KR101576680B1 - Audio system for vehicle and method for playing radio signal thereof - Google Patents

Abstract

The present application discloses a vehicle audio system having a radio unit for receiving analog / digital radio broadcasting and outputting information on whether or not to extract an HD (Hybrid Digital) radio signal, and a radio signal reproducing method therefor. The vehicle audio system may further include: an amplifying unit for amplifying an audio signal output from the radio unit; a speaker for outputting an audio signal amplified by the amplifying unit; And a control unit for operating the variable equalizer provided in the amplifying unit in one of a digital mode and an analog mode if the signal is an HD mixed radio signal and operating the variable equalizer in a digital exclusive mode if the received radio signal is an HD- . Thus, when receiving an HD mixed radio, it is possible to provide an optimal sound quality state in the case of a digital radio signal as well as an analog radio signal.

Vehicle, HD, Radio, Variable, Equalizer

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention [0001] The present invention relates to a vehicle audio system,

The present invention relates to a vehicle audio system, and more particularly, to a method of reproducing a radio signal of a vehicle audio system having a radio receiving unit.

HD (Hybrid Digital) radio broadcasting is a high-quality radio broadcasting which is commercialized in North America and implemented free of high-quality broadcasting through the existing analog network. HD radio receivers are portable, household, and automotive.

In the existing radio service, FM and AM radio broadcasting systems, we focused on providing clear sound quality to the users by limiting the low frequency and high frequency of the sound according to the characteristics of each broadcasting in order to ensure clean sound quality even in various electric field conditions. HD Radio is a hybrid digital radio broadcasting that has the function of automatically switching analog broadcasting and digital broadcasting according to the receiving electric field.

In the conventional FM and AM radio broadcasts, only one broadcast is transmitted to one frequency of the broadcast frequency. In the HD radio broadcast, three broadcasts (HD1, HD2, HD3) can be transmitted to one frequency. Among the three broadcasts, the HD1 broadcast is the mixed digital broadcast, and the HD2 and HD3 broadcasts the HD-only radio broadcast.

Conventional analog FM (Frequency Modulation) and AM (Analog Modulation) broadcasts are limited by using the EQ (EQualizer) function of DSP (Digital Signal Processing) to minimize the high frequency noise in the weak electronic system, It is basic to output sound quality. HD radio broadcasting provides much higher frequency information than conventional analog broadcasting, so that it can listen to high quality music.

However, as the HD radio service started, existing analog broadcasting and digital broadcasting were mixed. In the processing of the existing analog broadcasting signal, the high-band broadcasting signal is limited, so that the high-quality HD radio broadcasting can be properly reproduced There is no problem. In order to solve this problem, when the function of limiting the high frequency by using the EQ function is eliminated, there is a problem that the analog broadcasting has noise.

Therefore, a method for normally reproducing the HD radio broadcasting is required.

An object of the present invention is to provide a method for reproducing a radio signal of a vehicle audio system capable of reproducing not only analog radio signals but also HD radio signals with high quality when receiving HD mixed radio in a vehicle audio system.

According to an embodiment of the present invention, there is provided a vehicle audio system including a radio unit for receiving analog / digital radio broadcasting and outputting information on whether to extract an HD radio signal, the system comprising: an amplifier for amplifying an audio signal output from the radio unit; A speaker for outputting an audio signal amplified by the amplification unit, a variable equalizer provided in the amplification unit when the received radio signal is an HD mixed radio signal based on the HD radio signal extraction information of the radio unit, And a controller for operating the variable equalizer in a digital only mode if the received radio signal is an HD-only radio signal.

According to another embodiment of the present invention, there is provided a method of reproducing a radio signal in a vehicle audio system, the method comprising: receiving a radio signal and outputting information on whether to extract an HD radio signal; Extracting a radio signal based on information on whether or not to extract the radio part, if the received radio signal is an HD mixed radio signal, operating the variable equalizer in one of a digital mode and an analog mode, and if the received radio signal is an HD- And operating the variable equalizer in a digital only mode.

With the following configuration, it is possible to reproduce digital radio signals as well as analog radio broadcasts in high quality when receiving HD mixed radio in a vehicle audio system.

Various embodiments of the present invention will now be described in detail with reference to the accompanying drawings. In the following description, a detailed description of known functions and configurations will be omitted when it is unnecessary to obscure the gist of the present invention.

