KR20030061915A - An analog-digital-hybrid communication system for a FM HiFi wireless audio link - Google Patents

Abstract

PURPOSE: An FM wireless audio communication device in an analog/digital hybrid form for hi-fi audio transmission is provided to maximize user's convenience and enhance stability of an audio communication channel by adding a digital data transmission/reception unit to each receiver. CONSTITUTION: A master module(22) includes an FM audio/FSK data transmitter(2) for transmitting an FM audio signal and digital data, and an FSK data receiver(4) for receiving the digital data. The master module(22) also includes a controller(6) for controlling the units(2,4) and analyzes the digital transmission/reception data, and an electric field strength measuring unit(8) for analyzing a use state of a channel. A slave module(24) includes an FM audio/FSK data receiver(12) for receiving an FM audio signal and digital data, and an FSK data transmitter(14) for transmitting the digital data. The slave module(24) also includes a controller(16) for controlling the units(12,14) and analyzes the digital transmission/reception data.

Description

An analog-digital-hybrid communication system for a FM HiFi wireless audio link}

The present invention relates to an analog / digital hybrid FM wireless audio communication device. In particular, by adding digital data transmission and reception devices to each of FM wireless audio transmitter and receiver, analog / digital hybrid that maximizes user convenience and improves the stability of audio communication channel in using wireless audio transceiver. The present invention relates to an FM wireless audio transceiver and a communication protocol for communication between the devices.

As shown in FIG. 2, in the conventional FM wireless audio transmitter, the entire audio band formed through the stereo modulator 102, which sums the two left and right channels with the audio signal 100 in general, is frequency modulated by the FM modulator 104. After being amplified by the high-frequency amplifier 106 and refined into a limited frequency band in the band pass filter 110 is configured to be transmitted through the antenna 112. In addition, a transmission frequency setting device 108 for manually setting the transmission frequency may be included.

In such a conventional configuration, in most cases, the transmission frequency is fixed to one, and interference is inevitable in the case where an airwave channel exists at the transmission frequency of a conventional transmitter. In addition, there is a transmission device including a manual transmission frequency setting device 108 separately, but the user has to set manually through a switch, which causes considerable inconvenience.

Since the conventional transmission system as described above is a one-way transmission, there is no separate communication circuit for channel establishment and maintenance, which may cause problems related to interference with other devices.

Accordingly, an object of the present invention is to realize a high performance wireless audio connection system which is stable and user-friendly between an audio device and an FM wireless audio receiver.

In order to achieve the above object, the present invention adds a digital data transceiver of an FSK modulation method to an FM wireless audio transmitter (hereinafter referred to as a master module) and an FM wireless audio receiver (hereinafter referred to as a slave module), respectively. We propose a communication protocol that can improve the reliability and convenience of communication between modules.

In addition, the master module 22 includes an FM transmitter for transmitting FM audio, an FSK data transmitter 2 for transmitting digital data, an FSK data receiver 4 for receiving digital data, and these devices. A control device 6 for controlling and analyzing digital transmission / reception data, and an electric field strength measuring device 8 for analyzing the use state of a channel, and the like, for selecting an optimal communication channel by performing a communication protocol, and selecting a master module ( It was invented to secure a stable communication channel, prevent interference with other devices, and increase user convenience by performing functions such as communication channel setting, connection of audio signals, and short circuit between the slave module 24 and the slave module 24.

In addition, the slave module 24 includes an FM receiver for receiving FM audio and an FSK data receiver 12 for receiving digital data, an FSK data transmitter 14 for transmitting digital data, and these slave modules. Control devices 12 and 14, and a control device 16 for analyzing digital transmission / reception data to perform a communication protocol to achieve stable wireless audio reception using an optimal communication channel selected by the master module. It was invented to be.

1 is a block diagram of a hybrid communication system for transmitting and receiving FM wireless audio according to the present invention.

2 is a block block diagram showing a conventional FM audio transmitting apparatus.

3A and 3B are schematic diagrams illustrating a communication procedure between a master module and a slave module according to the present invention.

4 is a block diagram of a master module according to an embodiment of the present invention.

5 is a block diagram of a slave module according to an embodiment of the present invention.

6A and 6B are flowcharts illustrating communication procedures of a master module and a slave module according to an embodiment of the present invention.

