JPH099364A - Digital wireless transmitter - Google Patents

Abstract

PURPOSE: To keep transmission with high quality and to attain remote control without mistake by providing digitally modulated 2-way transmission path for the transmission between a reproducing device main body and headphone receiver so as to send a video signal and an audio digital signal at a high speed. CONSTITUTION: A 1st signal processing circuit 110 of a 1st equipment (cassette player main body) 100 converts video, audio or other data into a prescribed format, a digital modulation circuit 120 applies digital modulation to the data and the signal is sent in an optical signal or a radio wave. Furthermore, a remote control reception circuit 170 receives remote command data and a 1st control circuit 160 receives the data to control the entire operation. A 2nd equipment (headphone receiver) 200 receives the transmission signal from the 1st equipment 100, demodulates digitally the signal to reproduce the video, audio or other data. Furthermore, a remote control transmission circuit 270 sends remote command data.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a digital wireless transmission device used for transmission of video or audio data and other data, and in particular, by providing a bidirectional transmission path for verification, remote control data etc. The sub data is transmitted quickly and surely.

[0002]

2. Description of the Related Art As a technique related to a conventional wireless transmission device, there is, for example, Japanese Patent Laid-Open No. 2-179132. Hereinafter, a conventional analog wireless transmission device will be described with reference to the drawings. FIG. 6 is a block diagram showing the configuration of a conventional wireless transmission device.

FIG. 6 shows a transmitter for transmitting two carrier audio signals in which two carrier waves having a predetermined frequency interval are modulated by L and R two-channel audio signals of the main body of the player, and two carriers from the transmitter. It is configured by a receiver that receives an audio signal and demodulates it to obtain two audio signals. In the figure, reference numeral 100 denotes a first device (transmitter), that is, a cassette player main body side device, 101 denotes a cassette tape, 1
02 is a reproduction amplifier, 910 and 810 are FM modulation circuits, 9
20 and 820 are frequency shift circuits, and 930 and 830 are RF circuits.
The output circuit 940 is an antenna.

Reference numeral 200 is a second device (receiver), that is, a headphone receiver, 201 is a headphone, and 202 is a headphone receiver.
Is a driver, 720 and 620 are FM demodulation circuits, 730,
Reference numeral 630 is an RF receiving circuit, and 740 is an antenna. The operation of the wireless transmission device configured as described above will be described below. In the first device 100, the mechanism 150 constituting the cassette player, the cassette tape 1
01, L and R2 channel audio signals to be reproduced by the reproduction amplifier 102 are generated by the FM modulation circuits 910 and 810 to generate two FM analog modulated waves of intermediate frequencies, and the frequency shift circuits 920 and 820 further frequency-convert them into high frequency bands. ,
Radio waves are transmitted from the RF output circuits 930 and 830 and the antenna 940.

Two FM analog modulated carrier waves of f1 and f2 are transmitted, which correspond to L and R2 channel audio signals, respectively. In the second device 200, the RF signal transmitted from the first device 100 is transmitted to the antenna 740, RF
The FM demodulation circuit 72 receives the signals at the reception circuits 730 and 630.
0,620. FM demodulation output is driver 202
The headphones 201 are driven via the.

[0006]

However, in the above-mentioned conventional apparatus, since the voice signal is FM-analog modulated and transmitted, the SN ratio of the voice signal to be transmitted is deteriorated due to the noise of the transmission line or the influence of the propagation obstacle. There was a problem that sufficient sound quality could not be secured. Further, since a transmitting circuit and a receiving circuit for two carrier waves are required, the number of parts is large, the cost is high, and the space is large. It was also difficult to superimpose high-speed sub data on the audio signal.
Therefore, when a plurality of similar devices are used in close proximity to each other, there are many problems such as interference of voice signals and interference of control commands.

The present invention solves many of the above-mentioned problems of the prior art. A bidirectional transmission path of digital modulation is provided for transmission between the main body of the player and the headphone receiver to digitize a video or audio signal. It transmits at high speed. Further, since a conventional means such as a QPSK modulator for modulating at high speed is economically expensive, it is another object of the present invention to provide a digital wireless transmission device equipped with a low cost high speed modulating circuit.

