KR20130053133A - Auto gain controller using rf switch and radio communication device having the same - Google Patents

Abstract

PURPOSE: An AGC(Automatic Gain Control) device using an RF(Radio Frequency) switch and a wireless communication device including the same are provided to execute stable AGC through the switching control of the RF switch by extending an AGC range using the RF switch. CONSTITUTION: A level control unit(200) includes a plurality of transmission paths and a switching unit. A path control unit(300) determines the level of wireless signals. The path control unit controls the switching unit according to the range in which the level of the wireless signal by comparing the level of the wireless signal with a reference level. An AGC unit(400) the AGC of a signal outputted from the level control unit. [Reference numerals] (110) Coupler; (210) First switching unit; (220) Attenuator; (230) Second switching unit; (310) First converter; (320) Second converter; (330) Level discriminator; (340) Path selection signal generating unit

Description

ACG control device using RF switch and wireless communication device with same {AUTO GAIN CONTROLLER USING RF SWITCH AND RADIO COMMUNICATION DEVICE HAVING THE SAME}

An embodiment according to the concept of the present invention relates to an automatic gain control (AGC) technology of a wireless communication device, and more particularly, to improve the automatic gain control range by using an RF switch, and stable through switching control of the RF switch. The present invention relates to an AGC control device capable of automatic gain control and a wireless communication device having the same.

Auto Gain Control (AGC) is a technology that detects amplitude variations in a wireless receiver or amplifier input signal and automatically adjusts the gain so that the amplitude of the output signal remains constant. For example, in the high frequency field, it is used in a tuner of an FM receiver and the like, and refers to maintaining a constant sensitivity regardless of the strength or weakness of received radio waves. That is, when a signal with a large level is received, the level is adjusted to automatically level the level within a predetermined range, such as attenuating it to an appropriate range level. In the related art, an automatic gain control circuit is implemented using a dedicated chip for wireless communication automatic gain control (AGC). However, in this case, due to the limitation of the semiconductor constituting the chip dedicated to automatic gain control, a large level signal cannot be input and the input level range of the received signal is small. Particularly, when the corresponding counterpart is near when the installation of the wireless communication equipment is opened, a signal input of a large level is inevitable, and thus inconvenience of having to adjust the output of the corresponding device within the range of the input possible level. As a result, according to the conventional technology of performing the automatic gain control simply by using the chip exclusively for the automatic gain control, the installation opening takes a long time and the reliability of the equipment is deteriorated. Such conventional automatic gain control technology is described in detail in Patent No. 0325556, Publication No. 2006-0045501 and the like.

The technical problem to be achieved by the present invention is to provide an automatic gain control means and method that can extend the automatic gain control range using the RF switch and enable a stable automatic gain control through the switching control of the RF switch.

A wireless communication apparatus having an AGC controller according to an embodiment of the present invention includes a receiving unit for receiving and coupling a radio signal, a switching unit connected to the receiving unit, and a plurality of transmission paths connected in parallel to the switching unit Each of the plurality of transmission paths is connected to a level control unit having a different attenuation amount and the receiving unit to discriminate the level of the radio signal, compares the level of the radio signal with a reference level, A path control unit for controlling the switching unit so that the radio signal passes through any one of the plurality of transmission paths, and an automatic gain control unit (AGC) for performing automatic gain control (AGC) on a signal output from the level adjusting unit.

According to an embodiment, the switching unit may be implemented as an RF switch.

The plurality of transmission paths of the level control unit includes a first path and a second path, and the path control unit controls to pass through the second path when the level of the radio signal is greater than or equal to the reference level. If the level is less than or equal to the reference level, the control is performed via the first path.

According to an embodiment, the reference level is -40 dBm, the attenuation amount of the first path included in the level adjusting unit is 0, and the attenuation amount of the second path is 20 dBm.

In the case of changing the transmission path from the first path to the second path or the second path to the first path of the plurality of transmission paths, if the level of the wireless radio signal is within the re-change restriction range according to Equation 1 below: The transmission path can be controlled so as not to change.

