KR20060029813A - Digital broadcasting receiver and smart antenna controlling method for digital broadcasting receipt - Google Patents

Abstract

The present invention relates to a digital broadcast receiver for receiving digital broadcasting in a residual side band (VSB) method and a smart antenna control method for digital broadcast reception. In particular, the present invention can reduce the detection time required by the convergence time of the AGC unit by detecting the signal power from the input signal in a state where the gain of the AGC unit is fixed. When the signal power detection range is detected from the magnitude of the input signal and is out of the preset reference signal power detection range, a new signal power detection range may be set, thereby improving reliability of the signal power information. In addition, since the existing antenna scan controller is expanded, the separate hardware cost does not increase significantly, and all the control sections can be configured digitally, so it is easy to make a single chip, thereby increasing the system integration.

Fast scan, signal power, smart antenna

Description

Digital broadcasting receiver and smart antenna controlling method for digital broadcasting receipt}

1 is a block diagram of a general digital TV receiver

2 is a block diagram showing an embodiment of a digital TV receiver according to the present invention;

3 is a detailed block diagram illustrating an embodiment of an AGC unit of FIG. 2;

4 is a detailed block diagram illustrating an embodiment of the signal power detector of FIG. 2.

5 is an operation flowchart showing an embodiment of a fast antenna scan process according to the present invention;

6 is a view illustrating a signal power detection range and an operating principle of a fast antenna scan according to the present invention.

Explanation of symbols for main parts of the drawings

101: smart antenna system 102: VSB demodulator

103 antenna control unit 103-1 channel information detection unit

103-2: antenna direction acquisition control unit 103-3: antenna direction tracking control unit

111: signal power detector 121: tuner

122: IF AGC amplification unit 131: ADC

132: AGC unit 210: high speed antenna scan control unit

301 AGC error detector 302 IF loop filter

303 IF delta-sigma DAC 304 delay AGC controller

305: RF loop filter 306: RF delta-sigma DAC

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a digital broadcast receiver, and more particularly, to a smart antenna control method for digital television (TV) reception, which can be applied to a residual side band (VSB) receiver.

Although the research on the antenna of the VSB (Vestigial Side Band) receiver, which has been selected as the standard for the transmission method of the terrestrial channel of digital TV, is still in its infancy, concepts and ideas have recently been proposed. In addition, the Advanced Television Systems Committee (ATSC) has standardized on this, completing the commercial universal interface of the smart antenna called CEA / EIA909. Recently, VSB receiver chip makers are releasing commercial products that support the interface.

As such, active researches are being conducted to improve the reception performance of digital television, and in particular, efforts to improve indoor reception or mobile reception performance by using smart antennas and multiple antennas are continuously being developed.

However, many terrestrial paths and radio obstacles can exist in the terrestrial channels of digital television. Therefore, the reception characteristic of the receiving antenna has a great influence on the performance of the entire receiving system.

The following describes the problems and solutions for the antenna type, channel environment.

First, in a receiver using an omni-directional antenna, when the received main signal is strong and the multipath signal is weak, the receiver may receive the signal in all directions. In the opposite case, however, reception is not easy in a channel with a weak main signal and a strong multipath signal (for example, an urban building area or an indoor antenna), which degrades the performance of the reception system.

Second, the use of the directional antenna in the receiver can solve the problem of the omni-directional antenna described above. However, if the main signal is interrupted in a continuous environment of constant channel conditions, i.e., moving propagation obstacles, it is not easy to receive signals from other directions, which also degrades the performance of the receiving system. Therefore, the omnidirectional antenna and the directional antenna have a tradeoff relationship with each other.

Third, applying the smart antenna in the receiver can control the antenna pattern and directivity of the directional antenna can solve all the problems described above. However, an antenna control system is needed to control the smart antenna, and the performance of the receiving system depends on the performance of the antenna control system.

1 is a block diagram of a digital TV receiver using a general smart antenna, the smart antenna system 101 optimizes the broadcast signal received by the built-in smart antenna and outputs to the VSB demodulator 102. That is, the antenna phase and gain controller in the smart antenna system 101 is optimal for signal reception by adjusting the beam width, gain, frequency characteristics, etc. of the smart antenna according to the mechanical or electrical antenna control signal of the antenna control system 103. Configure the antenna pattern.

