KR101210608B1 - The automatic gain controller and the method that uses the efficient receiving structure of the impulse radio ultra-wide band wireless communication systems - Google Patents

Abstract

The present invention relates to an automatic gain control apparatus and method using an efficient reception structure of an impulse signal based ultra-wideband wireless communication system.

According to the present invention, an automatic gain control apparatus of an impulse signal based wireless communication system secures a signal-to-noise ratio received through an analog circuit unit, outputs a correlation value for an impulse preamble of the received signal, and every symbol among the correlation values. Each time the maximum value of the correlation value is output or the symbol interval is divided into a plurality of groups, the average value is obtained through the sum of the group units, and the maximum value thereof is output. The attenuation gain is determined by comparing the maximum correlation value according to the output result with at least one predetermined threshold, and the gain value of the low noise amplifier and the variable gain amplifier of the analog circuit unit are set or changed based on the determined attenuation gain result. do.

Accordingly, according to the present invention, it is possible to expect an effect of maintaining an optimal signal to noise ratio in various distances and indoor wireless channel environments through an efficient reception structure and automatic voltage gain control method for digital signal processing. .

WBAN, WPAN, Impulse, Ultra Wideband, UWB, AGC

Description

The automatic gain controller and the method that uses the efficient receiving structure of the impulse radio ultra-wide band wireless communication systems}

The present invention relates to an automatic gain control apparatus and method using an efficient reception structure of an impulse signal based ultra-wideband wireless communication system.

The present invention is derived from the research conducted as part of the IT growth engine technology development project of the Ministry of Knowledge Economy and the Ministry of Information and Communication Research and Development. [Task management number: 2006-S-070-03] ].

In general, in a wireless communication system, a signal propagated through a transmitting antenna suffers a propagation loss in a wireless channel. That is, in the real environment, various types of attenuation occur such as attenuation according to the propagation distance, shadows due to surrounding terrain or conditions, and multipath delay. Therefore, in order to maintain stable wireless communication in such a wireless channel environment, a voltage level of a received signal is uniformly maintained through devices such as a low noise amplifier (LNA) and a variable gain amplifier (VGA). You need to keep it.

Meanwhile, a structure of a conventional general orthogonal wireless communication receiver will be described with reference to FIG. 1.

1 illustrates a conventional wireless communication receiver of an in-phase and quadrature scheme.

Referring to FIG. 1, a conventional quadrature wireless communication receiver includes an antenna 10 for receiving a radio signal, an LNA 20 for low noise amplifying the gain of the received signal, and a local oscillator 50 for generating a carrier frequency. ), A mixer 30 for converting the generated carrier frequency by the output signal of the LNA 20 to a baseband or IF band signal, and a low pass filter for the signal output from the mixer 30. , LPF) or Band Pass Filter (BPF) 40 and Variable Gain Amplifier (VGA) 60 to adjust the gain of the signal, Analog-to-Digital Converter (ADC) ( 70) an automatic gain controller (AGC) for restoring the signal using the received signal and feeding back a gain control voltage to a variable gain amplifier (VGA) 60 to adjust the operating range of the received signal. Digital signal processing block 80.

The received signal of such a conventional wireless communication system is a continuous wave whose magnitude is a continuous voltage level. In addition, since the bandwidth of the signal is also a relatively narrowband signal, the receiver can accurately adjust the voltage level of the received signal by measuring the received signal strength indication (RSSI).

The automatic gain controller (AGC) of the digital signal processing block 80 measures the RSSI of the received signal to turn the LNA 20 on or off, or adjust the gain of the VGA 60 to adjust the size of the received signal within the input range. Can be adjusted to come. In this way, the size of the received signal is adjusted to have the maximum gain at the operation level of the input terminal of the ADC 70 to control the signal-to-noise ratio to the maximum.