[Equation 1] Reference level value-Rechange limit width ≤ Rechange limit range ≤ Reference level value + Rechange limit width

The magnitude of the rechange limit is 4 dBm.

The path controller may include a first converter converting the level of the radio signal received from the receiver into a DC value, and a second converter for converting the signal output from the first converter into a digital signal and outputting the digital signal. And a level selector for determining the level of the digital signal outputted from the digital signal output path, and a path selection signal generator for outputting a path selection signal corresponding to the level of the digital signal determined by the level discriminator to a level controller.

AGC control device and a wireless communication device having the same according to an embodiment of the present invention can improve the automatic gain control range according to the input level of the received signal using the RF switch and attenuator, and sets the switching limit of the RF switch As a result, stable automatic gain control is possible even in a wideband signal.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS In order to more fully understand the drawings recited in the detailed description of the present invention, a detailed description of each drawing is provided.
1 is an internal block diagram of a wireless communication device having an automatic gain control function according to an embodiment of the present invention.
2 illustrates a signal level deviation within a signal bandwidth according to an embodiment of the present invention.
3 is a diagram illustrating a level range of a first path and a second path for changing a path within a re-change restriction range according to an exemplary embodiment of the present invention.
FIG. 4 is a diagram for describing an RF switch control algorithm according to the level ranges of the first path and the second path shown in FIG. 3.
5 is a diagram illustrating an example of selectively forming a first path and a second path according to the level range of FIG. 3.

It is to be understood that the specific structural or functional descriptions of embodiments of the present invention disclosed herein are only for the purpose of illustrating embodiments of the inventive concept, But may be embodied in many different forms and is not limited to the embodiments set forth herein.

Embodiments in accordance with the concepts of the present invention are capable of various modifications and may take various forms, so that the embodiments are illustrated in the drawings and described in detail herein. It should be understood, however, that it is not intended to limit the embodiments according to the concepts of the present invention to the particular forms disclosed, but includes all modifications, equivalents, or alternatives falling within the spirit and scope of the invention.

The terms first, second, etc. may be used to describe various elements, but the elements should not be limited by the terms. The terms are intended to distinguish one element from another, for example, without departing from the scope of the invention in accordance with the concepts of the present invention, the first element may be termed the second element, The second component may also be referred to as a first component.

When a component is referred to as being "connected" or "connected" to another component, it may be directly connected to or connected to that other component, but it may be understood that other components may be present in between. Should be. On the other hand, when an element is referred to as being "directly connected" or "directly connected" to another element, it should be understood that there are no other elements in between. Other expressions describing the relationship between components, such as "between" and "immediately between," or "neighboring to," and "directly neighboring to" should also be interpreted.

The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. Singular expressions include plural expressions unless the context clearly indicates otherwise. In this specification, the terms "comprises ", or" having ", or the like, specify that there is a stated feature, number, step, operation, , Steps, operations, components, parts, or combinations thereof, as a matter of principle.

Unless otherwise defined, all terms used herein, including technical or scientific terms, have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. Terms such as those defined in commonly used dictionaries are to be interpreted as having a meaning consistent with the meaning of the context in the relevant art and, unless explicitly defined herein, are to be interpreted as ideal or overly formal Do not.

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, the present invention will be described in detail with reference to the preferred embodiments of the present invention with reference to the accompanying drawings.

1 is an internal block diagram of a wireless communication device having an automatic gain control function according to an embodiment of the present invention.

Referring to FIG. 1, the wireless communication apparatus 10 includes a receiver 100, a level adjuster 200, a path controller 300, and an automatic gain controller 400.

The receiver 100 performs a function as a wireless receiver and includes a coupler 110 and an amplifier 120.

The coupler 110 receives a radio frequency signal (RF) from an antenna, and outputs a radio signal RF1 obtained by bypassing the input radio signal RF to the amplifier 120. The RF signal coupled to the input radio signal RF (for example, 6 dB) is output to the path controller 300.

According to an embodiment, the coupler 110 may be implemented as a coupled line coupler, a 90 degree quadrature hybrid coupler, a ring hybrid coupler, a Lang coupler, or the like.