The VSB demodulator 102 includes an analog front-end, a demodulator, and a forward error correction (FEC), and the AGC information of the VSB signal is transmitted to the signal power detector 111. The demodulated I channel data is a multipath signal power detector 112, the phase tracked I channel data is a Signal / Noise Ratio (SNR) calculator 113, and the FEC error data is a packet error per second (Segment Error Rate; SER). ) Is output to the calculator 114, and the transport packet data is output for decoding.

The signal power detector 111, the multipath signal power detector 112, the SNR calculator 113, and the SER calculator 114 are included in the channel information detector 103-1 and the channel information detector 103-1. Is included in the antenna control system 103.

The antenna controller 103 includes a channel information detector 103-1, an antenna direction capture controller 103-2, and an antenna direction track controller 103-3.

The signal power detector 111 detects signal power information from AGC information of the received signal output from the VSB demodulator 102.

The multipath signal power detector 112 detects multipath signal power information by calculating a correlation function value during field synchronization period from the I channel data output from the VSB demodulator 102.

The SNR calculator 113 calculates SNR information by calculating a mean square error (MSE) value from the equalized I channel data output from the VSB demodulator 102.

The SER calculator 114 calculates SER information from the FEC error value output from the VSB demodulator 102.

The signal power information, the multipath signal power information, the SNR information, and the SER information are referred to as channel information.

The channel information (ie, signal power, multipath signal power, SNR, and SER) is output to the antenna scan controller 103-2. Among them, the signal power information is also applied to the antenna direction tracking control unit 103-3.

The antenna scan controller 103-2 captures the antenna direction by using the channel information output from the channel information detector 103-1, and outputs the antenna direction tracking controller 103-3 and the channel information detector ( 103-1) and to the VSB demodulation unit 102.

That is, the antenna scan controller 103-2 receives the signal power information from the channel information detector 103-1, detects the antenna direction of the maximum signal power, and transfers the information to the antenna direction tracking controller 103-3. do. In addition, the antenna scan controller 103-2 fixes the gain value of the automatic gain control (AGC) unit (not shown) in the VSB demodulator 102 to a specific value during the antenna acquisition process.

In addition, the antenna scan control unit 103-2 selectively combines channel information to determine whether to proceed with the antenna direction tracking process or to repeat the antenna direction recapture process.

Meanwhile, the antenna direction tracking controller 103-3 receives the signal power information from the channel information detector 103-1 and controls the antenna phase and gain controller of the smart antenna system 101 to optimally receive the signal at the maximum signal power capture point. It serves to converge the antenna direction to the point.

In this case, the signal power information detected by the signal power detector 111 is the most useful information for antenna control. However, since the receiver has a relatively wide input range, in order to ensure reliability, signal power information must be detected after converging the AGC unit in the VSB demodulator 102 according to the size of the received signal. This process is performed for all preset antenna directions to detect the maximum signal power direction.

Therefore, the convergence time of the AGC unit takes a long time to detect the maximum signal power direction occurs.

SUMMARY OF THE INVENTION The present invention has been made to solve the above problems, and an object of the present invention is to provide a digital broadcast receiver and a smart antenna control method for digital broadcast reception for quickly detecting the maximum signal power direction.

Another object of the present invention is to provide a digital broadcast receiver and a smart antenna control method for digital broadcast reception, which provide signal power information with improved reliability by automatically adjusting a power measurement range according to an input signal size.

According to an aspect of the present invention, there is provided a digital broadcast receiver comprising: a smart antenna system configured to configure an antenna pattern optimal for signal reception by adjusting a smart antenna according to an antenna control signal; Only a specific RF signal of the RF signal received through the smart antenna system is converted into an IF signal, the gain of the tuned RF signal is adjusted according to the RF gain control signal, and the gain of the IF signal is adjusted according to the IF gain control signal. Analog front end adjusting; An AGC unit which obtains an IF gain error and an RF gain error from the received signal output from the analog front end, generates an RF gain control signal and an IF gain control signal, respectively, and outputs them to the analog front end; And an antenna controller.

