KR100713454B1 - Method and Apparatus For controlling Gain to detect Transmitter indicator information signal - Google Patents

Abstract

In a digital broadcast receiving system, a gain control apparatus includes a receiving circuit for receiving an input signal from an antenna, obtaining TII (Transmitter Indicator Information) detection section information, and NULL section information from the received input signal. A receiving circuit in a TII detection section according to the TII detection section information by using a broadcast signal receiver, a demodulator for demodulating the received input signal to restore broadcast information, and using the TII detection section information and the NULL section information. A gain control unit configured to set a gain value used in a gain mode of the gain mode to a value higher than a gain value before a NULL section according to the NULL section information, and perform gain control. The terrestrial DMB of Korea and DAB of Europe In an area where cell areas of multiple base stations intersect in a digital broadcasting reception system that is applicable to There is an effect that it is possible by the large base station the signal for reducing the detection does not find a number of other small base station TII signal.

Gain controlling, transmitter indicator information (TTI)

Description

Method and apparatus for controlling gain for detecting transmission indicator information signal {Method and Apparatus For controlling Gain to detect Transmitter indicator information signal}

1 is a diagram showing a basic receiver system for broadcasting a general Korean terrestrial DMB and a European DAB.

2 is a view illustrating a NULL section information signal for an AGC controller of the DAB received input signal.

3 is a view showing an area where cell regions of a plurality of base stations intersect according to the prior art;

4 shows the structure of a receiver system according to a preferred embodiment of the present invention.

5 shows a TII detection signal according to a preferred embodiment of the present invention.

6 is a flow chart according to a preferred embodiment of the present invention.

The present invention relates to a digital broadcasting reception system applied to both terrestrial digital multimedia broadcasting (DMB) in Korea and digital audio broadcasting (DAB) in Europe. The present invention relates to a TII (Transmitter indicator information) in an area where cell regions of a plurality of base stations cross each other. signal) A method and apparatus for automatic gain control (AGC) for signal detection.

TII refers to information of a base station and is used to inform which base station a receiver receives a signal from. It is transmitted through a synchronization channel to distinguish each transmitter in a single frequency network (SFN). It is a signal.

FIG. 1 is a diagram illustrating a basic receiver system for broadcasting a general Korean terrestrial DMB and a European DAB.

Referring to FIG. 1, a receiver system includes an RF receiving circuit 101, A digital analog conveter (DAC) / pulse width modulation (PWM) 102, a TII detector 103, a DAB receiver 105, an AGC controller 107, and a DAB decoder 108 are included.

The RF receiving circuit 101 is composed of a low noise amplifier (LNA) + MIXER 101a at the front stage and an Amp 101b at the rear stage. The RF receiving circuit 101 receives an input signal and transmits the input signal to the TII detector 103 and the DAB receiver 105.

The TII detector 103 detects a TII signal from the input signal, and the DAB receiver 105 obtains the NULL section information appearing at a predetermined interval from the input signal and transmits it to the AGC 107.

The AGC controller 107 adjusts the gain in the form of adjusting the gain mode of the low noise amplifier (LNA) + MIXER 101a and finely adjusting the gain of the Amp 101b. Herein, the gain mode of the LNA + MIXER 101 may simply mean ON / OFF of the LNA, and may include a structure having multiple levels by combining LNA, multi-stage AMP, MIXER, and the like.

The AGC controller 102 maintains the gain mode of the LNA + MIXER 101a and the gain of the rear stage AMP 101b at a value before the NULL section for a predetermined time including the detected NULL section. make someone do. This is to avoid distortion of the signal after the NULL section by AGC control during the NULL section.

2 is a diagram illustrating a general DAB signal.

Referring to FIG. 2, there is a NULL section 201 of a predetermined interval among DAB signals. TII signal is transmitted during the NULL period.

The TII detector 103 detects a TII signal transmitted on a specific subcarrier of a NULL symbol in a frame of the input signal. The base station ID detector output can be applied by applying CAS for terrestrial DMB, in addition to detecting information of the base station received by the receiver. For these various purposes, the detection of TII signals from multiple base stations is very important in areas where cell regions of multiple base stations intersect.

In the conventional receiver system as shown in FIG. 2, in the areas 1 and 2 where cell areas of a plurality of base stations intersect, the AGC controller 107 is adapted to the size of the largest base station signal among the received signals. Adjust the gain of (101). Specifically, since the AGC controller is to fix the gain mode of the LNA + MIXER 101a and the gain value of the AMP 101b to a value before the NULL section, the AGC controller can sufficiently detect the TII signal of another base station. Even when, there was a problem that it is difficult to detect the TII signal of another base station.

Accordingly, an object of the present invention, which was devised to solve the problems of the prior art operating as described above, is TII of several different base stations having a sufficiently detectable signal size in a region where cell regions of a plurality of base stations intersect. It is to provide AGC algorithm that can effectively detect signal.