However, in ultra wideband (UWB) wireless systems based on impulse signals, a very small pulse of 2nS or less is transmitted by a spectral mask specification to transmit a transmission signal at a low power level of -41.3 dBm / MHz or less. do. In addition, it may be difficult to determine the presence or absence of transmission data at a long distance due to the characteristics of a transmission signal that generates impulses discretely rather than continuously. These factors increase the error of the signal detection by the RSSI method of the received signal, and thus there is a problem that the performance of the AGC using the RSSI eventually reduces the reception performance.

Accordingly, an object of the present invention is to provide an automatic gain control apparatus and method for stably receiving a received signal using an efficient reception structure of an impulse signal based ultra wideband wireless communication system.

In particular, in ultra-wideband wireless communication systems based on impulse signals of WPAN or WBAN systems, an automatic gain that adjusts the voltage level of the received signal to maintain an optimal signal to noise ratio for the digital demodulation system. It is to provide a control device and a method thereof.

Advantages of the present invention can be understood by the following description, and will be more clearly understood by the embodiments of the present invention.

In order to solve the above technical problem, an automatic gain control apparatus using an efficient reception structure of an impulse signal-based ultra-wideband wireless communication system according to an embodiment of the present invention,

A matched filter for securing a signal-to-noise ratio of the received signal received through the analog circuit unit; A correlator for outputting a correlated signal with respect to the preamble signal of the received signal; An adder for outputting a maximum value of the correlation value for every symbol among the correlation values of the correlation signal, or dividing a symbol period into a plurality of groups, obtaining an average value through the sum of the group units, and outputting a maximum value thereof; A comparator for determining attenuation gain by comparing a maximum correlation value according to an output result of the adder with at least one predetermined threshold; And a gain controller configured to set or change gain values of the low noise amplifier and the variable gain amplifier based on the determined attenuation gain result.

On the other hand, the automatic gain control method using the efficient reception structure of the impulse signal based ultra-wideband wireless communication system according to an embodiment of the present invention,

a) processing a received signal received through an analog circuit unit in parallel to secure a signal-to-noise ratio, and outputting a correlation value for the impulse preamble of the received signal; b) outputting a maximum value of the correlation value for each symbol among the correlation values, or dividing a symbol interval into a plurality of groups, obtaining an average value through the sum of the group units, and outputting a maximum value thereof; c) determining attenuation gain by comparing the maximum correlation value according to the output result with at least one preset threshold; And d) setting or changing gain values of the low noise amplifier and the variable gain amplifier of the analog circuit unit based on the determined attenuation gain result.

According to the above-described configuration, the automatic gain control apparatus according to the present invention provides an optimal signal to noise ratio in various distances and indoor wireless channel environments through an efficient reception structure and automatic voltage gain control method for digital signal processing. You can expect a sustained effect.

In addition, according to the present invention, since the gain is set to the maximum value at the beginning of reception, the gain is lowered to achieve an optimal reception state, and thus the reception gain has an effect on overshoot or undershoot. It is possible to reliably control the reception gain in an impulse signal based wireless system.

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings so that those skilled in the art can easily carry out 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, and like reference numerals denote like parts throughout the specification.

Throughout the specification, when a part is said to "include" a certain component, it means that it can further include other components, without excluding other components unless specifically stated otherwise. Also, the terms " part, "" module," and " module ", etc. in the specification mean a unit for processing at least one function or operation and may be implemented by hardware or software or a combination of hardware and software have.

Now, an automatic gain control apparatus and method using an efficient reception structure of an impulse signal based ultra-wideband wireless communication system according to an embodiment of the present invention will be described in detail with reference to the accompanying drawings.

2 illustrates an automatic gain control apparatus of an impulse signal based wireless communication system according to an exemplary embodiment of the present invention.

