KR20090117156A - The apparatus and method of trasmission and reception to conference - Google Patents

Abstract

PURPOSE: A transceiver for a conference having an audio mixing function in a short distance as using an ISM band multi-channel frequency and a method thereof are provided to transmit a voice signal without error or noise by selecting the voice signal of a speaker transmitted from one of plural cordless headsets. CONSTITUTION: A PWM power control unit(110) controls the power based on a PWM scheme. The first ISM(Industrial Scientific Medical) band receiver(130) receives a voice signal of a speaker from a signal input unit(120), and selectively passes signals of a desired channel which are transmitted from plural cordless headsets. The first ISM band transmitter(140) receives binary digital data of the voice signal from the first ISM band receiver, and then transmits the processed voice signal to the cordless headsets according to a channel.

Description

TECHNICAL FIELD OF THE INVENTION Conference and reception apparatus having a near-audio mixing function using an ISSM band multi-channel frequency

The present invention is connected to one side of the meeting room electronics (audio device, laptop, TV, PC) to the user using a plurality of wireless headsets by using a single wireless terminal for each channel to select the words spoken wirelessly in the ISM band In order to be able to hear the wireless terminal, the PWM power control unit (PWM POWER & BAT CONTROL), the signal input unit (Signal_Input), the first ISM band receiver (RX), the first ISM band transmitter (TX), the controller (MCU), The present invention relates to a conference transmitter and receiver having an audio mixing function in a short distance using an ISM band multi-channel frequency composed of a keypad control unit.

In general, a remote voice conferencing device is a device (hereinafter, referred to as a "conference telephone device") that allows a large number of geographically dispersed people to have a conference call as if they were gathered together in one place. It is common in the world to use the term 'conference call' or 'tele-conference'.

However, most conference telephone devices currently on the market connect only to a public switched telephone network (PSTN) or a voice over internet network (VoIP Network) to connect only to an internet network (IP network).

In practice, however, the actual meeting is usually conducted between the internal personnel connected to the IP network and the external personnel connected to the PSTN network.

Currently, although the teleconferencing device using voice over internet network (VoIP) has a standard specification defined, it is implemented by applying different standards according to each seller in actual implementation, so that devices having different standards are used. Many difficulties arise in the work.

On the other hand, if you look at the general type of meeting using the teleconference device, many related departments attend the meeting because there may be questions about what the representative does not know during the meeting. There was a problem that wasted time only.

In addition, most conference telephone apparatuses presently have a problem in that internal conference participants hear and talk to external conference counterparts.

In order to solve this problem, in Korean Patent No. 10-0791097, the dongle outputs a radio, a headset for transmitting the user's voice signal to the dongle, the dongle key signal for toggling the transmission and reception mode according to the user's operation It is composed of a PTT key device for transmitting to the dongle, the headset and the FT key device has been proposed a remote fitness device and hands-free communication system using Bluetooth for short-range wireless communication using Bluetooth ,

This enables 1: 1 communication between a portable radio and a headset.However, when a voice signal transmitted from a specific headset among a plurality of headsets is transmitted back to the plurality of headsets through a single portable radio, not only the interference of peripheral devices is provided but also the channel environment. In addition, the distortion was severe, there was a problem that the quality of the signal is reduced.

In addition, when communicating between the portable radio and the headset, a lot of power is consumed there was a problem that must be supplied with a separate battery charger.

In order to solve the above problems, the present invention can select a voice signal of a speaker transmitted from a specific wireless headset among a plurality of wireless headsets through one conference terminal, transmit the error signal without error and noise, and transmit and receive at low power. An object of the present invention is to provide a conference terminal having an audio mixing function in a short range using ISM band multi-channel frequency.