7A and 7B are flowcharts illustrating communication procedures of a master module and a slave module according to another embodiment of the present invention.

8 is a structural diagram of a communication frame according to an embodiment of the present invention.

9 is a communication timing diagram of a master module and a slave module according to an embodiment of the present invention.

10 is a communication timing diagram of a master module and a slave module according to another embodiment of the present invention.

Hereinafter, with reference to the accompanying drawings, the configuration and operation of the embodiment of the present invention will be described in detail.

1 is a block diagram of a hybrid communication system for transmitting and receiving FM wireless audio according to the present invention.

Referring to FIG. 1, the master module 22 for high performance audio transmission receives stereo input 0 and transmits audio in an FM manner, and also transmits data for forming a reliable audio channel. An FM audio / FSK data transmitter 2 is mounted so that it can be performed simultaneously, and an FSK data receiver 4 for data reception is provided. In addition, the apparatus (2) (4) is further provided with a control device (6) including a microprocessor and its peripherals to properly perform the communication protocol specified in the present invention.

Such a control device 6 performs not only the operation control of the transmission / reception unit but also the generation of transmission data and analysis of reception data. Another function of the control device 6 is to find and store the most suitable channel in the audio transmission by referring to the field strength information in the field strength measuring instrument 8 and to control the optimal channel to be applied to the final audio transmission and reception. Store and manage the device identification number assigned to each device. Data communication of the above-described master module is performed using a half-duplex communication scheme.

In addition, the slave module 24 which is in charge of receiving audio can demodulate and output the FM audio signal received from the antenna 20 to the speaker 18, and decode it if the received signal is FSK data. An FSK data transmitter 14 is provided to transmit digital data to the FM audio / FSK data receiver 12 and the master module 20. Since the slave module 24 also needs to perform the half-duplex communication as described above, the FM audio / FSK data receiving device 24 and the FSK data transmitting device should not be activated at the same time. Such activation timing control, generation of data to be transmitted, and analysis of received data are simultaneously performed by the controller 16.

3 is a communication procedure of a master module and a slave module according to the present invention, and a procedure of initiating an audio transmission channel by first calling a slave module as shown in FIG. 3A; The slave module calls the master module first and is divided into a procedure of initiating an audio transmission channel (FIG. 3B).

In the procedure in which the master module calls the slave module (FIG. 3A), the master module which has determined the audio transmission channel sends the slave call signal 200, and checks whether there is a call response 202 of the slave module at an appropriate timing. If there is no response, the slave module does not operate or is out of the communication area, so the slave module call continues for a certain period of time. The slave module enters the data reception mode at the start of operation to capture the slave call signal 200 of the master module. At this time, the slave module has information on which frequency channel the master module is still transmitting the call signal. Since it does not exist, it searches sequentially for available channels and checks whether there is a signal calling a slave module.

When the call signal is detected by the above-described procedure, the slave module changes to the transmission mode and sends a call response signal 202 to the master module. When the call response signal 202 is received by the master module, since a communication channel is established from the slave module to the master module, when the master module has an additional message to be sent to the slave module, the message is sent (204). When the reception response 206 for the transmission message is sent from the slave module, the master module checks this and switches to the audio transmission mode to transmit the audio to the analog FM (208). In the above operation, if there is no additional delivery message after the slave call 200 and the call response 202, it immediately leads to the FM audio transmission.

As another communication train according to the present invention, a procedure in which a slave module first calls a master module (FIG. 3B) will be described.

In this case, the initial master module is in the data reception mode and the slave module is in the data transmission mode. In order to capture the master call signal 210 transmitted from the slave, the master module performs acquisition of a call signal on the channel after searching for an optimal channel. At this time, since the master module and the slave module do not form a communication channel in the same channel with each other, the slave module sends a call signal 210 to the master module while sequentially searching for a communication capable channel and the call response of the master module thereto. Check if this exists. When the call response 212 of the master module is acquired, the slave module secures a communication channel with the master module by fixing a transmission / reception channel to the channel.

At this point, the master module also knows that the slave module is on the same channel, so if an additional message exists, an additional message transmission (214) is made from the master module to the slave module or an additional message is sent from the slave module to the master module. In the former case, as shown in FIG. 6B, when the master module receives the message reception response 216 of the slave module, the FM audio transmission 218 occurs in the master module. If no additional message delivery is required after channel establishment, the FM audio transmission mode may be immediately entered except for the message transmission 214 signal and the message reception response signal 216.