[0008]

In order to achieve this object, a digital wireless transmission apparatus of the present invention transmits a video or audio data and other data at high speed with optical or radio waves and transmits a remote control signal. And a first device for controlling the operating state and receiving light or radio waves to reproduce video or audio and other data,
The first device has a second device for transmitting remote control data or ID data, and the first device has a first signal processing circuit for inputting video or audio data and other data and converting the data into a predetermined format, and the first signal processing circuit. Digital modulation circuit for digitally modulating the converted signal, output means for transmitting these signals by light or radio waves, remote control receiving circuit for receiving remote control data or ID data, and input of received remote control data or ID data And a first control means for controlling the overall operation, wherein the second device receives the transmission signal from the first device, a digital demodulation circuit for digitally demodulating the reception signal, and a demodulated signal. A second signal processing circuit for reproducing video, audio or other data, remote control key operation data and a second signal processing circuit. A second control means for inputting the sub-data and generates the operation control and remote control data or ID data received from the remote control data or ID
And a remote control transmission circuit for transmitting data.

[0009]

According to the present invention, with the above-described structure, the first device transmits video or audio or other data by light or radio waves, receives a remote control signal, and controls the operation state. The second device receives light or radio waves to reproduce video, audio or other data, and transmits remote control data.

In the first device, the first signal processing circuit converts video or audio data or other data into a predetermined format, the digital modulation circuit performs digital modulation with the signal converted into the format, and the output means is These signals are transmitted by light or radio waves. Further, when the remote control receiving circuit receives the remote control data, it supplies the received remote control data to the first control means, and the first control means controls the entire operation.

In the second device, the receiving means receives the transmission signal from the first device, and the digital demodulation circuit is
The received signal is digitally demodulated, and the second signal processing circuit
Plays video or audio or other data from the demodulated signal. Further, the second control means inputs the remote control key operation data and the data received from the signal processing circuit to control the operation and generate the remote control data, and the remote control transmission circuit transmits the remote control data. Alternatively, the ID data is bidirectionally transmitted together with the remote control data to verify the collation. By doing so, the sound quality of the audio signal is improved, the accuracy of the remote control data is improved, and interference is prevented.

[0012]

An embodiment of the present invention will be described below with reference to the drawings. FIG. 1 is a schematic block diagram showing the configuration of a digital wireless transmission device according to an embodiment of the present invention. FIG. 1 shows wireless transmission between a cassette player body and a headphone receiver. 100
Is a first device, that is, a cassette player main body side device, 101 is a cassette tape, 102 is a reproducing amplifier, 1
03 is an AD converter, 150 is a mechanism, 110 is a first signal processing circuit, 120 is an FSK modulation circuit, 130
Is an RF output circuit, 140 and 180 are antennas, 17
Reference numeral 0 is a remote control receiving circuit, and 160 is a first control means.

Reference numeral 200 is a second device, that is, a headphone receiver, 201 is a headphone, 202 is a driver, 203 is a DA converter, 210 is a second signal processing circuit, 215 is a PLL for data reproduction, and 220 is FSK.
Demodulation circuit, 230 is RF receiving circuit, 240 and 280
Is an antenna, 250 is a remote control key for remote control operation, 255 is second control means, 260 is LCD display means, and 270 is a remote control transmission circuit.

The operation of the digital wireless transmission device configured as described above will be described below. First, the audio signal transmission operation and the sub-data bidirectional operation will be described. In the first device 100, the mechanism 150 constituting the cassette player, the cassette tape 1
01, and the L and R two-channel audio signals reproduced by the reproduction amplifier 102 by the AD converter 103.
16-bit linear quantization is performed at a sampling frequency of 1 kHz and converted into digital data. The first signal processing circuit 110 converts the digital data from the AD converter 103 into the format shown in FIG. As shown in FIG. 2, a synchronization pattern for synchronization pull-in and an error correction code for error correction are added, and sub data is added. The signal converted to this format is 2.1168 Mbps
It becomes the bit rate of. This is digitally modulated by the FSK modulation circuit 120 and an FSK modulated carrier wave is output. In addition,
In the present embodiment, the modulation speed of the FSK modulation circuit 120 is 2.1168 Mbps, but since it may be a compressed audio signal, 300 kbps or higher is desirable.

