KR20010097838A - Wireless transmitting and receiving device using fm broadcasting frequency for mp3 player and pc sound card - Google Patents

Abstract

The present invention relates to a wireless transceiver for an MP3 player and a PC sound card using the FM broadcast frequency band. The present invention provides an apparatus for transmitting / receiving a sound source using an FM broadcast frequency band, wherein a sound source wirelessly transmitted at an FM broadcast frequency by a wireless microphone, a wireless transceiver for a mobile phone, or the like is reproduced through an amplifier and a speaker of an audio device equipped with an FM broadcast receiver. In this respect, the conventional technology is similar to the conventional technology, but the conventional technology has a disadvantage in that it is a mono system using only one channel because the main function is message transmission through voice transmission, whereas the present invention is because the sound source is composed of stereo or four channels. The transmission and reception method is also a stereo or four-channel method, there is an excellent advantage that the amount of data transmitted and received is more than the mono method and the sound quality is not comparable with the mono method.

Description

WIRELESS TRANSMITTING AND RECEIVING DEVICE USING FM BROADCASTING FREQUENCY FOR MP3 PLAYER AND PC SOUND CARD}

The present invention relates to a wireless transceiver for an MP3 player and a PC sound card using the FM broadcast frequency band.

Recently, with the rapid spread of cultural life, there is a tendency to enjoy music in more various ways, better sound quality and convenient way.

Examples of this trend include MP3 players and PC sound cards.

However, when using an existing MP3 player (including both a portable or a vehicle in the form of a terminal) has the following disadvantages.

(1) If you want to listen to music, you have to connect the main body and earphones or headphones by wire. (2) If you want to listen to music output from MP3 player through other audio, The line-outs of the MP3 player must be wired to each other.

In addition, when using a conventional PC sound card has the following disadvantages.

(1) If you want to listen to music, you have to connect the sound card and earphone or headphone and speaker by wire. (2) If you want to listen to sound card music through other audio, the line-in provided in the audio. The line-out stage of the stage and sound card must be connected by wire.

Therefore, the present invention has been made to improve such a conventional problem, as well as not connecting the earphones or headphones worn by the user to the MP3 player body or PC sound card by wire, as well as the line of MP3 player and PC sound card It is an object of the present invention to provide a wireless transceiver for an MP3 player and a PC sound card that can listen to music without a wired connection between the -out stage and the audio line-in stage.

1A, 1B and 1C are schematic views showing a structure in which a wireless transmitter can be attached, detached, and connected to a main body according to an embodiment of the present invention.

2 is a block diagram of a stereo transmitter according to an exemplary embodiment of the present invention.

3 is a block diagram illustrating a stereo receiver according to an embodiment of the present invention.

4 is a configuration block diagram for performing MP3 decoding according to an embodiment of the present invention.

5 is a block diagram illustrating a four-channel transmitter according to an embodiment of the present invention.

6 is a diagram illustrating a signal input and output state of FIG. 4.