An apparatus according to an embodiment of the present invention, which is invented to achieve the above object, includes a receiving circuit for receiving an input signal from an antenna and a gain circuit in a digital broadcast receiving system. Transmitter Indicator Information (TII) detection section information, the broadcast signal receiver for obtaining NULL section information, a demodulator for demodulating the received input signal to restore broadcast information, and the TII detection section information and NULL section information. Gain by performing gain control by setting the gain value used in the gain of the receiving circuit in the TII detection section according to the TII detection section information to a value higher than the gain value before the NULL section according to the NULL section information. Characterized in that it comprises a control unit.

In a method according to an embodiment of the present invention, in a digital broadcast reception system, a gain control method includes receiving an input signal from an antenna, obtaining TII detection interval information and NULL interval information from the received input signal. Restoring the broadcast information by receiving the received input; and using the obtained TII detection section information and the NULL section information, gain of the high frequency receiving circuit in the acquired TII detection section, to the NULL section. It is characterized in that it consists of a process of performing gain control by setting a value higher by a predetermined size to the value before the NULL section according to the information.

Hereinafter, with reference to the accompanying drawings will be described in detail the operating principle of the preferred embodiment of the present invention. Like reference numerals are used to designate like elements even though they are shown in different drawings, and detailed descriptions of related well-known functions or configurations are not required to describe the present invention. If it is determined that it can be blurred, the detailed description thereof will be omitted. Terms to be described later are terms defined in consideration of functions in the present invention, and may be changed according to intentions or customs of users or operators. Therefore, the definition should be made based on the contents throughout the specification.

3 is a diagram illustrating a region where cell regions of a plurality of base stations cross each other according to the related art.

Referring to FIG. 3, there is a region 1 301 where the cell regions of the transmitter A and the transmitter C intersect, and an area 2 302 where the cell regions of the transmitter A and the transmitter B intersect.

In the conventional basic receiver system as shown in FIG. 2, in areas 1,2 (301 and 302) in which cell areas of a plurality of base stations intersect, the AGC controller 107 is adapted to the size of the largest base station signal among the received signals. The GAIN MODE of the LNA + MIXER 101a and the GAIN 101b of the AMP in the rear stage are adjusted. This is a basic method in the single frequency network (SFN) for broadcasting of terrestrial DMB in Korea and DAB in Europe, but it may not be effective for detecting TII signals.

That is, basically, the TII signal may be transmitted in a NULL section. In this case, the AGC controller 107 may adjust the LNA + MIXER 101a of the RF receiving circuit 101 according to the magnitude of the largest base station signal among the received signals. The gain mode of and the gain value of the AMP 101b of the rear stage are fixed to the value before a NULL section.

Therefore, when the AGC controller 107 is not fixed to the previous value, it is difficult to detect the TII signal of another base station even in a situation where the TII signal of other base stations can be sufficiently detected.

As an example, assume that the power of the signal of the largest base station is large and the LNA is turned off in the gain mode of the LNA + MIXER 101a to sufficiently detect the broadcast signal. At this time, if a signal close to a noise level that is difficult to detect when a signal of another base station does not turn on the LNA, the TII detector 103 can be clearly distinguished from noise when the signal of the other base station is turned on. Even in the case of a signal having a possible size, it is difficult to detect a TII signal thereto.

Accordingly, in the present invention, the TII detection interval information is acquired, and in the NULL interval in which the TII signal can be detected, the gain of the AGC fixed to be maintained as the signal before the NULL interval is detected during the interval in which the TII signal can be detected. We propose an AGC algorithm that can amplify the gain and detect TII signals of other base stations of relatively small magnitude. That is, the AGC controller does not fix the gain mode of the LNA + MIXER of the RF receiver circuit and the gain value of the AMP in the rear stage to the value before the NULL section during the TII detection section received from the DAB receiver, and according to the NULL section information. Set the value higher than the previous gain value.

4 is a structure of a receiver system according to a preferred embodiment of the present invention.

Referring to FIG. 4, the receiver system includes an RF receiver circuit 401, a DAC / PWM 402, a TII section gain control unit 403, a TII detector 405, a DAB receiver 407, and an AGC controller ( 408 and a DMB decoder 409.

The RF receiver circuit 401 is composed of an LNA + MIXER 401a at the front end and an AMP 401b at the rear end to receive an input signal from the antenna 400 to receive a TII detector 405 and a DAB receiver 407. To pass.

The TII detector 405 obtains TII detection interval information from the received input signal and transmits the TII detection interval information to the AGC controller 408.

The DAB receiver 407 obtains NULL section information from the received input signal and transfers the NULL section information to the AGC controller 408.

The AGC controller 408 uses the obtained TII detection section information and the NULL section information in the NULL section except for the TII detection section according to the highest base station signal before the NULL section in the same manner as before. Fix the gain mode and gain.