FIG. 5 is a circuit diagram of the FSK modulation circuit in the embodiment. In FIG. 5, 300 is a modulation data input terminal, 301 is a reference clock input terminal (omitted in FIG. 1), 302 is an FSK modulated wave output terminal, 303 is a phase comparator, and 304 is a frequency divider. Modulation data input terminal 3
The modulated signal to be supplied to 00 is shaped by the buffer 305, divided by the variable resistor 321 and divided by the capacitor 310 and the resistor 322.
Applied to the varicap 307 via the
The internal capacitance of 07 is changed. The inductance 326, the varicap 307, and the capacitor 313 are the main parts that determine the oscillation frequency of the VCO circuit that is the modified Clap oscillation circuit including the transistor 308. The oscillation frequency fluctuates according to the modulation signal, and FSK modulation is applied. The FSK modulated wave is amplified by the inverter 306 and output from the FSK modulated wave output terminal 302. On the other hand, the FSK modulated wave is divided by the frequency divider 30.
4, the frequency is divided into about 1/1700, and the phase comparator 303 compares the phase with the clock of 132.3 kHz input from the reference clock input terminal 301.
It is connected to the VCO circuit through a filter composed of 20, 322 and a capacitor 309. PL in this loop
L, and the average frequency of the FSK modulated wave is a predetermined 233
It operates to become MHz. In FIG. 5, the capacitor 3
Reference numerals 11 and 312 are for compensating that the modulation signal becomes dull due to the time constant of the resistor 322, the varicap 307, and the capacitor 313 to increase the modulation speed of the FSK modulation.

This FSK-modulated carrier wave is frequency-converted to R
It is transmitted from the first device 100 via the F output circuit 130 and the antenna 140. The electric field strength of this output means is limited to 500 μV / m or less at a point 3 m away. In the second device 200, the first device 100
The RF signal transmitted by the antenna 240 and the RF receiving circuit 230 are received and supplied to the FSK demodulating circuit 220.
The FSK demodulated output is sent to the second signal processing circuit 210 and PLL2.
Supply to 15. The PLL 215 is synchronized with the data 2.
The 1168 MHz clock is regenerated and supplied to the second signal processing circuit 210, and the 16.9344 MHz clock, which is eight times the data bit rate, is supplied to the DA converter 20.
Supply to 3. The second signal processing circuit 210 decodes according to the format. Sync pull-in is performed by detecting a sync pattern, and frame sync and sample sync are established. After the synchronization is established, the synchronization state is maintained by applying synchronization protection so as not to disturb even if noise enters. Further, the error correction code is decoded to correct a 1-bit error in one sample, an error of 2 bits or more is detected, and an average value interpolation process is performed. The corrected and interpolated data is supplied to the DA converter 203 to be converted into analog audio signals of L and R2 channels, and the headphone 2 is output via the driver 202.
01 is driven.

Next, bidirectional transmission of sub data will be described. FIG. 3 shows the contents of the sub data. The ID data of block 1 is an identification code commonly given to the pair of first device and second device, and is used to eliminate interference signals coming from other similar devices and prevent interference. The main body operation mode of the block 5 represents an operation state such as a reproduction mode, a stop mode, and an FF / REW mode of the cassette player. The transmission of these sub data will be described.

In the second device 200, the remote controller key 250 is operated to supply to the second control means 255 a command for instructing the operating states of the cassette player such as the reproduction mode, the stop mode and the FF / REW mode. The second control means 255 generates remote control transmission data. This remote control transmission data is the remote control transmission circuit 270.
FSK modulation oscillator circuit for remote control (OS in the figure
C) The signal is transmitted from the antenna 280 through the remote control transmission circuit (RF output in the figure). In the first device 100, the remote control data RF signal is received and demodulated by the antenna 180 and the remote control receiving circuit 170 and supplied to the first control means 160. The first control means 160 decodes the remote control data and controls the operation mode of each unit. At the same time, the first control means 160 supplies the first signal processing circuit 110 with the main body operation mode indicating the operation state of the first device 100 including the cassette player as sub data, and formats it together with the audio signal. The formatted signal is transmitted by the FSK modulation circuit 12 in the same manner as the audio signal transmission.
0, RF output circuit 130, antenna 140
From the device 100.

Similarly, in the second device 200, the signal is transmitted to the second signal processing circuit 210 through the antenna 240, the RF receiving circuit 230, and the FSK demodulating circuit 220, and goes through the bidirectional transmission path. In the second signal processing circuit 210, the transmitted main body operation mode is compared with the main body operation mode of the sub data received in one round. If the verification result is a match, it is determined that the transmission control is correctly performed, and the processing is completed.
If the result of the collation does not match, it is determined that the transmission control is incorrect, and the process is repeated. With this repeated transmission control, the processing is continued until the transmission control is correctly performed. In addition,
The result of the collation is displayed on the LCD via the second control means 255.
It is output to the display means 260 as a predetermined display.

