KR20060032336A - Receiving-end protection apparatus of time division duplexing radio system and method thereof - Google Patents

Abstract

The present invention relates to a receiver protection apparatus and method in a wireless system for transmitting or receiving a signal using the same frequency and antenna.

In the present invention, the on / off control signal of a predetermined period is output according to the signal transmission and reception interval, the power amplifier amplifies and outputs the magnitude of the transmission signal according to the output on control signal. Then, the circulator passes the transmission signal through the transmission path to be radiated through the antenna, and transmits the reception signal received from the outside through the antenna to the internal transmission path. Thereafter, the variable attenuator attenuates the transmission leakage signal leaked when the circulator outputs the transmission signal to a predetermined magnitude, or outputs a reception signal received from the outside through the antenna as it is. That is, the variable attenuator has a different signal attenuation rate in the signal transmission and reception interval, thereby effectively protecting the receiving end from the transmission leakage signal. To this end, the voltage converter adjusts the signal attenuation rate by supplying bias voltages having different magnitudes to the variable attenuator according to the on / off control signal.

Time Division Redundancy (TDD), Wireless Systems, Variable Attenuators, Diodes, Isolation

Description

Receiving end protection device and method therefor in TD wireless system {RECEIVING-END PROTECTION APPARATUS OF TIME DIVISION DUPLEXING RADIO SYSTEM AND METHOD THEREOF}

1 is a view schematically showing a receiving end protection device in a TDD wireless system according to the prior art.

2 is a diagram schematically illustrating an apparatus for protecting a receiver in a TDD wireless system according to an embodiment of the present invention.

3 is a view illustrating in detail the receiving end protection device shown in FIG.

4 is a flowchart sequentially illustrating an operation process of the receiver protection apparatus of FIG. 2.

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a time division duplexing wireless system, and more particularly, to an apparatus and method for protecting a receiver from a transmitter leakage signal.

Time-division duplex is a transmission scheme in which two-sided communication is performed in a single frequency by dividing the inside of one frame for transmission and reception. In general, different frequency is used for transmission and reception in wireless communication. Bi-directional communication is possible by time-dividing and dividing for transmission and reception.

Such a time division duplex wireless system forms various structures to separate transmission and reception signals in time, and a structure using a double circulator is common. A display example of a time division duplex wireless system using a circulator is attached to FIG. 1.

As shown in FIG. 1, a conventional wireless system separates a transmission signal and a reception signal by using a single number of circulators 102.

However, in the wireless system of the above-described structure, the isolation between the transmitting and receiving ends (the leaked transmission signal attenuation rate) depends only on the isolation of the circulator 102. In general, since the isolation of the circulator is about 20 dB, Decreases the signal sensitivity of the receiver. Therefore, a separate additional device is needed to protect the receiving end.

That is, in the above structure, when the high power transmission signal passing through the power amplifier 101 is radiated to the antenna 104 in the signal transmission interval, the transmission signal leaks to the receiving end by the isolation between transmission and reception. However, this may seriously damage the low noise amplifier 105 which receives a low power signal from the antenna 104 and amplifies it by a certain amount.

Therefore, the above structure has the advantage of reducing the power loss of the transmitting end to reduce the current consumption of the power amplifier 101, but in general, the circulator has a disadvantage of low isolation, which may damage the receiving circuit during high power transmission. There is this.

On the other hand, there is a US patent with the registration number US 6,567,648 B1 as another technology related to the protection of the receiving end, which protects the receiving end by filtering the leaked transmission signal only from the signal received from the antenna and the leaked transmission signal. do.

However, the above-described technology also requires additional devices such as a filter and an amplifier to cancel the leakage signal, and thus requires the additional device for protecting the receiver.

The technical problem to be solved by the present invention is to solve this problem, by using a variable attenuator whose signal attenuation rate is adjusted according to the signal transmission and reception interval, the receiving end protection device in a TDD wireless system that can protect the receiving end from the transmission leakage signal And a method thereof.