Next, in the obtained TII detection section, the AGC controller 408 detects the received TII by using the TII section gain control section 403 to obtain a gain mode to the LNA + MIXER 401a of the RF receiving circuit 401. Implement to export the value of register that is set to high value in advance. In addition, the TII interval gain control unit 403 exports the gain value of the AMP 401b during the TII detection interval to the value of a register that is set to a high value in advance, similar to the LNA + MIXER 401a, or the NULL interval. Implement to export by adding a certain value to the previous value to make it larger than the previous value.

That is, the AGC controller 408 increases the size of the signal during the received TII detection interval and detects TII because the TII signal itself uses the ON / OFF KEYING modulation method even when the signal has the largest size. Will not affect.

5 is a DAB signal according to a preferred embodiment of the present invention.

Referring to FIG. 5, the NULL section information 501 is NULL section information detected from the DAB signal received by the RF circuit receiver 401. Since the TII detection section information 503 is included smaller than the NULL section information 501, it is possible to avoid distortion of the signal after the NULL section.

Specifically, the signal of the largest base station is a situation in which the power is large so that the LNA is turned off in the gain mode to the LNA + MIXER 401 of the RF receiver circuit 401 and the broadcast signal is sufficiently detected. Assume that a signal is coming close to a noise level that is difficult to detect in a situation where ON is not turned on. In this case, since the AGC controller 408 operates the TII section gain control unit 403 to turn on the LNA by the value of the register set to a high value in advance during the TII detection interval, the TII detector 405 The TII signal of another base station can be detected through the gain value controlled by the TII interval gain control unit 403.

6 is a flowchart of a receiver system according to a preferred embodiment of the present invention.

Referring to FIG. 6, in step 601, the AGC controller receives NULL section information and TII detection section information of the received DAB signal.

In step 603, the AGC controller determines whether the current section is within the received NULL section and the received TII section. If the current section is not the TII detection section, the AGC controller controls the gain according to the largest signal value among base station signals received before the NULL section in the gain and gain mode of the RF receiving circuit in step 607.

As a result of the checking, if the current section is the TII detection section, in step 605, the AGC controller adjusts the gain mode of the LNA / Mixer of the RF receiver circuit and the gain of the AMP to a value preset to a high value during the TII section.

The TII detector can then detect the TII signal for multiple base stations using the gain adjusted to the preset value.

Meanwhile, in the detailed description of the present invention, specific embodiments have been described, but various modifications are possible without departing from the scope of the present invention. Therefore, the scope of the present invention should not be limited to the described embodiments, but should be defined not only by the scope of the following claims, but also by those equivalent to the scope of the claims.

In the present invention operating as described in detail above, the effects obtained by the representative ones of the disclosed inventions will be briefly described as follows.

According to the present invention, in a digital broadcasting receiver system applied to both a terrestrial DMB in Korea and a DAB in Europe, several small base station TII signals differed by the largest base station signal for the detection of the TII signal in a region where cell regions of a plurality of base stations intersect There is an effect that can reduce the case that can not find.

Claims (9)

In a digital broadcast receiving system, in a gain control device, A receiving circuit for receiving an input signal from an antenna, A broadcast signal receiver for obtaining transmitter indicator information (TII) detection section information and NULL section information from the received input signal; A demodulator for demodulating the received input signal to restore broadcast information; A gain value used in a gain mode of the receiving circuit in a TII detection section according to the TII detection section information, using the TII detection section information and the NULL section information, and a gain value before a NULL section according to the NULL section information. And a gain controller configured to set a higher value to perform gain control. The method of claim 1, wherein the high frequency reception circuit, A gain control device comprising a low noise amplifier (LNA) at the front and a mixer and an amplifier at the rear. The method of claim 1, wherein the gain control unit, A gain control device configured to set a gain value of a low noise amplifier (LNA) and a mixer constituting the receiving circuit and a gain value of the amplifier in the TII detection interval to a value higher than a gain value before the NULL period; . delete The method of claim 1, wherein the TII detection interval, Gain control apparatus, characterized in that included in the NULL interval. In a digital broadcast receiving system, in a gain control method, Receiving an input signal from an antenna, Obtaining TII detection section information and NULL section information from the received input signal; Restoring broadcast information by receiving the received input; By using the TII detection section information and the NULL section information, the gain value of the receiving circuit is set to a higher value than the gain value before the NULL section according to the NULL section information in the TII detection section according to the TII detection section information. Gain control method comprising the steps of performing gain control. The method of claim 6, wherein performing the gain control comprises: And adding the gain value used in the gain mode to a gain value before the NULL section according to the TII detection interval information by a predetermined value to make it larger than a previous value and outputting the larger gain value. delete The method of claim 6, wherein the TII detection interval, Gain control method, characterized in that included in the NULL interval.

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