According to the present invention, in order to optimize the sound quality of the HD radio, a variable equalizer for adjusting the audio signal is provided in the digital signal processing unit. In the HD1 broadcast, which is a mixed broadcast of digital radio and analog radio, And the digital equalizer mode is switched. In the digital private radio broadcasting HD2,3, the audio mode of the radio signal is tuned by dividing it into independent modes distinguishable from other audio modes, thereby providing high quality radio broadcasting to the user.

To this end, it is determined whether the received radio broadcast is analog or digital, so that the operation mode of the variable equalizer provided in the digital signal processing unit is changed in real time to suppress noise in the case of conventional analog broadcasting, Lt; / RTI >

Hereinafter, embodiments of the present invention will be described in detail with reference to FIGS. 1 to 7. FIG. FIG. 1 shows a configuration of a vehicle audio system to which the present invention is applied, FIG. 2 shows an internal configuration of the amplifying unit of FIG. 1, and FIG. 3 shows an internal configuration of the digital signal processing unit of FIG.

1, the vehicle audio system includes a sound source generating section including a CD player 40 and an external sound source reproducing apparatus 50, a radio section 10 for receiving analog / digital radio broadcasting, a sound source generating section An amplifier 20 for amplifying an audio signal output from the radio unit 10, a speaker 30 for outputting an audio signal amplified by the amplification unit 20 by sound, A CAN (Control Area Network) communication unit 70 for communication with the amplification unit 20, and a control unit 80 for controlling the respective components.

The radio unit 10 includes an RF receiving unit 11, an HD radio signal extracting unit 12, an IF (intermediate frequency) processing unit 13, and a radio and audio processing unit 14 for receiving a radio signal through an antenna. The radio unit 10 determines whether the radio signal has a digital signal and whether the digital signal is valid, and determines whether the received radio signal is an HD-only radio signal, an HD mixed radio signal, or an analog radio signal .

The HD radio signal extraction unit 12 provides the HD radio reception information to the control unit 80 when the HD radio signal is extracted.

The radio and audio processing unit 14 receives a control signal generated by the control unit 80 according to an operation of a radio user operation unit not shown and performs a radio channel change function and the like.

The control unit 80 generates HD radio signal reception information or analog radio signal reception information according to whether the HD radio signal is extracted from the radio signal received by the RF receiving unit 11. [

2, the amplifying unit 20 includes a digital signal processing unit 21 for receiving and processing a S / PDIF (Sony / Philips Digital Interconnect Format) signal, which is a digitized audio signal, a digital signal processing unit 21 for converting a digital audio signal into an analog audio signal A DAC (Digital Analog Converter) 22 for converting an analog signal, an audio amplifier 23 for amplifying an analog signal, a memory 24, and a microcomputer 25 for controlling each component.

The memory unit 24 includes a flash ROM for storing a code for the control process of the microcomputer 25 and a parameter for setting the digital signal processor 21 and a RAM do.

The microcomputer 25 converts the variable equalizer provided in the digital signal processing unit 21 into an analog sound quality mode (analog equalizer) or a digital sound quality mode (analog equalizer) based on the HD radio signal reception information or analog audio signal reception information provided from the control unit 80 (Digital equalizer) and HD-only sound quality mode (digital only equalizer).

As shown in FIG. 3, the digital signal processing unit 21 includes a volume unit 211 for adjusting the volume of the audio volume, a loudness unit 212 for enhancing the output of the low and high frequency bands, A front equalizer 215 for adjusting an audio signal outputted to a front speaker installed in front of the vehicle, a speaker equalizer 215 for adjusting the audio signal output from the front speaker, A tweeter equalizer 217 for outputting high-pitched audio, and a center speaker installed in the middle of the vehicle. The lane equalizer 216 adjusts an audio signal output to a rear speaker, A center equalizer 218 for adjusting the audio signal, a sub woofer equalizer 219 for increasing the bass of the audio signal, and an audio signal size outputted from each of the equalizers 215 to 219 Bow includes a variable equalizer 220, a limiter 221 for adjusting the sound so that it will not distort.

The speaker output position adjustment unit 214 functions to set a speaker to output an audio signal among a plurality of speakers including a front speaker, a rear speaker, a tweeter speaker for outputting a treble signal, and a sub-woofer speaker for outputting a low sound.