In addition, the present invention by using a variable attenuator including a predetermined number of diodes in the protection of the receiving end, to reduce the size of the receiving circuit and at the same time to reduce the manufacturing cost for a receiver protection apparatus and method in the TDD wireless system for providing will be.

A receiver protection apparatus in a TDD wireless system according to an aspect of the present invention for achieving the above object is a receiver protection apparatus in a wireless system for transmitting or receiving a signal using the same frequency and antenna, the transmission path of the transmission signal A circulator configured to pass through and radiate through the antenna, and transmit a received signal received from the outside through the antenna to an internal receiving path; A variable attenuator configured to attenuate a predetermined magnitude of a transmission leakage signal that is leaked when the circulator passes the transmission signal, and output a received signal transmitted through the internal reception path as it is; And a voltage converter configured to control a signal attenuation rate by supplying bias voltages having different magnitudes to the variable attenuator according to a signal transmission / reception interval.

And a baseband controller configured to output an ON / OFF control signal of a predetermined period to the power supply voltage unit according to the signal transmission / reception section. A power amplifier amplifying a magnitude of a transmission signal according to an on control signal output from the baseband controller and outputting the amplitude to the circulator; And a low noise amplifier for amplifying the magnitude of the received signal transmitted through the variable attenuator and outputting the amplified signal to the baseband controller.

In this case, the variable attenuator includes at least one diode.

In addition, the receiving end protection method in a TDD wireless system according to another aspect of the present invention, in the receiving end protection method in a wireless system that transmits or receives a signal using the same frequency and antenna, a) transmitting a signal to the internal transmission path Passing through and radiating through the antenna; b) outputting a predetermined bias voltage according to a control signal output when the transmission signal is radiated; And c) attenuating a predetermined magnitude of a transmission leakage signal, which is a signal leaked when radiating the transmission signal according to the output bias voltage.

At this time, d) transmitting a received signal received from the outside through the antenna to the internal receiving path; e) outputting a predetermined bias voltage according to a control signal output when the received signal is transmitted; And f) outputting the received signal as it is according to the output bias voltage.

DETAILED DESCRIPTION Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings so that those skilled in the art may easily implement the present invention. As those skilled in the art would realize, the described embodiments may be modified in various different ways, all without departing from the spirit or scope of the present invention. In the drawings, parts irrelevant to the description are omitted in order to clearly describe the present invention. Like parts are designated by like reference numerals throughout the specification.

FIG. 2 is a diagram schematically illustrating a receiving end protection device in a TDD wireless system according to an exemplary embodiment of the present invention, and FIG. 3 is a diagram illustrating an internal configuration of the receiving end protection device shown in FIG. 2 in detail.

First, as shown in FIG. 2, the receiver protection device 200 in the TDD wireless system according to the embodiment of the present invention includes a baseband controller 210, a power amplifier 220, a circulator 230, and a bidirectional coupler. A basic configuration of the 240, the antenna 250, and the low noise amplifier 270 further includes a variable attenuator 260 and a voltage converter 280.

In this case, the variable attenuator 260 is located between the circulator 230 and the low noise amplifier 270, and the voltage converter 280 is located between the baseband controller 210 and the variable attenuator 260.

The variable attenuator 260 includes first and second diodes D1 and D2 and strip lines 261, as shown in FIG. 3, wherein one terminal of the strip line 263 is a circulator 230. ) Is connected in series with the signal output terminal, and the other terminal is connected in series with the low noise amplifier 270 signal input terminal.

One terminal of the first diode D1 connected in series with the second diode D2 is connected in series with the signal output terminal of the circulator 230, and the other terminal of the second diode D2 is connected with the ground terminal.

The voltage converter 280 includes an operational amplifier (OP-AMP) 281 and first and second variable resistors R1 and R2. The signal input terminal of the OP-AMP 281 includes a baseband controller. A signal output terminal 210 is connected, and the signal output terminal is connected to a power supply voltage V_Bias 262 of the variable attenuator 260.