The amplifier 120 receives the signal RF1 bypassed and output from the coupler 110, and amplifies the amplitude of the received output signal RF1 to a predetermined level suitable for the wireless communication device 10 to adjust the level. Transfer to the unit (200).

The level adjusting unit 200 selects one of the first path L1 and the second path L2 to expand the reception input range of the automatic gain control unit 400, and the first switching unit 210. ), The second switching unit 220 and the attenuator 230.

The first switching unit 210 and the second switching unit 220 are the first path L1 or the second path L2 in response to the path selection signal LSS1 or LSS2 applied from the path control unit 300 to be described later. And transmit the amplified signal RF3 received from the amplifier 120 to the automatic gain control unit 400 through the formed first path L1 or the second path L2.

That is, the first switching unit 210 and the second switching unit 200 form the first path L1 in response to the first path selection signal LSS1 applied from the path control unit 300, and the path control unit ( In response to the second path selection signal LSS2 applied from 300, the second path L2 is formed.

According to an embodiment, the first switching unit 210 and the second switching unit 230 may be implemented as RF switches.

In general, the RF switch manufactured by MEMS (Micro Electro Mechanical Systems, MEMS) technology exhibits a low insertion loss when the switch is ON, and a high attenuation characteristic when the switch is OFF, compared to a conventional semiconductor switch. Power is also significantly lower than that of the semiconductor switch.

In this case, the first switching unit 210 and the second switching unit 230 are directly connected through the first path L1, and the active attenuation amount of the first path L1 is zero.

On the other hand, the attenuator 220 is provided on the formed second path (L2), the attenuator 220 of the signal to be transmitted from the first switching unit 210 to the second switching unit 230 through the second path (L2). Attenuate the level.

According to an embodiment, the attenuator 220 may attenuate the level of the signal transmitted from the first switching unit 210 to the second switching unit 230 by 20 dBm through the second path L2.

 Therefore, the amplified signal transmitted through the first path L1 is transmitted to the automatic gain control unit 400 as a signal of the same level, and the amplified signal transmitted through the second path L2 is automatically gained as attenuated signal by 20 dBm. It is transmitted to the control unit 400.

Meanwhile, the path controller 300 is connected to the coupler 110 in the receiver 100 to determine the level of the radio signal RF2 coupled and output from the coupler 110, and the level of the radio signal RF2. Is compared with a predetermined reference level, and the level adjusting unit 200 controls to form one of the first path L1 and the second path L2 according to the comparison result.

The path controller 300 includes a first converter 310, a second converter 320, a level discriminator 330, and a path selection signal generator 340.

The first converter 310 is connected to the coupler 110 and coupled to the coupler 110 to convert the radio signal RF2 output to the DC value (DC) to output to the second converter (320).

The second converter 320 samples the DC value DC output from the first converter 310, and outputs the sampled digital value DIG to the level discriminator 330.

According to an embodiment, the second converter 320 measures the level of the signal that varies according to the modulation scheme within the bandwidth of the signal and makes it into a DB, and the memory for the level discriminator 330 to refer to the measured result of the DB. Can be stored in

The level discriminator 330 determines the level of the digital value DIG output from the second converter 320, and determines a path between the first switching unit 210 and the second switching unit 230 according to the determination result. Determine whether to form (L1 or L2).

According to the above determination, the level discriminator 330 transmits a corresponding path control signal CS1 or CS2 to the path selection signal generator 340.

For example, the level discriminator 330 determines whether the digital value DIG output from the second converter 320 is larger or smaller than a reference level (eg, −40 dBm) (S10).

In this case, when the digital value DIG is greater than −40 dBm, the level determiner 330 may convert the second path control signal CS2 into a path selection signal generator 340 so that the second path L2 may be formed. To send).

In contrast, when the digital value DIG is not greater than −40 dBm, the level discriminator 330 may convert the first path control signal CS1 into a path selection signal generator so that the first path L1 may be formed. Send to 340.

Meanwhile, in the exemplary embodiment of the present invention, the bandwidth of the received wireless signal is 3.7 MHz, and there is a deviation of the signal level even within the signal bandwidth.

