KR20110062071A

KR20110062071A - Apparatus and method for controlling automatic gain of radio receiver

Info

Publication number: KR20110062071A
Application number: KR1020090118655A
Authority: KR
Inventors: 조상호
Original assignee: 현대모비스 주식회사
Priority date: 2009-12-02
Filing date: 2009-12-02
Publication date: 2011-06-10

Abstract

PURPOSE: An automatic gain controller of a radio receiver and method thereof are provided to reduce the intensity of an RF signal and to minimize the inflow of radio interference broadcast component. CONSTITUTION: A level detecting unit(2) detects the electric field level of an intermediate frequency signal. An attenuation control unit(3) compares the electric field level of the intermediate frequency signal with the electric field level of high frequency. The attenuation control unit decides the inflow of the radio interference broadcast component. If so, the attenuation control unit outputs an attenuation control signal.

Description

APPARATUS AND METHOD FOR CONTROLLING AUTOMATIC GAIN OF RADIO RECEIVER}

The present invention relates to an apparatus and method for automatic gain control of a radio receiver, and more particularly, to an apparatus and method for automatic gain control of a radio receiver for minimizing the influx of interference broadcasts under a strong electric field environment so as to smoothly listen to a desired broadcast. It is about.

In-car radio receivers provide the ability to listen to radio broadcasts in a car. Such a vehicle radio receiver is provided in a car audio system provided in an automobile.

Such a vehicle radio receiver includes an automatic gain control device that adjusts an RF amplification rate according to the strength of an RF signal input from an antenna.

The automatic gain control device adjusts the strength of the RF signal by lowering the amplification gain of the RF signal with one attenuation circuit when the RF signal input from the antenna is too large.

The technical structure described above is a background technique for assisting the understanding of the present invention, and does not mean the prior art widely known in the technical field to which the present invention belongs.

Since the automatic gain control device lowers the amplification gain of the RF signal with one attenuation circuit, there is a limit in properly lowering the RF signal input under the strong electric field environment, and thus there is a problem that the interference broadcast is introduced.

Accordingly, an object of the present invention is to provide an automatic gain control apparatus of a radio receiver capable of smoothly listening to a desired broadcast by minimizing the influx of interference broadcasts by further lowering the strength of an RF signal in a strong electric field environment.

The configuration of the present invention, which is invented to achieve the above-described object, is as follows.

An automatic gain control apparatus of a radio receiver according to the present invention includes a digital signal processor for outputting an IF signal by adjusting the amplification gain of the RF signal according to the strength of the RF signal, a level detector for detecting an electric field level of the IF signal; An attenuation control unit for comparing the electric field level of the IF signal with an electric field level of a high frequency among all broadcasting frequencies to determine the influx of interference broadcasting components, and outputting an attenuation control signal if it is determined that the interference broadcasting components are inflow; And an attenuator for attenuating the RF signal according to the signal.

In the present invention, the attenuation control unit is characterized in that it is determined that the interference broadcasting component inflow if there is a high frequency component equal to the electric field level of the IF signal in the frequency of the electric field level of the entire broadcast frequency.

In the present invention, the attenuator attenuates the RF signal input from the antenna in accordance with the attenuation control signal and outputs to the low noise amplifier, and the attenuation control signal attenuated the RF signal output from the low noise amplifier in accordance with the attenuation control signal And an external attenuator for outputting the signal to the signal processor.

In addition, the automatic gain control method of the radio receiver according to the present invention comprises the steps of detecting the level of the IF signal output from the digital signal processing unit, determining whether the interference broadcasting component is introduced into the electric field level of the IF signal, And attenuating the strength of the RF signal input to the digital signal processor according to the determination result.

In the present invention, the step of determining whether the interference broadcast component is introduced, characterized in that the high frequency component equal to the electric field level of the IF signal in the frequency of the electric field level of all the broadcast frequency, characterized in that it is determined as the interference broadcasting component inflow.