The antenna controller obtains signal power for each preset antenna direction from the received signal output from the analog front end, detects the antenna direction of maximum signal power, and outputs the antenna power to the smart antenna system as an antenna control signal. If the signal power value obtained from the predetermined reference signal power detection range is out of range, the RF gain control signal and the IF gain control signal of the AGC unit is changed, and if not, characterized in that the capture process is performed by fixing to a specific value.

When the signal power value in a specific antenna direction is out of a preset reference signal power detection range, the antenna controller controls the AGC unit to vary the gain of the RF signal and the gain of the IF signal, and then varies the gain of the RF and IF signals. When the signal power value in the corresponding antenna direction is within the reference signal power detection range, the signal power value is updated to the maximum signal power value together with the antenna direction value at this time.

The antenna controller controls the AGC unit to continuously fix the RF signal gain and the IF signal gain to a specific value when the signal power value in a specific antenna direction does not deviate from a preset reference signal power detection range, and the signal power value is stored in a maximum value. The signal power value is updated to the maximum signal power value together with the corresponding antenna direction value only when the signal power value is larger than the signal power value.

The antenna controller may control the IF gain control signal and the RF gain control signal of the AGC unit to decrease the RF signal gain and the IF signal gain when the signal power value is out of a preset reference signal power detection range in a specific antenna direction. do.

Smart antenna control method for digital broadcast reception according to the present invention,

(a) adjusting an smart antenna according to an antenna control signal to configure an antenna pattern optimal for signal reception;

(b) tuning only a specific RF signal among the RF signals received through step (a) to adjust the gain of the RF signal and converting it into an IF signal, and then adjusting and amplifying the gain of the IF signal;

(c) obtaining signal power in a corresponding antenna direction from the received signal output in step (a) and determining whether it is out of a preset reference signal power detection range;

(d) If it is determined in step (c) that the reference signal power detection range is not exceeded, the gain of the RF signal and the gain of the IF signal are kept fixed to a specific value, and the signal power value is larger than the pre-stored maximum signal power value. Updating the signal power value to the maximum signal power value with a corresponding antenna direction value;

(e) If it is determined in step (c) that it is out of the reference signal power detection range, the gain of the RF signal and the gain of the IF signal are varied, and the signal power value in the corresponding antenna direction is changed by the gain variation of the RF and IF signals. If the reference signal is within the detection range of power, including the step of updating the signal power value to the maximum signal power value with the antenna direction value,

The above-described steps are repeated for each preset antenna direction to detect the antenna direction of the maximum signal power, and then the antenna control signal is output in the step (a).

In step (e), if it is determined in step (c) that the signal power value is out of the reference signal power detection range, the gain of the RF signal gain and the IF signal may be reduced.

Other objects, features and advantages of the present invention will become apparent from the following detailed description of embodiments taken in conjunction with the accompanying drawings.

Hereinafter, with reference to the accompanying drawings illustrating the configuration and operation of the embodiment of the present invention, the configuration and operation of the present invention shown in the drawings and described by it will be described as at least one embodiment, By the technical spirit of the present invention described above and its core configuration and operation is not limited.

In general, digital TV receivers require a limited settling time, and since signal power detection time is the largest part of the processing time in the antenna control process, the detection time is an important factor that has a dominant influence on the acquisition performance of the system.

Currently, we are aiming for a typical initial acquisition time of a smart antenna in less than a second. To meet this limitation, we need fast antenna acquisition performance, which will be a big part of the smart antenna's performance factor.

Therefore, in the present invention, it is possible to conditionally converge the AGC unit in a specific direction of the antenna to detect signal power information, thereby reducing signal power detection time and ensuring reliability.

FIG. 2 is a block diagram illustrating a digital TV receiver according to the present invention, which further extends the antenna scan control unit of the antenna control system 103 of FIG.

In the present invention, the high-speed antenna scan control unit 210 will be referred to to distinguish it from the existing antenna scan control unit 103-2.

The high speed antenna scan control unit 210 may be configured by hardware according to a designer, or may be designed by middleware or software.