One terminal and the other terminal of the first variable resistor R1 are connected to the signal output and input terminal of the OP-AMP 281, respectively, and one terminal of the second variable resistor R2 is the first variable resistor R1. The other terminal of is connected in parallel and the other terminal is connected to the ground terminal.

As described above, although the variable attenuator 260 includes two first and second diodes D1 and D2, the present invention is not limited to the present invention. It may include only a number of diodes, or three or more diodes.

Next, a description will be given of the receiving end protection device 200 forming the above connection structure.

The baseband controller 210 outputs the ON / OFF control signals (DC_a and DC_b of FIG. 2) to the power amplifier 220 and the voltage transformer 280 at predetermined intervals according to the signal transmission and reception intervals, respectively. The transmit TDD control signal DC_a and the transmit signal are output to the power amplifier 220, and the transmit TDD control signal DC_a is output to the voltage converter 280.

In addition, the signal reception section outputs the reception TDD signal DC_b to the voltage converter 280.

For reference, the baseband controller 210 may be implemented using an erasable programmable logic device (EPLD) or a field programmable gate array (FPGA) device to output the transmit and receive TDD control signals DC_a and DC_b according to a corresponding section, respectively. This is not limited to the present invention, but may be implemented using other elements in some cases.

Next, the power amplifier 220 amplifies the transmission signal received from the baseband controller 210 by a predetermined magnitude according to the transmission TDD control signal DC_a and outputs the amplified signal to the circulator 230.

The circulator 230 outputs the high power transmission signal output from the power amplifier 210 to the bidirectional coupler 240 through the transmission path ① in the signal transmission section, and through the antenna 250 in the signal reception section. The received signal received from the outside is transmitted to the variable attenuator 260 through the internal transmission path.

The bidirectional coupler 240 radiates the transmission signal received through the transmission path ① of the circulator 230 to the antenna 250 or applies the reception signal received from the antenna 250 to the circulator 230. do.

The variable attenuator 260 attenuates the transmission leakage signal, which is a signal leaked when the circulator 230 outputs the transmission signal in the signal transmission section, to a predetermined magnitude, and receives the received signal received from the outside through the antenna 250 in the signal reception section. The low noise amplifier 270 is transmitted as it is.

That is, the variable attenuator 260 has a high signal attenuation rate (a kind of signal attenuation value) in the signal transmission section to protect the receiving end (low noise amplifier) from the transmission leakage signal, and has a signal attenuation rate of 0 dB in the signal reception section to receive the received signal. Pass it as it is. As such, the variable attenuator 260 according to the present invention has different signal attenuation rates according to signal transmission / reception intervals.

In detail, the baseband control unit 210 outputs the transmission TDD control signal DC_a to the voltage source unit 280 in the signal transmission period, and the OP-AMP 281 of the voltage source unit 280 outputs the output signal. The forward bias voltage is output to the variable attenuator 260 according to the TDD control signal DC_a.

Then, the forward bias voltage is applied to the first and second diodes D1 and D2 of the variable attenuator 260, which makes the impedance of the first and second diodes D1 and D2 very small. To cause high signal attenuation.

For this reason, the variable attenuator 260 attenuates the transmission leakage signal leaked when the circulator 230 outputs the transmission signal by a certain amount. Through this, it is possible to effectively protect the receiving end from the transmission leakage signal.

In addition, by using only the first and second diodes D1 and D2 to protect the receiving end, the circuit size constituting the receiving end can be reduced, and manufacturing and cost are effective.

Meanwhile, the baseband controller 210 also outputs the received TDD control signal DC_b to the voltage converter 280, and the voltage converter 280 is a variable attenuator according to the output TDD control signal DC_b. A reverse bias voltage is output at 260.

Then, the reverse bias voltage is applied to the first and second diodes D1 and D2 of the variable attenuator 260, which causes the impedance of the first and second diodes D1 and D2 to be very high, thereby reducing the received signal. Is output to the low noise amplifier 270.