In the same manner as remote control data, ID data is bidirectionally transmitted and collated with each other. If the collation results are the same, the first control means 160 determines that there is no interference and performs processing based on the received remote control data. ID
If the data collation results do not match, the first control means 16
0 determines that there is interference, discards the received remote control data and waits for the retransmission processing, and also the second signal processing circuit 210
Outputs a display control signal to cause the LCD display unit 260 to perform a display unique to interference. The user can recognize the display indicating the interference and take an action to eliminate the interference.

As described above, according to the present embodiment, the L and R channel audio signals are converted into digital data of 16-bit linear quantization and sampling frequency of 44.1 kHz and transmitted, and error correction and protection processing are performed for decoding DA. Since it is converted to an analog signal by the converter, high sound quality can be maintained without being affected by noise on the transmission line. In addition, by incorporating a verification confirmation procedure that uses bidirectional transmission, the remote control data that controls the main unit operation mode from the headphone receiver side will continue to be processed until correct transmission control and error-free remote control can be performed. .

Further, in FIG. 4, in order to further ensure the control, the comparison result of the transmission / reception remote control data and the transmission / reception ID code is transmitted from the second device 200 to the first device 100 to control the first device 100. 6 is a flowchart in the case where the first control means 160 performs the above. The operation will be briefly described. The left side of the flowchart shows the headphone receiver side state, and the right side shows the cassette player side state. Step 10 is a start, and in step 15, the mode designation of the remote control operation is input by the key of the second device. The second step is to add ID data to the remote control data in step 20.
Send from the device. The first device receives this, and in step 30, the ID data of itself is collated with the received ID data. If they match, in step 40, the ID data is attached and the remote control data is returned to the second device. The second device receives this, collates the ID data of itself with the received ID data in step 50 and the remote control data sent at the beginning with the received remote control data, and if both match, the collation result is obtained in step 60. The information shown is added to the ID data and transmitted to the first device. The first device receives this,
When it is checked in step 70 that the collation results match, the operation mode of the first device is switched in step 80, and the series of operations is ended in step 90. If the description in the above flowchart is omitted, the operation ends abnormally.

By transmitting the ID data bidirectionally and collating with each other in this way, interference can be detected and interference of the remote control data can be prevented, and the presence or absence of interference can be determined and displayed. It is possible to recognize and take action to eliminate interference. For example, the channel may be automatically or manually switched to another channel having a different carrier frequency.

In the present embodiment, the case where the audio from the cassette tape 101 is transmitted as a signal to be transmitted and heard through the headphones 201 has been described. However, the image signal or the audio signal from another medium is transmitted. May be In other words, the input to the first signal processing circuit 110 may be an arbitrary digital signal, and the reproduced digital signal from the second signal processing circuit 210 may be output to a device that matches the transmitted signal.

As the transmission method in this embodiment,
We have described the case of wireless radio waves that use weak radio waves that set the electric field strength at a point 3 m away to 500 μV / m or less.
It may be transmission by light.

[0026]

As described above, according to the present invention, the first device transmits video or audio or other data by light or radio waves, receives a remote control signal to control the operation state, and the second device transmits the light. Alternatively, it receives radio waves to reproduce video, audio, and other data, and transmits remote control data.

In the first device, the first signal processing circuit converts video or audio data or other data into a predetermined format, the digital modulation circuit digitally modulates the signal converted into the format, and the output means outputs these signals. Send signals by light or radio waves. Further, when the remote control receiving circuit receives the remote control data, it supplies the received remote control data to the first control means, and the first control means controls the entire operation.

In the second device, the reception means receives the transmission signal from the first device, the digital demodulation circuit digitally demodulates the reception signal, and the second signal processing circuit converts the demodulated signal into video or audio or other signals. Play the data. The second control means inputs the remote control key operation data and the data received from the signal processing circuit to control the operation and generate the remote control data, and the remote control transmitting circuit transmits the remote control data.

With the above configuration, for example, L and R two-channel audio signals are converted into digital data of 16-bit linear quantization and sampling frequency of 44.1 kHz and transmitted, and error correction and protection processing are performed for decoding. High quality transmission can be maintained without being affected by noise on the transmission line, such as when converting to an analog signal with a converter. Further, the remote controller data for controlling the first device from the second device side is incorporated with the procedure of the collation confirmation using the bidirectional transmission, so that the process is continued until the transmission is correctly controlled, and the remote control without error is performed. Will be able to.