The fast antenna scan controller 210 may output an AGC operation control signal (AGC_freeze control signal) for determining whether to update the loop filter in the AGC unit 132 according to the signal power information output from the signal power detector 111. Create

2, the multi-path signal power detector 112, the SNR calculator 113, and the SER calculator 114 of the channel information detector 103-1 in the antenna control system 103 are the fast signal power of the present invention. The illustration and description are omitted since they are not related to detection. In addition, only the parts related to the present invention will be described in the high speed antenna scan control unit 210.

In FIG. 2, the analog processor 120 and the VSB receiver 130 correspond to the VSB demodulator 102 of FIG. 1. The analog processor 120 is also called an analog front end, and includes a tuner 121 and an IF AGC amplifier 122.

The VSB receiver 130 includes an analog / digital converter (ADC) 131 and an AGC unit 132.

At this time, the received signal digitized by the ADC 131 is output to the AGC unit 132 and also to the signal power detector 111 of the antenna control system 103.

The signal power detector 111 detects signal power from the digitized received signal and outputs the signal power to the fast antenna scan control unit 210. For example, the signal power detector 111 takes an absolute value on the digitized received signal, or squares it and accumulates for a predetermined period to obtain an average signal power. The average signal power is output to the fast antenna scan control unit 210 and the antenna direction tracking control unit 103-3.

4 shows a relationship between the signal power detector 111 and the fast antenna scan control unit 210.

In the present invention, in order to reduce the hardware cost, the signal power detector 111 includes an absolute value calculator 401 and an accumulator 402 as shown in FIG. 4. That is, the absolute value calculator 401 takes the absolute value of the digitized received signal and outputs the absolute value to the accumulator 402. The accumulator 402 accumulates the absolute value by a predetermined window size and divides the absolute value by the window size and outputs the average signal power information to the high speed antenna scan control unit 210.

The accumulator 402 is initialized by a reset signal of the fast antenna scan control unit 210. That is, it is reset for each preset antenna direction.

On the other hand, the gain of a signal transmitted from a transmitter such as a broadcasting station is always constant, but due to the distance to the TV receiver and the amount of gain of the signal varying through various channels until reaching the TV receiver. do. The gain-modulated signal is input to the receiver, and most of the digital parts of the receiver are designed assuming that the signal is always input with a constant magnitude of gain. Therefore, it is necessary to adjust the gain of the analog signal input to the receiver so that it always has a constant gain, and then convert it into a digital signal.

It is the automatic gain control (AGC) unit 132 that performs this role.

3 is a detailed block diagram showing an embodiment of the AGC unit 132. A received signal digitized by the ADC 131 is output to an AGC error detector 301, and the AGC error detector 301 is shown. The AGC error detected at) is output to the IF loop filter 302. The accumulated value in the IF loop filter 302 is output to the IF delta-sigma DAC 303 and fed back to the delay AGC controller 304. The IF delta-sigma DAC 303 converts the output of the IF loop filter 302 into a 1-bit analog signal and outputs it to the IF AGC amplifier 122 as an IF AGC control signal.

The delay AGC controller 304 obtains a difference between the output of the IF loop filter 302 and a preset RF AGC reference signal and outputs the difference to the RF loop filter 305. The RF loop filter 305 accumulates the difference value and outputs the difference to the RF delta-sigma DAC 306, and the RF delta-sigma DAC 306 outputs the output of the RF loop filter 305 to 1-bit analog. The signal is converted into a signal and output to the tuner 121 as an RF AGC control signal.

In addition, the AGC_freeze control signal generated by the fast antenna scan control unit 210 is output to the IF loop filter 302 and the RF loop filter 305 to determine the update of the loop filter.

That is, the tuner 121 tunes only a channel frequency selected by a user among the RF signals received through the smart antenna system 101 and increases or decreases the gain of the tuned RF signal according to the RF AGC control signal. Allow the gain to be the desired state and convert it to an IF signal. The IF AGC amplification unit 122 raises or lowers the gain of the IF signal output from the tuner 121 according to the IF AGC control signal so that the gain of the IF signal is in a desired state, and amplifies the VSB receiver 130. ) Is output to the ADC 131.