The above objects and various advantages of the present invention will become more apparent from the preferred embodiments of the present invention described below with reference to the accompanying drawings.

4 is a preferred embodiment of the master module proposed in the present invention.

Referring to FIG. 4, when searching for an optimal audio channel in the master module, first, the microcomputer 332 deactivates the transmission block 340, activates the reception block 342, and then uses the PLL to perform the microcomputer ( The output value of the electric field strength measurer 326 is measured while changing the frequency channel to be selected using the local oscillator 328 capable of controlling the oscillation frequency. The signal of the channel selected by the microcomputer 332 is amplified by the high frequency amplifier 324 and transitioned to the intermediate frequency by the high frequency mixer 322, and the electric field strength measuring instrument 326 converts the energy value of the intermediate frequency signal into a potential. .

At this time, the output value of the electric field strength measurer 326 is converted into a digital value through the A / D converter 330 is input to the microcomputer 332. As described above, the optimal channel selected based on the extracted electric field strength value is separately stored in the memory unit 336 to be used again later.

In addition, when receiving data from the master module, the transmission block 340 is deactivated and the reception block 342 is activated, and data transmitted from the slave module is input to the receiving end through the antenna 314; Amplified by the high frequency amplifier 324 and the signal is input to the high frequency mixer 322; In the high frequency mixer 322, the frequency of the local oscillator 328 oscillating at the frequency selected by the microcomputer 332 is applied to transition to the intermediate frequency. The signal of this intermediate frequency band is restored to a digital waveform by the FSK decoder 320, and the digital waveform is analyzed by the data decoder 318, valid information is extracted, and transmitted to the microcomputer 332.

As a transmission mode applied to the master module, there are an analog audio transmission mode and a digital FSK data transmission mode. First, an operation in the data transmission mode will be described with reference to FIG. 4.

In the data transmission mode, the transmission block 340 is activated, the reception block 342 is deactivated, and the multiplexer 304 is fixed so as to select a signal of the data encoder 316, all of which is controlled by the microcomputer 332. Controlled. The data to be transmitted is generated in the microcomputer 332, linecoded in the form defined in the data encoder 316, and transferred to the FM modulator 306 by the selection of the multiplexer 304. The FSK modulated signal from the FM modulator 306 is amplified by the high frequency amplifier 308 and only an appropriate frequency band is extracted from the band pass filter 310 and transmitted through the antenna 314.

Next, in the audio transmission mode, the multiplexer 304 is determined by the microcomputer 332 to select the audio signal from the stereo modulator 302, and the transmission block 340 is activated in the same manner as the data transmission mode. The reception block 342 is deactivated. The stereo audio input signal 300 is modulated by the L + R signal and the L-R signal in the stereo modulator 302, and is combined. The signal is transmitted to the FM modulator 306 by the multiplexer 304. In the FM modulator 306, the input audio signal is FM modulated to a frequency corresponding to the oscillation frequency selected by the local oscillator 328, amplified by the high frequency amplifier 308, and an appropriate frequency band is selected by the band pass filter 310. It is sent out through the antenna 314.

The master module in charge of the audio transmission operates as described above, and in addition, as an interface with the user, it provides a key input device 334 for transmitting user commands from the outside and information on the current state of the master module to the user. The display device 338 and a non-volatile memory for storing a unique identification number for each device and a memory unit consisting of RAM, ROM, and the like may be included. In addition, in FIG. 4, a structure in which one local oscillator 328 is shared and used in transmission and reception, or a local oscillator for transmission and reception may be separately installed.

5 is a preferred embodiment of the slave module in the present invention.

As shown in FIG. 5, the slave module is very similar in shape to the master module, except that an audio receiver is specially installed in the reception block 444 instead of the audio transmitter. First, when the slave module is in the data reception mode, the transmission block 442 is inactivated and the reception block 444 is activated. The signal input through the antenna 400 is extracted only the appropriate frequency band from the band pass filter 404, this signal is amplified by the high-frequency amplifier 406 and then to the intermediate frequency in the FM demodulator 408 with a mixer Transition is restored to a digital waveform in the FSK decoder 418, which in the data decoder 420 is analyzed, extracted as meaningful data and transferred to the microcomputer 424.