In order to solve the above problems, a conference transmitter / receiver having an audio mixing function at a short range using an ISM band multi-channel frequency according to the present invention,

For meetings that can be connected to one side of conference room electronics (audio device, laptop, TV, PC), and users who use multiple wireless headsets can talk and listen to the speech wirelessly in the ISM band by selecting each channel through one terminal. In the terminal,

The conference terminal is a PWM power control unit (PWM POWER & BAT CONTROL) to control the power in a PWM method to prevent unnecessary power use to use for a long time after charging,

A signal input unit (Signal_Input) which selects and receives only a voice signal of a specific channel output according to the operation of a voice key provided at one side of the wireless headset, and transmits it to the ISM band receiving unit RX;

After receiving the speaker's voice signal from the signal input unit, it amplifies low-noise, performs frequency down-conversion, moves the signal to a low frequency band, and selects only signals of desired channels transmitted from a plurality of radio headsets. A first ISM band receiver (RX) for amplifying the signal so that the channel signal size becomes a size suitable for processing by the demodulator,

It consists of time division duplexing (TDD), receives the voice signal of the speaker transmitted from the first ISM band receiver as binary digital data, pulses it, and passes it through an analog FM modulator. A first ISM band transmitter (TX) for dividing channels and transmitting them to a plurality of wireless headsets;

When communicating with a plurality of wireless headsets and ISM bands in a multi-channel manner from the first ISM band transmitter TX and the first ISM band receiver RX, a channel change is controlled to prevent collision between channels, Control unit (MCU) for controlling the operation,

It is achieved by including a keypad control unit for controlling a command input from the button keys located on the front panel of the conference terminal.

Conference transmission and reception method having an audio mixing function in the near field using the ISM band multi-channel frequency according to the present invention,

When receiving a connection signal that is connected to one side of an electronic device for a conference room (audio device, laptop, TV, PC), the PWM power control unit (PWM POWER & BAT CONTROL) to control the power in a PWM method (S100),

In step S200, the signal input unit selects and inputs only a voice signal of a specific channel output according to a manipulation of a voice key provided at one side of the wireless headset, and transmits it to the ISM band receiver RX;

After receiving the voice signal of the speaker from the signal input unit through the first ISM band receiving unit (RX) and amplifying low noise, performing frequency down-conversion to move the signal to a low frequency band and a plurality of wireless headsets. Selectively passing only a signal of a desired channel transmitted from the signal, and amplifying the signal such that the channel signal size becomes a size suitable for processing in a demodulator (S300);

Time division duplexing (TDD) is performed through the first ISM band transmitter TX to receive voice signals of a speaker transmitted from the first ISM band receiver as binary digital data, and pulse shaping is performed. After passing through the analog FM modulator, the channel is separated and transmitted to a plurality of wireless headset (S400),

The second ISM band transmitter TX of the wireless headset receives the speaker's voice signal transmitted from the first ISM band transmitter TX of the conference terminal, amplifies low noise, and then performs frequency down-conversion. Transferring the signal to a band having a low frequency, selectively passing only a signal of a desired channel transmitted from the wireless headset, and amplifying the signal such that the channel signal size becomes a size suitable for processing in a demodulator (S500);

A voice signal of a speaker generated through a voice key is received by the second ISM band receiver (RX) of the wireless headset as binary digital data, pulsed, and then passed through an analog FM modulator. Transmitting the signal to the signal input unit of the conference terminal by dividing the channel (S600);

In the call control unit of the wireless headset, the wireless headsets of the selected channel are communicated with each other through a microphone formed at one side of the wireless headset, or control is performed so as to record the conversation (S700).

As described above, in the present invention, one speaker can select a voice signal transmitted from a specific wireless headset among a plurality of wireless headsets and transmit the same without error and noise, and transmit and receive at low power. There is.

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

First, the ISM band (Industrial Scientific Medical Band) will be described.

The ISM band (Industrial Scientific Medical Band), originally part of the FCC regulations in the United States, is an industry-licensed and medical-use band that was originally licensed under weak licenses and is primarily 900 MHz (902 MHz to 928 MHz), 2.4 GHz (2.4 GHz). ~ 2.4835 GHz) and 5.8 GHz (5.725 GHz to 5.825 GHz) are most actively used for wireless LAN applications.