Explanation of symbols on the main parts of the drawings

2 ------ Micom 4 ------ D / A converter

5, 6 --- amplifier 7, 8 --- switching part

9 ------ Oscillation part 10 ----- Dispensing part

11 ----- Mixer 12 ----- Main Oscillator

13 ----- Modulator 14 ----- Frequency multiplier

15, 18, 20-filter 16 ------ transmit antenna

17 ----- Receive Antenna 19 ----- Resonant Circuit

21 ----- Intermediate Frequency 23 ----- Speaker

In order to achieve the above object, a wireless transmitter / receiver for an MP3 player and a PC sound card according to the present invention includes a wireless transmitter and a wireless receiver, and the transmitter is configured to read and read digital audio files stored in a storage device. A microcomputer that decodes the digital audio file in a format to be in an original waveform format and transmits the restored digital audio stream according to a predetermined standard; A D / A converter for converting the digital audio stream input from the microcomputer into an analog signal to be output as a Line out R, Line out L signal (Front R, Front L, Rear R, Rear L in case of 4 channels); An amplifier for amplifying the line out R, line out L (Front R, Front L, Rear R, RearL) signals at a predetermined level in order to increase the signal-to-noise ratio (S / N ratio) during modulation; An oscillator for generating a predetermined clock frequency to control a switching unit composed of an analog switch, and generating a predetermined clock frequency having a different phase for each switching unit; The switching unit is configured of an analog switch, and receives a predetermined clock frequency having a different phase, and connects when the clock is high level, and repeats the blocking operation when it is low level; A divider for dividing a predetermined clock frequency input from an oscillator for generating a clock frequency to generate a predetermined pilot signal; A mixer which mixes one modulation signal generated while passing through each switching unit with a predetermined pilot signal; A main oscillator for generating a basic carrier; A modulator for generating a fundamental modulated wave by a frequency modulation method based on a modulated signal input through a mixer and a fundamental carrier input from a main oscillator; A frequency multiplier for amplifying the modulated wave of the fundamental frequency output from the modulator several times up to the frequency of the modulated wave to be used for actual transmission several times; A filter unit for generating only a modulated wave to be finally transmitted by filtering only a frequency to be used for transmission from a modulated wave input from the frequency divider; And a transmission antenna for radiating the modulated wave inputted from the filter unit to the space in the form of electromagnetic wave,

The receiving end comprises: a receiving antenna which selects only a radio wave of a desired frequency among radio waves propagating in the air and inputs it to the receiving unit; A filter unit for filtering only signals in a frequency band used for transmission among modulated waves inputted through a reception antenna; A resonant circuit unit generating the same frequency as the modulated wave to synchronize with the modulated wave input from the filter unit; A secondary filter unit for attenuating the received modulated wave to a predetermined frequency; An intermediate frequency break for recovering the original sound source signal from the predetermined frequency signal; An amplifier for amplifying to reproduce an original stereo or four channel signal input from the intermediate frequency terminal; And a speaker for converting the amplified sound source input from the amplifier into sound that can be heard through the human ear.

MP3 player body is characterized in that the removable slot is formed so that the radio transmitter can be detached as needed.

The transmitter is a detachable type which is detachable to the MP3 player main body, a built-in type and an independent terminal device which is built in the main body, and has a line-in end and is configured as one of the connected types so that it can be used by connecting the line-out end of the main body with a cable. It is done.

The receiver is manufactured as a separate terminal device to wirelessly receive the radio wave transmitted from the transmitter while the user wears it on the ear.

In the wireless transmission and reception apparatus for an MP3 player and a PC sound card using the FM broadcasting frequency band according to the present invention having the above characteristics, the FM broadcasting receiver includes a sound source transmitted at an FM broadcasting frequency by a wireless microphone, a wireless transceiver for a mobile phone, or the like. While similar to the conventional technology in that the sound source is reproduced through the amplifier and the speaker of a conventional audio device, the conventional technology has a disadvantage in that it is a mono method using only one channel because the main function is a message transmission through voice transmission. According to the present invention, since the sound source is composed of stereo or four channels, the transmission and reception method is also a stereo or four channel method, and the amount of data transmitted and received is superior to the mono method, and the sound quality is also incomparably improved with the mono method.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings.

1A, 1B and 1C are schematic views showing a structure in which a wireless transmitter is detachable, embedded and connected to a main body according to an embodiment of the present invention, and FIG. 2 is a block diagram of a stereo transmitter according to an embodiment of the present invention. 3 is a block diagram illustrating a stereo receiver according to an embodiment of the present invention, FIG. 4 is a block diagram illustrating MP3 decoding according to an embodiment of the present invention, and FIG. 5 is a block diagram illustrating another embodiment according to another embodiment of the present invention. 6 is a block diagram illustrating a signal input and output state of FIG. 4.

As shown in FIG. 1A, the main body 30 of the MP3 player is provided with a detachable slot 32 having a depth to which the transmitter 31 is inserted so that the transmitter 31 for transmitting music according to the FM broadcast frequency can be detached. do. This slot 32 is just an example and can be implemented in a variety of ways.

As shown in FIG. 1B, the transmitter 31 may be configured in a built-in manner in which the main body 30 is onboard, or as an independent terminal having a line-in end 36 as shown in FIG. 1C. The line-in end 36 may be manufactured by connecting the line-out end 35 and the cable 37 provided in the main body 30.

The receiver 33 capable of wirelessly receiving the radio wave transmitted from the transmitter 31 is manufactured as a separate terminal device so that the user can wear it on the ear so that it can be used more conveniently than the wire.