Also in the audio reception mode, the transmission block 442 is inactivated and the reception block 444 is activated similarly to the data reception mode. The signal input through the antenna 400 is extracted only the appropriate frequency band from the band pass filter 404, this signal is amplified by the high frequency amplifier 406 and then to the intermediate frequency in the FM demodulator 408 including the mixer After the transition, the L + R and LR signals are converted to the L and R signals by the stereo decoder 420, and then amplified by the audio amplifier 412 and output to the speaker 414.

In addition, when the slave module operates in the data transmission mode, the transmission block 442 is activated and the reception block 444 is deactivated. Data to be transmitted is generated by the microcomputer 424, line-coded in the form defined by the data encoder 440, and input to the FM modulator 438. The input signal is modulated by the FM modulator 438 according to the transmission frequency set by the microcomputer and then amplified by the high frequency amplifier 436, extracted by the band pass filter 434 into an appropriate frequency band, and then through the antenna 400. It is sent out.

In the embodiment of the slave module shown in FIG. 5, the local oscillator 430 is shared and used for transmission and reception as one, but may be separately mounted for transmission and reception. In addition, a separate key input device 432 and a nonvolatile memory for storing a unique identification number for each device and a memory unit 426 including RAM, ROM, etc. may be provided to transmit an external command of a user.

As the system structure as described above, it is possible to provide an analog FM audio transceiver based on digital data communication. Such a system operates under the premise that it is a half-duplex communication channel, and thus the same protocol as in the embodiment of the communication procedure described later is required.

6A and 6B show communication procedures when the master module first calls a slave module. A communication procedure will be described based on the embodiment of the operation procedure 526 of the master module shown in FIG. 6A and the operation procedure 582 of the slave module shown in FIG. 6B.

First, when the operation of the master module is started, the reception mode 502 is set, and the channel for optimal audio transmission is found and fixed while changing the channel (504). Thereafter, the apparatus 100 switches to the digital signal transmission mode (506) and transmits a slave call signal (508). After the call signal is transmitted, switch to the digital reception mode (510), wait for the call response of the slave module for a predetermined time (512), and if the call response is not captured, switch back to the digital transmission mode (506), and (506) to ( Repeat the procedure up to 512). When the call response of the slave module is detected, the signal is switched to the digital transmission mode (514), and then an additional message is transmitted (516). . If a normal message response is not detected here, the operations 514 to 520 are repeated to send the message. When the normal message response is detected, the audio signal is transmitted (524) after switching to the analog FM audio transmission mode (522).

On the other hand, in the embodiment of the operation procedure 582 of the slave module shown in Figure 6b, since the current transmission frequency of the master module is not known at the start of the slave module, it is set based on any initial channel among the predetermined channels ( In operation 552, the receiver receives the call signal transmitted from the master module (556) after fixing to the digital reception mode (554). If the call signal of the master module is not captured in the initial setting channel, the channel switching 558 is performed to another channel to perform the call signal acquisition attempt again. In this way, the procedures from 556 to 560 are repeated until the signal of the master module is acquired. If the call signal of the master module is captured, the process switches to the digital transmission mode (562) to send a response signal for the call (564). After receiving the call response signal 564, the additional message is expected to be received. Therefore, the user switches to the digital receiving mode 566 and attempts to capture the additional message 568. If an error occurs as a result of the additional message analysis upon reception (570), an error response (572) is transmitted after switching to the digital transmission mode (574), and again (566) is attempted to capture the additional message (568). Once the message has been successfully captured (570), a response to the message reception is sent (576), followed by switching to analog FM audio reception mode (578) and receiving audio (580).

A preferred embodiment of another communication procedure protocol for operating a master module and a slave module according to the present invention under the premise of a half-duplex communication channel is shown in FIG. 7.

7A and 7B illustrate a procedure until an audio channel is formed when a slave module first calls a master module. A communication procedure will be described based on the embodiment of the operation procedure 618 of the master module shown in FIG. 7A and the operation procedure 670 of the slave module shown in FIG. 7B.

First, when the master module starts, it switches to the digital reception mode 602 and searches for and sets an optimal channel for transmitting audio (604). The master module attempts to acquire the call signal 606 of the slave module on the established channel. If the call signal is not captured (608), the call signal capture (606) is repeated. When the master module captures the call signal (608), it switches back to the digital transmission mode (610) and sends a call response to the slave module (612). In the case of the master module, if the above processes 600 to 612 are successfully performed, the master module switches to the analog FM audio transmission mode 614 and transmits an audio signal 616.