Referring to FIG. 2, an automatic gain control apparatus according to an embodiment of the present invention includes an antenna 110, a low noise amplifier (LNA) 120, a mixer 130, a low pass filter (LPF) 140. ), Including a variable gain amplifier (VGA) 150, an analog circuit unit 100 and an analog-to-digital converter (ADC) 200 for processing a received signal received from the outside, and a signal-to-noise ratio (SNR) of the received signal. Matching filter 300 to secure, a correlation unit 400 for outputting a correlation signal (correlation value) for the preamble signal of the received signal, the average of the maximum value or M for each symbol of the correlation value after The analog circuit unit 100 according to the result of the comparison unit 600 and the comparison unit 600 that determines the attenuation gain by comparing the results of the adder 500 and the adder 500 with the thresholds. The LNA 120 to ON or OFF, or set or change the gain value of the VGA 150 by feeding back the result of Which includes a gain control section 700. The

The analog circuit unit 100 serves to process a radio frequency (RF) signal received from the antenna 110, and in this case, various reception structures such as a direct conversion method and a heterodyne method are applied. can do. In particular, the LNA 120 and the VGA 150 of the analog circuit unit 100 serve to variably amplify the gain of the received signal. The LNA 120 may be turned on or off by receiving a command from the gain controller 700. It serves to vary the gain of 150.

The ADC 200 converts the analog received signal received from the analog circuit unit 100 into a digital signal.

The matched filter 300 may be inserted before the ADC 200 and implemented using an analog filter. In the embodiment of the present invention, the matched filter 300 may be inserted after the ADC 200 to process a high-speed sampled received signal. It can be implemented by a parallel processing digital matched filter (Parallel Matched Filter) (160).

The purpose of the matched filter 300 is to use the matched filter 300 having the same filter coefficients as the transmitted pulse shaping filter so that the received signal has an optimal SNR.

이며, 정합필터(300)의 계수는

이고, 출력 신호는

일 때 정합필터(300)는 다음의 수학식 1과 같이 표현된다.For example, the received input signal is

The coefficient of the matched filter 300 is

And the output signal is

In this case, the matched filter 300 is expressed as Equation 1 below.

3A and 3B illustrate a general finite impulse response (FIR) digital filter structure and a parallel processing digital matched filter structure, respectively.

First, referring to FIG. 3A, a structure of a FIR filter for implementing a matched filter is shown.

The FIR filter consists of memory 310 for delay, multiplier 320 and adder 330. However, high-speed digital signal processing is required to process a received signal sampled at high speed in an ultra-wideband demodulation structure through such an FIR filter.

Therefore, the processing speed can be lowered through parallel processing of the digital matching filter as shown in FIG. 3B. However, the digital matched filter can be processed at a low frequency of 1 / M times by performing parallel operation with M branches, but has a disadvantage in that the area is increased by M times.

Meanwhile, FIG. 3C illustrates an efficient parallel processing digital matched filter structure according to an embodiment of the present invention.

Referring to FIG. 3C, the digital matched filter 300 according to an exemplary embodiment of the present invention can reduce the number of multipliers of the filters per branch to 1/2 using original function symmetry. have.

That is, the coefficient of the transmission pulse shaping filter used in the impulse signal based wireless communication system has the same linear phase characteristics as the root raised cosine (RRC) filter. Therefore, the filter coefficient has an advantage of reducing the number of multipliers of the filters per branch by 1/2 by using the right function symmetry characteristic as shown in Equation 2 below.

Next, the correlator 400 outputs a correlation value of an impulse preamble of the received signal by using the correlation characteristic. The primitive purpose of the correlation unit 400 is to detect packets and to obtain synchronization, and to obtain initial synchronization of packets using the output of the matching filter 300.

A feature of the correlator 400 according to an embodiment of the present invention is that by using the output value of the correlator 400 for the purpose of adjusting the voltage level of the received signal in addition to the existing purpose, a separate received field strength (RSSI) It is easy to implement, easy to operate, and does not need a block for measuring the advantages of gaining in terms of area.

4A and 4B show the structure of the impulse ultra wideband preamble correlator and the parallel processing preamble correlator structure, respectively.

Referring to FIG. 4A, an impulse ultra-wideband preamble correlator structure for direct implementation is illustrated, and may be expressed as Equation 3 below.