As described above, the present invention further reduces the strength of the RF signal in a strong electric field environment, thereby minimizing the influx of interference broadcasts so that the desired broadcast can be listened to smoothly.

Hereinafter, the present invention will be described in more detail with reference to Examples. These embodiments are only for illustrating the present invention, and the scope of rights of the present invention is not limited by these embodiments.

In this process, the thickness of the lines or the size of the components shown in the drawings may be exaggerated for clarity and convenience of description. In addition, the terms described below are defined in consideration of the functions of the present invention, which may vary depending on the intention or custom of the user, the operator. Therefore, definitions of these terms should be made based on the contents throughout the specification.

1 is a view for explaining the configuration of an automatic gain control apparatus of a radio receiver according to an embodiment of the present invention.

Referring to FIG. 1, the automatic gain control apparatus of the radio receiver according to the present embodiment includes a digital signal processor 1, a level detector 2, an attenuation control unit 3, and an attenuation unit 4.

The digital signal processor 1 outputs an IF signal by adjusting the amplification gain of the RF signal according to the strength of the RF signal input through the antenna 5.

The digital signal processor 1 includes an internal attenuator 11, an input tuner 12, an RF amplifier 13, an inter-stage tuner 14, a mixer 15, an AGC detector 16 and an oscillator ( 17), IF amplifier 18 and IF filter 19 are included.

Here, the internal attenuator 11 attenuates the strength of the RF signal under the control of the AGC detector 16, the input tuning unit 12 passes a predetermined band of the RF signal, and the RF amplifier 13 The RF signal is amplified by the control unit of the AGC detection unit 16, and the inter-terminal tuning unit 14 passes a predetermined band among the RF signals from the RF amplifying unit 13.

The oscillator 17 generates an oscillation signal corresponding to the selected channel, and the mixer 15 mixes the RF signal from the inter-stage tuning unit 14 and the oscillation signal corresponding to the selected channel to download the RF signal as an IF signal. In converting, the AGC detector 16 controls the internal attenuator 11 and the RF amplifier 13 according to the strength of the RF signal to adjust the strength of the RF signal.

The IF amplifier 18 amplifies the down-converted IF signal, and the IF filter 19 filters the IF signal from the IF amplifier 18.

When the strength of the input RF signal is large, the AGC detector 16 detects this and controls the internal attenuator 11 and the RF amplifier 13 to reduce the strength of the RF signal. Adjust

The level detector 2 detects the level of the IF signal output from the digital signal processor 1.

The attenuation control unit 3 receives the level of the IF signal detected by the level detection unit 2, and determines the influx of the interference broadcast component by comparing the electric field level among all the broadcast frequencies. Output the signal.

The attenuation control unit 3 determines whether the broadcast frequencies f1, f2, f3, f4, f5, and f6 having a high electric field level among all broadcast frequencies have a high probability of being congested at the present broadcast frequency fd. The interference component broadcast discrimination is determined as the inflow of the interference broadcast component if there is a high frequency component equal to the broadcast frequency fd at the frequencies f1, f2, f3, f4, f5, and f6.

In other words, if it is determined that neighboring broadcasts f1 to f6 having a high electric field level in addition to the main broadcast fd are likely to be disturbed (if it is determined that influx of mixed components is introduced, for example, 2xf1-f2 = fd), By attenuating the RF signal to the input signal to minimize interference.

For example, when fd = 2 × f1-f2 among the broadcast frequencies having a high electric field level among all broadcast frequencies, it is determined that frequencies f1 and f2 include a hybrid broadcast component, that is, a high frequency component, to be interferenced in the present broadcast fd.

If it is determined that inflow of the broadcast component is suppressed, the attenuator 4 is controlled to further lower the strength of the RF signal to suppress the influx of the interference broadcast.

The attenuation part 4 attenuates the RF signal according to the attenuation control signal of the attenuation control part 3.

