings.

6 is a block diagram of a peripheral block including an automatic gain control apparatus using a reception strength detection of a base station receiver in a mobile communication system according to the present invention.

As shown therein, the variable attenuators 105 and 108 perform variable attenuation on the received RF signal; RSSI circuit unit 120 for receiving the received RF signal and detects RSSI; The controller 130 may be configured to determine the strength of the received signal using the RSSI detected by the RSSI circuit unit 120 and to perform AGC control on the variable attenuators 105 and 108.

The RSSI circuit unit 120 includes: a log amplification unit 121 for receiving the received RF signal and performing log amplification; Operation amplification unit 122 for receiving the output of the log amplification unit 121 and the operation amplification to transmit the analog RSSI value to the control unit 130 is configured.

The controller 130 may include an analog to digital (A / D) converter 131 for receiving an analog RSSI value from the RSSI circuit unit 120 and converting the analog RSSI value into a digital signal; The A / D converter 131 receives the RSSI value converted into a digital signal, determines the strength of the received signal by referring to a look-up table, calculates an AGC control voltage, and calculates a digital AGC control voltage. A processor 134 for outputting a signal; A lookup table (133) for providing a lookup table to the processor (134); Digital-to-Analog (D / A), which receives the digital AGC control voltage signal from the processor 132 and converts it into an analog signal and outputs the analog AGC control voltage signal to the variable attenuators 105 and 108. It is configured to further include an analog) conversion unit 134.

Here, reference numeral 101 denotes an RF signal receiver for receiving an RF (Radio Frequency) signal input from the outside, and 102 denotes a frequency converter for outputting an IF (Intermediate Frequency) signal by frequency converting the output of the RF receiver 101. , 103 is a band pass filter for band-filtering the output of the frequency converter 102, 104 is a directional coupler for branching the output of the band filter 103 to the variable attenuator 105 and the RSSI circuit unit 120 to be.

In addition, reference numeral 106 denotes a band filter for performing band filtering on the output of the variable attenuator 105, 107 denotes an amplifier amplifying the output of the band filter 107 and sending it to the variable attenuator 108, 109 A receiving baseband signal processing unit which receives the output of the variable attenuator 17 and performs receiving baseband signal processing, and 110 is an RF local signal generator which generates an RF local signal and supplies it to the frequency converter 102.

7 is a flowchart illustrating an automatic gain control method using detection strength of a base station receiver in a mobile communication system according to the present invention.

As shown therein, when receiving a signal at the receiver of the base station, a tenth step (ST11 to ST13) of detecting the RSSI of the received signal to determine the strength of the received signal; After the tenth step, an AGC control voltage is calculated to perform AGC control.                     

In the mobile communication system according to the present invention configured as described above with reference to the accompanying drawings, the operation of the automatic gain control apparatus and method using the reception strength detection of the base station receiver in detail as follows.

First, the present invention is to automatically control the gain of the receiver using the reception strength detection circuit used for the reception path check.

Thus, the variable attenuators 105 and 108 perform variable attenuation on the received RF signal according to the AGC control voltage of the controller 130.

In addition, the RSSI circuit unit 120 receives the received RF signal and detects the RSSI.

In the RSSI circuit unit 120, the log amplifier 121 receives the received RF signal and logs amplifies the signal, and the operational amplifier 122 receives the output of the log amplifier 121 and amplifies the operation to control the controller 130. Transmits an analog RSSI value.

In addition, the controller 130 determines the strength of the received signal using the RSSI detected by the RSSI circuit unit 120 and performs AGC control on the variable attenuators 105 and 108.

Thus, the A / D converter 131 of the controller 130 receives the analog RSSI value from the RSSI circuit unit 120 and converts the analog RSSI value into a digital signal.

The processor 132 receives the RSSI value converted from the A / D converter 131 into the digital signal, determines the strength of the received signal with reference to the lookup table 133, and calculates the AGC control voltage to calculate the digital AGC. Output a control voltage signal.

The lookup table 133 stores a lookup table necessary for the AGC control voltage.                     

The D / A converter 134 receives the digital AGC control voltage signal from the processor 132, converts the digital AGC control voltage signal into an analog signal, and outputs the analog AGC control voltage signal to the variable attenuators 105 and 108.

Referring to the operation of the present invention in more detail as follows.