이며, 출력되는 상관 값은

, 프리앰블 심볼의 3진 코드(Ternary code)의 계수는

를 각각 의미한다.Here, the signal output from the matched filter 300 is

The correlation value that is output is

The coefficient of the ternary code of the preamble symbol is

Means each.

The impulse ultra wideband preamble has a time interval of F clock per pulse. Therefore, if the number of ternary codes is R, the number of samples (S) of one preamble symbol is equal to F times R as shown in Equation 4 below.

In addition, if one symbol is divided into N groups by M groups, it may be defined as M times N, and when C is defined as an oversampling number, it may be expressed as M times C times R.

At this time, since the coefficient value of the ternary code is 1, 0, -1, the multiplier 420 used may be implemented by the adder 430 without performing the actual multiplication operation. In addition, in order to process the high-speed sampled received signal, a high-speed correlator 400 is required. Instead of the high speed arithmetic unit, as shown in FIG. 4B, the operation speed can be lowered through M parallel processing. In this case, it should be noted that in parallel processing, the size of the delay element 410 should be F / M.

Next, the adder 500 outputs the maximum value of the correlation value for each symbol by using the correlation value output from the correlation unit 400, or divides the symbol interval for a predetermined period into N groups and adds M by each. The average value is obtained and the maximum value is output during one symbol period.

For example, when the M branch is implemented through parallel processing, since M correlation values are output at the same time, the M values may be simultaneously summed to obtain an average, and the maximum value may be extracted by comparing them for one symbol period. In addition, the adder 500 may arrange the correlation values in order of increasing magnitude in consideration of the spread of correlation energy due to the multipath of the channel, and then obtain and output the average of some of the larger magnitudes.

Next, the comparator 600 determines the attenuation gain by comparing the average value of the correlation output from the adder 500 with a set threshold value. The attenuation gain is then output to the gain control unit 700. That is, the comparator 600 sets the attenuation gain when the output value of the adder 500 exceeds the threshold voltage, and sets the attenuation gain to zero otherwise.

The gain controller 700 receives the attenuation gain output from the comparator 600, calculates and determines a gain value to be changed by reflecting the gain setting of the current state, and feeds back the analog circuit unit 100 to LNA. The control unit 120 controls ON or OFF to set or change the gain of the VGA 150.

Meanwhile, an automatic gain control method using an efficient reception structure of an impulse signal based ultra-wideband wireless communication system according to an embodiment of the present invention will be described with reference to FIG. 5.

5 is a flowchart illustrating an automatic gain control method of an impulse signal based wireless communication system according to an exemplary embodiment of the present invention.

Referring to FIG. 5, it is assumed that the automatic gain control method according to the embodiment of the present invention operates according to the configuration of the automatic gain control apparatus according to FIG. 2, and is coupled with a reception procedure in which a receiver receives a signal from the outside. Assume to perform an action.

First, when the reception state is turned on, the automatic gain control device turns on to the operation mode, sets the gain value of the VGA 150 to the maximum available value, and initializes all related variables (S501). At this time, in step S501 it is preferable to set the initial value of the gain (Gain) of the VGA 150 to the maximum value in order to ensure the maximum receiving distance.

It is determined whether the packet is received (S502). In step S502, the correlation value output from the adder 500 is compared with a predetermined threshold value to determine whether a packet is received at the receiver. If the packet is received because the correlation value is higher than the threshold value, the size of the correlation value is determined and the control proceeds to controlling the gain of the VGA 150. Otherwise, the packet waits until the packet is received.

Next, when the packet is received, it is determined whether the packet reception is completed (S503). The step S503 is for the automatic gain control device to return the gain of the VGA 150 to its original initial state when the reception of the packet is terminated and to prepare to receive the next packet.

On the other hand, if the packet reception is not completed, it is determined whether synchronization is obtained (S504). This means that the synchronization acquisition procedure should be switched to the synchronization acquisition mode from the time point after the operation of the AGC is completed. Therefore, if synchronization is obtained, the gain should not be changed any more, and the packet waits until the reception ends.