Next, the voltage transformer 280 outputs a forward or reverse bias voltage having a predetermined magnitude to the variable attenuator 260 according to the transmit and receive TDD control signals DC_a and DC_b output from the baseband controller 210. At this time, the size of the output bias voltage is adjusted by the number of variable resistors or the connection method.

That is, since the transmission signal is different for each base station, the size of the transmission leakage signal is also different. Therefore, when the magnitude of the transmission leakage signal is large, the signal attenuation rate of the variable attenuator 260 should also be high. For this purpose, the voltage converter 280 changes the number or connection method of the variable resistors 282 to change the variable attenuator 260. Change the magnitude of the applied voltage.

The low noise amplifier 270 amplifies a predetermined magnitude of a received signal transmitted as it is through the variable attenuator 260 in the signal reception period and transmits it to the baseband controller 210.

Next, the operation of the receiver protection apparatus in the TDD wireless system having the above configuration will be described.

FIG. 4 is a flowchart sequentially illustrating an operation process of a receiver protection apparatus in the TDD wireless system shown in FIG. 3. First, an operation process of a signal transmission interval will be described.

As shown in FIG. 4, the baseband controller 210 of the receiver protection device 200 transmits the ON / OFF control signals (DC_a and DC_b of FIG. 2) of a predetermined period in accordance with a signal transmission / reception interval to the power amplifier 220 and the voltage. The output unit 280 outputs the transmission signal and the transmission TDD control signal DC_a to the power amplifier 220 in the signal transmission section (S410).

Then, the power amplifier 220 amplifies the transmission signal by a predetermined magnitude in accordance with the transmission TDD control signal DC_a output from the baseband controller 210 and outputs it to the circulator 230 (S411).

Thereafter, the circulator 230 outputs the high power transmission signal output from the power amplifier 210 to the bidirectional coupler 240 through the transmission path ①, and the bidirectional coupler 240 transmits the transmission signal. Radiating to the antenna 250 (S413).

Meanwhile, the voltage transformer 280 applies a forward bias voltage to the variable attenuator 260 according to the transmission TDD control signal DC_a output from the baseband controller 210 in a signal transmission period (S420) (S421). The first and second diodes D1 and D2 of the variable attenuator 260 are subjected to a forward bias voltage, which causes the signal attenuation of the first and second diodes D1 and D2 to be very small, thereby providing high signal attenuation. Get up.

For this reason, the variable attenuator 260 attenuates the transmission leakage signal, which is a signal leaked when the circulator 230 outputs the transmission signal, by a predetermined magnitude (S422). Through this, it is possible to effectively protect the receiving end from the transmission leakage signal.

Next, referring to the signal reception section, the bidirectional coupler 240 transmits a received signal received from the outside through the antenna 250 to the circulator 230 (S430), and accordingly, the baseband controller 210 receives the received TDD. The control signal DC_b is output to the voltage transformer 280 (S331).

Then, the voltage transformer 280 applies the reverse bias voltage to the variable attenuator 260 according to the received TDD control signal DC_b (S332), and the first and second diodes D1 of the variable attenuator 260 are applied. , D2) is subjected to a reverse bias voltage, which causes the impedance of the first and second diodes D1 and D2 to be very high.

Accordingly, the variable attenuator 260 outputs the received signal received from the circulator 230 to the low noise amplifier 270 without signal attenuation (S433).

Thereafter, the low noise amplifier 270 amplifies a predetermined magnitude of the received signal transmitted through the variable attenuator 260 and transmits it to the baseband controller 210.

As such, the receiver protection apparatus and method thereof according to an embodiment of the present invention use a variable attenuator capable of adjusting a signal attenuation rate according to a signal transmission / reception interval in a wireless system for transmitting or receiving a signal using the same frequency and antenna. It can protect the receiving end from the signal.