Since it is a license-free band, it can be used for free data communication, can be used all over the world, is easy to install, and can be configured in a small network in a home that can be freely deployed.

Representative wireless LAN standards using the ISM band include 2.1 Bluetooth, HomeRF, IEEE802.11, IrDA, and HIPERLAN.

Method name Bluetooth IEEE 802.11 Home RF IrDA HIPERLAN Transmission speed 1 Mbps (actually 721 kbps) 2 Mbps (IEEE 802.11b: 11 Mbps) 0.8 Mbps, 1.6 Mbps 4 Mbps (advanced IR: 16 Mbps) 23.5 Mbps Frequency band 2.4 GHz band 2.4 GHz band 2.4 GHz band infrared ray 5 GHz vs 17 GHz Modulation method Frequency hopping spread spectrum technology (hopping frequency up to 1600 times per second) Direct spreading and frequency hopping spread spectrum technology Frequency hopping spread spectrum technology (hopping frequency up to 50 times per second) 4-step PPM / 16-step PPM (primary modulation only) Frequency hopping spread spectrum technology Dedicated Voice Channel (Coding by CSVD or logarithmic PCM) radish radish radish 32 kbps ADPCM Transmission distance 10 m (1 mW, 0 dBm), 100 m (100 mW, +20 dBm) 100m (30m for 802.1b) 50 m 3.8m 30 m Primary Modulation GAUSSIAN Freq.Shift Keying (GMSK) BPSK / QPSK and GFSK GFSK remind Diff. GMSK Connection control method Master-Slave, Polling CSMA / CA CSMA / CA, TDMA Pplling EY-NPMA security Standard (Authentication, Encryption) option Standard (Encryption) radish NA

In the present invention, a conference terminal is provided to be connected to one side of a conference room electronic product (audio device, laptop, TV, PC), and a multi-channel wireless access module using the ISM band is embedded in the terminal, Transmitting / receiving modules (RX, TX) corresponding to the channel are built-in, so that users who use a plurality of wireless headsets can select and listen to the contents wirelessly in the ISM band by selecting a channel for each user through a single terminal. Audio data can be provided to a plurality of wireless headsets in multiple channels.

That is, if there are four attendees in the conference room and each uses a wireless headset, the first wireless headset is the first channel, the second wireless headset is the second channel, and the third wireless headset is the third channel. And transmits the voice signal spoken by the speaker using the first wireless headset while pressing the voice key button to the multi-channel wireless connection module of the conference terminal during the conference using the fourth wireless headset as the fourth channel. The module may be configured to transmit the second channel, the third channel, and the fourth channel to a user who uses the second wireless headset, the third wireless headset, and the fourth wireless headset.

In addition, the multi-channel wireless access module uses the first wireless headset, the second wireless headset, the third wireless headset, and the fourth wireless headset using audio data as the first channel, the second channel, the third channel, and the fourth channel. Each user can provide audio data.

First, a multichannel wireless access module configured in a conference terminal according to the present invention will be described.

The conference terminal according to the present invention is formed slim in a shape of a circle, a square, a triangle, and the like so as to be attached to one side of an electronic device for a conference room (audio device, a notebook computer, a TV, and a PC), and an operation of the terminal body on the front panel. An LED display unit for displaying the state and the operating state, and the keypad unit is configured.

The keypad part of the conference terminal sets A, B, C, D, E, F .... channels in multiple rooms such as A, B, C, D, E, F .... channels, or A, B, C in close proximity to each other. The voice signal of the speaker or the audio data signal is transmitted to a plurality of wireless headsets consisting of, D, E, F ... channels.

Here, each channel setting of the wireless headset can be changed by the user through a button and a switch input.

1 is a block diagram illustrating a conferencing terminal 100 and a wireless headset 200 in a conference transmitting and receiving device having an audio mixing function at a short range using an ISM band multi-channel frequency according to the present invention. The present invention relates to a block diagram showing components of a conference terminal among conference transmitter / receiver having an audio mixing function in a short range using an ISM band multi-channel frequency.