If the synchronization is not obtained, it is determined whether the AGC operation period is performed (S505). The role of step S505 is to control the AGC dynamic section to operate only during a certain section of the preamble. For example, a count may be counted for each preamble symbol and AGC may be performed only during a limited symbol period. Therefore, in the case of not the AGC operation period, the AGC operation may be divided into a step in which the AGC operation is immediately completed and a time point after the AGC operation is completed.

If the result of the determination in step S505 is not the AGC operation section, it is determined whether the AGC operation is completed immediately (S511), and if the AGC operation is completed immediately, generates a signal (Flag) for instructing the synchronization acquisition procedure (S512). ). Then, the number of symbols while receiving the preamble symbol is counted (S513). At this time, even if the AGC operation is completed, the symbol may continue to count if it is before the acquisition of synchronization.

As a result of the determination in step S505, the correlation value generated by the adder 500 in the AGC operation section is compared with a threshold to determine attenuation gain, and is compared with the first threshold value (S506). In step S506, a relatively high threshold value is set, and a magnitude of attenuation gain is set to help the reception gain to be quickly converged.

At this time, when the correlation value exceeds the first threshold as a result of the comparison of step S506, attenuation gain is determined (S508), and accordingly, a gain value to be applied to the LNA 120 and the VGA 150 is determined. On the other hand, it is fed back to the analog circuit unit 100 to adjust the reception gain (S510). The method of determining the attenuation gain is as shown in Equation 5 below. Decreases the gain by the step from the currently set gain.

Gain = Gain-step

On the other hand, if the correlation value does not exceed the first threshold as a result of the comparison in step S506, the correlation value is compared with the second threshold in the AGC operation interval (S507). In step S507, as a step for fine adjustment of the reception gain, a threshold value is determined to approximate a threshold to be converged, and the attenuation gain is set to be small and gradually converged.

The attenuation gain is determined according to the comparison result of step S507 (S509), and the process proceeds to step S510.

Thereafter, a count for the preamble symbol is performed (S513). The reception gain set by the end of the preamble, before synchronization acquisition, or by an abnormal correlation value is initialized (S514).

If the correlation value is higher than the threshold value due to noise rather than the normal sequence, a gain value may change. In such an abnormal situation, since synchronization is not obtained even if the gain value changes, a situation in which the symbol count value is larger than the number of preamble symbols occurs. That is, when a situation in which synchronization is not obtained during the preamble period occurs, the process may be switched to the step S501, which is an initial variable setting step, in step S514 to protect from an incorrect gain setting.

As described above, the automatic gain control method according to an exemplary embodiment of the present invention passes the above steps for every preamble symbol at the initial reception of the preamble and gains the gain of the VGA 150 to have a correlation value less than a threshold within the AGC operation interval range. ), It is advantageous to keep the received voltage gain in an optimal SNR state.

In addition, since the automatic gain control method according to an embodiment of the present invention initially sets the gain to a maximum value and adjusts the gain to an optimal reception state while lowering the gain, the reception gain may be overshoot or undershoot. There is no effect of under-shoot, so the impulse signal-based wireless system can reliably control the reception gain.

6 shows a normalized output waveform of an impulse signal based ultra-wideband wireless communication system. The transmission frame is composed of a preamble symbol period (SHR), a PHY header period (PHR), and a payload.

7A and 7B illustrate a baseband analog signal waveform and a matched filter output signal waveform in a 1 m distance simulation according to an embodiment of the present invention, respectively.

7A and 7B, in the ultra-wideband wireless channel model, a carrier frequency offset between transceivers is simulated by applying 100 KHz and a clock offset between transceivers by 30 KHz.