First, in the present invention, the automatic gain control operation and the reception intensity detection operation are performed in connection with each other.

Therefore, the RF signal input from the outside is converted into an IF signal through the frequency converter 102 and the RF local signal generator 110.

Then, the coupled signal of the signal passing through the band filter 103 and the directional coupler 104 is input to the RSSI circuit unit 120, and the main signal is the variable attenuator 105, 108, the band filter 106, and the amplifier. Input to the receive baseband signal processing section 109 via 107.

The signal input to the RSSI circuit unit 120 converts the signal strength into a voltage through the log amplifier 121 and the operational amplifier 122, and converts the signal strength into a digital signal from the controller 130 through the A / D converter 131. Change.

The lookup table 133 may be compared with the processor 132 to determine an input signal strength.

After determining the signal strength in this manner, in order to perform automatic gain control, the processor 132 internally considers the reference gain from the variable attenuator 105 to the input of the receiving baseband signal processor 109 in advance. The appropriate AGC control voltage to control the variable attenuator 105, 108 is calculated so that the signal is input to the receive baseband signal processor 109.

The digital signal of the AGC control voltage calculated as described above is converted into an analog AGC control voltage via the D / A converter 134 and input to the variable attenuators 105 and 108.

Therefore, when the input signal inputted to the RF signal receiver 101 is large, the AGC control voltage is lowered to increase the attenuation amount of the variable attenuators 105 and 108, and conversely, when the input signal inputted to the RF signal receiver 101 is low, the AGC The control voltage becomes large so that the attenuation amounts of the variable attenuators 105 and 108 become small.

Accordingly, the signal magnitude input to the reception baseband signal processor 109 can be kept constant.

As described above, the automatic gain control operation can be calculated mathematically by the processor 132 in the controller 130, so that a separate circuit for automatic gain control is unnecessary.

As such, the present invention is to automatically control the gain of the receiver by using the reception strength detection circuit used for the reception path check.

Although the preferred embodiment of the present invention has been described above, the present invention may use various changes, modifications, and equivalents. It is clear that the present invention can be applied in the same manner by appropriately modifying the above embodiments. Accordingly, the above description does not limit the scope of the invention as defined by the limitations of the following claims.

As described above, in the mobile communication system according to the present invention, the automatic gain control apparatus using the reception strength detection of the base station receiver and its method automatically adjust the gain of the receiver using the reception strength detection circuit used for the reception path checking. There is a controllable effect.

In addition, according to the present invention, a separate circuit for automatic gain control is unnecessary by performing the automatic gain control function by mathematically calculating the processor in the controller.

In addition, it is possible to prevent a change in reception characteristics due to deterioration of analog components by calculating AGC control voltages digitally in the control unit without using conventional analog circuits (log amplifiers and integration circuits).

Claims (4)

A variable attenuator for performing variable attenuation on the received RF signal; An RSSI circuit unit configured to receive the received RF signal and detect RSSI; And a control unit configured to determine the strength of the received signal using the RSSI detected by the RSSI circuit unit, and to perform AGC control on the variable attenuator. Automatic Gain Control. The method of claim 1, wherein the RSSI circuit unit, A log amplifier configured to receive the received RF signal and log amplify the received RF signal; And an operational amplification unit configured to receive an output of the log amplification unit and amplify the amplification unit to transmit an analog RSSI value to the control unit. The method according to claim 1 or 2, wherein the control unit, An A / D converter configured to receive an analog RSSI value from the RSSI circuit and convert the analog RSSI value into a digital signal; A processor configured to receive the RSSI value converted by the A / D converter into a digital signal, determine the strength of the received signal by referring to a lookup table, calculate an AGC control voltage, and output a digital AGC control voltage signal; A lookup table for providing a lookup table to the processor; Receiving strength of the base station receiver in the mobile communication system further comprises a D / A converter for receiving a digital AGC control voltage signal from the processor and converts it into an analog signal to output an analog AGC control voltage signal to the variable attenuator Automatic gain control device using detection. A tenth step of detecting a RSSI of the received signal and determining the strength of the received signal when the receiver of the base station receives the signal; And a twentieth step of performing AGC control by calculating an AGC control voltage after the tenth step. The automatic gain control method using the reception strength detection of a base station receiver in a mobile communication system.

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