The IF signal digitized by the ADC 131 is output to the AGC error detector 301 of the AGC unit 132.

The AGC error detector 301 detects an AGC error, that is, an IF gain error value, from the digitized received signal and outputs it to the IF loop filter 302. In one embodiment, the AGC error detector 301 may output the difference between the square value of the received signal and a predetermined AGC reference value as an IF gain error value.

The IF loop filter 302 accumulates the IF gain error value and outputs it to the IF delta-sigma DAC 303 and feeds it back to the delay AGC controller 304. The IF delta-sigma DAC 303 converts the output of the IF loop filter 302 into a 1-bit analog signal and outputs it to the IF AGC amplifier 122 as an IF AGC control signal.

The delay AGC controller 304 obtains a difference between a signal fed back from the IF loop filter 302 and a preset RF AGC reference signal and outputs the difference value as an RF gain error value to the RF loop filter 305. do. The RF loop filter 305 accumulates the RF gain error value and outputs the accumulated RF gain error value to the RF delta-sigma DAC 306. The RF delta-sigma DAC 306 converts the output of the RF loop filter 305 into a 1-bit analog signal and outputs it to the tuner 121 as an RF AGC control signal.

In this case, the update of the IF loop filter 302 and the RF loop filter 305 is determined by an AGC_freeze control signal output from the fast antenna scan control unit 210. That is, the high speed antenna scan control unit 210 outputs an AGC operation control signal AGC_freeze control signal in an inactive state when the average signal power value in the corresponding antenna direction is larger than a preset reference signal power detection range, thereby outputting the IF loop filter 302. ) And the RF loop filter 305. That is, the gain value of the IF AGC amplifier 122 is changed, for example, reduced.

If the average signal power value in the corresponding antenna direction is not greater than the preset reference signal power detection range, an AGC_freeze control signal in an active state is output to output the IF loop filter 302 and the RF loop filter 305. Do not update. That is, the gain value of the IF AGC amplifier 122 is fixed.

In addition, the high speed antenna scan control unit 210 determines the reset of the signal power detector 111.

5 is an operation flowchart illustrating an embodiment of a fast scan process of the fast antenna scan controller 210 according to the present invention.

That is, the antenna control system captures signal power at a certain angle (eg, -180 degrees, -90 degrees, 0 degrees, 90 degrees, 180 degrees) through a 360 degree antenna scan, among which the maximum signal power capture point Tracks the antenna direction of the optimal signal converged by the antenna direction tracking loop.

Next, a detailed operation of the high speed antenna scan control unit 210 and the operation of the IF loop filter 302 and the RF loop filter 305 to capture the signal of the antenna in each preset direction will be described with reference to FIGS. 2 to 5. Take a look.

First, the IF and RF loop filters 302 and 305 of the AGC unit 132 are set to constant initial values (step 501).

For example, the RF AGC control signal and the IF AGC control signal, which are gain control values of the AGC unit 132 when the received input signal is 60 dB, are set to initial values of the IF and RF loop filters 302 and 305. Since the initial value can be obtained empirically through experiment, the present invention will not be limited to the above-described embodiment.

When the initial value is set in the IF and RF loop filters 302 and 305, the fast antenna scan control unit 210 outputs an AGC operation control signal AGC_freeze control signal in an active state to the IF and RF loop filters 302 and 305 to tune the receiver. The gain of 121 and the IF AGC amplifier 122 are fixed. In this case, the gains of the tuner 121 and the IF AGC amplifier 122 of the receiver are fixed until the average signal power is larger than a preset reference signal power detection range.

In order to start a high speed scan for capturing a signal of the antenna at high speed (step 502), the high speed antenna scan control unit 210 outputs a reset signal to the signal power detector 111 to initialize the accumulator 402 (step). 503). That is, the high speed antenna scan control unit 210 resets the accumulator 402 for each preset angle, that is, the direction of each antenna.

Then, the signal power detector 111 obtains the average signal power by taking an absolute value or squared the absolute value for a predetermined period for the received signal digitized in the corresponding antenna direction, and dividing it by the cumulative period to obtain the average signal power. And the antenna direction tracking control unit 103-3 (step 504).