According to the condition of FIG. 7, when the 1m distance between the transceivers is spaced apart, a high energy signal is applied to the receiver due to the high SNR region. In general, such a largely applied received signal saturates RF and analog device and ADC output characteristics, resulting in severe performance degradation. However, through the automatic gain control method according to an embodiment of the present invention, the signal level is controlled in accordance with the input range of the ADC within several symbols to prevent performance degradation.

First, FIG. 7A shows that the AGC operates as a baseband analog real part signal of the ADC input terminal, and the size of the signal is adjusted according to the ADC input range while passing through 20 preamble symbols.

Next, FIG. 7B illustrates a signal obtained by adjusting the size of a signal digitally converted through a 4-bit ADC through the matching filter 300 so that the signal has an optimal SNR.

8A and 8B illustrate a baseband analog signal waveform and a matched filter output signal waveform in a 20m distance simulation according to an exemplary embodiment of the present invention, respectively.

Referring to FIGS. 8A and 8B, a simulation result of a situation in which it is difficult to distinguish an initial noise region and a signal region due to a low SNR region because the distance between the transceivers is 20m apart is shown. In this case, the SNR characteristics are sensitive, and the performance may be greatly degraded due to a slight reception gain error.

Even in such a situation, there is an advantage in that the communication distance can be maximized by adjusting to an optimum level through fine reception gain adjustment according to an embodiment of the present invention.

In the step, as a step for fine adjustment of the reception gain, the threshold value is determined to approximate the threshold to be converged, and the size of the attenuation gain is set to be small and the convergence can be gradually converged.

9 is a graph illustrating a performance comparison with a fixed reception gain structure according to an embodiment of the present invention.

Referring to FIG. 9, the results of comparing the performance of the structure without the AGC and the structure employing the AGC according to the embodiment of the present invention according to the distance in the channel shown in FIGS. 7 and 8 are shown. That is, when the AGC according to the embodiment of the present invention is adopted, it can be seen that relatively stable performance is maintained even at a distance between transmission and reception periods.

10 illustrates a hardware experiment result compared with a fixed reception gain structure according to an embodiment of the present invention.

Referring to FIG. 10, a variable attenuator via a cable is located between the transmitter and the receiver, and the attenuator is measured to enter a PER (Packet Error Ratio) 1% range while varying the attenuator.

At this time, in the method of fixing the reception gain to the maximum value, the range of the attenuator satisfying PER 1% was 20 dB to 59 dB, and the method using the automatic reception gain control device according to the embodiment of the present invention was 17 dB to 63 dB. Through this test it can be seen that the automatic receiving gain control apparatus according to an embodiment of the present invention shows a dynamic range gain of about 17dB.

As described above, the automatic gain control apparatus according to the embodiment of the present invention provides an optimal signal to noise ratio in various distances and indoor wireless channel environments through an efficient reception structure and automatic voltage gain control method for digital signal processing. You can expect a sustained effect.

The embodiments of the present invention are not limited to the above-described apparatuses and / or methods, but may be implemented through a program for realizing functions corresponding to the configuration of the embodiment of the present invention, a recording medium on which the program is recorded And such an embodiment can be easily implemented by those skilled in the art from the description of the embodiments described above.

While the present invention has been particularly shown and described with reference to exemplary embodiments thereof, it is to be understood that the invention is not limited to the disclosed exemplary embodiments, It belongs to the scope of right.

1 illustrates a conventional general orthogonal wireless communication receiver.

2 illustrates an automatic gain control apparatus of an impulse signal based wireless communication system according to an exemplary embodiment of the present invention.

Figure 3a shows a typical finite impulse response (FIR) digital filter structure

3b shows a general parallel processing digital matched filter structure.

3C illustrates an efficient parallel processing digital matched filter structure according to an embodiment of the present invention.

4A shows the structure of an impulse ultra-wideband preamble correlator.

4B illustrates a parallel processing preamble correlator structure according to an embodiment of the present invention.

5 is a flowchart illustrating an automatic gain control method of an impulse signal based wireless communication system according to an exemplary embodiment of the present invention.