The multi-channel wireless access module embedded in the conference terminal 100 includes a PWM power control unit (PWM POWER & BAT CONTROL) 110, a signal input unit 120, a first ISM band receiver (RX) 130, and a first ISM. Band transmission unit (TX) 140, the control unit (MCU) 150, and the keypad unit 160.

The PWM power control unit (PWM POWER & BAT CONTROL) 110 is configured to use a long time after charging by controlling the power in a PWM method to prevent unnecessary power usage.

As shown in FIG. 4, as a constant current control circuit, when a connection signal that is connected to one side of a conference room electronic product (audio device, notebook computer, TV, PC) is inputted, current flows toward the base terminal of the transistor Q1, whereby the transistor Q1 In the ON state, the battery power is sensed by the resistors R1 and R5, and current flows toward the base terminal of the transistor Q2, thereby turning on the transistor Q2.

At this time, the DC current is sensed through the resistor R2 connected to the collector side of the transistor Q2 and input to the DC-DC converter NJM2360.

Here, the DC-DC converter (NJM2360) has 5.5V, 680mA, and 70% power efficiency, so that the dispersion of the output current can be ± 5% or less even when a current detection resistor of ± 1% is used for the external resistor.

Subsequently, as a PWM method, the input DC is switched to 1.5 A in the DC-DC converter (NJM2360) to be alternating current, and the output alternating voltage is boosted or stepped down using the coil L1 and the capacitance C3 and then diode D1 again. Rectify to output.

It can be used for a long time after charging by controlling by PWM method to prevent unnecessary power usage.

The signal input unit 120 selects and receives only a voice signal of a specific channel output according to the operation of a voice key provided at one side of the wireless headset, and transmits the received voice signal to the ISM band receiver RX. .

In other words, the first wireless headset is the first channel, the second wireless headset is the second channel, the third wireless headset is the third channel, and the fourth wireless headset is the fourth channel. In this case, if the voice is pressed on the third wireless headset, only the voice signal of the speaker output from the third wireless headset is selected and received, and the voice signal of another speaker output to the remaining wireless headset is held.

Subsequently, the voice signal of the speaker output from the received third wireless headset is transmitted to the ISM band receiver RX.

The first ISM band receiver (RX) 130 receives a speaker's voice signal from the signal input unit, amplifies low noise, performs frequency down-conversion, and moves the signal to a band having a low frequency, Only the signals of the desired channels transmitted from the two wireless headsets 200 are selectively passed, and amplifies the signals so that the channel signal size becomes a size suitable for processing in the demodulator.

The first ISM band receiver 130 according to the present invention includes an RF front-end 131, a channel select filter 132, and a baseband amplifier 133.

The RF front end 131 performs low frequency amplification of the input signal of the RF band introduced from the antenna, and then performs frequency down-conversion to move the signal to a band having a low frequency.

The channel selection filter 132 serves to selectively pass only a signal of a desired channel. Since the channel selection filter 132 is performed in several MHz IF bands, it is possible to implement an on-chip filter and have information in a very low frequency part. There is no problem with DC offset and 1 / f noise.

This channel select filter 132 is configured such that the output current of the I-Q combiner is added to the LPF input resistance and then converted to a voltage.

That is, in the LPF, the output current of the combiner is converted into a voltage at the input termination resistor RT, and a source degeneration resistor R is inserted to increase the linear region. The HPF serves to remove interference channels existing in 2 MHz, 1 MHz, and DC regions.

The baseband amplifier 133 amplifies the signal such that the signal size is a size suitable for processing in the demodulator.

Frequency downconversion of the first ISM band receiver (RX) 130 according to the present invention refers to lowering the speech signal of a speaker received through a down converter to an IF or baseband frequency.

That is, the first ISM band receiver (RX) 130 according to the present invention separates the voice signal of the speaker, which is a complex digital IF signal, for each channel and selectively passes only a signal of a desired channel, and downlinks the frequency to the baseband. By converting and up-converting to a predetermined frequency to amplify and outputting at least two or more digital IF signals in a demodulator, the frequency of the system clock is reduced to reduce power consumption and cost.