In addition, in order to wirelessly transmit and receive a stereo or four-channel sound source, it is necessary to use a modulation and demodulation method that is different from the conventional modulation and the modulation method used in a wireless microphone and a wireless transceiver for a mobile phone. The modulation unit 100, which is an element, is configured to enable stereo or 4-channel modulation instead of mono modulation, and the intermediate frequency terminal 21, which is a component of the receiver of FIG. 3, is stereo or 4-channel instead of mono demodulation. Configure to enable demodulation.

The transmitter shown in FIG. 2 includes a storage device 1, a microcomputer 2, a D / A converter 4, an amplifier 5, 6, a switch 7, 8, an oscillator 9, and a minute. The main part 10, the mixer 11, the main oscillator 12, the modulator 13, the frequency multiplier 14, the filter 15 and the transmission antenna 16.

The receiving end shown in FIG. 3 is composed of a receiving antenna 17, a filter 18, a resonant circuit 19, a secondary filter 20, an intermediate frequency end 21, an amplifier 22 and a speaker 23. .

Referring to the operation of the wireless transceiver of the present invention configured as described above is as follows.

First, the microcomputer 2 configured at the transmitting end of FIG. 2 reads a digital audio file (for example, MP3, WMA, AAC, etc.) stored in the existing storage device 1. In this case, the digital audio format may be various formats.

Thereafter, the microcomputer 2 decodes digital audio files of various formats read from the storage device 1 so as to be in an original waveform format, and converts the restored digital audio stream into a D / A converter according to a predetermined standard. 4) to transmit.

At this time, decoding is performed using a different decoding library according to each format, and this signal is a digital audio stream as a stereo or four channel stream.

The D / A converter 4 modulates the digital audio stream input from the microcomputer 2 into an analog signal to output line out R and line out L signals (Front R, Front L, Rear R, Rear L in the case of 4 channels). Is output to each amplifier (AMP) 5 (6). In this case, the signal is an amplified signal which is the same as the output form of the line-out terminal of general audio and is an analog signal of stereo or 4 channels.

The Line out R, Line out L (Front R, Front L, Rear R, Rear L) signals pass through amplifiers 5 and 6 to increase the signal-to-noise ratio (S / N ratio) during modulation. Up to 10 times or more.

In this state, the oscillation unit 9 generates a clock frequency of 38 KHz (96 KHz for four channels) to control the switching units 7 and 8 composed of analog switches, and to each of the switching units 7 and 8. It generates clock frequency of 38KHz (96KHz for 4 channels) with different phases.

The switching unit (7) (8) is composed of an analog switch, and receives a clock frequency of 38KHz (96KHz for four channels) of different phases, the connection when the clock is high level, and the operation to cut off when the low level Repeat. That is, the modulation signals R and L are 38KHz (96KHz in the case of 4 channels), which are combined into one modulation signal by repeating connection and disconnection operations.

Subsequently, the divider 10 divides a clock frequency of 38 KHz (96 KHz for 4 channels) input from the oscillator 9 generating the clock frequency to generate a pilot signal of 19 KHz (38 KHz for 4 channels), respectively. The mixer 11 performs an operation of mixing one modulated signal generated while passing through the switching unit 7 and 8 with a pilot signal of 19 KHz (38 KHz in the case of 4 channels).

In such a state, the main oscillator 12 generates a basic carrier and inputs it to the modulator 13, and the modulator 13 inputs the modulated signal input through the mixer 11 and the basic inputted from the main oscillator 12. A fundamental modulated wave is generated by a frequency modulation method based on a carrier wave.

The modulated wave of the fundamental frequency output from the modulator 13 is amplified by the frequency multiplier 14 several times up to the frequency of the modulated wave to be used for actual transmission. Here, since the frequency multiplier 14 uses the FM broadcast frequency band, the finally amplified modulated wave is within the FM broadcast frequency band.

Thereafter, the filter unit 15 filters only the frequencies to be used for transmission from the modulated wave input from the frequency divider 14 to generate a modulated wave to be finally transmitted, and transmits the modulated wave input from the filter unit 15 to a transmission antenna ( 16) it radiates into space in the form of electromagnetic waves.

Next, the receiver shown in FIG. 3 recognizes a pilot signal of 19 KHz (38 KHz in the case of four channels) generated by the transmitter of FIG. 2 and determines whether the modulated signal is mono, stereo, or four channels. That is, the presence or absence of the pilot signal is a criterion for determining whether the transmitted signal is mono or stereo, and the criterion for determining whether the pilot signal is 19 KHz or 38 KHz is stereo and 4 channels.