Further, the ID is the same as the remote control data.
By transmitting data bidirectionally and collating with each other, interference of remote control data due to interference can be prevented, and the presence or absence of interference can be determined and displayed.The user can recognize this display and eliminate interference. You will be able to take action.

[Brief description of drawings]

FIG. 1 is a schematic block diagram showing a configuration of a digital wireless transmission device according to an embodiment of the present invention.

FIG. 2 is a diagram showing a format in the embodiment.

FIG. 3 is a diagram showing a structure of sub data in the same embodiment.

FIG. 4 is a flowchart of sub data matching and control in the same embodiment.

FIG. 5 is a circuit diagram of an FSK modulation circuit according to the same embodiment.

FIG. 6 is a block diagram showing a conventional wireless transmission device.

[Explanation of symbols]

 100 first device 110 first signal processing circuit 120 FSK modulation circuit 130 RF output circuit 140, 180, 240, 280 antenna 170 remote control receiving circuit 160 first control means 200 second device 210 second signal processing circuit 220 FSK demodulation circuit 230 RF reception circuit 250 Remote control key 255 Second control means 260 LCD display means 270 Remote control transmission circuit

Claims (7)

[Claims] 1. A first device for transmitting video or audio and other data by light or radio waves and receiving remote control data to control an operating state; and receiving the light or radio waves to transmit the data. Along with playing
A second device for transmitting the remote control data,
The first device includes a first signal processing circuit for inputting video or audio and other data and converting the data into a predetermined format, a digital modulation circuit for digitally modulating the signal converted into the format, and a digital modulation circuit for these signals. The second device includes output means for transmitting a signal by light or radio waves, a remote control receiving circuit for receiving the remote control data, and first control means for inputting the received remote control data and controlling the overall operation. Are receiving means for receiving the transmission signal from the first device, a digital demodulation circuit for digitally demodulating the reception signal, and a second signal processing circuit for reproducing video or audio and other data from the demodulation signal, The remote control key operation data and the data received from the second signal processing circuit are input to perform operation control and remote control data generation. And second control means for performing digital wireless transmission apparatus characterized by comprising a remote control transmitter circuit for transmitting remote control data. 2. The digital modulation circuit of the first device performs FSK modulation at a modulation speed of 300 kbps or more, and the output means outputs a radio wave limited so that the electric field strength at a point 3 m away is 500 μV / m or less. The digital wireless transmission device according to claim 1, wherein: 3. The second device is provided with display means, and is controlled by a display control signal from the second control means.
Remote control data is transmitted from the second device to the first device through the remote control key, the second control means, and the remote control transmission circuit, and the remote control is received by the first device through the remote control reception circuit and the first control means. The entire operation is controlled by the data, and the remote control data is supplied to the first signal processing circuit, and the first device to the second device through the digital modulation circuit and the output means as a part of the video or audio and other data. 2. The remote controller data is sent back to the remote controller and the remote controller data is transmitted and received by the second control means through the receiving means of the second device, the digital demodulation circuit, and the second signal processing circuit. 2. The digital wireless transmission device according to any one of items 1 to 3. 4. The remote control data collation for transmission / reception when the remote control data collation of the two transmission / reception does not match, the second control means performs a predetermined display indicating that the remote control data is unconfirmed, and repeatedly outputs the remote control data. 4. The digital control system according to claim 3, wherein the second control means performs a predetermined display indicating that the remote control data is confirmed and / or sends information indicating that the remote control data is confirmed. Wireless transmission equipment. 5. When the remote control data collation of the transmission and reception does not match, the remote control data is repeatedly output and waits until the remote control data collation of the transmission and reception coincides, and when the remote control data collation of the transmission and reception coincides, the second control means is the remote controller. 4. The transmission of data is ended, and the first control means controls the entire device using the remote control data.
The described digital wireless transmission device. 6. The first device and the second device hold ID data set so as to be common to the respective devices and different from other devices, and the second data is provided as part of the sub data together with the remote control data. From the first device to the first device and from the first device to the second device.
4. The digital wireless transmission device according to claim 3, wherein the D data is returned, and the ID data of transmission and reception is collated by the first control means or the second control means. 7. The second control means performs a predetermined display indicating an interference state and repeatedly outputs the ID data when the ID data collation of the two transmission / reception does not match, and the above-mentioned transmission / reception 2
If the two ID data collations are coincident with each other, the second control means displays or sends out the collation result of the ID data.
7. The digital wireless transmission device according to claim 6, wherein the control means controls the entire device using the received remote control data according to the collation result of the received ID data.