In addition, the ISM band reception through the digital frequency down-conversion according to the present invention can prevent the degradation of signal characteristics caused by harmonic components generated in the conventional analog signal processing method, thereby improving the quality of the received signal. Have

The first ISM band transmitter (TX) 140 is configured by time division duplexing (TDD), and receives a voice signal of a speaker transmitted from the first ISM band receiver as binary digital data. After shaping, it passes through the analog FM modulator, and separates channels and transmits them to a plurality of wireless headsets.

Here, the time division method divides the voice signals of the speakers transmitted from the plurality of wireless headsets into selected channels and divides them in time so that a user using another wireless headset can listen.

That is, the voice signal of the speaker output from the first wireless headset of the first channel, the voice signal of the speaker output from the second wireless headset of the second channel, the voice signal of the speaker output from the third wireless headset of the third channel, The voice signal of the speaker output from the fourth wireless headset of the fourth channel is divided in time and output to a plurality of other wireless headsets.

As described above, the first ISM band transmitter TX according to the present invention transmits to a plurality of wireless headsets through a time division scheme, which is overlapped with an audio signal transmitted from an external device, or is distorted due to noise in a channel environment. This is to prevent the degradation of the deep sea signal.

The control unit 150 communicates with the plurality of wireless headsets 200 and the ISM band in a multi-channel manner from the first ISM band transmitter (TX) 140 and the first ISM band receiver (RX) 130, and each channel. It controls channel change to prevent collision between them and controls the operation of each device.

When receiving the connection signal that is connected to one side of the meeting room electronic products (audio device, laptop, TV, PC), the control unit is controlled to operate the first ISM band receiving unit 130 is switched from the standby state to the operating state through the signal input unit Controlling the LED display unit to display the operating state and operating state of the terminal, and transmits to a plurality of wireless headsets by dividing the channel by the time division duplexing (TDD) through the first ISM band transmitter (TX) 140 Control as possible.

Next, the components of the wireless headset 200 according to the present invention will be described.

The wireless headset 200 according to the present invention is composed of a microphone and a headset, one wireless headset or more wireless headsets are paired with each other after forming a conference network, two wireless headsets to communicate with each other or from the conference terminal It is a place to receive audio data signal.

The wireless headset includes a second ISM band receiver (TX) 210, a call controller 220, and a second ISM band receiver (RX) 230.

The second ISM band receiver (RX) 210 is configured by time division duplexing (TDD), and receives a voice signal of a speaker, which is generated through a voice key, as binary digital data. pulse) After shaping, it passes through the analog FM modulator and divides the channel and transmits it to the signal input part of the conference terminal.

The call controller 220 controls the wireless headsets of the selected channel to have a 1: 1 conversation with each other through a microphone formed at one side of the wireless headset 200 or record the conversation.

The second ISM band transmitter 230 receives a voice signal of a speaker transmitted from the first ISM band transmitter TX of the conference terminal, amplifies low noise, and then performs frequency down-conversion. Thus, the signal is moved to a low frequency band, selectively passes only a signal of a desired channel transmitted from the wireless headset, and amplifies the signal so that the channel signal size becomes suitable for processing in a demodulator.

Hereinafter, a transmission / reception method using a conference terminal having an audio mixing function at a short range using an ISM band multichannel frequency according to the present invention will be described.

First, upon receiving a connection signal that is connected to one side of an electronic device for a conference room (audio device, laptop, TV, PC), the PWM power control unit (PWM POWER & BAT CONTROL) controls the power in a PWM manner (S100).

That is, when a connection signal is connected to one side of a conference room electronic product (audio device, notebook computer, TV, PC), current flows toward the base terminal of the transistor Q1, and the transistor Q1 is turned on. By sensing the resistors R1 and R5, current flows toward the base terminal of the transistor Q2, thereby turning on the transistor Q2.