Meanwhile, since the slave module illustrated in FIG. 7B has no information on which frequency the master module attempts to receive at the start of operation, the slave module is set based on an arbitrary initial channel among predetermined channels and fixed in the digital transmission mode (652). After calling (654), a call signal for calling the master module is sent (656). After the call signal is sent, it immediately switches to the digital receiving mode (658) and waits for a call response. If there is no call response (660), it is determined that there is no master module in that channel and changes to another channel (662) to resend (656) the call signal. Repeat steps 654 through 662 until the call response from the master module is captured, and when the call response is captured, fix the channel (664) and receive analog FM audio to receive audio from the master module. After switching to the mode 666, an audio signal is received.

8 illustrates an embodiment of a communication data frame according to a preferred embodiment of the present invention.

Referring to FIG. 8, the transmission frame includes a preamble code 700 for capturing a transmission signal at a receiving side; A synchronization code 702 for synchronizing information delivery points; An identification number 704 exists for confirmation between the transmitting and receiving devices, followed by a user-defined area 706 containing a message and a stop code 708. Since this frame is transmitted through modulation using PLL, when NRZ code is applied, if 0 or 1 is repeatedly repeated by the limit length, DC bias occurs and it is difficult to maintain the information or additional cost. do.

In order to solve the above problems, special field structures such as fields 0 (710) and (714) are shown, which are subdivided to avoid repetition of the same information, that is, continuous 0 or continuous 1 data types, above a threshold length. use. Referring to the field 714 of FIG. 8, a field is divided into two parts such that consecutive identical information does not exceed a predetermined length, and one part uses a structure in which a message to be transmitted is reversed by another part. In this way, not only the same information can be prevented from being continuously exceeded beyond the limit length, but also the error detection function can be additionally provided by providing the effect of repetitive codes. However, the spirit of the present invention is not limited to the field structure of the user-defined region described above, and other coding schemes for canceling the DC bias may be used.

6A, 6B and 7A, 7B, the empty channel search / set 504 of the master module and the initial channel set-up 552 of the slave module are performed by the system of the present invention. Operation is optionally performed only in the initial situation, such as when the operation is first initiated or the user resets the channel, and the result is stored in the memory units 336 and 426 and then reused. In the general channel initiation process, only the validity of a channel stored in the memory units 336 and 426 of the master module and the slave module is re-examined when a channel start request is received by the user.

Therefore, the master module and the slave module, which have successfully performed the initial channel setting process, recognize the same frequency channel and perform the subsequent communication start process. The above-described communication channel setting process or communication start process (506 to 524) (554 to 580) (606 to 616) (654 to 668) is a case in which normal communication procedures are performed according to the spirit of the present invention. Detailed description of the case is beyond the scope of the present specification will be omitted.

9 and 10 are timing charts of main control signals of the master and slave modules according to the preferred embodiment of the present invention. 9 and 10 illustrate that the initial channel setup process 504, 552, 604, 652 is already performed, a master module and a slave module.

9 is a control signal timing when a master module requests communication start from a slave module first, and additional message transfer is required in addition to a communication start request, and FIG. 10 shows control when a slave module requests communication start from a master module. Signal timing.

First, a case in which the master module shown in FIG. 9 requests communication start will be described. In the case of FIG. 9, the master module and the slave module periodically search for each other's call signal in the standby mode (STBY) before requesting communication commencement (814). If there is, the master module sends a call signal to the slave module (820) and searches for a response signal (816). This call signal is detected by the slave module that is periodically searching for the call signal (828), and transmits an acknowledgment response signal (832) for the call (820) of the master at a given timing.

In this case, since the master has additional data to be transmitted to the slave in addition to the communication establishment request signal, the master module receives the slave's acknowledgment response signal 832 and transmits the additional data at a given timing (822). The slave module receiving the additional data transmission of the master (822) sends an acknowledgment signal to the master (834). After completing the data transmission and reception process, the master module and the slave module initiate audio transmission 824 and audio reception 836 at predetermined timings, respectively.

10 illustrates timing of main control signals according to an embodiment when a slave module makes a communication start request to a master module. In the case of FIG. 10, there is no additional data or all data can be included in the communication start request frame.