The attenuator 4 attenuates the RF signal input from the antenna 5 according to the attenuation control signal and outputs the attenuator 41 to the low noise amplifier 42 and the low noise amplifier 42 according to the attenuation control signal. And an external attenuator 43 for attenuating the RF signal output from the signal and outputting the attenuated RF signal to the signal processor 1.

As described above, the present invention further reduces the strength of the RF signal under the strong electric field environment, thereby minimizing the influx of the interference broadcast, so that the desired broadcast can be listened to smoothly.

2 is a flowchart illustrating an automatic gain control method of a radio receiver according to an embodiment of the present invention.

2, in the automatic gain control method of the radio receiver according to the present embodiment, first, the level of the IF signal output from the digital signal processor 1 is detected through the level detector 2 (S1).

Then, the electric field level of the IF signal detected by the level detector 2 is compared with the frequency of the electric field level among all the broadcasting frequencies to determine whether the interference broadcast frequency is introduced.

The interference broadcasting frequency discrimination is performed by calculating the broadcasting frequencies f1, f2, f3, f4, f5, and f6 having a high electric field level among all broadcasting frequencies, and determining that the interference broadcasting component is introduced (S3).

If it is determined that the interference broadcast frequency is introduced to the attenuator 4 outputs the attenuation control signal to attenuate the RF signal (S4). That is, the RF signal input from the antenna 5 is attenuated in accordance with the attenuation control signal, and the RF signal output from the low noise amplifier 42 is attenuated and outputted to the signal processor 1.

In summary, the present invention adjusts the amplification gain of the RF signal through the signal processing unit 1 to adjust the strength of the RF signal, and additionally compares the electric field level of the IF signal with a frequency with a high electric field level among all broadcasting frequencies to prevent interference. If it is determined that the broadcast is introduced, the intensity of the RF signal input to the signal processing unit 1 is further attenuated to suppress the influx of the interference broadcast.

As described above, the present invention has been described with reference to the embodiments shown in the drawings, but this is merely exemplary, and various modifications and equivalent other embodiments of the present invention may be made by those skilled in the art. I understand that it is possible. Therefore, the true technical protection scope of the present invention will be defined by the claims below.

1 digital signal processor 2 level detector

3: attenuation control section 4: attenuation section

11: internal attenuator 12: input tuning unit

13: RF amplification unit 14: inter-stage tuning unit

15 mixer section 16 AGC detection section

17: oscillator 17 17: IF amplifier

19: IF filter 41: antenna attenuator

42: low noise amplifier 43: external attenuator

Claims

A digital signal processor for controlling an amplification gain of the RF signal according to the strength of the RF signal and outputting an IF signal;

A level detector detecting an electric field level of the IF signal;

An attenuation control unit for comparing the electric field level of the IF signal with the electric field level of the high frequency of all the broadcasting frequencies to determine the influx of the interference broadcasting component, and outputting an attenuation control signal if it is determined that the interference broadcasting component is inflow; And

And an attenuator for attenuating the RF signal according to the attenuation control signal.

The method of claim 1, wherein the attenuation control unit

And a high frequency component equal to the electric field level of the IF signal at a frequency having a high electric field level among all broadcasting frequencies, determining that the interference broadcasting component is introduced.

The method of claim 1, wherein the attenuation portion

An antenna attenuator for attenuating the RF signal input from the antenna according to the attenuation control signal and outputting the attenuated signal to a low noise amplifier; And

And an external attenuator for attenuating the RF signal output from the low noise amplifier according to the attenuation control signal and outputting the attenuated control signal to the signal processor.

Detecting a level of an IF signal output from the digital signal processor;

Determining whether an interference broadcasting component is introduced into an electric field level of the IF signal; And

And attenuating the strength of the RF signal input to the digital signal processor according to the determination result.

The method of claim 4, wherein the determining whether the interference broadcasting component is introduced

And a high frequency component equal to the electric field level of the IF signal at a frequency having a high electric field level among all broadcasting frequencies, determining that an interference broadcasting component is introduced.