At this time, the DC current is sensed through the resistor R2 connected to the collector side of the transistor Q2 and input to the DC-DC converter NJM2360.

Then, as a PWM method, the input DC is switched to 1.5A by the DC-DC converter (NJM2360) to make AC, and the output AC is boosted or stepped down using the coil L1 and the capacitance C3, and then the diode D1 is again. Rectify to output.

It can be used for a long time after charging by controlling by PWM method to prevent unnecessary power usage.

Subsequently, the signal input unit selects and inputs only a voice signal of a specific channel output according to the operation of a voice key provided on one side of the wireless headset, and transmits it to the ISM band receiver RX (S200).

Subsequently, the voice signal of the speaker is received from the signal input unit through the first ISM band receiver RX, amplified low noise, frequency down-conversion is performed, and the signal is shifted to a low frequency band. Only a signal of a desired channel transmitted from the wireless headset is selectively passed, and the signal is amplified so that the channel signal size becomes a size suitable for processing by the demodulator (S300).

Subsequently, time division duplexing (TDD) is performed through the first ISM band transmitter TX to receive a voice signal of a speaker transmitted from the first ISM band receiver as binary digital data, thereby shaping a pulse. After the shaping, the analog FM modulator is passed and the channels are transmitted to the plurality of wireless headsets (S400).

Subsequently, the second ISM band transmitter TX of the wireless headset receives the voice signal of the speaker transmitted from the first ISM band transmitter TX of the conference terminal, amplifies low noise, and then performs frequency down-conversion. The signal is moved to a band having a low frequency, selectively passes only a signal of a desired channel transmitted from the wireless headset, and amplifies the signal so that the channel signal size becomes a size suitable for processing by the demodulator (S500).

Subsequently, the second ISM band receiver RX of the wireless headset is configured by time division duplexing (TDD), and receives a voice signal of a speaker generated through a voice key as binary digital data. After shaping and passing through the analog FM modulator, the channels are divided and transmitted to the signal input unit of the conference terminal (S600).

Subsequently, the call control unit of the wireless headset controls 1: 1 wireless conversation between the wireless headsets of the selected channel through a microphone formed at one side of the wireless headset, or records the conversation (S700).

1 is a block diagram illustrating a conference terminal 100 and a wireless headset 200 in a conference transmission / reception apparatus having an audio mixing function at a short range using an ISM band multi-channel frequency according to the present invention.

2 is a block diagram showing the components of the conference terminal 100 according to the present invention;

3 is a block diagram illustrating the components of a first ISM band receiver of a conference terminal according to the present invention;

4 is a block diagram illustrating the components of a wireless headset 200 having an audio mixing function at a short range using an ISM band multi-channel frequency according to the present invention;

5 is a circuit diagram showing a configuration of a PWM power control unit among the components of the conference terminal 100 according to the present invention;

FIG. 6 is a flowchart illustrating a conference transmitting / receiving method having an audio mixing function at a short range using an ISM band multi-channel frequency according to the present invention. FIG.

※ Brief description of reference numerals ※

100: conference terminal 110: PWM power control unit

120: signal input unit 130: first ISM band receiver

140: first ISM band transmitter 150: controller (MCU)

160: keypad portion 200: wireless headset

Claims (3)