The variable equalizer 220 is a block added according to the present invention and adjusts an audio signal by adjusting a center frequency, a frequency bandwidth, and a gain, and operates in one of an HD sound quality mode, a digital sound quality mode, and an analog sound quality mode do. According to one embodiment, the variable equalizer 220 includes a high-pass filter and a low-pass filter. By setting whether a high-pass filter and a low-pass filter are operated, only a mid-range radio signal is output, or a low-, mid-, All of them can be outputted. For example, in the case of an analog radio signal, both the high-pass filter and the low-pass filter of the variable equalizer 220 are set to 'ON' in order to limit the low and high frequencies so that only the mid-range radio signal is output. In the case of the HD mixed radio signal or the HD exclusive radio signal, the 'on' setting is canceled so that the high-pass filter and the low-pass filter of the variable equalizer 220 do not operate so as to pass both the low and high frequencies. Particularly, in the case of an HD mixed radio signal, since the analog broadcast signal and the digital broadcast signal change from time to time, the setting of the high-pass filter and the low-pass filter must be changed from time to time.

Hereinafter, a process of controlling the amplifying unit 20 for optimizing and outputting sound quality both in receiving the HD radio signal and in receiving the analog radio signal according to the present invention will be described.

FIG. 4 is a flowchart illustrating a method of reproducing a radio signal of a vehicle audio system according to an exemplary embodiment of the present invention. FIG. 5 is a frequency graph illustrating a sound quality tuning state of an analog FM broadcast in which a low frequency band and a high frequency band are limited using a variable equalizer FIG. 6 is a frequency graph showing a sound quality tuning state of an analog / digital hybrid radio broadcasting using a variable equalizer according to the present invention, and FIG. 7 is a graph showing a sound quality tuning state of an HD radio broadcasting using a variable equalizer It is the frequency graph shown.

As shown in FIG. 4, a radio signal is received at the RF receiver 11 of the radio unit 10 of the vehicle audio system (S1). The HD radio signal extracting unit 12 of the radio unit 10 extracts the HD radio signal (S2). When the HD radio signal is extracted, the HD radio signal is provided to the control unit 80, and the control unit 80 recognizes that the signal is the HD radio signal. The control unit 80 checks whether the received HD radio signal is an HD-only radio signal or an HD mixed radio signal in which an HD radio signal and an analog radio signal are mixed, and if the signal is an HD mixed radio signal or an HD- Mixed radio signal or HD-only radio signal reception information to the microcomputer 25 of the amplification unit 20 via the antenna.

The microcomputer 25 of the amplifying unit 20 determines whether the HD radio signal is an HD mixed radio signal, whether it is an analog radio signal or a digital radio signal (S4). If the HD radio signal is an HD mixed radio signal, the microcomputer 25 operates the variable equalizer 220 in an analog sound quality mode (S5). If the digital radio signal is a digital radio signal, the variable equalizer 220 of the digital signal processing unit 21 is operated in the digital sound quality mode (S6).

When the HD radio signal extracting unit 12 extracts the HD radio signal and recognizes that the radio signal received by the RF receiving unit 11 is the analog radio signal, the control unit 80 controls the amplification And transmits the analog radio signal information to the microcomputer 25 of the unit 20. The microcomputer 25 of the amplifying unit 20 operates the variable equalizer 220 of the digital signal processing unit 21 in the analog sound quality mode (S5).

The frequency graph of FIG. 5 shows a state in which sound quality is improved by limiting the low and high frequencies by the variable equalizer 220 as a sound quality tuning state of analog radio (FM) broadcasting when the variable equalizer 220 is operated in the analog sound quality mode Respectively. When receiving analog radio (FM) broadcasting, the sound quality can be improved by lowering the low-frequency range and the high-frequency range in order to remove the noise of the phonetic indicator.

6, when the variable equalizer 220 is operated in the digital sound quality mode, the variable frequency equalizer 220 is switched to the analog sound quality mode or the digital sound quality mode according to whether the received radio signal is an analog radio broadcast or a digital mixed radio broadcast And the sound quality is improved.

On the other hand, if the received radio signal is an HD-only radio signal, the control unit 80 provides the HD exclusive radio signal to the microcomputer 25 of the amplifying unit 20 via the CAN communication unit 80. The microcomputer 25 operates the variable equalizer 220 of the digital signal processing unit 21 in the HD sound quality mode (S7). Referring to FIG. 7, in the HD2 and HD3 modes, it is possible to receive broadcasts in a high quality state when switching modes separately from HD1. In the HD-only radio mode, the high-pass filter and the low-pass filter of the variable equalizer are set to change the operation setting value so that the whole band is output without attenuation and high quality is maintained.