As in the embodiment of FIG. 9, the master module and the slave module periodically search for a call signal in the standby mode until there is a communication start request (914, 922). When the user makes a communication start request to the slave module, the slave module stops the periodic call signal search, sends a communication start request frame to the master module (926), and retrieves the acknowledgment response signal of the master module (924). At the same time, the master module searching for the call signal detects and recognizes a communication start request signal of the slave module (916), and sends an acknowledgment response signal (918) to the slave module.

After the above process is successfully completed, the master module and the slave module start audio transmission and audio reception at a predetermined timing. However, the timing of the main control signals shown in FIGS. 9 and 10 is when data communication is normally performed between the master module and the slave module, and embodiments of the case where the data communication is not normally performed vary in the number of cases and the present invention. The detailed description is omitted here because it is irrelevant to the idea of.

Based on the structure and protocol as described above, it is possible to implement a system capable of automatically setting an optimal audio transmission channel based on digital communication in a half-duplex channel and transmitting / receiving an FM-type wireless audio signal.

As described above, according to the analog / digital hybrid FM wireless audio communication apparatus according to the present invention, each module in charge of audio transmission and reception searches for an optimal transmission / reception channel that is not occupied by a frequency used by another device and communicates with the communication channel. By setting to, it automatically establishes a communication channel with each other, and enables wireless audio transmission and reception by the FM method to promote user convenience and stability of audio transmission and reception. In addition, through the invention of the present disclosure in the various types of audio devices can be produced and provided to the user convenience, such as wireless headphones or wireless earphones at a minimum cost.

Claims (9)

An FM audio / FSK data transmitter for receiving a stereo input and transmitting audio in an FM manner and simultaneously performing digital data transmission for forming an audio channel; An FSK data receiver for receiving digital data from a wireless audio receiver; An electric field strength measurer for finding an optimal communication channel from the FSK data receiving apparatus; A master module for FM audio transmission, comprising: a control device including a microprocessor and a peripheral device for controlling the above devices and performing a prescribed communication protocol; An FM audio / FSK data receiver for demodulating the FM audio signal received from the antenna and outputting the same to a speaker and decoding the received signal when the received signal is FSK data; An FSK data transmitter for transmitting digital data to the master module; A control device for controlling the above devices; Analog wireless digital communication system of the analog / digital hybrid type, characterized in that consisting of a slave module for FM audio reception. The control apparatus of claim 1, wherein the control unit of the master module performs generation of transmission data and analysis of reception data, finds and stores an optimal communication channel secured from the field strength meter, and controls it to be applied to final audio transmission and reception. An analog / digital hybrid FM wireless audio communication device, characterized in that it stores and manages the identification number of the device assigned to each device. The analog / digital hybrid FM wireless audio communication apparatus according to claim 1, wherein one local oscillator is used in common for RF frequency control of a transmitter and a receiver provided in the master module and the slave module, respectively. The analog / digital hybrid FM wireless audio communication device of claim 1, wherein the electric field strength tester serves to search for a channel in which no external broadcast wave currently exists. The apparatus of claim 1, wherein data communication between the master module and the slave module is performed using a half-duplex communication method. The analog / digital hybrid FM system according to claim 5, wherein the data communication between the master module and the slave module is based on a half-duplex communication method and includes a call signal and a call response procedure to initiate a communication channel. Wireless audio communication device. The method of claim 6, wherein the slave module call of the master module transmits a call signal from a master module in charge of audio transmission first, and retrieves and confirms a call signal from a slave module in charge of audio reception, and then sends a call response. An analog / digital hybrid FM wireless audio communication device, characterized in that it is sequentially operated to transmit an audio signal based. The audio module of claim 6, wherein the master module call of the slave module sends a call response by first transmitting a call signal from a slave module in charge of audio reception and searching and confirming a call signal from a master module in charge of audio transmission. And the slave module recognizes that a channel with the channel is formed, and is operated in sequence of transmitting audio from the master module. The data communication between the master module and the slave module according to claim 1 or 5, wherein in order to prevent a situation in which the original signal is not modulated by repeating the same code over a limit length when FSK transmission of an NRZ code is performed, An analog / digital hybrid FM wireless audio communication device, characterized by applying a field consisting of a sequence of normal information and inversion information.