The fast antenna scan control unit 210 determines whether the signal power data input from the signal power detector 111 is larger than a preset reference signal power detection range (step 505).

In the present invention, the AGC unit 132 is converged to detect signal power information only when the average signal power is larger than a preset reference signal power detection range, thereby reducing signal power detection time and ensuring reliability. do. That is, in the prior art, the AGC unit 132 is converged in each antenna direction, and then signal power is detected with the information. However, in the present invention, the AGC unit 132 is applied only when the average signal power is larger than the preset reference signal power detection range. After convergence, the signal power information is detected, and when it is not large, the average signal power is used as it is.

Therefore, if the average signal power value is not greater than the preset reference signal power detection range in step 505, the average signal power value is compared with the previously stored maximum signal power value. The average signal power value is stored as the maximum signal power value only when the current average signal power value is larger than the previously stored maximum signal power value (step 506). That is, the maximum signal power value is updated. At this time, the antenna direction value corresponding to the average signal power value is also updated.

If the average signal power value is smaller than the previously stored maximum signal power value, the current average signal power value is discarded and the process of obtaining the average signal power for the next antenna direction is repeated.

6 is a diagram illustrating a signal power detection range and an operating principle of a fast antenna scan.

For example, assuming that the average signal power value output from the signal power detector 111 is the signal power value obtained in the received signal2 section, the average signal power value detected in the received signal0 section as the maximum signal power value is the antenna direction at this time. It is stored with the value. Since the average signal power value of the received signal 2 section is smaller than the average signal power value of the received signal 0 section, it is discarded without being stored.

Then, it is determined whether the antenna direction to be scanned remains (step 507). If it is determined that it remains, the next antenna direction is determined and the above-described operation is repeated to finally detect the maximum signal power value and the antenna direction value at this time. After that, output to the antenna direction tracking control unit 103-3.

On the other hand, if it is determined in step 505 that the average signal power value is larger than the preset reference signal power detection range, the previously stored maximum signal power value and the antenna direction value are initialized (step 508). That is, if it is determined that the average signal power value obtained in the current antenna direction is larger than the preset reference signal power detection range, the maximum signal power value previously stored is meaningless since it is the largest value among the signal power values thus far obtained.

In this case, the fast antenna scan control unit 210 converts the AGC operation control signal AGC_freeze control signal in the inactive state into an inactive state and outputs the result to the IF loop filter 302 and the RF loop filter 305 of the AGC unit 132. . That is, the AGC operation control signal AGC_freeze control signal in the active state stops the operation of the AGC unit 132 to fix the gain of the receiver, and the AGC operation control signal AGC_freeze control signal in the inactive state is the AGC unit 132. Operate to vary the gain of the receiver.

Accordingly, the fixed IF and RF loop filters 302 and 305 of the AGC unit 132 are reset to new values by the AGC free control signal in the inactive state.

That is, set the AGC gain to the new signal power detection range. For example, the IF and RF loop filters 302 and 305 of the AGC unit 132 are set to reduce the gain of the RF and IF signals in the tuner 121 and the IF AGC amplifier 122. In this case, the IF and RF loop filters 302 and 305 of the newly set AGC unit 132 are set according to the current antenna direction and the magnitude of the received signal.

Therefore, the RF AGC control signal and the IF AGC control signal output from the AGC unit 132 reduce the gains of the RF and IF signals in the tuner 121 and the IF AGC amplifier 122, thereby reducing the average signal power of the received signal. Set within the set detection range.

When the average signal power value of the received input signal falls within a preset signal power detection range, the fast antenna scan control unit 210 transmits the AGC operation control signal AGC_freeze control signal in the active state to the IF and the IF of the AGC unit 132. The RF loop filters 302 and 205 are output to the RF loop filters 302 and 205 to fix the IF and RF loop filter 302 and 305 values of the AGC unit 132 again.