First, the reception antenna 17 selects only the radio wave of the desired frequency radiated through the antenna 16 from the radio wave propagating through the air and inputs it to the receiver, and transmits to the transmission of the modulated wave input through the reception antenna 17. Only the signal of the used frequency band is filtered by the filter unit 18. In this case, the receiver is set in advance so that only the signal of the modulated wave used for transmission can be received.

After that, the resonant circuit unit 19 generates the same frequency as the modulated wave for synchronization with the modulated wave input from the filter unit 18, and the secondary filter unit 20 attenuates the received modulated wave to 10.7 MHz. do.

Accordingly, the intermediate frequency stage IF stage 21 recovers the original sound source signal from the 10.7 MHz signal attenuated by the secondary filter unit 20 and inputs it to the amplifier 22. In other words, the pilot signal is detected by the modulated wave to determine whether the channel is mono, stereo, or 4, and then reconstructed accordingly.

The amplifier 22 amplifies to a predetermined level and reproduces the original stereo or four-channel signal input from the intermediate frequency terminal 21 to the speaker 23, and the speaker 23 is input from the amplifier 22. The amplified sound source is converted into sound that can be heard through the human ear. The reconstructed sound represents the effect of stereo or four channels.

FIG. 4 illustrates a decoding apparatus of an MP3 player according to the present invention, in which a microcomputer 25 reads digital audio files of various formats stored in a conventional storage device 26 and decodes them in a synchronous serial manner. 27, the decoder 27 decodes the digital bit stream input from the microcomputer 25, restores the original digital file, and then decodes the LRCK signal (Fig. 6B) and the signal width of 128 clocks shown in Fig. 6A. The CLOCK signal (FIG. 6C) and the data signal (FIG. 6D) are transmitted to the D / A converter 28. FIG. Accordingly, the D / A converter 28 converts the signal input from the decoder 27 into an analog signal and outputs the left and right signals.

Basically, MP3 file is encoded from wave file, and wave file is modulated by Pulse Code Modulation (PCM). It is a digital audio file composed of sampling frequency 44K and quantization 16bit.

MP3 files are obtained using wave files as the source, sampling frequency of 8KHz ~ 44KHz, quantization of 8 ~ 16bit, but the technique that does not damage the original sound during sampling, i.e. parts that cannot be recognized by the human ear (for example, treble) By selecting and sampling the bass just behind, etc., it is almost same as the original sound by sampling and removing. In this case, there is a compression effect of about 10 to 12 times.

One MP3 file consists of several frames, and one frame structure consists of a header, compressed data and auxiliary data of the first 128 bits.

5 is another embodiment of the present invention, since the transmitting end is composed of four channels, only the number of channels is increased, and the operation of other components is the same, and thus a detailed description thereof will be omitted.

Although the present invention has been described with reference to specific examples as described above, the present invention is not limited thereto, and modifications and variations may be made within the technical scope of the present invention.

According to the wireless transceiver for MP3 and PC sound card of the present invention as described above has the advantage that can be eliminated the following disadvantages.

In other words, the connected transmitter and receiver are manufactured as independent devices and applied to an existing sound card, and the wireless card is wirelessly output from the user by wearing a wireless receiver to the user's ear while the transmitter is connected to the line-out terminal of the sound card. I can listen to music. In addition, since the transmitter uses the FM broadcast frequency band, music output from the audio provided with the FM broadcast receiver and reproduced on a PC can be wirelessly heard through the audio amplifier and the speaker.

In addition, by applying the present invention to the MP3 player and PC sound card, the following inconvenience can be eliminated.

That is, in order to listen to music of an existing MP3 player, the main body and earphones or headphones must be connected by wire, but according to the present invention, a detachable type that can be detached and detached from the main body of the MP3 player, a built-in type built into the main body, and connected to the main body The transmitter is configured as a connection type, and the sound source signal is transmitted and received to enable stereo or 4-channel wireless communication using the FM broadcasting frequency band while wearing a receiver such as a wireless earphone or a headphone manufactured as an independent terminal device. Can solve the inconvenience caused by.