2 illustrates a signal level deviation within a signal bandwidth according to an embodiment of the present invention.

Referring to FIG. 2, the path to be routed by the radio signal RF3 output from the amplifier 120 may be known based on a reference level (-40 dBm) that is a path determination criterion.

As shown in FIG. 2, when the first path L1 and the second path L2 are alternately switched around the reference level (-40 dBm), the automatic gain control time in the automatic gain control unit 400 to be described later ( Since the AGC TIME is later than the time for alternately switching the first path L1 and the second path L2, a data error may occur.

In order to prevent such a data error from occurring, the level determiner 330 according to an embodiment of the present invention controls the path redirection limitation to select the first path L1 and the second path L2.

That is, when the level discriminator 330 is formed by changing any one of the paths L1 and L2 of the level adjusting unit 200 to another path, the level discriminator 330 is within the range of re-change according to condition 1 below. It can be controlled to prevent the path change.

[Condition 1]

Reference level value-Rechange limit range ≤ Rechange limit range ≤ Reference level value + Rechange limit range

For example, in the wireless communication apparatus using the 16QAM modulation scheme according to the embodiment, the level of the changed signal, that is, the re-change limit is ± 4dBm, so the reference level value is -40dBm, so the condition 1 is the following condition 2 and It has the same redo restriction.

[Condition 2]

-44 dBm ≤ re-change limit ≤ -36 dBm

The 16QAM is a type of digital modulation method, which is one of modulation methods used to convert digital data into an analog signal, and also means that one signal has 16 levels, that is, four bits can be expressed. Modulation is represented by a signal.

As a result, the level determiner 330 selects one of the first path L1 and the second path L2 by the first signal input DIG, and then changes the path after the condition 1 (or Control not to be performed within the re-change restriction range under condition 2).

FIG. 3 is a diagram illustrating level ranges of a first path and a second path for changing a path within a re-change restriction range according to an exemplary embodiment of the present invention, and FIG. 4 is a diagram illustrating first and second paths shown in FIG. 3. It is a figure for demonstrating the RF switch control algorithm according to the level range of a path | route.

1, 3, and 4, when the level of the first input sampling signal DIG is greater than −40 dBm, when the second path L2 is formed by the level determination S10 of the first input signal, the second path L2 is subsequently formed. The first path L1 is formed and the path is changed only when it is determined that the level of the input sampling signal is equal to or smaller than -45 dBm (S20), and the second path (L2) is smaller than -45 dBm even though it is smaller than -40 dBm. ) Is maintained.

In contrast, when the first path L1 is formed, the second path L2 is formed only when the level of the input sampling signal is determined to be greater than or equal to −35 dBm (S30), thereby changing the path. Even if the level of the signal is greater than -40 dBm but less than -35 dBm, that is, within the re-change restriction range, the first path L1 is not changed.

5 is a diagram illustrating an example of selectively forming a first path and a second path according to the level range of FIG. 3.

The radio signal RF3 output from the receiver 100 is transmitted via the first path L1 because the level of the sampling signal DIG at the first point P1 is smaller than the reference level value of −40 dBm.

Thereafter, even when the level of the sampling signal DIG is greater than -40 dBm until the second point P2 is reached, the path for transmitting the radio signal RF3 is transmitted because the re-change limit range (-35 dBm or more) has not been reached. The path L1 is maintained.

On the other hand, in the case of the second point P2, since the level of the sampling signal DIG is greater than -35 dBm to reach the re-restriction limit range, the path for transmitting the radio signal RF3 is transmitted from the first path L1 to the second. The path is changed to L2.

Thereafter, there are a number of sections or points whose level is smaller than the reference level of -40 dBm including the third point P3 to the fourth point P4, but in this case, the re-change limit range (below -45 dBm or less) is the same. Since it has not reached, the path through which the radio signal RF3 is transmitted is maintained as the second path L2.

 Since the level of the sampling signal DIG is less than -45 dBm at the fourth point P4, the path through which the radio signal RF3 is transmitted is changed from the second path L2 to the first path L1, and the fifth point ( In P5), a level larger than the reference level value of −40 dBm, but smaller than −35 dBm, the path through which the radio signal RF3 is transmitted is maintained as the first path L1.