For example, assuming that the average signal power value obtained in the current antenna direction through the signal power detector 111 is the average signal power value obtained in the received signal3 section, the maximum signal power value and antenna direction up to the received signal2 section are initialized. do. Subsequently, when the average signal power value of the received signal falls within the preset signal power detection range in the received signal3 section by AGC gain adjustment, the average signal power value is stored as the maximum signal power value. In addition, the antenna direction value at this time is also stored.

Then, it is determined whether the antenna direction to be scanned remains, and if it is determined to remain, the next antenna direction is determined and the above-described operation is repeated. That is, the average signal power value is detected in the received signal 4 section, and then compared with the maximum signal power value detected and stored in the received signal 3 section. At this time, since the average signal power value obtained in the received signal4 section is larger than the average signal power value obtained in the received signal3 section, the maximum signal power value of the previously received signal3 section is updated with the average signal power value obtained in the received signal4 section. The antenna direction information of the received signal 3 section is also updated with the antenna direction information of the received signal 4 section.

Then, if there is no antenna direction to be scanned, that is, if all the predetermined antenna directions have been scanned, the maximum signal power value detected and stored in the received signal section 4 and the antenna direction information at this time are output to the antenna direction tracking control unit 103-3.

As described above, the present invention detects the maximum signal power information for the magnitudes of all the input signals within the input range of the receiver by automatically adjusting the signal power detection range by sensing the magnitude of the input signal. In addition, when the magnitude of the input signal is detected and the signal power detection range is exceeded, the AGC unit 132 is controlled to newly set an appropriate signal power detection range, thereby shortening the signal power detection time and improving reliability.

In addition, the present invention is applicable to the field of wireless communication to which a smart antenna is applied, such as a VSB type digital broadcast receiver.

On the other hand, the terms used in the present invention (terminology) are terms defined in consideration of the functions in the present invention may vary according to the intention or practice of those skilled in the art, the definitions are the overall contents of the present invention It should be based on.

In addition, since the present invention has been described through the preferred embodiment of the present invention, in view of the technical difficulty aspects of the present invention, those having ordinary skill in the art can easily and other embodiments of the present invention. Other variations can be made. Therefore, it is apparent that all of the embodiments and variations cited in the above description belong to the claims of the present invention.

As described above, the method for controlling the digital broadcast receiver and the smart antenna for receiving the digital TV according to the present invention has the following advantages.

First, by detecting the signal power from the input signal in a state where the gain of the AGC unit is fixed, the detection time can be reduced by the convergence time of the AGC unit.

Second, when the signal power detection range is sensed from the magnitude of the input signal and is out of the preset reference signal power detection range, a new signal power detection range may be set, thereby improving reliability of the signal power information.

Third, since the existing antenna scan controller is extended, the separate hardware cost does not increase significantly.

Fourthly, all the control sections can be configured digitally, so it is easy to make a single chip and increase the density of the system.                     

Those skilled in the art will appreciate that various changes and modifications can be made without departing from the spirit of the present invention.

Therefore, the technical scope of the present invention should not be limited to the contents described in the embodiments, but should be defined by the claims.

Claims (12)