In addition, in order to listen to music of an existing MP3 player through other audio, it is possible only after connecting the line-in stage provided in the audio and the line-out stage provided in the MP3 player with each other by wire, but according to the present invention, MP3 By transmitting the music played on the main body to the FM broadcasting frequency by using a detachable, built-in and connection type transmitter to the main body of the player, it is possible to listen to music through the amplifier and speaker of the audio device set according to the frequency. have.

In addition, if you want to listen to music using the existing sound card must be connected to the sound card and earphones or headphones and speakers by wire, according to the invention the wireless transmitter is connected to the line-out terminal of the sound card and the earphone or By using a wireless receiver of the headphone type, the user can conveniently enjoy music because the user can conveniently exchange the sound signal of the stereo or 4 channel method of the FM broadcasting frequency band.

In addition, when the music of the existing sound card is to be heard through other audio, it is possible only after connecting the line-in end of the audio and the line-out end of the sound card to each other by wire, but according to the present invention By transmitting the music played on the PC to the FM broadcast frequency with the transmitter connected to the line-out of the card, there is an advantage that the music can be heard through the amplifier and the speaker of the audio device set to the frequency.

Such a feature could be applied to car audio, general home or commercial audio that does not have an MP3 player.

Claims (4)

Consists of a transmitter terminal and a receiver terminal of a separate terminal device type combined with the MP3 player body and PC sound card, The transmitting end, A microcomputer that reads digital audio files related to music stored in a storage device, software decodes the digital audio files of various formats into an original waveform format, and transmits the restored digital audio streams according to a predetermined standard; A D / A converter for converting the digital audio stream input from the microcomputer into an analog signal to be output as a Line out R, Line out L signal (Front R, Front L, Rear R, Rear L in case of 4 channels); An amplifier for amplifying the line out R, line out L (Front R, Front L, Rear R, Rear L) signals to increase the signal-to-noise ratio (S / N ratio) during modulation; An oscillator for generating a predetermined clock frequency to control a switching unit composed of an analog switch, and generating a predetermined clock frequency having a different phase for each switching unit; The switching unit is configured of an analog switch, and receives a predetermined clock frequency having a different phase, and connects when the clock is high level, and repeats the blocking operation when it is low level; A divider for dividing a predetermined clock frequency input from an oscillator for generating a clock frequency to generate a predetermined pilot signal; A mixer which mixes one modulation signal generated while passing through each switching unit with a predetermined pilot signal; A main oscillator for generating a basic carrier; A modulator for generating a fundamental modulated wave by a frequency modulation method based on a modulated signal input through a mixer and a fundamental carrier input from a main oscillator; A frequency multiplier for amplifying the modulated wave of the fundamental frequency output from the modulator several times up to the frequency of the modulated wave to be used for actual transmission several times; A filter unit for generating only a modulated wave to be finally transmitted by filtering only a frequency to be used for transmission from a modulated wave input from the frequency divider; And a transmission antenna for radiating the modulated wave inputted from the filter unit to the space in the form of electromagnetic wave, The receiving end, A receiving antenna which selects only a radio wave of a desired frequency radiated from an antenna of a transmitting end among radio waves propagating in the air and inputs it to a receiving unit; A filter unit for filtering only signals in a frequency band used for transmission among modulated waves inputted through a reception antenna; A resonant circuit unit generating the same frequency as the modulated wave to synchronize with the modulated wave input from the filter unit; A secondary filter unit for attenuating the received modulated wave to a predetermined frequency; An intermediate frequency break for recovering the original sound source signal from the predetermined frequency signal; An amplifier for amplifying to a predetermined level to reproduce an original stereo or four channel signal input from the intermediate frequency terminal; And a speaker configured to convert the amplified sound source input from the amplifier into a sound that can be heard through a human ear. The MP3 player body of claim 1, wherein a detachable slot is formed in the MP3 player body so that the wireless transmitter is detachable. The apparatus of claim 1, wherein the transmitter is a detachable type that is detachable to an MP3 player body, a built-in type, and an independent terminal device that is embedded in the main body, and has a line-in end, and is connected to a line-out end of the main body to be used by a cable. Wireless transmitter for MP3 player and PC sound card, characterized in that consisting of any one of the type. The wireless receiver of claim 1, wherein the receiver is manufactured as a separate terminal device to wirelessly receive a radio wave transmitted from a transmitter while the user wears it on an ear.