Meanwhile, the path selection signal generator 340 transmits the first path selection signal LSS1 to the level adjuster 200 in response to the first path control signal CS1 transmitted from the level discriminator 330, and level The second path selection signal LSS2 is transmitted to the level adjuster 200 in response to the second path control signal CS2 transmitted from the discriminator 330.

Thereafter, the level adjusting unit 200 transmits the output signal RF3 through the first path L1 or the second path L3 in response to the path selection signal LSS1 or LSS2 transmitted from the path selection signal generator 340. The method of transmitting to the automatic gain control unit 400 is as described above.

The automatic gain control unit 400 receives the signal RF4 output from the level adjusting unit 200 and automatically corrects the gain.

As a result, the automatic gain control range of the wireless communication device using only the conventional automatic gain control chip is -96 dBm to -40 dBm, whereas the automatic gain control range of the wireless communication device 10 according to the embodiment of the present invention is -96 dBm to It reaches -20dBm.

That is, the signal RF3 output from the amplifier 120 is transmitted through the first path L1 in the range of -96 dBm to -45 dBm, and the second path L2 in the range of -35 dBm to -20 dBm. ), The output signal RF3 is transmitted.

In addition, even if the level of the input signal changes from ± 4dB from the reference level, the transmission path of the output signal is maintained, thereby enabling stable automatic gain control.

Although the present invention has been described with reference to one embodiment shown in the drawings, this is merely exemplary, and those skilled in the art will understand that various modifications and equivalent other embodiments are possible therefrom. Therefore, the true technical protection scope of the present invention will be defined by the technical spirit of the appended claims.

100:
110: coupler
120: amplification unit (AMP)
200: level control
210: first switching unit
220: attenuator
230: second switching unit
300: path control unit
310: first converter
320: second converter
330: Level discriminator
340: path selection signal generator
400: automatic gain control unit

Claims (7)

A receiver for receiving and coupling a wireless signal;
A level adjusting unit having a switching unit connected to the receiving unit and a plurality of transmission paths connected in parallel to the switching unit, each of the plurality of transmission paths varying an attenuation amount;
A transmission path of any one of the plurality of transmission paths, wherein the wireless signal is connected to the receiver to determine a level of the wireless signal, and compares the level of the wireless signal with a reference level according to a range to which the level of the wireless signal belongs. A path control unit controlling the switching unit to pass through; And
And an automatic gain control unit (AGC) for automatic gain control (AGC) of the signal output from the level control unit. The method of claim 1,
The switching unit is a wireless communication device having an AGC control device which is an RF switch. The method of claim 1,
The plurality of transmission paths of the level control unit includes a first path and a second path,
The path control unit includes an AGC control unit that controls the control unit to pass through the second path when the level of the radio signal is greater than or equal to the reference level, and control the control unit so as to pass through the first path when the level of the radio signal is less than or equal to the reference level. Wireless communication device. The method of claim 3,
The reference level is -40 dBm,
And attenuation amount of the first path including the level control unit is 0, and attenuation amount of the second path is 20 dBm. The method of claim 3,
In the case of changing the transmission path from the first path to the second path or the second path to the first path of the plurality of transmission paths, if the level of the wireless radio signal is within the re-change restriction range according to Equation 1 below: Wireless communication device having an AGC control unit to prevent the change of the transmission path.
[Formula 1]
Reference level value-Rechange limit range ≤ Rechange limit range ≤ Reference level value + Rechange limit range The method of claim 5,
And the re-change limit width is 4 dBm. The method of claim 1, wherein the path control unit,
A first converter converting the level of the radio signal received from the receiver into a DC value and outputting the converted DC value;
A second converter converting the signal output from the first converter into a digital signal and outputting the digital signal;
A level discriminator for discriminating the level of the digital signal output from the second converter; And
And a path selection signal generation unit for outputting a path selection signal corresponding to the level of the digital signal determined by the level discriminator to a level adjustment unit.

Images