Smart antenna system to configure the antenna pattern that is optimal for signal reception by adjusting the smart antenna according to the antenna control signal; Only a specific RF signal of the RF signal received through the smart antenna system is converted into an IF signal, the gain of the tuned RF signal is adjusted according to the RF gain control signal, and the gain of the IF signal is adjusted according to the IF gain control signal. Analog front end adjusting; An AGC unit which obtains an IF gain error and an RF gain error from the received signal output from the analog front end, generates an RF gain control signal and an IF gain control signal, respectively, and outputs them to the analog front end; And Signal power is obtained for each preset antenna direction from the received signal output from the analog front end to detect the antenna direction of the maximum signal power, and then output to the smart antenna system as an antenna control signal. And an antenna controller configured to change the RF gain control signal and the IF gain control signal of the AGC unit when the value is out of a preset reference signal power detection range and to fix the specific signal to a specific value. Digital broadcast receiver. The method of claim 1, wherein the antenna controller A signal power detector for detecting a signal power value in a specific antenna direction from the received signal output from the analog front end; When the signal power value of the specific antenna direction obtained by the signal power detector is out of a preset reference signal power detection range, the AGC unit is controlled to vary the gain of the RF signal and the gain of the IF signal, and then the gain of the RF and IF signals. And a high-speed antenna scan control unit configured to update the signal power value to the maximum signal power value together with the antenna direction value at this time when the signal power value in the corresponding antenna direction is within the reference signal power detection range. Broadcast receiver. 3. The signal power detector of claim 2, wherein the signal power detector is And taking an absolute value by digitizing the received signal output from the analog front end, accumulating the absolute value for a predetermined period, and then dividing the absolute value into an accumulated period to detect an average signal power. 3. The signal power detector of claim 2, wherein the signal power detector is And digitizing the received signal output from the analog front end, taking a square, accumulating the squared value for a predetermined period, and then dividing the squared signal into the accumulated interval to detect average signal power. The method of claim 2, wherein the fast antenna scan control unit And resetting the signal power detector for each antenna direction. The method of claim 2, wherein the fast antenna scan control unit If the signal power value of the specific antenna direction obtained by the signal power detector does not deviate from the preset reference signal power detection range, the AGC unit is controlled to continuously fix the RF signal gain and the IF signal gain to a specific value. And updating the signal power value with the corresponding antenna direction value to the maximum signal power value only when the stored maximum signal power value is larger than the stored maximum signal power value. The method of claim 1, wherein the AGC unit An AGC error detector for digitizing a received signal output from the analog front end to obtain an IF gain error value; An IF loop filter for determining whether to update by the control of the fast antenna scan control unit and accumulating the IF gain error value; An IF delta-sigma digital-to-analog converter (DAC) for converting the IF gain error values accumulated in the IF loop filter into analog signals of 1 bit and outputting them as IF gain control signals to the analog front end; A delay AGC controller for obtaining an RF gain error value from a signal fed back from the IF loop filter; An RF loop filter for determining whether to update by the control of the fast antenna scan control unit and accumulating the RF gain error value; And an RF delta-sigma DAC configured to convert the RF gain error values accumulated in the RF loop filter into 1-bit analog signals and output the RF gain control signals to the analog front end as RF gain control signals. The method of claim 7, wherein the fast antenna scan control unit And updating the IF and RF loop filters so that the RF signal gain and the IF signal gain are reduced when the signal power value is out of a preset reference signal power detection range in a specific antenna direction. (a) adjusting an smart antenna according to an antenna control signal to configure an antenna pattern optimal for signal reception; (b) tuning only a specific RF signal among the RF signals received through step (a) to adjust the gain of the RF signal and converting it into an IF signal, and then adjusting and amplifying the gain of the IF signal; (c) obtaining signal power in a corresponding antenna direction from the received signal output in step (a) and determining whether it is out of a preset reference signal power detection range; (d) If it is determined in step (c) that the reference signal power detection range is not exceeded, the gain of the RF signal and the gain of the IF signal are kept fixed to a specific value, and the signal power value is larger than the pre-stored maximum signal power value. Updating the signal power value to the maximum signal power value with a corresponding antenna direction value; (e) If it is determined in step (c) that it is out of the reference signal power detection range, the gain of the RF signal and the gain of the IF signal are varied, and the signal power value in the corresponding antenna direction is changed by the gain variation of the RF and IF signals. If the reference signal is within the detection range of power, including the step of updating the signal power value to the maximum signal power value with the antenna direction value, And repeating the above-described steps for each preset antenna direction to detect the antenna direction of the maximum signal power, and outputting the antenna control signal in step (a). The method of claim 9, wherein step (c) And taking an absolute value by digitizing the received signal, accumulating the absolute value for a predetermined period, and then dividing the absolute value into the accumulated interval to detect the average signal power. The method of claim 9, wherein step (c) A method of controlling a digital antenna for digital broadcast reception, comprising: digitizing a received signal, taking a square, and accumulating the squared value for a predetermined period, and then dividing the squared signal into an accumulated period to detect average signal power. The method of claim 9, wherein step (e) And if the signal power value is determined to be out of the reference signal power detection range in step (c), reducing the gain of the RF signal and the gain of the IF signal.

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