In addition, the present invention can reduce the size of the receiving circuit and at the same time reduce the manufacturing cost by using a variable attenuator including a predetermined number of diodes for the protection of the receiver.

The drawings and detailed description of the invention are exemplary only, and are used for the purpose of illustrating the invention only, and are not intended to be limiting or to limit the scope of the invention described in the claims. Therefore, those skilled in the art will understand that various modifications and equivalent other embodiments are possible from this. Therefore, the true technical protection scope of the present invention will be defined by the technical spirit of the appended claims.

Receiving end protection device and method in a TDD wireless system according to the present invention is a transmission leakage by using a variable attenuator that can adjust the signal attenuation rate according to the signal transmission and reception interval in a wireless system that transmits or receives a signal using the same frequency and antenna It can protect the receiving end from the signal.

In addition, the present invention has the effect of reducing the size of the receiving circuit and at the same time lower the manufacturing cost by using a variable attenuator including a predetermined number of diodes when protecting the receiving end.

Claims (11)

A receiver protection apparatus in a wireless system for transmitting or receiving a signal using the same frequency and antenna, A circulator configured to pass a transmission signal through a transmission path to radiate through the antenna, and transmit a reception signal received from the outside through the antenna to an internal reception path; A variable attenuator configured to attenuate a predetermined magnitude of a transmission leakage signal that is leaked when the circulator passes the transmission signal, and output a received signal transmitted through the internal reception path as it is; And A voltage transformer for controlling a signal attenuation rate by supplying bias voltages having different magnitudes to the variable attenuator according to signal transmission / reception intervals. Receiver protection device in a TDD wireless system comprising a. According to claim 1, A baseband controller configured to output an ON / OFF control signal of a predetermined period to the power supply voltage unit according to the signal transmission / reception section; A power amplifier amplifying a magnitude of a transmission signal according to an on control signal output from the baseband controller and outputting the amplitude to the circulator; And A low noise amplifier for amplifying the magnitude of the received signal transmitted through the variable attenuator and outputting the amplified signal to the baseband controller. Receiving end protection device in a TDD wireless system further comprising. The method of claim 2, The variable attenuator, Receiver protection device in a TDD wireless system including at least one diode. The method of claim 3, wherein The voltage source unit, The receiver protection device of the TDD wireless system to reduce the impedance by applying a forward bias voltage to the diode in the signal transmission period. The method of claim 3, wherein The voltage source unit, The receiver protection device of the TDD wireless system to increase the impedance by applying a reverse bias voltage to the diode in the signal receiving period. The method according to claim 3 or 4, The voltage source unit, A receiver protection device in a TDD wireless system including an operational amplifier (OP-AMP) coupled with at least one variable resistor. The method of claim 2, The baseband control unit, Receiving end protection device in a TDD wireless system for outputting the on / off control signal using an EPLD (Erasable Programmable Logic Device) or a field programmable gate array (FPGA) device. In the receiver protection method in a wireless system for transmitting or receiving signals using the same frequency and antenna, a) passing a transmitted signal through an internal transmission path to be radiated through the antenna; b) outputting a predetermined bias voltage according to a control signal output when the transmission signal is radiated; And c) attenuating a predetermined magnitude of a transmission leakage signal, which is a signal leaked when radiating the transmission signal according to the output bias voltage; Receiver protection method in a TDD wireless system comprising a. The method of claim 8, d) transmitting a received signal received from the outside through the antenna to an internal receiving path; e) outputting a predetermined bias voltage according to a control signal output when the received signal is transmitted; And f) outputting the received signal as it is according to the output bias voltage Receiving end protection method in a TDD wireless system further comprising. The method of claim 8, Step b), Outputting a forward bias voltage in a signal transmission section according to the control signal Receiver protection method in a TDD wireless system comprising a. The method of claim 10, Step c) is Attenuating the transmission leakage signal by reducing an impedance according to the output forward bias voltage; Receiver protection method in a TDD wireless system comprising a.

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