With this configuration, it is possible to provide the optimum sound quality by automatically converting the variable equalizer 220 in real time at the time of analog and digital automatic switching at the time of reception of a mixed HD radio broadcast using analog and digital. When an HD radio broadcast is received, the equalizer in the case of the analog radio broadcasting and the equalizer in the case of the digital radio broadcasting can be real-time converted to provide the optimum sound quality state.

While the present invention has been particularly shown and described with reference to exemplary embodiments thereof, it is evident that many alternatives, modifications and variations will be apparent to those skilled in the art. It is understandable. Accordingly, the true scope of the present invention should be determined by the appended claims.

1 is a diagram showing a configuration of a vehicle audio system to which the present invention is applied.

FIG. 2 is a diagram showing an internal configuration of the amplification unit of FIG. 1; FIG.

FIG. 3 is a diagram showing an internal configuration of the digital signal processing unit of FIG. 2. FIG.

4 is a flowchart of a method of reproducing a radio signal of a vehicle audio system according to an embodiment.

FIG. 5 is a frequency graph showing a state in which sound quality is tuned by limiting low and high frequencies of analog radio broadcasting using a variable equalizer in HD hybrid broadcasting.

6 is a frequency graph showing a state in which a sound quality of a digital radio broadcast is tuned by using a variable equalizer in an HD hybrid broadcast.

7 is a frequency graph showing the sound quality tuning state in HD-only radio broadcasting.

DESCRIPTION OF THE REFERENCE NUMERALS

10: Radio section 11: RF receiving section

12: HD radio signal extracting unit

13: IF processing unit 14: radio and audio processing unit

20: amplifying unit 21: digital audio signal processor

22: DAC 23: Audio amplifier section

25: Micom 30: Speaker

40: audio reproducing unit 60: memory unit

70: CAN communication unit 80:

211: volume unit 212: loudness unit

213: Tone section 214: Speaker output position setting section

220: Variable equalizer

Claims (7)

1. A vehicle audio system having a radio unit receiving an analog / digital radio broadcast and outputting information on whether or not to extract an HD radio signal, An amplifier for amplifying an audio signal output from the radio unit, A speaker for outputting an audio signal amplified by the amplifying unit by a sound, Wherein the control unit operates the variable equalizer provided in the amplification unit in one of a digital mode and an analog mode if the received radio signal is an HD mixed radio signal based on the HD radio signal extraction information of the radio unit, And if so, operating the variable equalizer in a digital only mode. The method according to claim 1, The radio unit includes an RF receiving unit for receiving a radio signal through an antenna, an HD radio signal extracting unit for extracting an HD radio signal from the received radio signal, an IF processing unit, a radio and an audio processing unit, The CAN communication unit is connected to the control unit. When receiving the HD radio signal extraction signal from the radio unit, the control unit confirms whether the signal is an HD mixed radio signal or an HD exclusive radio signal, and controls the amplification unit through the CAN communication unit. Audio system. 3. The method of claim 2, The amplifying unit includes a digital signal processing unit for receiving and processing the S / PDIF signal, which is a digitized audio signal, and the radio signal received from the radio unit, a DAC for converting the digital audio signal output from the digital signal processing unit into an analog audio signal, An audio amplifier unit for amplifying a signal, a memory unit, and a microcomputer for controlling each component unit. 3. The method of claim 2, The control unit determines whether the received radio signal is an HD radio signal or an analog radio signal based on the HD radio signal extraction information of the HD radio extracting unit to form HD radio reception information or analog radio reception information To the microcomputer of the amplifying unit through the CAN communication unit. The method of claim 3, The digital signal processing unit includes a volume unit for adjusting the volume of the audio volume, a loudness unit for enhancing the output of the low and high frequencies, a tone unit for adjusting the height of the sound, a speaker output position control unit, A car audio system, including a speaker equalizer, a rear speaker equalizer, a tweeter equalizer, a center speaker equalizer, a sub woofer equalizer, a variable equalizer, . The method of claim 3, Wherein the microcomputer operates the variable equalizer provided in the digital signal processing unit for analog or digital based on the HD radio signal reception information or analog radio signal reception information from the control unit. A radio signal reproducing method for a vehicle audio system having a radio unit receiving an analog / digital radio broadcast and outputting information on whether to extract an HD radio signal, Receiving the radio signal and extracting the HD radio signal; If the received radio signal is an HD mixed radio signal, operating the variable equalizer in one of a digital mode and an analog mode based on information on whether or not to extract the radio portion, and if the received radio signal is an HD- The method comprising the steps of: receiving a radio signal from a vehicle audio system;

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