Connected to one side of conference room electronic products (audio device, laptop, TV, PC), users who use a plurality of wireless headsets 200 can select and listen to the contents of the speech wirelessly in the ISM band by selecting each channel through a single terminal. In a conference transceiver comprising a conference terminal 100 that can be, The conference terminal 100 is a PWM power control unit (PWM POWER & BAT CONTROL) 110 to control the power in a PWM method to prevent unnecessary power use to use for a long time after charging, Signal input unit (Signal_Input) 120 to receive and input only the audio signal of a specific channel output according to the operation of the voice key (Voice Key) provided on one side of the wireless headset 200, and to transmit it to the ISM band receiver (RX) (120) )Wow, After receiving the speaker's voice signal from the signal input unit 120 and amplifying low noise, frequency down-conversion is performed to move the signal to a low frequency band and to transmit a desired channel transmitted from a plurality of radio headsets. A first ISM band receiver (RX) 130 which selectively passes only the signal, and amplifies the signal such that the channel signal size is large enough to be processed by the demodulator, It consists of time division duplexing (TDD), receives the voice signal of the speaker transmitted from the first ISM band receiver as binary digital data, pulses it, and passes it through an analog FM modulator. A first ISM band transmitter (TX) 140 that separates channels and transmits them to a plurality of wireless headsets; When a plurality of wireless headsets communicate with a plurality of radio headsets in an ISM band from a first ISM band receiver (RX) 130 and a first ISM band transmitter (TX) 140, a channel change is performed to prevent a collision between channels. A control unit (MCU) 150 for controlling and controlling an operation of each device, Audio at a short distance using ISM band multi-channel frequency, comprising a keypad 160 for controlling commands inputted from button keys located on the front panel of the conference terminal, comprising one multi-channel wireless access module. Conference transceiver with mixed functions. According to claim 1, The wireless headset 200 receives a speaker's voice signal transmitted from the first ISM band transmitter (TX) of the conference terminal therein after low noise amplification, and then performs frequency down-conversion (Frequency down-conversion) A second ISM which transfers the signal to a lower frequency band, selectively passes only signals of a desired channel transmitted from the wireless headset, and amplifies and transmits the signal to a speaker so that the channel signal size is large enough to be processed by the demodulator. Band receiver (RX) 210, The call controller 220 controls the wireless headsets of the selected channel to have a 1: 1 conversation with each other through a microphone formed on one side of the wireless headset, or records the conversation. It consists of time division duplexing (TDD), receives the voice signal of the speaker generated through the voice key as binary digital data, and pulses it after shaping the analog FM modulator. A second ISM band transmitter (TX) 230 passing through and classifying channels and transmitting the signals to a signal input unit of a conference terminal is composed of a single module, which is composed of a chip in a short range using ISM band multi-channel frequency. Conference transceiver with audio mixing. When receiving a connection signal that is connected to one side of an electronic device for a conference room (audio device, laptop, TV, PC), the PWM power control unit (PWM POWER & BAT CONTROL) to control the power in a PWM method (S100), In step S200, the signal input unit selects and inputs only a voice signal of a specific channel output according to a manipulation of a voice key provided at one side of the wireless headset, and transmits it to the ISM band receiver RX; After receiving the voice signal of the speaker from the signal input unit through the first ISM band receiving unit (RX) and amplifying low noise, performing frequency down-conversion to move the signal to a low frequency band and a plurality of wireless headsets. Selectively passing only a signal of a desired channel transmitted from the signal, and amplifying the signal such that the channel signal size becomes a size suitable for processing in a demodulator (S300); Time division duplexing (TDD) is performed through the first ISM band transmitter TX to receive voice signals of a speaker transmitted from the first ISM band receiver as binary digital data, and pulse shaping is performed. After passing through the analog FM modulator, the channel is separated and transmitted to a plurality of wireless headset (S400), The second ISM band transmitter TX of the wireless headset receives the speaker's voice signal transmitted from the first ISM band transmitter TX of the conference terminal, amplifies low noise, and then performs frequency down-conversion. Transferring the signal to a band having a low frequency, selectively passing only a signal of a desired channel transmitted from the wireless headset, and amplifying the signal such that the channel signal size becomes a size suitable for processing in a demodulator (S500); A voice signal of a speaker generated through a voice key is received by a second ISM band receiver (RX) of the wireless headset as binary digital data, pulsed, and then passed through an analog FM modulator. Transmitting the signal to the signal input unit of the conference terminal by dividing the channel (S600); ISM band, characterized in that the call control unit of the wireless headset comprises a one-to-one conversation between the wireless headsets of the selected channel through a microphone formed on one side of the wireless headset, or control to record the conversation (S700) Conference transmission / reception method with audio mixing function in short distance using multi-channel frequency.

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