6 shows an example of an output waveform of an impulse signal based ultra-wideband wireless communication system

7A shows a baseband analog signal waveform in a 1 m distance simulation according to an embodiment of the invention.

7B illustrates a matched filter output signal waveform in a 1 m distance simulation according to an embodiment of the present invention.

8A shows a baseband analog signal waveform in a 20m distance simulation according to an embodiment of the invention.

8B illustrates a matched filter output signal waveform in a 20m distance simulation according to an embodiment of the present invention.

 9 illustrates a performance comparison graph compared to a fixed reception gain structure according to an embodiment of the present invention.

10 shows hardware experiment results compared to a fixed receive gain structure in accordance with an embodiment of the present invention.

Claims (12)

An automatic gain control apparatus for an impulse signal based wireless communication system, A matched filter for securing a signal-to-noise ratio of the received signal received through the analog circuit unit; A correlator for outputting a correlated signal with respect to the preamble signal of the received signal; An adder for outputting a maximum value of the correlation value for every symbol among the correlation values of the correlation signal, or dividing a symbol period into a plurality of groups, obtaining an average value through the sum of the group units, and outputting a maximum value thereof; A comparator for determining attenuation gain by comparing a maximum correlation value according to an output result of the adder with at least one predetermined threshold; And A gain controller configured to set or change gain values of the low noise amplifier and the variable gain amplifier based on the determined attenuation gain result, The matched filter is an automatic gain control device, characterized in that for processing the high-speed sampled received signal in parallel, by reducing the number of multipliers using a linear phase characteristic according to the right function symmetry characteristics. delete The method of claim 1, The correlation unit, And an automatic gain control device for acquiring whether a packet is received and synchronizing the packet by using the output of the matched filter. The method of claim 3, wherein The correlation unit, An automatic gain control device, which is implemented only by an adder without performing a multiplication operation, and performs parallel processing of the high-speed sampled received signal. The method of claim 1, Wherein, Automatic gain control device for comparing the average value of the correlation signal output from the adder with the at least one threshold value and thereby lowers the received gain. The method of claim 1, The gain control unit, And receiving the attenuation gain output from the comparator to calculate a gain value to be reflected in a current gain setting. In the automatic gain control method of the automatic gain control device of the impulse signal-based wireless communication system, a) processing a received signal received through an analog circuit unit in parallel to secure a signal-to-noise ratio, and outputting a correlation value for the impulse preamble of the received signal; b) outputting a maximum value of the correlation value for each symbol among the correlation values, or dividing a symbol interval into a plurality of groups, obtaining an average value through the sum of the group units, and outputting a maximum value thereof; c) determining attenuation gain by comparing a maximum correlation value according to any one of the output results of step b) with at least one predetermined threshold value; And d) setting or changing gain values of the low noise amplifier and the variable gain amplifier based on the determined attenuation gain result, In the step a), the matched filter performs parallel processing on the received signal sampled at high speed, and reduces the number of multipliers by using the linear phase characteristic according to the right function symmetry characteristic. The method of claim 7, wherein Before step a), And setting a gain value of the variable gain amplifier to a maximum available value, and initializing the gain value and related variables. 9. The method according to claim 7 or 8, Between steps b) and c), Determining whether a packet is received when the packet is received by determining whether a packet is received; Determining whether to acquire synchronization when the packet reception is not completed; And Determining whether the automatic gain control operation is performed when the synchronization is not acquired Automatic gain control method comprising a. The method of claim 9, Whether the packet is received, And comparing the correlation value with a predetermined threshold value to determine whether a packet is being received at a receiver. The method of claim 7, wherein Step c) Comparing the maximum correlation with a first threshold; Determining attenuation gains when the first threshold is exceeded; or Determining attenuation gain when the second threshold is exceeded when compared with a second threshold when the first threshold is not exceeded Automatic gain control method comprising a. The method of claim 7, wherein Step d), And a gain value initialized by an abnormal correlation value for which synchronization is not obtained during the preamble period.

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